Changes in glial cell activation and extracellular vesicles production precede the onset of disease symptoms in transgenic hSOD1G93A pigs

SOD1 gene is associated with progressive motor neuron degeneration in the familiar forms of amyotrophic lateral sclerosis. Although studies on mutant human SOD1 transgenic rodent models have provided important insights into disease pathogenesis, they have not led to the discovery of early biomarkers or effective therapies in human disease. The recent generation of a transgenic swine model expressing the human pathological hSOD1G93A gene, which recapitulates the course of human disease, represents an interesting tool for the identification of early disease mechanisms and diagnostic biomarkers. Here, we analyze the activation state of CNS cells in transgenic pigs during the disease course and investigate whether changes in neuronal and glial cell activation state can be reflected by the amount of extracellular vesicles they release in biological fluids. To assess the activation state of neural cells, we performed a biochemical characterization of neurons and glial cells in the spinal cords of hSOD1G93A pigs during the disease course. Quantification of EVs of CNS cell origin was performed in cerebrospinal fluid and plasma of transgenic pigs at different disease stages by Western blot and peptide microarray analyses. We report an early activation of oligodendrocytes in hSOD1G93A transgenic tissue followed by astrocyte and microglia activation, especially in animals with motor symptoms. At late asymptomatic stage, EV production from astrocytes and microglia is increased in the cerebrospinal fluid, but not in the plasma, of transgenic pigs reflecting donor cell activation in the spinal cord. Estimation of EV production by biochemical analyses is corroborated by direct quantification of neuron- and microglia-derived EVs in the cerebrospinal fluid by a Membrane Sensing Peptide enabled on-chip analysis that provides fast results and low sample consumption. Collectively, our data indicate that alteration in astrocytic EV production precedes the onset of disease symptoms in the hSODG93A swine model, mirroring donor cell activation in the spinal cord, and suggest that EV measurements from the cells first activated in the ALS pig model, i.e. OPCs, may further improve early disease detection.

Performance Evaluation of a Commercial Real-Time PCR Method for the Detection of Lupin Traces in Food

In accordance with U.S. FDA Foods Program Regulatory Science Steering Committee guidelines, with this study, we optimized and validated a commercial real-time PCR method for the detection of low amounts of lupin in four classes of food matrices: chocolate cookies, ragù, Olivier salad, and barley and rice flour. DNA extracted from blank (true negative) samples artificially contaminated with lupin (Lupinus albus) flour at 1000 ppm underwent dilutions with the DNA extracted from the true negative samples up to 0.5 ppm. The limit of detection for real-time PCR was 0.5 ppm in the complex matrices (range, Ct 26-34), making this a specific, robust, and rapid method for lupin allergen detection and labeling. Our validation data support the suitability of this commercially available real-time PCR method for this purpose.

The long-term effect on surgery-free survival of biological compared to conventional therapy in Crohn's disease in real world-data: a retrospective study

BACKGROUND

The introduction of biological drugs has led to great expectations and growing optimism in the possibility that this new therapeutic strategy could favourably change the natural history of Inflammatory Bowel Disease (IBD) and, in particular, that it could lead to a significant reduction in surgery in the short and long term. This study aims to assess the impact of biological versus conventional therapy on surgery-free survival time (from the diagnosis to the first bowel resection) and on the overall risk of surgery in patients with Crohn's disease (CD) who were never with the surgical option.

METHODS

This is a retrospective, double-arm study including CD patients treated with either biological or conventional therapy (mesalamine, immunomodulators, antibiotics, or steroids). All CD patients admitted at the GI Unit of the S. Salvatore Hospital (L'Aquila. Italy) and treated with biological therapy since 1998 were included in the biological arm. Data concerning the CD patients receiving a conventional therapy were retrospectively collected from our database. These patients were divided into a pre-1998 and post-1998 group. Our primary outcome was the evaluation of the surgery-free survival since CD diagnosis to the first bowel resection. Surgery-free time and event incidence rates were calculated and compared among all groups, both in the original population and in the propensity-matched population.

RESULTS

Two hundred three CD patients (49 biological, 93 conventional post-1998, 61 conventional pre-1998) were included in the study. Kaplan-Meier survivorship estimate shows that patients in the biological arm had a longer surgery-free survival compared to those in the conventional arm (p = 0.03). However, after propensity matching analysis, conducted on 143 patients, no significant difference was found in surgery-free survival (p = 0.3). A sub-group analysis showed shorter surgery-free survival in patients on conventional therapy in the pre-biologic era only (p = 0.02; Hazard Ratio 2.9; CI 1.01-8.54) while no significant difference was found between the biologic and conventional post-biologic groups (p = 0.15; Hazard Ratio 2.1; CI 0.69-6.44).

CONCLUSION

This study shows that the introduction of biological therapy has only a slight impact on the eventual occurrence of surgery in CD patients over a long observation period. Nevertheless, biological therapy appears to delay the first intestinal resection.

Brain-Derived Neurotrophic Factor, Kynurenine Pathway, and Lipid-Profiling Alterations as Potential Animal Welfare Indicators in Dairy Cattle

Complete animal welfare evaluation in intensive farming is challenging. With this study, we investigate new biomarkers for animal physical and mental health by comparing plasma expression of biochemical indicators in dairy cows reared in three different systems: (A) semi-intensive free-stall, (B) non-intensive tie-stall, and (C) intensive free-stall. Additionally, protein levels of mature brain-derived neurotrophic factor (mBDNF) and its precursor form (proBDNF) and indoleamine 2,3-dioxygenase (IDO1) specific activity were evaluated in brain samples collected from 12 cattle culled between 73 and 138 months of age. Alterations in plasma lipid composition and in the kynurenine pathway of tryptophan metabolism were observed in the tie-stall-reared animals. The total plasma BDNF concentration was higher in tie-stall group compared to the two free-housing groups. Brain analysis of the tie-stall animals revealed a different mBDNF/proBDNF ratio, with a higher level of proBDNF (p < 0.001). Our data are similar to previous studies on animal models of depression, which reported that inhibition of the conversion of proBDNF in its mature form and/or elevated peripheral kynurenine pathway activation may underlie cerebral biochemical changes and induce depressive-like state behavior in animals.

