Determination of volatile organic compound patterns characteristic of five unifloral honey by solid-phase microextraction-gas chromatography-mass spectrometry coupled to chemometrics

We report the evaluation of the floral origin of honey by analysis of its volatile organic compounds (VOCs) profile, joined with the use of combined pattern recognition techniques. Honey samples, from five floral origins, were analyzed by headspace solid-phase microextraction-gas chromatography-mass spectrometry, selecting 35 VOCs out of the entire profiles, which were analyzed by hierarchical cluster analysis (HCA), stepwise discriminant analysis (SDA), and K-nearest-neighbor (KNN). Both HCA and SDA were used as exploratory tools to select a group of VOCs representing similitude and differences among studied origins. Thus, six out of 35 VOCs were selected, verifying their discriminating power by KNN, which afforded 93% correct classification. Therefore, we drastically reduced the amount of compounds under consideration but kept a good differentiation between floral origins. Selected compounds were identified as octanal, benzeneacetaldehyde, 1-octanol, 2-methoxyphenol, nonanal, and 2-H-1-benzopyran-2-one. The analysis of VOC profiles, coupled to HCA, SDA, and KNN, provides a feasible alternative to evaluate the botanical source of honey.     

Pre-exposure to infectious hypodermal and haematopoietic necrosis virus or to inactivated white spot syndrome virus (WSSV) confers protection against WSSV in Penaeus vannamei (Boone) post-larvae

Larvae and post-larvae of Penaeus vannamei (Boone) were submitted to primary challenge with infectious hypodermal and haematopoietic necrosis virus (IHHNV) or formalin-inactivated white spot syndrome virus (WSSV). Survival rate and viral load were evaluated after secondary per os challenge with WSSV at post-larval stage 45 (PL45). Only shrimp treated with inactivated WSSV at PL35 or with IHHNV infection at nauplius 5, zoea 1 and PL22 were alive (4.7% and 4%, respectively) at 10 days post-infection (p.i.). Moreover, at 9 days p.i. there was 100% mortality in all remaining treatments, while there was 94% mortality in shrimp treated with inactivated WSSV at PL35 and 95% mortality in shrimp previously treated with IHHNV at N5, Z1 and PL22. Based on viral genome copy quantification by real-time PCR, surviving shrimp previously challenged with IHHNV at PL22 contained the lowest load of WSSV (0-1x10(3) copies microg-1 of DNA). In addition, surviving shrimp previously exposed to inactivated WSSV at PL35 also contained few WSSV (0-2x10(3) copies microg-1 of DNA). Consequently, pre-exposure to either IHHNV or inactivated WSSV resulted in slower WSSV replication and delayed mortality. This evidence suggests a protective role of IHHNV as an interfering virus, while protection obtained by inactivated WSSV might result from non-specific antiviral immune response.     

Application of polymerase chain reaction and virus isolation techniques for the detection of viruses in aborted and newborn foals

The occurrence of two important pathogens, equine herpesvirus 1 (EHV1) and equine arteritis virus (EAV) causing abortions, perinatal foal mortality and respiratory disease, was investigated by polymerase chain reaction (PCR) and virus isolation to demonstrate the presence of abortigenic viruses in samples from 248 horse fetuses in Hungary. We found 26 EHV1- and 4 EAV-positive aborted or prematurely born foals from 16 and 4 outbreaks, respectively, proving that despite the widely applied vaccination, EHV1 is a far more important cause of abortions in the studs than EAV. We compared the virus content of different organs of the fetuses by PCR and isolation to identify the organ most suitable for virus demonstration. Our investigations indicate that the quantity of both viruses is highest in the lungs; therefore, according to our observations, in positive cases the probability of detection is highest from lung samples of aborted or newborn foals. Both the PCR and the virus isolation results revealed that the liver, though widely used, is not the best organ to sample either for EHV1 or for EAV detection. From the analysis of the epidemiological data, we tried to estimate the importance of the two viruses in the Hungarian horse population.     

Seroprevalence of neosporosis in beef and dairy cattle breeds in Northeast Hungary

In order to assess the seroprevalence of bovine neosporosis with indirect fluorescent antibody test (IFAT), blood samples were collected randomly from 1063 beef and dairy cattle belonging to 12 different breeds in Northeast Hungary. Antibodies to Neospora caninum were detected in 27 (2.5%) of the animals, kept on 19 of the 42 settlements included in this survey. Since samples were collected on 50 farms, herd prevalence amounted to 38%. The percentage of cattle with seroconversion increased with age, suggesting a postnatal source of infection. The highest rate of positivity was detected in Aberdeen Angus (3.3%) and Holstein-Friesian cows (3.2%), and the lowest in Limousine (0.9%), but no breed predisposition was statistically substantiated. Neosporosis was more prevalent in dairy (3.4%) than in beef (1.9%) cattle, although the difference was not significant. Only three out of the seropositive cows, all of them Holstein-Friesians, had a history of abortion.     

