Echinococcus granulosus ss in dog - A report in center-northern Portugal.

Routine parasitic control and health care of the dog is lacking in many Portuguese rural communities. Freely roaming and stray dogs are responsible for the maintenance of a permanent parasitic infection pressure, namely of zoonotic importance. Therefore, a good understanding of the epidemiology of Echinococcus granulosus including the transmission to man is of great significance to further the awareness within the rural populations and the local health authorities of this zoonotic parasite. This report aims at a better understanding of the epidemiology of Echinococcus granulosus in the Cantanhede region, located in the Central region of Portugal, through the necropsy of stray dogs. At the Official Veterinary Kennel of this Municipality, 105 stray dogs were studied for the presence of Echinococcus granulosus following the adult cestode recovery with necropsy procedure of the first third part of the small intestine. One dog revealed to be positive (1.05%) and the sampled Echinococcus were genotyped and identified as E. granulosus ss. As this genotype is widely spread and has been reported in different parts of the world, further work is necessary to be conducted in this and other regions of Portugal for a better understanding of E. granulosus epidemiology within the typical small rural farms where pig rearing plays an important economic role.

A Burkholderia sacchari cell factory: production of poly-3-hydroxybutyrate, xylitol and xylonic acid from xylose-rich sugar mixtures.

Efficient production of poly-3-hydroxybutyrate (P(3HB)) based on glucose-xylose mixtures simulating different types of lignocellulosic hydrolysate (LCH) was addressed using Burkholderia sacchari, a wild strain capable of metabolizing both sugars and producing P(3HB). Carbon catabolite repression was avoided by maintaining glucose concentration below 10g/L. Xylose concentrations above 30g/L were inhibitory for growth and production. In fed-batch cultivations, pulse size and feed addition rate were controlled in order to reach high productivities and efficient sugar consumptions. High xylose uptake and P(3HB) productivity were attained with glucose-rich mixtures (glucose/xylose ratio in the feed=1.5w/w) using high feeding rates, while with xylose-richer feeds (glucose/xylose=0.8w/w), a lower feeding rate is a robust strategy to avoid xylose build-up in the medium. Xylitol production was observed with xylose concentrations in the medium above 30-40g/L. With sugar mixtures featuring even lower glucose/xylose ratios, i.e. xylose-richer feeds (glucose/xylose=0.5), xylonic acid (a second byproduct) was produced. This is the first report of the ability of Burkholderia sacchari to produce both xylitol and xylonic acid.

The occurrence of zoonotic parasites in rural dog populations from northern Portugal.

A survey of intestinal parasites in dogs was carried out in a rural region around Cantanhede, in northern Portugal, where 301 dog faecal samples were collected from small-ruminant farms. Saturated salt flotation and formol-ether sedimentation techniques were used. An enquiry was conducted in 234 farms and a risk factor evaluation for zoonotic helminths was determined among the 195 farmers who owned dogs. The overall parasite prevalence in faecal samples of dogs was 58.8%, with specific prevalences for Ancylostomidae being 40.9% followed by species of Trichuris (29.9%), Toxocara (8%), Isospora (4%), Capillaria (0.7%) and Spirometra (0.3%). Taeniidae eggs were present in five samples (1.7%) which were analysed with the polymerase chain reaction (PCR) technique and revealed to be from Taenia sp., and not Echinococcus granulosus. This rural region has a traditional small-farm system, in which farm products are mainly for in-house consumption and home slaughtering is a current practice (57%). Analysis showed home slaughtering to be a statistically significant risk factor for the presence of Ancylostomidae (P= 0.007) and Toxocara sp. (P= 0.049). Owning cattle was found to be a significant risk factor for Taenia sp. (P= 0.031).

Genetic characterization of orthobunyavirus Melao, strains BE AR633512 and BE AR8033, and experimental infection in golden hamsters (Mesocricetus auratus).

