Atypical/Nor98 scrapie in the Basque Country: a case report of eight outbreaks.

BACKGROUND: Since 2002, an active surveillance program for transmissible spongiform encephalopathy in small ruminants in European Union countries allowed identification of a considerable number of atypical cases with similarities to the previously identified atypical scrapie cases termed Nor98. CASE PRESENTATION: Here we report molecular and neuropathological features of eight atypical/Nor98 scrapie cases detected between 2002 and 2009. Significant features of the affected sheep included: their relatively high ages (mean age 7.9 years, range between 4.3 and 12.8), their breed (all Latxa) and their PRNP genotypes (AFRQ/ALRQ, ALRR/ALRQ, AFRQ/AFRQ, AFRQ/AHQ, ALRQ/ALRH, ALRQ/ALRQ). All the sheep were confirmed as atypical scrapie by immunohistochemistry and immunoblotting. Two cases presented more PrP immunolabelling in cerebral cortex than in cerebellum. CONCLUSIONS: This work indicates that atypical scrapie constitutes the most common small ruminant transmissible spongiform encephalopathy form in Latxa sheep in the Spanish Basque Country. Moreover, a new genotype (ALRQ/ALRH) was found associated to atypical scrapie.

Validation of the Biofish-300 SUL Enzymatic Biosensor for the Detection of Sulfite in Crustacean.

Background: Sulfites are some of the oldest and most widespread preservatives in our food supply. They are food additives that have antioxidant properties, but they are also recorded as allergens by the main international regulatory bodies on food safety because of their adverse health effect. Hence, sulfites maximum concentration in foodstuff is regulated and they must be ensured by the agro-food processing industries. The most widely used technique for the quantification of sulfites is the Modified Monier-Williams (AOAC Official Method 990.28). Objective: In this method, SO2 is released from sulfites and some bound compounds when the sample is mixed with an acid (normally hydrochloric acid, but sometimes phosphoric acid) and heated. The SO2 is distilled using a stream of nitrogen gas, which carries the gaseous SO2 into an absorbing solution of hydrogen peroxide (H2O2) where it is oxidised to sulphuric acid. The amount of SO2 distilled into the H2O2 is determined by titration with 0.1M sodium hydroxide. Apart from being time consuming (at least 2 h) and the usage of toxic solvents, the method presents some other disadvantages that make it inappropriate as a routine-control technique for the agro-food industry. Hence, the industry demands simple, fast and accurate methods for sulfite level monitoring. Methods: BIOLAN is a SME that develops and commercializes biosensors for quantitative analysis of food quality and safety parameters, based on its proprietary enzyme-based electrochemical biosensor technology platform. This technology enables high accurate and robust analysis with a compact device that help the users to control the quality in an easy and safety manner. Biofish-300 SUL method is a highly specific enzimatic biosensor for the rapid quantification of sulfite, measured as SO2 content, in crustaceans. It consists on the extraction of sulfite in an aqueous based solution, by the aid of an Ultra-turrax or similar, and its subsequent quantification by the biosensor after previous calibration (3 min). Results: Sulfite in raw shrimp head-on, raw shrimp head-off, and boiled shrimp was analyzed, and performance was examined using naturally contaminated and spiked samples by comparisons with AOAC Official Methods of AnalysisSM (OMA) 990.28. Linearity, selectivity, matrix, consistency, and robustness were evaluated. All results were within acceptable ranges except robustness, which reflected deviation in the sample volume and ultraturrax time compared with the standard assay procedures described in the Biofish 300 SUL Instruction Manual. Accuracy, assessed as a comparison of the Biofish results with the OMA results, ranged from 82 to 115% in all samples except for fortified raw shrimp head-on, in which the low level yielded an accuracy of 138%. The method bias was in general negative in both incurred and fortified high levels, and slightly positive in incurred low levels. Repeatability was very good as shown by the low RSDr values, demonstrating acceptable repeatability precision with results <10% in most of the evaluated values. Regression analyses showed a good correlation between the Biofish and OMA methods with R² = 0.99 in all cases. Conclusions: As a whole, accuracy, recovery and bias within range results indicate that the kit provides accurate and precise sulfite quantification for all the evaluated matrices, confirming that sample preparation and assay procedures produce acceptable results. Biofish 300 SUL has proved to be a suitable tool for monitoring sulfite levels in quality control routines due to its high accuracy, precision, rapid response and ease of use. Highlights: With a simple sample preparation, results are obtained in approximately 3 min, making a big difference with other technologies that require specific skills or tedious sample pretreatments and analysis procedures.

Validation of the Biofish-300 HIS Enzymatic Biosensor for the Detection of Histamine in Fishery Products.

The Biofish-300 HIS method is a simple, reliable, and specific enzymatic biosensor for the detection of histamine. This technology is highly specific and selective and allows quantification of histamine in fishery products (fresh/frozen and processed) in a short time frame (2-3 min). Histamine in raw tuna, raw mackerel, raw sardine, raw anchovy, boiled tuna, canned tuna in water, canned tuna in oil, canned mackerel in tomato sauce, canned pickled sardine, and canned salted anchovy was analyzed using a water-based extract. Matrix-specific assay procedures and calibration curves were used to enable analyses to be carried out across multiple sample types. The performance of this assay was examined using samples that were naturally contaminated (reference materials and interlaboratory studies) and spiked with histamine. All data were judged against previously established acceptance criteria. Performance measures were evaluated for linearity, selectivity, matrix, lot consistency, and robustness. Results produced in all performance measures, except robustness, were within acceptable ranges. Out-of-range robustness results reflected deviation in sample volume compared to the standard assay procedures. Positive interferences from the presence of agmatine were shown.

Evaluación oftalmológica de un foco de oncercosis en Río Chiquito, Estado Monagas / Oftalmological evaluation of an onchocerciasis focus in Río Chiquito, Monagas

Debido a las pocas modificaciones del tratamiento de la oncocercosis en los últimos años, se practicó estudio doble ciego en 49 pacientes infectados con oncocercosis en la región de Río Chiquito del Estado Monagas, con una droga nueva, el albendazole. La dosis fue de 400 mg. diarios por diez días consecutivos en un grupo escogido al azar, y al otro grupo se le suministró un placebo por igual número de días. Los pacientes fueron hospitalizados para su tratamiento y observación clínica. Se les practicó una evaluación general, oftalmológica, hematológica yparasistológica previa al tratamiento, y durante los días 1, 3 y 10 post-tratamiento, así como controles periódicos post-tratamiento. El examen oftalmológico realizado fue: test de A.V.; test de colores; examen del segmento anterior com lámpara de hendidura; examen del fondo de ojo; tonometría y campimetría. Los hallazgos oftalmológicos no se diferencian del patrón standard del foco norte del país. Excepto de los hallazgos del examen campimétrico, ya que por la comodidad de la evaluación de los pacientes en el ambiente hospitalario, se determina en un 48,44% neuropatía óptica. La droga tuvo buena tolerancia desde el punto de vista general, desde el punto de vista oftalmológico se elevó el conteo de M.F. en cámara anterior en 1 paciente; la T.O. se elevó, en un alto porcentaje, en 3 ó 4 mmHg. pero por debajo de lo normal y en un porcentaje de 11.53% por encima de 20 y por debajo de 28 mmHg, pero sin modificaciones en el nervio óptico ni en sus campos visuales