Effect of open pulled straw (OPS) vitrification on the fertilisation rate and developmental competence of porcine oocytes

Freezing technologies are very important to preserve gametes and embryos of animals with a good pedigree or those having high genetic value. The aim of this work was to compare immature and in vitro matured porcine oocytes regarding their morphology and ability to be fertilised after vitrification by the open pulled straw (OPS) method. In four experiments 830 oocytes were examined. To investigate the effect of cumulus cells on oocyte survival after OPS vitrification, both denuded and cumulus-enclosed oocytes were vitrified at the germinal vesicle (GV) stage, then after vitrification they were matured in vitro. Besides, in vitro matured oocytes surrounded with a cumulus and those without a cumulus were also vitrified. The survival of oocytes was evaluated by their morphology. After in vitro fertilisation the rates of oocytes penetrated by spermatozoa were compared. Our results suggest that the vitrification/warming procedure is the most effective in cumulus-enclosed oocytes (22.35 +/- 1.75%). There was no difference between the order of maturation and vitrification in cumulus-enclosed oocytes, which suggests the importance of cumulus cells in protecting the viability of oocytes during cryopreservation.     

Fatal toxoplasmosis and concurrent Calodium hepaticum infection in Korean squirrels (Tanias sibericus)

Four Korean squirrels (Tanias siberius) imported in Spain from People's Republic of China died 2 days after their arrival at a pet shop. They had neurological signs associated with generalized toxoplasmosis involving brain, lungs, liver, and the heart. Toxoplasma gondii-like tachyzoites and tissue cysts were found in organs of all four squirrels. The protozoa stained positively with T. gondii polyclonal antibodies and were ultrastructurally similar to T. gondii. Calodium (Capillaria) hepaticum infection was found in the liver of one squirrel.     

Levels of detection of Cryptosporidium oocysts in mussels (Mytilus galloprovincialis) by IFA and PCR methods

Cryptosporidium spp. are monoxenous protozoan parasites that cause gastrointestinal diseases in humans and animals. Shellfish harvesting areas can become contaminated by the infectious stage of the parasite and humans are therefore at risk of infection either by consumption of shellfish, or by taking part in recreational activities in these areas. In the present study we determined the levels of detection, by IFA and PCR techniques, of Cryptosporidium oocysts in mussels experimentally contaminated with a theoretical number of oocysts. There was a significant correlation between the results obtained by both techniques (P<0.05). IFA and PCR were also applied to a total of 222 samples of mussels (Mytilus galloprovincialis) destined for human consumption. In the naturally contaminated samples, we detected a 31.1% of contamination and only Cryptosporidium parvum (previously denominated C. parvum genotype II) was identified.     

Effects of biochar on microbial community in bioflocs and gut of Oreochromis niloticus reared in a biofloc system

Aquaculture International - This study investigated the effects of biochar application on the bacterial community structure in bioflocs and intestines of Oreochromis niloticus cultured in a biofloc...     

Fourteen years of applying zero and conventional tillage,crop rotation and residue management systems and its effect on physical and chemical soil quality

Soil management systems may negatively affect the quality of the soil. Policymakers and farmers need scientific information to make appropriate land management decisions. Conventional (CT) and zero tillage (ZT) are two common soil management systems. Comparative field studies under controlled conditions are required to determine the impact of these systems on soil quality and yields. The research presented studied plant and soil physical and chemical characteristics as affected by different agricultural management practices, i.e. ZT and CT, cropped with continuous wheat or maize in monoculture (M) or in a yearly rotation (R) of these two crops, either with residue retention (+r) or without residues retention (?r), in an experimental field in the Transvolcanic Belt of Mexico after 14 years. The dominant factors defining soil quality were organic C, total N, moisture, aggregate stability, mechanical resistance, pH and EC. The principal component combining the variables organic C, total N, aggregate stability and moisture content showed the highest correlations with final yield (R = 0.85 for wheat and 0.87 for maize).After 14 years of continuous practice, ZTM + r and ZTR + r had the best soil quality and produced the highest wheat and maize yields of average 2001–2004 (6683 and 7672 kg ha^?1 and 5085 and 5667 kg ha^?1, respectively). Removing the residues, i.e. treatments ZTM ? r with maize (average 2001–2004: 1388 kg ha^?1) and ZTR ? r and CTR ? r with wheat (average 2001–2004: 3949 and 5121 kg ha^?1), gave the lowest yields and less favourable soil physical and chemical characteristics compared to the other practices. It was found that zero tillage with residue retention is a feasible management technology for farmers producing maize and wheat in the agro-ecological zone studied, resulting in a better soil quality and higher yields than with the conventional farmer practice (maize monoculture, conventional tillage and residue removal).