Melao virus (MELV) strains BE AR8033 and BE AR633512 were isolated from pools of Ochlerotatus scapularis mosquitoes in Belém, Pará State (1955), and Alta Floresta, Rondônia State (2000), Brazil, respectively. The aim of the present study was to molecularly characterize these strains and to describe the histopathological, biochemical and immunological changes in golden hamsters (Mesocricetus auratus) following intraperitoneal injection of MELV strains. Hamsters were susceptible to both of the MELV strains studied. Viraemia was observed 3-6 days post-infection (p.i.) for BE AR633512 and only on the second day p.i. for BE AR8033. Neutralizing antibodies against both strains were detected in blood samples obtained at 5 days p.i. and persisted up to 30 days p.i. Aspartate aminotransferase, alanine aminotransferase and blood urea nitrogen were significantly altered in animals infected with the two MELV strains, while creatinine was only altered in animals inoculated with BE AR633512. Histopathological changes were observed in the central nervous system, liver, kidney and spleen of hamsters, and infection was confirmed by detection of specific MELV antigens by immunohistochemistry. Strain BE AR633512 caused more severe tissue damage than strain BE AR8033, showing increased neurovirulence and pathogenicity. Genetic analysis based on the full-length sequences of the glycoprotein (Gn and Gc) and nucleocapsid protein (N) genes revealed high levels of homology between the MELV strains. Interestingly, the greatest genetic divergence was found for the Gn gene of strain BE AR633512, in which several synonymous and non-synonymous mutations causing changes in RNA secondary structure were observed. Further studies will be necessary to investigate the role of Gn and Gc mutations in the MELV pathogenicity.

Araguari virus, a new member of the family Orthomyxoviridae: serologic, ultrastructural, and molecular characterization.

This paper reports the results of serologic, structural, biochemical, and genetic studies indicating that Araguari virus, a previously unassigned viral agent, is a member of the family Orthomyxoviridae and genus Thogotovirus. Araguari virus has six RNA fragments; biologically, it shares several properties with other viruses in the family Orthomyxoviridae. Nucleotide sequencing of the RNA segments 4 (glycoprotein) and 5 (nucleoprotein) of Araguari virus aligned with the orthomyxoviruses, showing the closest relationship with Thogoto virus (sequence similarity = 61.9% and 69.1%, respectively, for glycoprotein and nucleoprotein), but also sharing a more distant similarity with Dhori and Influenza C viruses, especially for the glycoprotein gene. Based on these results, we propose that Araguari virus should be assigned as a new member of the family Orthomyxoviridae and genus Thogotovirus.

Herd-level seroprevalence of fasciolosis in cattle in north central Portugal.

An epidemiological study of Fasciola hepatica in cattle was implemented in the north central region of Portugal. Both an enzyme-linked immunosorbent assay and an egg shedding quantification technique were used in the follow-up of seven herds. Two of these herds were negative and the other five were positive for F. hepatica. A herd cut-off of value of 0.425 optical density was calculated and herd sensitivity (HSe) and herd specificity (HSp) were defined. Three seroprevalence studies were also implemented in the region with stratification by county sub-regions for a period of 18 months. Overall mean herd prevalence in Vagos of 11, 23 and 48% was progressively found for the three studies, respectively.

Air hygiene in a pullet house: spatial homogeneity of aerial pollutants.

1. The spatial distribution of aerial pollutants was measured in a large deep-litter pullet house, initially holding 10,000 birds, at 12 sites within the birds' breathing zone: on 6 occasions when the birds were between 8 and 27 d of age and on two occasions when the birds were 29 and 34 d of age and the flock size was halved. 2. The distribution of most pollutants appeared uniform, implying that all sites could be considered representative of the overall concentration of pollutant. 3. The concentration of ammonia differed between sites, probably because of local variations in the rate of release from the litter. The number concentration of non-respirable particles (greater than 5 microns in diameter) became heterogeneous when the flock size was halved. 4. The operation of two punka fans had no effect on the spatial distribution of aerial pollutants, but increased the maximum air speed from 0.08 to 0.16 m/s. 5. Recommendations are given for the minimum number of sampling sites necessary for a predetermined level of statistical accuracy. Eight sites at least are recommended for most aerial pollutants, though more are needed for the concentration of gaseous ammonia.