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  • Author or Editor: J.-P. Gupta x
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Mothbean plants (resistant and susceptible genotypes) were inoculated with Yellow mosaic virus (YMV) at 30 days after sowing (DAS), under controlled conditions in a naturally lit net house. Leaves samples were collected at 31, 33, 35, 37, 48 and 66 DAS and analysed for pathogenesis related enzymes and chlorophyll content. Yellow mosaic virus affects the activities of enzymes related to pathogenesis in mothbean even at 24 hours after inoculation. Activities of enzymes like peroxidase, polyphenol oxidase, phenylalanine ammonia lyase and tyrosine ammonia lyase were increased, whereas catalase activity was found to decrease in the leaves of inoculated plants of all the four genotypes tested, RMO 225 and HM 61 (resistant), GMO 9703 and GMO 9704 (susceptible), as compared to the uninoculated plants. Peroxidase activity increased markedly in the susceptible genotypes as compared to the resistant genotypes of inoculated plants. The activities of polyphenol oxidase showed an increasing trend in the inoculated leaves of resistant genotypes, as compared to the resistant genotypes of uninoculated ones. The results indicate that the differences between tolerance and susceptibility of hosts are quantitative as well as qualitative so defence against a pathogen entails major changes in the biochemical components of the plant. A probable role of these enzymes for defence against YMV in mothbean is discussed.

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Methyl ethyl ketone peroxide (MEKPO) is an unstable material above certain limits of temperature, decomposing into chain reactions by radicals. The influence of runaway reactions on this basic characteristic was assessed by evaluating kinetic parameters, such as activation energy (E a), frequency factor (A), etc., by thermal activity monitor III (TAM III). This was done under three isothermal conditions of 70, 80, and 90 °C, with MEKPO 31 mass% combined with nitric acid (HNO3 6 N) and sodium nitrate (NaNO3 6 N). Nitric acid mixed with MEKPO gave the maximum heat of reaction (△H d) and also induced serious reactions in the initial stage of exothermic process under the three isothermal temperatures. The time to maximum rate (TMR) also decreased when HNO3 was mixed with MEKPO. Thus, MEKPO combined with HNO3 6 N forms a very hazardous mixture. Results of this study will be provided to relevant plants for alerting their staff on adopting best practices in emergency response or accident control.

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Lyme disease is a tick-borne multisystemic disease caused by Borrelia burgdorferi. Administering antibiotics is the primary treatment for this disease; however, relapse often occurs when antibiotic treatment is discontinued. The reason for relapse remains unknown, but recent studies suggested the possibilities of the presence of antibiotic resistant Borrelia persister cells and biofilms.

In this study, we evaluated the effectiveness of whole leaf Stevia extract against B. burgdorferi spirochetes, persisters, and biofilm forms in vitro. The susceptibility of the different forms was evaluated by various quantitative techniques in addition to different microscopy methods. The effectiveness of Stevia was compared to doxycycline, cefoperazone, daptomycin, and their combinations. Our results demonstrated that Stevia had significant effect in eliminating B. burgdorferi spirochetes and persisters. Subculture experiments with Stevia and antibiotics treated cells were established for 7 and 14 days yielding, no and 10% viable cells, respectively compared to the above-mentioned antibiotics and antibiotic combination. When Stevia and the three antibiotics were tested against attached biofilms, Stevia significantly reduced B. burgdorferi forms. Results from this study suggest that a natural product such as Stevia leaf extract could be considered as an effective agent against B. burgdorferi.

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European Journal of Microbiology and Immunology
Authors: E. Sapi, K. Balasubramanian, A. Poruri, J. S. Maghsoudlou, K. M. Socarras, A. V. Timmaraju, K. R. Filush, K. Gupta, S. Shaikh, P. A. S. Theophilus, D. F. Luecke, A. MacDonald, and B. Zelger

Lyme borreliosis, caused by the spirochete Borrelia burgdorferi sensu lato, has grown into a major public health problem. We recently identified a novel morphological form of B. burgdorferi, called biofilm, a structure that is well known to be highly resistant to antibiotics. However, there is no evidence of the existence of Borrelia biofilm in vivo; therefore, the main goal of this study was to determine the presence of Borrelia biofilm in infected human skin tissues. Archived skin biopsy tissues from borrelial lymphocytomas (BL) were reexamined for the presence of B. burgdorferi sensu lato using Borrelia-specific immunohistochemical staining (IHC), fluorescent in situ hybridization, combined fluorescent in situ hybridization (FISH)–IHC, polymerase chain reaction (PCR), and fluorescent and atomic force microscopy methods. Our morphological and histological analyses showed that significant amounts of Borrelia-positive spirochetes and aggregates exist in the BL tissues. Analyzing structures positive for Borrelia showed that aggregates, but not spirochetes, expressed biofilm markers such as protective layers of different mucopolysaccharides, especially alginate. Atomic force microscopy revealed additional hallmark biofilm features of the Borrelia/alginate-positive aggregates such as inside channels and surface protrusions. In summary, this is the first study that demonstrates the presence of Borrelia biofilm in human infected skin tissues.

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