Validation of p53 Immunohistochemistry (PAb240 Clone) in Canine Tumors with Next-Generation Sequencing (NGS) Analysis

In human medicine, p53 immunohistochemistry (IHC) is a common method that is used for the identification of tumors with TP53 mutations. In veterinary medicine, several studies have performed IHC for p53 in canine tumors, but it is not known how well it actually predicts the mutation. The aim of this study was to estimate the accuracy of the IHC method for p53 (clone PAb240) using a lab-developed NGS panel to analyze TP53 mutations in a subset of malignant tumors in dogs. A total of 176 tumors were analyzed with IHC and then 41 were subjected to NGS analysis; among them, 15 were IHC positive and 26 were negative, and 16 out of 41 (39%) were found to be inadequate for NGS analysis. Excluding the non-evaluable cases at NGS, of the remaining eight IHC-positive cases, six were mutants and two were wild-type. Among the 17 IHC-negative cases, 13 were wild type, and 4 were mutants. The sensitivity was 60%, specificity was 86.7%, and the accuracy was 76%. These results suggest that when using IHC for p53 with this specific antibody to predict mutation, up to 25% wrong predictions can be expected.

Validation of serum paraoxonase/arylesterase 1 (PON1) as a protein marker of illicit dexamethasone treatment in veal calves

The illicit use of dexamethasone and other glucocorticoids for cattle fattening in livestock production has been widely described; evidence for illegal treatments can be obtained by direct or indirect detection. In our previous study, we applied two-dimensional electrophoresis (2DE) to identify plasma protein markers of dexamethasone administration in veal calves. Comparison of 2DE maps obtained from blood samples before and after treatment showed the disappearance of two protein spots identified as serum paraoxonase/arylesterase 1 precursor (PON1). In the present study, we validated PON1 as a marker by analysing a larger number of samples treated with dexamethasone for illicit use. Analysis of samples from experimental treatment with other glucocorticoids, androgens and oestrogens confirmed that their influence on PON1 could be excluded. The specificity of the PON1 protein marker was verified on expected negative field samples to exclude interfering factors. However, there is poor statistical evidence to support a significant association between the outcome of PON1 and the considered variables. The results on field samples were compared with histological examination of the thymus as a biomarker of corticosteroid treatment monitored in the Italian histological plan for the control of growth promoters in animals. Two suspect cases were identified from two Piedmont farms where other animals had tested positive at histological examination. In conclusion, the absence of PON1 in the plasma of veal calves can indirectly reveal illicit dexamethasone treatment in individual animals and so identify suspect farms for further investigation. It is effective in a period ranging from 3 to about 10 days from illicit treatment, covering a time span that goes beyond the limits of official chemical controls and preceding histological controls on the thymus of slaughtered animals. PON1 detection in plasma can be coupled with other tests to identify illegal dexamethasone use on veal calf farms.

Processed animal proteins (PAPs) in animal nutrition: Assessment of the chemical risk of essential and non-essential elements

BACKGROUND

Processed animal products (PAPs) could be a great alternative to common protein supplements and represent a good example of recycling and valorization of by-products. Due to the reintroduction of certain types of PAPs in feed, a deeper knowledge of these heterogeneous matrices is needed. Thus, the aim of this study is to evaluate the levels of essential elements and inorganic contaminants in 55 PAPs considered as potential alternatives to common protein supplements.

METHODS

PAPs samples were analysed for essential (cobalt, nickel, chromium, copper, zinc, iron and manganese) and non-essential elements (arsenic, cadmium, lead and mercury) by Inductively Coupled Plasma Mass Spectrometer (ICP-MS), Graphite Furnace Atomization Atomic Absorption Spectrometer (GF-AAS) and dual cell Direct Mercury Analyzer spectrometer (DMA-80).

RESULTS

Essential elements were found with the following decreasing order iron>zinc>copper>manganese>chromium>nickel>cobalt (mg kg-1). Only one sample was found non-compliant to lead concentration according to the European Union Regulation while negligible values of others non-essential elements were found.

CONCLUSIONS

This study suggests that PAPs could be a useful supplement for animal diet due to their natural content of essential elements. A careful monitoring of chemical elements should be required and eventually guidelines have to be drafted for a correct use of PAPs to ensure a safe and sustainable feed production.

The interplay between immune system and microbiota in gynecological diseases: a narrative review

OBJECTIVE

The vaginal microbiome is a dynamic environment, depending on the results of a complex interplay between microbiota and the host. In physiological conditions, Lactobacillus species are the most represented, regulating glycogen metabolism in order to maintain normal pH. Vaginal flora has been divided into five subtypes. Pattern recognition receptors are present on both squamous epithelial cells lining the vagina and columnar cells lining the upper female genital tract. They respond directly to bacterial product expressed by vaginal microbiome. The vagina contains different immune related cells and receptors which can recognize and react with the microbial environment. Altered microbiota and altered interplay between microbiota and immune system underlie several gynecologic diseases.

MATERIALS AND METHODS

In this review, literature data related to vaginal microbiota, vaginal inflammation, immune system and menopause, preterm labor and miscarriage, were summarized. Relevant publications were retrieved from: PubMed, Medline, Scopus and Web of Science.

RESULTS

The vaginal microbiome and the relationship with immune system has been analyzed in different gynecologic conditions. Menopause is associated to estrogen loss which causes vaginal atrophy, reduced abundance of Lactobacilli and increased amount of other bacterial species. Estrogens influence vaginal immunity through known and unknown mechanisms. In bacterial vaginosis (BV), due to many bacterial species, there has been found an inhibition of the chemotaxis and cytokine secretion. A decreased concentration of Lactobacilli seems to be playing a role in preterm labor as well as the increased levels of pro-inflammatory cytokines. Finally, the disequilibrium in the Th1/Th2 immune adaptive response, with a shift from Th2 to Th1, appears to be playing a role in miscarriage.

CONCLUSIONS

The interplay between microbiota and the host closely involves the immune system. In particular, the vaginal microbiota is classically characterized by Lactobacilli even if vaginal microbiome of asymptomatic woman of reproductive age includes multiple aerobic and facultative or obligate anaerobic species. The role of microbiota and immune system in determining gynecological and obstetric events has been studied throughout recent years reaching new advancements. Therefore, additional studies are needed to better comprehend the complexity of the issue.

General practitioners' management of symptomatic uncomplicated diverticular disease of the colon by using rifaximin, a non-adsorbable antibiotic

OBJECTIVE

Symptomatic uncomplicated diverticular disease of the colon (SUDD) is generally managed by gastroenterologists rather than General Practitioners (GPs). The aim of this study was to assess the efficacy of the treatment of SUDD with rifaximin, a non-absorbable antibiotic, in a primary care setting by GPs.

PATIENTS AND METHODS

This retrospective, observational study investigated the use of rifaximin at a dose of 400 mg b.i.d. for 5, 7 or 10 days monthly, up to 3 months. The symptoms were reported by the patients using a visual analogic scale (VAS) of 0-10.

