Microbiologyhttp://irgu.unigoa.ac.in/drs/handle/unigoa/202024-03-28T11:02:30Z2024-03-28T11:02:30ZToxicological aspects of nanomaterials in biomedical research (Chapter 13)D'Costa, A.H.Shaikh, S.Kundaikar, G.Furtado, S.http://irgu.unigoa.ac.in/drs/handle/unigoa/72562024-02-29T06:48:12Z2023-01-01T00:00:00ZToxicological aspects of nanomaterials in biomedical research (Chapter 13)
D'Costa, A.H.; Shaikh, S.; Kundaikar, G.; Furtado, S.
Nanomaterials are used extensively in medicine owing to their size and unique properties. A number of engineered nanomaterials appear to be promising with regard to their applications in medicine such as targeted drug delivery, hyperthermia for cancer therapy, prosthetics, dentistry, tissue engineering, bone regeneration, and pharmaceuticals as well as in diagnostics and imaging. However, such nanomaterials may have undesirable effects in the body other than its intended use. Nanomaterials such as carbon nanotubes, quantum dots, and many metallic and nonmetallic nanoparticles have been reported to be toxic to cells in vivo and in vitro. These nanomaterials have been found to induce oxidative stress, genotoxicity, neurotoxicity, and biochemical alterations in several studies. Long-term exposure could lead to detrimental effects in humans such as cancer and neurodegeneration. Therefore, the safety against toxic effects of these nanomaterials is of utmost importance. Such effects can be neutralized using various strategies such as biocompatible materials, surface modification, and use of immunosuppressant nanoparticles. This chapter summarizes the toxicity of various nanomaterials used in biomedical applications as well as approaches to ameliorate their toxic side effects.
2023-01-01T00:00:00ZApplication of nanoparticles as quorum quenching agent against bacterial human pathogens: a prospective therapeutic nanoweapon (Chapter 11)Salkar, K.Charya, L.S.http://irgu.unigoa.ac.in/drs/handle/unigoa/72552024-02-29T06:47:09Z2023-01-01T00:00:00ZApplication of nanoparticles as quorum quenching agent against bacterial human pathogens: a prospective therapeutic nanoweapon (Chapter 11)
Salkar, K.; Charya, L.S.
Bacteria communicate by producing signaling molecules called autoinducers by a mechanism called Quorum sensing (QS). QS in both Gram-positive and Gram-negative bacteria control their gene expression, thereby coordinating their behavior in a cell-density-dependent manner. In bacterial human pathogens, QS synchronizes gene expression and gene regulation that promotes multidrug resistance and virulence. Growth of bacterial pathogens can be inhibited or controlled by a quorum sensing inhibition strategy also called quorum quenching (QQ). In recent years, owing to their unique properties, nanoparticles have found application as quorum quenchers against human pathogenic bacteria. The major problem with the use of antibiotics is the development of resistance to them by bacterial pathogens. Thus, utilization of nanoparticles as quorum quenchers serves as an efficient alternative since the incidence of resistance development toward nanoparticles is negligible and therefore has tremendous potential to be used as therapeutic nanoweapons.
2023-01-01T00:00:00ZRootstocks for the Management of Bacterial Wilt in Eggplant (Solanum melongena L.) and Tomato (Solanum lycopersicum L.) in the coastal regions of IndiaRamesh, R.Asolkar, T.http://irgu.unigoa.ac.in/drs/handle/unigoa/72032024-01-11T09:34:46Z2022-01-01T00:00:00ZRootstocks for the Management of Bacterial Wilt in Eggplant (Solanum melongena L.) and Tomato (Solanum lycopersicum L.) in the coastal regions of India
Ramesh, R.; Asolkar, T.
Cultivation of solanaceous vegetables such as eggplant and tomato is severely affected by bacterial wilt in the coastal regions of India. The causal agent Ralstonia pseudosolanacearum is soilborne bacterium, highly diverse, and able to survive in soil for many years without a host. Five bacterial wilt resistant eggplant (Solanum melongena) rootstock lines were evaluated by challenge inoculation and were found to show different levels of wilt incidence. Grafts of eggplant made on two rootstocks (S0004 and Surya) recorded reduced incidence of bacterial wilt (10 to 40 percent) during greenhouse evaluation while in nongrafted seedlings, the wilt incidence was 80 to 100 percent. Field evaluation of eggplant grafts made on Solanum torvum (Turkey berry), S0004, and Surya reduced the incidence of bacterial wilt compared to nongrafted seedlings. The lowest wilt incidence (0 and 15-40 percent) was observed in the field evaluations where S. torvum was used as rootstock, while the nongrafted control recorded 93-100 percent wilt. Tomato seedlings grafted on S. torvum, Surya, and S0004 recorded very low bacterial wilt incidence (0 to 15 percent) under greenhouse evaluation while the nongrafted seedlings recorded 80 to 100 percent wilt. Reduced bacterial wilt incidence (23 to 40 percent) was observed in grafts of polyhouse-grown tomato hybrid (GS-600) made on S. torvum while the nongrafted seedlings were severely affected (80 to 100 percent) in evaluation trials conducted for two years. From this study, it is evident that grafting of susceptible eggplant and tomato on resistant rootstocks, viz., S. torvum and Surya, could be a promising strategy in bacterial wilt management.
2022-01-01T00:00:00ZRapid arsenite oxidation by Paenarthrobacter nicotinovorans strain SSBW5: unravelling the role of GlpF, aioAB and aioE genesMujawar, S.Y.Shamim, K.Vaigankar, D.C.Naik, M.M.Dubey, S.K.http://irgu.unigoa.ac.in/drs/handle/unigoa/71472023-10-25T06:24:03Z2023-01-01T00:00:00ZRapid arsenite oxidation by Paenarthrobacter nicotinovorans strain SSBW5: unravelling the role of GlpF, aioAB and aioE genes
Mujawar, S.Y.; Shamim, K.; Vaigankar, D.C.; Naik, M.M.; Dubey, S.K.
A novel arsenite resistant bacterial strain SSBW5 was isolated from the battery waste site of Corlim, Goa, India. This strain interestingly exhibited rapid arsenite oxidation with an accumulation of 5 mM arsenate within 24 h and a minimum inhibitory concentration (MIC) of 18 mM. The strain SSBW5 was identified as Paenarthrobacter nicotinovorans using 16S rDNA sequence analysis. Fourier-transformed infrared (FTIR) spectroscopy of arsenite-exposed cells revealed the interaction of arsenite with several important functional groups present on the cell surface, possibly involved in the resistance mechanism. Interestingly, the whole genome sequence analysis also clearly elucidated the presence of genes, such as GlpF, aioAB and aioE encoding transporter, arsenite oxidase and oxidoreductase enzyme, respectively, conferring their role in arsenite resistance. Furthermore, this strain also revealed the presence of several other genes conferring resistance to various metals, drugs, antibiotics and disinfectants. Further suggesting the probable direct or indirect involvement of these genes in the detoxification of arsenite thereby increasing its tolerance limit. In addition, clumping of bacterial cells was observed through microscopic analysis which could also be a strategy to reduce arsenite toxicity thus indicating the existence of multiple resistance mechanisms in strain SSBW5. In the present communication, we are reporting for the first time the potential of P. nicotinovorans strain SSBW5 to be used in the bioremediation of arsenite via arsenite oxidation along with other toxic metals and metalloids.
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