Validation of a Lateral Flow Test for the Presumptive Identification of the Presence of Burkholderia mallei or Burkholderia pseudomallei in Environmental Samples.

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 Burkholderia mallei or Burkholderia pseudomallei, used in conjunction with the Omni Array Reader (OAR) for the rapid detection of B mallei or B pseudomallei in environmental (nonclinical) samples at 2 sites. The limit of detection, using reference strains B mallei strain ATCC 23344 and B pseudomallei strain ATCC 11668, was determined to be 103 to 104 CFU/mL. In different phases of the evaluation, inclusivity strains that included geographically diverse strains of B mallei (N = 13) and B pseudomallei (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. A total of 1,753 tests were performed, which included positive and negative controls. Visual and OAR results showed that the AMD test detected 92.3% of B mallei and 95.5% of B pseudomallei strains. Of the 66 near-neighbor strains tested, cross-reactivity was observed with only B stabilis 2008724195 and B thailandensis 2003015869. Overall, the specificity and sensitivity were 98.8% and 98.7%, respectively. The results of this evaluation support the use of the AMD test as a rapid, qualitative assay for the presumptive detection of B mallei and B pseudomallei in suspicious environmental samples such as white powders and aerosol samples by first responders and laboratory personnel.

Quantification of ricin, RCA and comparison of enzymatic activity in 18 Ricinus communis cultivars by isotope dilution mass spectrometry.

The seeds of the Ricinus communis (Castor bean) plant are the source of the economically important commodity castor oil. Castor seeds also contain the proteins ricin and R. communis agglutinin (RCA), two toxic lectins that are hazardous to human health. Radial immunodiffusion (RID) and the enzyme linked immunosorbent assay (ELISA) are two antibody-based methods commonly used to quantify ricin and RCA; however, antibodies currently used in these methods cannot distinguish between ricin and RCA due to the high sequence homology of the respective proteins. In this study, a technique combining antibody-based affinity capture with liquid chromatography and multiple reaction monitoring (MRM) mass spectrometry (MS) was used to quantify the amounts of ricin and RCA independently in extracts prepared from the seeds of eighteen representative cultivars of R. communis which were propagated under identical conditions. Additionally, liquid chromatography and MRM-MS was used to determine rRNA N-glycosidase activity for each cultivar and the overall activity in these cultivars was compared to a purified ricin standard. Of the cultivars studied, the average ricin content was 9.3 mg/g seed, the average RCA content was 9.9 mg/g seed, and the enzymatic activity agreed with the activity of a purified ricin reference within 35% relative activity.

Comprehensive laboratory evaluation of a highly specific lateral flow assay for the presumptive identification of ricin in suspicious white powders and environmental samples.

Ricin, a heterodimeric toxin that is present in the seeds of the Ricinus communis plant, is the biothreat agent most frequently encountered by law enforcement agencies in the United States. Even in untrained hands, the easily obtainable seeds can yield a highly toxic product that has been used in various types of threats, including "white-powder" letters. Although the vast majority of these threats are hoaxes, an impediment to accurate hazard assessments by first responders is the unreliability of rapid detection assays for ricin, such as lateral flow assays (LFAs). One of the complicating factors associated with LFAs is the incorporation of antibodies of poor specificity that cross-react with near-neighbors or with plant lectins that are capable of nonspecifically cross-linking the capture and detector antibodies. Because of the compelling and critical need to promote the interests of public safety and public health, the Department of Homeland Security conducted a comprehensive laboratory evaluation study of a commercial LFA for the rapid detection of ricin. This study was conducted using comprehensive inclusivity and exclusivity panels of ricin and near-neighbor plant materials, along with panels of lectins and "white-powders," to determine the specificity, sensitivity, limits of detection, dynamic range, and repeatability of the assay for the specific intended use of evaluating suspicious white powders and environmental samples in the field.

Effect of the HMG-CoA reductase inhibitor rosuvastatin on early chronic kidney injury in obese zucker rats fed with an atherogenic diet.

The obese Zucker rat (OZR) spontaneously develops hyperlipidemia, insulin resistance, and microalbuminuria. In this study, the initial metabolic, functional, and glomerular pathology in young OZR fed with an atherogenic diet resembles the characteristics of metabolic syndrome. Hyperlipidemia and other metabolic derangement cause early glomerular damage in OZR by 10 weeks of age, before overt diabetes is developed. Consequently, the effects of potential interventions should also be evaluated at the young age. In OZR fed with an atherogenic high-fat diet, low (5 mg/kg) and high (20 mg/kg) dosages of rosuvastatin started at 5 weeks and maintained for 10 weeks induced a significant improvement in metabolic abnormalities, blood pressure, and renal function, including microalbuminuria. The low dose of rosuvastatin significantly decreased mesangial expansion, and the high dose exerted a marked protective effect on the development of both glomerular hypertrophy and mesangial expansion. The statin also attenuated the inflammatory expression in the kidney cortex.