RESULTS

286 SUDD patients were enrolled (44.4% of men, average age 70.92±10.98). Respectively, 15 (5.2%) patients received the treatment for 5 days, 205 (71.7%) for 7 days and 66 (23.1%) for 10 days. After three months, a significant reduction of VAS score was observed in almost all symptoms assessed: 135 (47.2%) patients reported no abdominal pain (p<0.001) and 23 (8.1%) reported no symptom. Adverse events related to the treatment were recorded in 3 (1.04%) patients, all of them mild and not requiring interruption of the treatment. Acute diverticulitis occurred in 9 (3.1%) patients, but only 2 of them [0.7% (n=2)] underwent surgery due to complicated diverticulitis. Analysis within the different treatment groups (5, 7 and 10 days) shows that rifaximin treatment is effective in reducing the severity of symptoms in almost all groups except for the constipation in the 5-day group.

CONCLUSIONS

Rifaximin can be effectively used by GPs in real-life for the management of SUDD.

Using network analysis to identify seasonal patterns and key nodes for risk-based surveillance of pig diseases in Italy

The description of the pattern of livestock movements between herds provides essential information for both improving risk-based surveillance and to understand the likely spread of infectious diseases. This study provides a description of the temporal pattern of pig movements recorded in Italy on a 4-year period (2013-2016). Data, provided by the National Livestock registry, were described by social network analysis and the application of a walk-trap algorithm for community detection. Our results show a highly populated community located in Northern Italy, which is the focal point of the Italian industrial pig production and as a general pattern an overall decline of medium and backyard farms and an increase in the number of large farms, in agreement with the trend observed by other EU pig-producing countries. A seasonal pattern of all the parameters evaluated, including the number of active nodes in both the intensive and smaller production systems, emerged: that is characterized by a higher number of movements in spring and autumn, linked with the breeding and production cycle as pigs moved from the growing to the finishing phase and with periods of increased slaughtering at Christmas and Easter. The same pattern was found when restricting the analysis to imported pig batches. Outbreaks occurring during these periods would have a greater impact on the spread of infectious diseases; therefore, targeted surveillance may be appropriate. Finally, potential super-spreader nodes have been identified and represent 0.47% of the total number of pig holdings (n = 477). Those nodes are present during the whole study period with a similar ranking in their potential of being super-spreaders. Most of them were in Northern Italy, but super-spreaders with high mean out-degree centrality were also located in other Regions. Seasonality, communities and super-spreaders should be considered when planning surveillance activity and when applying disease control strategies.

Evaluation of the effects of hydroxyethyl starch (130/0.4) administration as a constant rate infusion on plasma colloid osmotic pressure in hypoabluminemic dogs

OBJECTIVE

To evaluate the effects of 2 constant rate infusions of hydroxyethyl starch (HES) 130/0.4 on plasma colloid osmotic pressure (COP) in hypoalbuminemic dogs.

DESIGN

Prospective, randomized clinical trial.

ANIMALS

A total of 24 client-owned dogs.

INTERVENTIONS

Hypoalbuminemic euvolemic dogs (albumin < 20 g/L [<2 g/dL]) with normal perfusion parameters requiring IV fluid therapy were enrolled. In addition to crystalloid, HES 130/0.4 was administered as a constant rate infusion over 24 hours at 1 mL/kg/h (group 1, n = 15) or at 2 mL/kg/h (group 2, n = 9), in order to support plasma COP. Before infusion, a blood sample was collected to perform CBC, serum electrophoresis, and serologic tests for some infective diseases. Plasma COP, albumin concentration, PCV, and total plasma protein concentration were evaluated serially at baseline (T0) and then at 6, 12, and 24 hours after the start of infusion, and a multilevel model was performed for these parameters to detect statistically significant differences between the 2 groups.

MEASUREMENT AND MAIN RESULTS

Twenty-four dogs were included. No statistically significant differences in COP were found between the 2 groups; however, a high level of variability has been identified within the single individual. Among the other laboratory analyses, PCV was significantly decreased in group 1 at T12 and T24 compared with T0 (P < 0.001) and total plasma protein concentration was significantly increased in group 2 at T12 and T24 compared with T0 (P < 0.008).

CONCLUSION

No significant effect on plasma COP was found following infusion with HES 130/0.4 at doses of 1 mL/kg/h and 2 mL/kg/h for 24 hours to hypoalbuminemic dogs. The administered concomitant dose of crystalloids, underlying disease, and small sample size were all potential confounding factors.

Occupational exposure for asbestos-related disease groups: geomapping of the last 5 years in Italy

Background

Asbestos-related diseases are a public health challenge in Italy: the country has been a major producer and user of asbestos since World War II until complete ban in 1992. Several contaminated sites and structures across the country have never been decontaminated: incidence peak of asbestos-related diseases is expected somewhen between 2015 and 2020. Study objective is to investigate incidence of asbestos-related diseases in Italy in the last 5 years, from both a chronological and geographical perspective.

Methods

Ascertained diagnoses of asbestos-related diseases among workers were collected from the INAIL public registry from 2014 to 2018. Yearly incidence rate was estimated per province (incident cases per million workers) and mapped by year. Global incidence quota by working sector and sub-sector was also calculated.

Results

8.620 cases have been reported. Incidence rate rapidly increased from 2014, peaking at 7,2 new cases per 100.000 workers in 2015. Afterwards, the number of ascertained cases decreased. There is a clear gradient distribution between northern and southern Italian provinces, with the highest rates in Northern Italy (especially in year 2014) and declining over time. Mesothelioma (all variants) was the most common disease, (2.995 cases, 35% of total), followed by pleural plaques (2.955 cases, 34%), pneumoconiosis (1.327 cases, 15%) and cancer of lungs/respiratory tract (1.298 cases, 14%). Most affected category was that of metal workers, but construction, transportation and electricity workers were also affected.

Conclusions

Detailed surveillance with mapping support is an effective tool for public health servants to locally manage prevention programs targeted on occupational risk. This is especially true for areas with active industries in the most affected sectors.

Key messages

Asbestos does not mean mesothelioma, but also other diseases that impact on workforce health status. Pneumoconiosis and other oral and respiratory cancers are also associated with asbestos exposure. Risk management should be tailored for a wider array of worker types than usually considered, since such exposure happens in sectors that are not traditionally related to asbestos exposure.

Wild rats as urban detectives for latent sources of asbestos contamination

Based on a large body of evidence asbestos minerals have been classified as carcinogens. Despite the Italian ban on asbestos in 1992 and the subsequent remediation activities, latent sources of contamination may still represent a hazard where asbestos were particularly used. Using wild rats as sentinel animals, this study aimed at uncovering sites with the greatest potential for non-occupational exposure to asbestos in the city of Casale Monferrato (Piedmont Region, Italy), where the largest Italian manufacturing plant of asbestos-cement had been active. During the study period (2013-2015) a total of 40 wild rats were captured from 16 sampling capture points. The lungs of wild rats have been investigated by using scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS). The SEM-EDS detected the presence of asbestos fibers (tremolite/actinolite, amosite, and chrysotile) in rats' lungs from 11 sampling points. The hypothetical rats' home-range and the observed site-specific concentration of asbestos fibers per gram of dry lung tissue were used to identify areas to be targeted by additional search of latent sources of asbestos. In conclusion, our results showed that the use of wild rats as sentinel animals may effectively integrate the strategies currently in use to reduce the exposure to asbestos.

