Publications by authors named "Nagarajan Thirunavukkarasu"

In this article, we detail a comprehensive laboratory evaluation of an immunoassay for the rapid detection of ricin using the Meso Scale Diagnostics Sector PR2 Model 1800. For the assay evaluation, we used inclusivity, exclusivity, and informational panels comprised of extracts of 35 near-neighbor plant cultivar-extracts, 66 lectins, 26 white powders, 16 closely related toxins and proteins/toxoids, and a pool of 30 BioWatch filter extracts. The results show that the Meso Scale Diagnostics ricin detection assay exhibits good sensitivity and specificity with a limit of detection of 1.

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We present the closed genome sequence of the strain isolated from the stool specimen of an infant diagnosed with botulism. With 4.33-Mb genome size and 28.

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We conducted a comprehensive, multiphase laboratory evaluation of the InBios Active Melioidosis Detect (AMD) rapid test, a lateral flow immunoassay designed to detect capsular polysaccharides produced by or , used in conjunction with the Omni Array Reader for the rapid identification of culture isolates of or to support clinical diagnosis for response and triage during a mass casualty event, such as a biological attack. The study was conducted at 2 sites to assess the performance of the AMD test. The sensitivity, specificity, and reproducibility of the assay was determined using 5 replicates of 35 inclusivity strains and 64 clinical background strains.

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We conducted a comprehensive, multiphase laboratory evaluation of InBios Active Melioidosis Detect (AMD) rapid test, a lateral flow immunoassay designed to detect capsular polysaccharides produced by or , used in conjunction with the Omni Array Reader (OAR) for the rapid detection of or in environmental (nonclinical) samples at 2 sites. The limit of detection, using reference strains strain ATCC 23344 and strain ATCC 11668, was determined to be 10 to 10 CFU/mL. In different phases of the evaluation, inclusivity strains that included geographically diverse strains of (N = 13) and (N = 22), geographically diverse phylogenetic near neighbor strains (N = 66), environmental background strains (N = 64), white powder samples (N = 26), and environmental filter extracts (N = 1 pooled sample from 10 filter extracts) were also tested.

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Carbapenems-one of the important last-line antibiotics for the treatment of gram-negative infections-are becoming ineffective for treating infections. Studies have identified multiple genes (and mechanisms) responsible for carbapenem resistance. In some strains, the presence/absence of putative resistance genes is not consistent with their resistance phenotype-indicating the genomic factors underlying carbapenem resistance in are not fully understood.

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In this article, we detail a comprehensive laboratory evaluation of an immunoassay for the rapid detection of abrin using the Meso Scale Diagnostics Sector PR2 Model 1800. For the assay evaluation, we used inclusivity and exclusivity panels comprised of extracts of 11 cultivars and 35 near-neighbor plants, 65 lectins, 26 white powders, 11 closely related toxins and proteins, and a pool of 30 BioWatch filter extracts. The results show that the Meso Scale Diagnostics abrin detection assay exhibits good sensitivity and specificity with a limit of detection of 4 ng/mL.

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Botulism outbreak due to consumption of food contaminated with botulinum neurotoxins (BoNTs) is a public health emergency. The threat of bioterrorism through deliberate distribution in food sources and/or aerosolization of BoNTs raises global public health and security concerns due to the potential for high mortality and morbidity. Rapid and reliable detection methods are necessary to support clinical diagnosis and surveillance for identifying the source of contamination, performing epidemiological analysis of the outbreak, preventing and responding to botulism outbreaks.

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is a strictly anaerobic, Gram-positive, spore-forming bacterium that produces botulinum neurotoxin, a potent and deadly proteinaceous exotoxin. strain CFSAN064329 (62A) produces an A1 serotype/subtype botulinum neurotoxin and is frequently utilized in food challenge and detection studies. We report here the closed genome sequence of strain CFSAN064329 (62A).

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Clostridial neurotoxins, including botulinum and tetanus neurotoxins, are among the deadliest known bacterial toxins. Until recently, the horizontal mobility of this toxin gene family appeared to be limited to the genus We report here the closed genome sequence of , a Gram-negative bacterium containing coding sequences with homology to clostridial neurotoxin family proteins.

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Here we report the genome sequence of a Clostridium botulinum strain IBCA10-7060 producing botulinum neurotoxin serotype B and a new toxin serotype. Multilocus sequence typing analysis revealed that this strain belongs to a new sequence type, and whole-genome single nucleotide polymorphism analysis showed that this strain clustered with strains in lineage 2 from group I.

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Botulinum neurotoxin A (BoNT/A) is used clinically to treat several neurological and metabolic diseases. However, the mechanisms that underlie the clinical use of the toxin remain still to be elusive. BoNT/A inhibits acetylcholine (ACh) release at the motor nerve terminals (MNT) and causes neuroparalysis.

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Several neuronal disorders require drug treatment using drug delivery systems for specific delivery of the drugs for the targeted tissues, both at the peripheral and central nervous system levels. We describe a review of information currently available on the potential use of appropriate domains of clostridial neurotoxins, tetanus and botulinum, for effective drug delivery to neuronal systems. While both tetanus and botulinum neurotoxins are capable of delivering drugs the neuronal cells, tetanus neurotoxin is limited in clinical use because of general immunization of population against tetanus.

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Azospirillum brasilense Sp7 has been shown to overproduce carotenoids if the anti-sigma factor (anti-sigma(E))-encoding gene is inactivated. The anti-sigma mutant (Car-1) of A. brasilense Sp7 was more tolerant to the stresses generated by elevated temperature (40 degrees C), PEG-200 (30 mg mL(-1)) and the antibacterial agent Polymyxin-B (PMB, 25 microg mL(-1)) but not to elevated salinity (15 mg mL(-1)).

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Strains Sp7 and Cd of Azospirillum brasilense, a plant growth-promoting rhizobacterium, differ in synthesis of carotenoids. While colonies of strain Sp7 have a white-cream colour on plates, colonies of strain Cd are orange-pink coloured because of the synthesis of carotenoids. Screening of a mini-Tn5 mutant library of A.

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Plant growth promoting rhizobacteria such as Azospirillum brasilense are agronomically important as they are frequently used for crop inoculation. But adverse factors such as increasing soil salinity limit their survival, multiplication and phytostimulatory effect. In order to understand the role of the genes involved in the adaptation of A.

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Salinity stress inhibits the growth and nitrogen fixation ability of the plant growth-promoting rhizobacterium Azospirillum brasilense. Five strains of A. brasilense were isolated from the rhizosphere of Indian cereals and grasses and identified on the basis of their phenotypic features and 16S rRNA gene sequence.

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Azospirillum brasilense is a microaerophilic, plant growth-promoting bacterium, whose nitrogenase activity has been shown to be sensitive to salinity stress. Growth of A. brasilense in semi-solid medium showed that diazotrophic growth in N-free medium was relatively less sensitive to high NaCl concentrations (200-400 mM) than that in presence of NH4+.

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