High pressure processing treatment prevents embryonation of eggs of Trichuris vulpis and Ascaris suum and induces delay in development of eggs

High hydrostatic pressure processing (HPP) is an effective non-thermal treatment used to inactivate pathogens from a variety of food and food products. It has been extensively examined using prokaryotic organisms and protozoan's but has had limited study on metazoans. Treatment using HPP has been shown to be effective in inactivating nematode larvae in food and preventing embryonation of Ascaris suum eggs. We conducted experiments using eggs of the canine whipworm Trichuris vulpis collected from naturally infected dogs and A. suum eggs from naturally infected pigs. We observed a delay in development of eggs of T. vulpis in a preliminary experiment and conducted 2 experiments to test the hypothesis that appropriate HPP levels can induce a delay in embryonation of nematode eggs. In experiment 1, nonembryonated T. vulpis eggs in tap water were packaged in sealable bags and exposed to 138-600 megapascals (MPa; 1 MPa=10 atm=147 psi) for 60s in a commercial HPP unit. In a second experiment, nonembryonated eggs of A. suum were exposed to 138-600 MPa and treated for 60s in the same commercial HPP unit. Embyronation of T. vulpis eggs was delayed by 4 and 5 days for eggs treated with 207 and 241 MPa but eventually eggs developed and the numbers of embryonated eggs was similar to controls on day 55. Embryonation of T. vulpis eggs treated with 345 or 350 MPa was delayed by 9 days and never reached more than 5% of eggs embryonated. On day 55 post treatment, 95% of control nontreated T. vulpis eggs were embryonated, 100-65% of eggs treated with 138-276 MPa were embryonated, a maximum of 5% of eggs treated with 345-350 MPa were embryonated, and 0% of eggs treated with ≥ 400 MPa were embryonated. T. vulpis eggs treated with ≥ 400 MPa did not undergo cell division. Embryrnation of A. suum eggs was delayed by 4, 10, and 16 days for eggs treated with 207, 241, and 250MPa, respectively, compared to nontreated control eggs. A. suum eggs treated with 207 MPa eventually embryonated to similar % embryonation values as controls and 138 MPa treated eggs but eggs treated with 241 or 250 MPa were always <5% embryonated. A. suum eggs treated with ≥ 300 MPa did not undergo cell division. On the final day of examination at day 56 after treatment, the % of embryonated eggs was 92% nontreated controls, 94% treated with 138 MPa, 84% treated with 207 MPa, 2% treated with 241 or 250 MPa, and 0% treated with 276, 200, 345, 400, or 414 MPa, respectively.     

The space requirement of potatoes in pallet boxes and the weight loss of such potatoes during storage

Summary Over a period of 3 years potatoes in pallet based boxes, having a nominal capacity of 1016 and 508 kg, were weighed as they were placed in and removed from a ventilated store. A total of 136 boxes were weighed and a value of 1.4 m³/ton can be used for estimating the capacity of such boxes. Average weight loss/day of potatoes in the stores was between 0.03 and 0.05%. The weight loss from the individual boxes varied from 2.4 to 14.6% over a storage period of 95 to 262 days.

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Zusammenfasung Es ist wichtig, den Raumbedarf von in Kisten gelagerten Kartoffeln zu bestimmen, weil dieser Faktor einen Einfluss auf die Konstruktion eines Kartoffellagers, sowohl in Bezug auf das Gewicht der eingelagerten Kartoffeln als auch auf die n?tige W?rnmeabführung, ausüben kann. Auf zwei Betrieben wurde eine dreij?hrige Untersuchung durchgeführt, wobei die Kartoffeln in auf Paletten gestellten Kisten eingelagert waren. Die Kartoffellagerr?ume wurden mit Klimaanlagen ausgerüstet, und die Temperatur wurde zwischen 7 und 10°C gehalten. Zwei Kistengr?ssen mit einem Rauminhalt von 1016 und 508 kg wurden benutzt. Die Kisten einschliesslich Inhalt wurden bei der Ein- und Auslagerung gewogen. Der Raumbedarf der Kartoffeln war 1,4 m³/ 1000 kg für die beiden Kistengr?ssen (Tabelle 1). Der Gewichtsverlust der Kartoffeln in den Lagern belief sich auf 0,02–0.05% pro Tag. Gem?ss der Einlagerungsperiode von 95–262 Tagen lag der gesamte Verlust in den Kisten im Bereich von 2,4–14,6% (Tabelle 2). Im Herbst 1968 war das Wetter so nass, dass ein überm?ssiger Anteil an Erde mit den Kartoffeln in die Kisten gefüllt wurde. Bei den gr?sseren Kisten betrug das Nettogewicht der Kartoffeln nur 305–464 kg, d.h. unter ungünstigen Erntebedingungen k?nnte bis zur H?lfte des Inhalts eines Kartoffellagers aus Erde bestehen.