Neurofilaments in blood is a new promising preclinical biomarker for the screening of natural scrapie in sheep

Scrapie is a fatal neurodegenerative disease of sheep and goats belonging to the group of Transmissible Spongiform Encephalopathy or prion diseases. The EU has adopted mandatory measures for scrapie surveillance to safeguard public and animal health because it is highly contagious and might decimate all genetic susceptible animals in affected flocks. Definite diagnosis of scrapie relies on the detection of the pathological prion protein in brain tissues and there are still no blood biomarkers available for making diagnosis in living animals that can be used for the screening of sheep in scrapie-affected flocks. Neurofilament light (NfL) protein, a valid biomarker for neuronal and axonal damages, can now be easily measured in blood by the ultra-sensitive single molecule array (Simoa) technology. Recent work reported that serum NfL is increased in neurodegenerative diseases, including human prion diseases, but no data are available for scrapie or other animal prion diseases. Here, we found that the median serum NfL concentration in scrapie animals (56.2, IQR 42.2–84.8, n = 9) was more than 15 times higher (p = 0.00084) than that found in control samples (3.4, IQR 3.0–26.3, n = 11). Moreover, serum NfL concentration in scrapie sheep with clinical signs (n = 2; 75.3, 15.7 pg/ml) did not significantly (p = 0.541; t-test) differ from scrapie animals without clinical signs (n = 7; 61.0, 10.7 pg/ml). The receiver operating characteristic (ROC) curve analysis estimated the cut-off value of 31 pg/ml serum NfL for distinguishing scrapie-infected sheep from controls. The application of this cut-off value gives an accuracy of the test of 95% (percent error of 5.23%). These data indicate that the Simoa test for serum NfL might be a useful screening method for detecting preclinical scrapie in living sheep. Finally, the preliminary data reported here need confirmation in large and more structured studies.

Serum indirect immunofluorescence assay and real-time PCR results in dogs affected by Leishmania infantum: evaluation before and after treatment at different clinical stages

We compared results of a serum immunofluorescence assay (IFA) and lymph node quantitative PCR (qPCR) in dogs classified as exposed, infected, or sick because of leishmaniasis. We also determined how IFA or qPCR results changed in response to treatment and reflected different clinical and clinicopathologic improvement of dogs. We included 108 dogs in our retrospective study: 12 exposed, 25 infected, and 71 sick, as classified according to Canine Leishmaniasis Working Group standards. Between-group comparison showed higher IFA values ( p < 0.01) for sick dogs; qPCR values were higher for sick than infected dogs ( p < 0.01). A novel clinical and clinicopathologic score was created and applied to 50 sick dogs. Using this score, 41 were reclassified as partially recovered (PR) within 3 mo, and 37 as totally recovered (TR) 3-6 mo after presentation. Statistically significant differences in IFA values were found between the sick and TR dogs ( p < 0.01), but not between sick and PR dogs ( p = 0.98). During follow-up, qPCR revealed a progressive decrease in parasite load, with a statistically significant difference in sick versus PR ( p < 0.01), sick versus TR ( p < 0.01), and PR versus TR ( p < 0.01) dogs. A decrease of 1 point in the clinical score corresponded to 1.3 Leishmania/μL qPCR decrease ( p < 0.01) and decrease of 1:42 in IFA ( p < 0.01). Our findings confirm that the clinical status of dogs affected by leishmaniasis is closely related to parasite load and antibody level, both before and after treatment.

A cross-sectional study to identify a set of risk factors for caprine herpesvirus 1 infection

BACKGROUND

Caprine herpesvirus 1 (CpHV-1) causes neonatal mortality and reproductive failure in goats. Despite its impact on herd reproductive performance, few studies have investigated the risk factors associated with CpHV-1 infection. The aim of this cross-sectional study was to identify potential herd- and host-level risk factors associated with CpHV-1 prevalence in a goat population with heterogeneous seropositivity for CpHV-1.

RESULTS

Blood samples and individual data from 4542 goats were collected from 255 herds in Piedmont, Italy. Enzyme-linked immunosorbent assay (ELISA) and serum neutralization tests were carried out to detect antibodies against CpHV-1. A mixed-effects model was applied to identify any statistical association between CpHV-1 seropositivity and a set of putative host-level and herd-level risk factors. A total of 630 samples tested were found positive by ELISA (prevalence = 13.9%; 95% confidence interval (CI) 12.9-14.9). Of the 255 tested herds, 85 were classified as positive for the presence of at least one gB-positive animal (herd prevalence 33.3%, 95% CI 27.5-39.2), with a within-herd prevalence between 0.7 and 100% (Q1 = 17.6%; median = 32.3%; Q3 = 50%) (Q = quartiles). The prevalence ratios showed a statistical association with the following risk factors: breeds other than Saanen, older age, larger herd size, meat and extensive herds, and co-existence of CAEV-infected animals.

CONCLUSIONS

Results from this cross sectional study may help to elucidate the natural history of the infection and inform targeted strategies to control a disease with a potentially important impact on animal health and goat farming economy.

Predicting the impact of selection for scrapie resistance on PRNP genotype frequencies in goats

The European Union has implemented breeding programmes to increase scrapie resistance in sheep. A similar approach can be applied also in goats since the K222 allele provides a level of resistance equivalent to that of ARR in sheep. The European Food Safety Authority stated that breeding for resistance could be offered as an option for Member States to control classical scrapie in goats. We assessed the impact of different breeding strategies on PRNP genotype frequencies using a mathematical model that describes in detail the evolution of K222 in two goat breeds, Chamois Coloured and Saanen. Different patterns of age structure and replacement rate were modelled as factors affecting response to selection. Breeding for scrapie resistance can be implemented in goats, even though the initial K222 frequencies in these breeds are not particularly favourable and the rate at which the resistant animals increase, both breeding and slaughtered for meat production, is slow. If the goal is not to achieve the fixation of resistance allele, it is advisable to carry out selection only until a desired frequency of K222-carriers has been attained. Nucleus selection vs. selection on the overall populations is less expensive but takes longer to reach the desired output. The programme performed on the two goat breeds serves as a model of the response the selection could have in other breeds that show different initial frequencies and population structure. In this respect, the model has a general applicability.

Arthroscopic treatment of osteochondritis dissecans of the shoulder in 126 dogs

Osteochondritis dissecans of the shoulder joint was treated by arthroscopy in 126 dogs. Twenty-four dogs had bilateral surgery, making a total of 150 joints treated. The OCD flaps were removed in small pieces through the cannula or in a single piece through a stab incision. The lameness resolved completely within seven-60 days following arthroscopy in 137 out of 150 affected limbs. Within a subset of 47 dogs with unilateral OCD, it was found that lesions located on the caudo-medial region of the humeral head had a better functional outcome than those lesions located in the caudo-central region of the humeral head.

Low fraction of the 222K PrP variant in the protease-resistant moiety of PrPres in heterozygous scrapie positive goats

The presence of lysine (K) at codon 222 has been associated with resistance to classical scrapie in goats, but few scrapie cases have been identified in 222Q/K animals. To investigate the contribution of the 222K variant to PrPres formation in natural and experimental Q/K scrapie cases, we applied an immunoblotting method based on the use of two different monoclonal antibodies, F99/97.6.1 and SAF84, chosen for their different affinities to 222K and 222Q PrP variants. Our finding that PrPres seems to be formed nearly totally by the 222Q variant provides evidence that the 222K PrP variant confers resistance to conversion to PrPres formation and reinforces the view that this mutation has a protective role against classical scrapie in goats.

EU-approved rapid tests might underestimate bovine spongiform encephalopathy infection in goats

We report the diagnostic sensitivity of 3 EU-approved rapid tests (ELISAs; 1 from IDEXX and 2 from Bio-Rad) for the detection of transmissible spongiform encephalopathy diseases in goats. Ninety-eight goat brainstem samples were tested. All the rapid tests had 100% specificity and ≥80% sensitivity, with the IDEXX test significantly more sensitive than the 2 Bio-Rad tests. All tests detected 100% of samples from goats with clinical scrapie, but missed 8% (IDEXX) to 33% (Bio-Rad SG) of samples from preclinical goats. Importantly, only IDEXX picked up all samples from clinical bovine spongiform encephalopathy (BSE)-infected goats, whereas the other 2 rapid tests missed 15% (Bio-Rad SG) to 25% (Bio-Rad SAP). These results show that a fraction of preclinical scrapie infections are likely missed by EU surveillance, with sensitivity of detection strongly dependent on the choice of the rapid test. Moreover, a significant proportion of clinical BSE infections are underestimated by using either Bio-Rad test. Assuming that the same sensitivity on preclinical goats would also occur in BSE-infected goats, our data suggest that IDEXX is likely the most sensitive test for detecting preclinical field cases of BSE infection in goats, although with an 8% failure rate. These results raise some concerns about the reliability of current EU surveillance figures on BSE infection in goats.

Prevalence of antibodies against Bubaline herpesvirus (BuHV-1) among Mediterranean water buffalo (Bubalus bubalis) with implications in buffalo trade

BACKGROUND

Both Bovine herpesvirus (BoHV-1) and Bubaline herpesvirus (BuHV-1) have been reported to cross the species barrier. Antibody seroconversion in glycoprotein E (gE) blocking ELISA during BuHV-1 infection has been documented. Recent diagnostic efforts have focused on the development and application of discriminatory tests to distinguish between infections with BoHV-1 and BuHV-1.

OBJECTIVE

To evaluate the impact and distribution of these two infections in water buffalo farms in two regions (Piedmont (n = 3) and Campania (n = 10), Italy) where infectious bovine rhinotracheitis control programs have been implemented.

ANIMALS AND METHODS

Sampling was carried out on 13 buffalo farms comprising 1089 animals using specific gE-indirect ELISA's test able to discriminate among BoHV-1 and BuHV-1 infections.

RESULTS

59.0% of animals reacted positive to ELISA (irrespective of whether BoHV-1 or BuHV-1 antigen was used) and 86.4% of these were reactive to BuHV-1 only, whereas 11.8% showed absorbance values for both antigens and were classified as inconclusive. There was a statistically significant age-related difference in BuHV-1 infection rates but not in overall individual (47% vs. 58%) or herd prevalence (100% vs. 90%) of infection between the two regions.

CONCLUSION

The low percentage of sera reactive to BoHV-1 (1.8%, 12/643) indicates that BuHV-1 may be the main circulating alphaherpesvirus infection in Mediterranean water buffalo in the two study areas. Since Bubalus bubalis is included in Directive 64/432/EEC on animal health problems affecting intra-community trade in bovine animals, diagnostic testing with nonspecific ELISA for BoHV-1 infection in buffalo may yield false-positive reactions. This scenario could lead to economic losses and hamper buffalo trade and movement, particularly for reproduction purposes.

Diets with different lipid contents do not modify the neuronal membrane lipid raft profile in a scrapie murine model

In Transmissible Spongiform Encephalopathies (TSEs), the localization of the prion protein in the neuronal membrane lipid rafts (LR) seems to play a role in sustaining the protein misfolding. Changes in membrane properties, due to altered lipid composition, affect their organization and interaction between lipids and protein therein, and consequently also membrane resident protein functionality; dietary polyunsaturated fatty acids (PUFAs), gangliosides and cholesterol seem to influence these processes.

AIMS

In this work, the influence of administration of different feed, able to change the composition of lipid membrane, on the clinical progression of prion disease was studied.

MAIN METHODS

The activity of three diets (hyperlipidic with 6% fats; hypolipidic with 0.1% fats; and purified with 4% fats) was tested in CD1 mouse model experimentally infected with RML scrapie strain. Presence and distribution of typical central nervous system (CNS) lesions and deposits of PrP(sc) were evaluated by histopathological analysis and immunohistochemistry. Analysis of lipids was performed in homogenate and insoluble brain fraction of the neuronal membrane rich in LR.

KEY FINDINGS

Results show that a diet with a different lipid level has not a significant role in the development of the scrapie disease. All infected mice fed with different diets died in the same time span. Histology, immunohistochemistry, and neuropathological analyses of the infected brains did not show significant differences between animals subjected to different diets.

SIGNIFICANCE

Independently of the diet, the infection induced a significant modification of the lipid composition in homogenates, and a less noticeable one in insoluble brain fraction.