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Résumé Il est important de déterminer l'espace occupé par les pommes de terre stockées en caisses-palettes, cette donnée pouvant influencer la construction des entrepots sant du point de vue poids de pommes de terre stockées que de la quantité de chaleur à évacuer. Pendant trois années, des études ont été poursuivies dans deux fermes dans lesquelles des pommes de terre étaient stockées en caisses-palettes placées dans des entrep?ts aérés où la température contr?lée variait de 7 à 10 C. Deux types de caisses furent utilisées dont la capacité normale était de 1016 kg et 508 kg. On a pesé les caisses avec leur contenu à l'entrée et à la sortie de l'entrep?t. L'exigence en espace était de 1,4m³ pour 1000 kg de pommes de terre pour les deux types de caisses (Tableau 1). La perte de poids pour les deux types de caisses était de 0,03–0,05% par jour tandis que celle-ci pour période de stockage de 95 à 262 jours variait de 2,4 à 14,6% (Tableau 2). En automne 1968, les conditions atmosphériques étaient tellement humides qu'une quantité exagérée de terre remplissait les caisses avec les pommes de terre. Dans le cas des caisses les plus grosses le poids net des pommes de terre était seulement de 305–464 kg; ainsi dans des conditions défavorables de récolte, une quantité allant jusqu'à la moitié du contenu d'une caisse peut être constituée de terre.

     

Experimentally induced infections in turkeys with Cryptosporidium baileyi isolated from chickens

Oocysts of Cryptosporidium baileyi isolated from chickens were inoculated by different routes into 3 groups of turkey poults. Intratracheal inoculation of oocysts produced clinical signs of respiratory tract disease, deaths, and gross lesions of airsacculitis. Parasites developed in the microvillous border of the nasopharynx, larynx, trachea, bronchi, and air sacs. Oral and intracloacal inoculations of oocysts caused no deaths or clinical signs of disease, but did produce patent infections. Respiratory tract infections limited to the nasopharynx, larynx, and trachea occurred in 3 orally inoculated poults. Respiratory tract infections were not observed in intracloacally inoculated poults. The mode of inoculation did not influence the distribution of C baileyi in the digestive tract. The cloaca was parasitized in 100% of the birds with intestinal infections, and the bursa of Fabricius was parasitized in 72.7%.     

Water-mediated proton hopping on an iron oxide surface

The diffusion of hydrogen atoms across solid oxide surfaces is often assumed to be accelerated by the presence of water molecules. Here we present a high-resolution, high-speed scanning tunneling microscopy (STM) study of the diffusion of H atoms on an FeO thin film. STM movies directly reveal a water-mediated hydrogen diffusion mechanism on the oxide surface at temperatures between 100 and 300 kelvin. Density functional theory calculations and isotope-exchange experiments confirm the STM observations, and a proton-transfer mechanism that proceeds via an H(3)O(+)-like transition state is revealed. This mechanism differs from that observed previously for rutile TiO(2)(110), where water dissociation is a key step in proton diffusion.     

The increasing risk of Lyme disease in Canada

There is an increasing risk of Lyme disease in Canada due to range expansion of the tick vector, Ixodes scapularis. The objectives of this article are to i) raise public awareness with the help of veterinarians on the emerging and expanding risk of Lyme disease across Canada, ii) review the key clinical features of Lyme disease in dogs, and iii) provide recommendations for veterinarians on the management of Lyme disease in dogs.     

Transplacental Neospora caninum infection in dogs

A Beagle bitch was inoculated SC and IM with 1.5 million Neospora caninum tachyzoites on the 35th day of gestation. Eight pups were born alive 28 days after N caninum inoculation of the bitch. Pup 1 did not breathe and died while still enclosed in fetal membranes. Pup 2 died 2 days after birth (DAB). Pups 3, 4, and 5 were euthanatized on 2, 3, and 20 DAB, respectively, because they were hypothermic and not nursing. Pups 6, 7, and 8 remained clinically normal. Indirect fluorescent N caninum serum antibody titers were: less than 50 (pups 1 and 8 at 17 DAB, and the bitch before inoculation), 50 (pups 2 and 3 on 2 DAB), 200 (pups 6 and 7 on 17 DAB), and 800 (bitch on day 17 after parturition). Neospora caninum was recovered in cultured cells inoculated with placenta and tissues from all 5 pups necropsied, and N caninum was seen in histologic sections of the heart of pup 5. Results indicate that N caninum can be transplacentally transmitted in dogs.