Expression and antigenic characterization of bubaline herpesvirus 1 (BuHV1) glycoprotein E and its potential application in the epidemiology and control of alphaherpesvirus infections in Mediterranean water buffalo

Bubaline herpesvirus 1 (BuHV1) is a member of ruminant alphaherpesviruses antigenically related to bovine herpesvirus 1 (BoHV1). The impact of BuHV1 infection in infectious bovine rhinotracheitis control program is difficult to establish, due to the lack of specific diagnostic test. The ectodomain of glycoprotein E of BuHV1 was expressed as recombinant secreted protein and used in indirect ELISA as well as in a discriminatory test using the BoHV1 counterpart. A panel of monoclonal antibodies was produced against BuHV1; 6 out of 7 anti-gE monoclonal antibodies specifically recognized the BuHV1 gE. Results indicated BuHV1 gE as a sensitive marker of infection compared to seroneutralization (SN) test or blocking ELISA. When BoHV1 and BuHV1 gEs were immobilized in different wells of the same ELISA microplate, bovine and water buffalo sera were more reactive against the respective infecting virus. About one third of seropositive buffaloes with no history of contact with cattle and having higher SN titres, reacted in BoHV1 gE blocking ELISA, possibly because of steric hindrance. Since in two occasions BuHV1 was also isolated from water buffalo scoring gB+/gE+ BoHV1 blocking ELISA, we conclude that the combination of the two blocking ELISAs is not suitable to differentiate between BoHV1 and BuHV1.

Reproducibility study for the detection of Staphylococcal enterotoxins in dairy products between official Italian national laboratories

Staphylococcal food poisoning is a common foodborne disease caused by the ingestion of staphylococcal enterotoxins (SEs) produced mainly by enterotoxigenic strains of Staphylococcus aureus. To date, 21 SEs and/or enterotoxin-like types have been identified, several of which represent a potential hazard for consumers. To protect consumer health and to reduce the amount of SE-contaminated food entering the market, European Union legislation regulating food safety requires testing for SEs. The Italian National Reference Laboratory organized a ring trial to test technical and analytical proficiency in the national network of official food laboratories. Twenty-four laboratories took part, and each received and analyzed 24 blind dairy samples. Reproducibility of the results from the laboratories was assessed by the Cohen k index, and accuracy (sensitivity and specificity) was evaluated according to the International Organization for Standardization definition (ISO 16140:2003). Trial results revealed partially satisfactory agreement: 254 of 276 possible paired participants (92%) reached a k value >0.60, which is conventionally recognized as satisfactory. Accuracy was deemed satisfactory; 100% sensitivity and 100% specificity were achieved by 22 and 18 of the 24 laboratories, respectively.

Lysine at position 222 of the goat prion protein inhibits the binding of monoclonal antibody F99/97.6.1

Prion protein (PrP) is encoded by the PRNP gene, which is highly polymorphic in goats, with polymorphisms encoding amino acid substitutions at the protein level. In the current study, the reactivity of monoclonal antibody (mAb) F99/97.6.1 in binding PrP from goats polymorphic at PRNP codon 222 was investigated. Nervous tissue from 30 scrapie-negative goats with 3 different genotypes (222Q/Q, 222Q/K, and 222K/K) was analyzed by Western blot using mAbs P4 and F99/97.6.1. Although PrP was detected in all 30 samples by mAb P4, detection of PrP by mAb F99/97.6.1 was limited to 222Q/Q (12/12). No PrP was detected by mAb F99/97.6.1 in the 222K/K samples (n = 6), and the signal intensity of mAb F99/97.6.1 for PrP was lower for the 222Q/K samples (12/12 samples). To further investigate these results, additional Western blot analyses were performed, and the PrP signals detected by mAbs F99/97.6.1 and SAF84 were then quantified. The mean F99/SAF84 ratio (± standard deviation) calculated for the 222Q/Q group was 0.73 ± 1.26, and the mean for the 222Q/K group was 0.27 ± 1.31. Statistical analysis of these values evidenced statistically significant differences between the 222Q/Q and 222Q/K samples. The results of the study thus revealed an inhibition by lysine at position 222 on the binding of mAb F99/97.6.1 to goat PrP. This has implications for the use of mAb F99/97.6.1 for diagnostic purposes. Because the 222K allele could be a target for genetic selection in goats, the differential reactivity of mAb F99/97.6.1 could be exploited with a genotyping test setup.

EU-approved rapid tests for bovine spongiform encephalopathy detect atypical forms: a study for their sensitivities

Since 2004 it become clear that atypical bovine spongiform encephalopthies (BSEs) exist in cattle. Whenever their detection has relied on active surveillance plans implemented in Europe since 2001 by rapid tests, the overall and inter-laboratory performance of these diagnostic systems in the detection of the atypical strains has not been studied thoroughly to date. To fill this gap, the present study reports on the analytical sensitivity of the EU-approved rapid tests for atypical L- and H-type and classical BSE in parallel. Each test was challenged with two dilution series, one created from a positive pool of the three BSE forms according to the EURL standard method of homogenate preparation (50% w/v) and the other as per the test kit manufacturer's instructions. Multilevel logistic models and simple logistic models with the rapid test as the only covariate were fitted for each BSE form analyzed as directed by the test manufacturer's dilution protocol. The same schemes, but excluding the BSE type, were then applied to compare test performance under the manufacturer's versus the water protocol. The IDEXX HerdChek ® BSE-scrapie short protocol test showed the highest sensitivity for all BSE forms. The IDEXX® HerdChek BSE-scrapie ultra short protocol, the Prionics®--Check WESTERN and the AJ Roboscreen® BetaPrion tests showed similar sensitivities, followed by the Roche® PrionScreen, the Bio-Rad® TeSeE™ SAP and the Prionics®--Check PrioSTRIP in descending order of analytical sensitivity. Despite these differences, the limit of detection of all seven rapid tests against the different classes of material set within a 2 log(10) range of the best-performing test, thus meeting the European Food Safety Authority requirement for BSE surveillance purposes. These findings indicate that not many atypical cases would have been missed surveillance since 2001 which is important for further epidemiological interpretations of the sporadic character of atypical forms.

A relevant long-term impact of the circulation of a potentially contaminated vaccine on the distribution of scrapie in Italy. Results from a retrospective cohort study

A sudden increase in the incidence of scrapie in Italy in 1997 was subsequently linked to the use of a potentially infected vaccine against contagious agalactia. The relative risk for the exposed farms ranged between 6 and 40. The aim of this study was to assess the long-term impact of exposure to the potentially scrapie-contaminated vaccine on the Italian classical scrapie epidemic. We carried out a retrospective cohort study, fitting mixed-effects Poisson regression models, dividing national geographic areas into exposure categories on the basis of the vaccine circulation levels. We took into account the sensitivity of the surveillance system applied in the different areas. The population attributable fraction (PAF) was used to assess the impact on the total population of farms associated with the effect of circulation of the vaccine. The provinces where the vaccine was more often sold were noted to have a higher level of disease when compared to those provinces where the vaccine was sold less often (incidence rate ratio [IRR]: 2.7; 95% confidence interval [CI]: 1.1-6.5). The population attributable fraction was high (68.4%). Standardization techniques allowed to account for the potential of geographical variability in the sensitivity of the Italian surveillance system. Although the number of the directly exposed farms was limited, an important long-term impact of the vaccine circulation could be quantified in terms of secondary outbreaks likely due to the exchange of animals from directly exposed flocks.

Histology as a valid and reliable tool to differentiate fresh from frozen-thawed fish

Selling fish products as fresh when they have actually been frozen and thawed is a common fraudulent practice in seafood retailing. Unlike fish products frozen to protect them against degenerative changes during transportation and to extend the product's storage life, fish intended for raw consumption in European countries must be previously frozen at -20° C for at least 24 h to kill parasites. The aim of this study was to use histological analysis to distinguish between fresh and frozen-thawed fish and to evaluate this method for use as a routine screening technique in compliance with the requirements of European Commission Regulation No. 882/2004 on official food and feed controls. Method performance (i.e., accuracy and precision) was evaluated on tissue samples from three common Mediterranean fish species; the evaluation was subsequently extended to include samples from 35 fish species in a second experiment to test for method robustness. Method accuracy was tested by comparing histological results against a "gold standard" obtained from the analysis of frozen and unfrozen fish samples prepared for the study. Method precision was evaluated according to interrater agreement (i.e., three laboratories with expertise in histopathology in the first experiment and three expert analysts in the second experiment) by estimating Cohen's kappa (and corresponding 95 % confidence intervals) for each pair of laboratories and experts and the combined Cohen's kappa for all three experts and laboratories. The observed interrater agreement among the three laboratories and the three experts indicated high levels of method accuracy and precision (high sensitivity and specificity) and method reproducibility. Our results suggest that histology is a rapid, simple, and highly accurate method for distinguishing between fresh and frozen-thawed fish, regardless of the fish species analyzed.

Heat-related mortality in dairy cattle: A case crossover study

The relationship between mortality and stressful weather is not only a complex health, social and environmental issue, but also becomes an economical problem when considering livestock. Future-climate scenarios suggest that higher global mean temperatures could result in marked changes in the frequency of extreme temperatures. The relationship between high temperature and mortality is well known in people living in urban areas, but it has been poorly investigated in livestock such as dairy cows. The aim of this study was to quantify the relationship between heat and mortality from all causes among dairy cows in Italy. We studied 6697 adult (≥24 months) dairy cows that died during the summer in the 5-year period 2002-2006 in three Italian districts (Brescia, Cuneo, Rome) which were selected because of the high livestock production and the availability of weather data for these geographical areas. A case-crossover design was applied using the temperature-humidity index (THI) as exposure of interest. Pooled odds ratio (OR) of mortality at high exposure values versus low exposure values was estimated. An exposure over the THI cut-off increased the risk of mortality by 1.6 times, with a 4% increase in mortality for each THI degree increase above the threshold. We found no effect modification for age-class, herd size or breed, but a certain degree of geographical heterogeneity was identified. The increased dairy cow mortality highlighted in this study should be considered when adopting animal welfare and farm management measures. This phenomenon can be prevented by adopting appropriate interventions to mitigate environmental thermal challenges.

Effect of autolysis on the specificity of bovine spongiform encephalopathy rapid tests

Background

Routine rapid testing for Bovine Spongiform Encephalopathy (BSE) has highlighted some problems with BSE rapid test performance, the most significant being the number of initially reactive samples and the false positive results on autolyzed tissue. This point is important for BSE active surveillance in risk populations, because tissue autolysis is often unavoidable in routine cases. A robust test suitable for use on field material is therefore needed. To date, very limited information regarding the effect of autolysis on the robustness of rapid tests has been documented; therefore, the National Reference Centre for Animal Encephalopathies (CEA) rapid test laboratory selected 450 autolyzed and negative brain stem samples from fallen stock bovines older than 24 months to assess the specificity of four tests approved for BSE active surveillance: Biorad TeSeE, Enfer TSE version 2.0, Prionics^® Check LIA, and IDEXX Herd Check BSE Antigen Kit EIA. The samples were graded according to the degree of autolysis and then dissected into five portions, four of which randomly assigned to processing by rapid tests and one to be available for confirmatory Western blot analysis.

Findings

The specificity of the four systems was 100% for all three grades of autolysis, while the percentage of initially reactive results was 0.00 (95%CI 0.00-0.82), 0.22 (95%CI 0.006-1.23), 0.44 (95%CI 0.05-1.60), and 0.89 (95%CI 0.24-2.26) for the Biorad TeSeE, the Prionics^® Check LIA, the IDEXX Herd Check BSE and the Enfer TSE tests, respectively. No association with the degree of autolysis could be drawn.

Conclusions

The present study demonstrates that the four rapid tests can be considered well-running diagnostic tools regardless of tissue quality; nevertheless, the number of initial reactive samples reported for some systems must not be underestimated in routine testing.

Furthermore the compliance with the reported performance can be guaranteed only when an ongoing high careful batch quality control system is in place.

The prevalence of atypical scrapie in sheep from positive flocks is not higher than in the general sheep population in 11 European countries

Background

During the last decade, active surveillance for transmissible spongiform encephalopathies in small ruminants has been intensive in Europe. In many countries this has led to the detection of cases of atypical scrapie which, unlike classical scrapie, might not be contagious. EU legislation requires, that following detection of a scrapie case, control measures including further testing take place in affected flocks, including the culling of genotype susceptible to classical scrapie. This might result in the detection of additional cases. The aim of this study was to investigate the occurrence of additional cases in flocks affected by atypical scrapie using surveillance data collected in Europe in order to ascertain whether atypical scrapie, is contagious.

Results

Questionnaires were used to collect, at national level, the results of active surveillance and testing associated with flock outbreaks in 12 European countries. The mean prevalence of atypical scrapie was 5.5 (5.0-6.0) cases per ten thousand in abattoir surveillance and 8.1 (7.3-9.0) cases per ten thousand in fallen stock. By using meta-analysis, on 11 out of the 12 countries, we found that the probability of detecting additional cases of atypical scrapie in positive flocks was similar to the probability observed in animals slaughtered for human consumption (odds ratio, OR = 1.07, CI_95%: 0.70-1.63) or among fallen stock (OR = 0.78, CI_95%: 0.51-1.2). In contrast, when comparing the two scrapie types, the probability of detecting additional cases in classical scrapie positive flocks was significantly higher than the probability of detecting additional cases in atypical scrapie positive flocks (OR = 32.4, CI_95%: 20.7-50.7).

Conclusions

These results suggest that atypical scrapie is not contagious or has a very low transmissibility under natural conditions compared with classical scrapie. Furthermore this study stressed the importance of standardised data collection to make good use of the analyses undertaken by European countries in their efforts to control atypical and classical scrapie.

Interlaboratory trial on TSE rapid tests for the control of the Italian scrapie surveillance network

Scrapie, a neurodegenerative disease of sheep and goats and one of several transmissible spongiform encephalopathies (TSEs) has been subject to mandatory active surveillance in EU through rapid testing since 2002. Regulation EC/999/2001 on TSE surveillance requires that each Member State's National Reference Laboratory for TSE periodically verifies diagnostic standards and methods by comparative testing. In 2007 the Italian Reference Centre carried out the first ring trial for classical scrapie on a set of 21 negative and 9 positive homogenated brainstems, the latter consisting of three replicates of an ARQ/ARQ scrapie positive sample diluted 1:10, 1:20 and 1:50. The purpose of the study was to verify the interlaboratory agreement in term of Cohen's kappa (k) of the rapid systems currently used by the 25 national rapid test laboratories (RTLs) [laboratories: Biorad TeSeE (17 laboratories), Enfer TSE version 2.0 (4 laboratories), Idexx Herd chek BSE-scrapie antigen kit (3 laboratories) and Prionics check LIA SR (1 laboratory)]. Our results show that the agreement among the laboratories using the same rapid test varied between 0.84 and 1, while the estimated overall agreement among the 25 laboratories was very good (k-combined=0.87, 95% confidence interval 0.85-0.89). Nevertheless, as regards differences in analytical sensitivity among the rapid tests in use, under-recognition of pre-clinical scrapie cases by lower performing systems must be expected.

Changes in haptoglobin, C-reactive protein and pig-MAP during a housing period following long distance transport in swine

The aim of this study was to investigate the effects of a housing period following long distance transport on haptoglobin (Hp), C-reactive protein (CRP) and pig major acute phase protein (pig-MAP) in swine. After transportation, 80 gilts were allotted to group A, B, C, or D. Blood samples were collected on arrival and 28 days later; additional samples were collected from Group C on day 14, and from Group D on days 3, 5 and 14. Acute phase proteins (APPs) in Group A were significantly lower on day 28 than on day 1; the opposite occurred in Group B because of a tail biting episode. In Group C, values remained elevated on day 14 and showed a reduction on day 28; in Group D elevated levels detected on day 14 were preceded by a decrease from days 1 to 5. The results indicate that stressors associated with transportation and new accommodation can cause an increase in APPs that could be useful indicators of welfare during transport and routine management.

Comparison of histologic techniques for the diagnosis of bovine tuberculosis in the framework of eradication programs

Rapid diagnosis of tuberculosis in cattle reacting positive in antemortem assays is crucial in countries where eradication programs are operated to confirm the presence of the infection in tuberculosis-free herds. This study evaluated the accuracy of histopathologic examination by hematoxylin and eosin and Ziehl-Neelsen (ZN) staining applied in this framework, when suspected lesions are caused by low infectious doses and are detected in early stages of the disease. For this purpose, histologic methods were compared with mycobacterial culture as reference test on suspected lymph node samples from 173 cattle reacting positive in antemortem tests. Histopathology demonstrated high sensitivity (93.4%) and specificity (92.3%), while ZN sensitivity and specificity were respectively 33.9% and 100%. There was good agreement between histopathology and bacterial culture, suggesting that histopathologic examination is a reliable tool for rapid diagnosis in countries where active tuberculosis eradication programs allow the prompt identification and elimination of reactor cattle. Histopathology permits identification of typical mycobacterial lesions and its differentiation from other causes.

European interlaboratory trial regarding the official microscopic method for the detection of the presence of animal constituents in feedstuffs

The bovine spongiform encephalopathy epidemic is thought to have occurred as a consequence of feeding prion-infected material to cattle. To avoid the risk of bovine spongiform encephalopathy diffusion, the European Commission (Directive 2003/126/EC) established an official method to detect the presence of animal-derived constituents in feedstuffs, using microscopic examination. This method allows easy identification of bone fragments among other animal constituents. The analysis is based on morphological conformation of the fragments and their characterization (mainly of the shape of lacunae) to discriminate among mammalian, poultry, and fish tissues. The aim of this study was to assess the performances of nine European laboratories through a ring trial of the official microscopic method, and to calculate accuracy and reproducibility of the method. In general the reproducibility of the microscopic method was very good (kappa overall = 0.83), with a high sensitivity for all laboratories. Concerning the analysis on the different animal-derived constituents, the results show values of sensitivity with large variability between fish and poultry or mammal. It was generally more difficult to discriminate between mammalian and poultry tissues than fish tissue.

Detection of animal-derived proteins in feedstuffs in Italy: a reproducibility study

Bovine spongiform encephalopathy is a prion disease of ruminants that was first recognized in 1986 in the United Kingdom. Early in the epidemic, it became obvious that the presence of meat and bone meal in feed rations was a common factor in all bovine spongiform encephalopathy cases. The first ban of derived animal proteins in feed was enforced in Europe in 1994 and implemented by Regulation 999/2001 that prohibited the feeding of animal-derived protein to farm animals. The only official method currently accepted by the European Union Commission for test for the presence of animal-derived proteins in feedstuffs is feed microscopy. In Italy, monitoring of feedstuff safety is provided by both the Ministry of Health and the Ministry of Agriculture. The quality of official control, usually assessed by verifying the reproducibility and the accuracy of the testing method, is of fundamental importance for all laboratories and institutions using these results for comparative purposes. The aims of this study were to assess the reproducibility of the official method over all the Italian surveillance network and to provide a model for evaluating the performance of the monitoring system. The accuracy of the identification of the animal class of derived protein detected (avian, mammalian, or aquatic organism) was assessed. The interlaboratory agreement within the overall network reached 0.97 (95% confidence interval of 0.95 to 0.98) for determining the presence or absence of animal-derived proteins (e.g., for mammalian, avian, or aquatic species), and specificity of the identification of the animal class indicated that fish proteins are more easily recognized than are avian or mammalian proteins.

Arthroscopic treatment of osteochondritis dissecans of the shoulder in 126 dogs

Osteochondritis dissecans of the shoulder joint was treated by arthroscopy in 126 dogs. Twenty-four dogs had bilateral surgery, making a total of 150 joints treated. The OCD flaps were removed in small pieces through the cannula or in a single piece through a stab incision. The lameness resolved completely within seven-60 days following arthroscopy in 137 out of 150 affected limbs. Within a subset of 47 dogs with unilateral OCD, it was found that lesions located on the caudo-medial region of the humeral head had a better functional outcome than those lesions located in the caudo-central region of the humeral head.