A survey of Culicoides developmental sites on a farm in northern Spain,with a brief review of immature habitats of European species

Culicoides species (Diptera: Ceratopogonidae) belonging to the Obsoletus and Pulicaris groups are considered to be the main vectors of bluetongue virus (BTV) in non Mediterranean Europe. Selected terrestrial microhabitats (n = 17) on a farm in northern Spain were sampled repeatedly over a year-long period and characterized for use by Culicoides species for immature development. Concurrent use of CDC light traps showed the presence of 37 species and 66,575 specimens of adult Culicoides. A total of 28 species and 11,396 individuals emerged from laboratory-maintained soil samples. Culicoides obsoletus and Culicoides scoticus (pooled as Obsoletus complex) were particularly abundant (comprising 58.6% and 74.5% of the total collections in light traps and emergence traps respectively). Potential key vectors of animal viruses (such as BTV) were found in two main terrestrial types of microhabitats. In the case of C. obsoletus, different types of manure (old and composted manure, manure mixed with organic matter, and fresh manure) produced most of the specimens. In contrast, larvae of C. scoticus and Culicoides lupicaris were associated with soil substantially comprised of rotting leaf litter that included the parasitic plant Lathraea clandestina. Several species, Culicoides festivipennis, Culicoides punctatus and Culicoides brunnicans, were very common in mud at pond margins. Indeed, pond microhabitats and runoff below barn rooflines supported the greatest species richness. In the pond habitat, 49.4% of Culicoides specimens emerged from mud at the water edge, as opposed to 50 cm above (32.4%) and 1 meter above waterline (18%). Similar species richness, but statistically significant differences in abundance, were observed among the four pond microhabitats. Overall, the majority of the specimens were found in the upper layer (0–3 cm), except in manure, where they preferred deeper layers (>6 cm). Maximum peaks of abundance occurred in both light traps and soil samples in summer months, whereas increased captures in autumn were noticed only in light traps. Both trapping systems failed to collect adult Culicoides midges in the coldest months of December, January and February. The literature on immature habitats of species suspected in BTV transmission in Europe, the Pulicaris group and particularly the Obsoletus group, is briefly reviewed.     

Optimization of the pepsin digestion method for anisakids inspection in the fishing industry

During the last 50 years human anisakiasis has been rising while parasites have increased their prevalence at determined fisheries becoming an emergent major public health problem. Although artificial enzymatic digestion procedure by CODEX (STAN 244-2004: standard for salted Atlantic herring and salted sprat) is the recommended protocol for anisakids inspection, no international agreement has been achieved in veterinary and scientific digestion protocols to regulate this growing source of biological hazard in fish products. The aim of this work was to optimize the current artificial digestion protocol by CODEX with the purpose of offering a faster, more useful and safer procedure for factories workers, than the current one for anisakids detection. To achieve these objectives, the existing pepsin chemicals and the conditions of the digestion method were evaluated and assayed in fresh and frozen samples, both in lean and fatty fish species. Results showed that the new digestion procedure considerably reduces the assay time, and it is more handy and efficient (the quantity of the resulting residue was considerably lower after less time) than the widely used CODEX procedure. In conclusion, the new digestion method herein proposed based on liquid pepsin format is an accurate reproducible and user-friendly off-site tool, that can be useful in the implementation of screening programs for the prevention of human anisakiasis (and associated gastroallergic disorders) due to the consumption of raw or undercooked contaminated seafood products.     

Alteration of body composition in rats: effect of organic chromium and L-carnitine

A growth trial was carried out to test the effect of organic, trivalent chromium and L-carnitine on the body composition of growing rats. At the same time, an evaluation of different measurement methods (weight of epididymal fat pad, adipocyte morphometry, total body electrical conductivity) was performed. Outbred Wistar rats of 30 days of age were fed diets of different (0, 10 and 20%) protein level. The diets were supplemented with 4 mg/kg Cr as chromium nicotinate, and 100 mg/kg L-carnitine. The experimental feeding lasted 15 days, after a 5-day-long adjustment period. It was found that Cr addition increased feed intake. Both treatments caused changes in body composition, increasing fat and protein deposition. Organic chromium had no effect at either protein level, while L-carnitine improved the protein retention only at an optimum (20%) protein supply. No statistically significant correlation was found between total body electrical conductivity (TOBEC) and body composition, which could be attributed to the great individual differences. A close correlation was found among total body fat percentage, weight of epididymal fat pad and the adipocyte surface. The data suggest that there is an interaction between dietary protein supply and the effect of repartitioning agents.     

Upregulation of LENK and VIP in paracervical ganglion neurons supplying the urinary bladder of tetrodotoxin- and resiniferatoxin-treated female pigs

Both resiniferatoxin (RTX) and tetrodotoxin (TTX) have been reported to be effective in several clinical trials aiming to cure urinary bladder dysfunction. The goal of this experiment was to study the effect of intravesical administration of RTX and TTX on the chemical coding of paracervical ganglion (PCG) neurons that supply the urinary bladder in pigs. The vasoactive intestinal peptide (VIP) and the opioid family member Leu5-enkephalin (LENK) are both known for their regulatory effects in the function of the porcine genitourinary tract. The PCG neurons innervating the urinary bladder were identified by application of the retrograde tracer Fast Blue (FB), injected into the bladder wall prior to intravesical RTX or TTX administration. Immunocytochemical detection of LENK and VIP expression in the FB-labelled perikarya revealed that in the control group 25.15% of the FB-positive PCG neurons contained LENK, and 9.22% of them expressed VIP. Intravesical infusion of RTX resulted in an increase in the number of LENKIR neurons to 48.19% and VIP-IR perikarya to 11.25%. Optional treatment with TTX induced increase of LENK-IR neurons up to 81.67% and VIP-IR population to 16.46% of the FB-positive PCG cells. The present results show that both neurotoxins affect the chemical coding of PCG nervous cells supplying the porcine urinary bladder and that they stimulate both LENK and VIP expression. Furthermore, the results indicate a possible involvement of LENK and VIP neurons in the mechanisms of action of RTX and TTX in the therapy of overactive bladder disorder.     

Acute phase proteins as a tool for differential diagnosis of wasting diseases in growing pigs

The concentrations of haptoglobin (Hp), C-reactive protein (CRP) and serum amyloid A (SAA) were measured in wasted pigs, first to evaluate their usefulness in the diagnosis of infectious, wasting diseases in pigs, and second, to evaluate whether their concentrations can distinguish the lymphoid depletion score in the lymph tissues of wasted affected pigs. Fifty-three wasted pigs and seven specific pathogen free (SPF) pigs were postmortem examined. Gross lesions were evaluated and samples for histopathological, immunohistochemical, molecular biology and microbiological analysis were taken. Thirty-one pigs were diagnosed as postweaning multisystemic wasting syndrome (PMWS) and 22 as porcine respiratory disease complex (PRDC). Lymphoid depletion degree in lymph tissues of PMWS and PRDC affected pigs was determined. Serum Hp was significantly higher in pigs with PRDC in comparison with the PMWS affected pigs. Serum CRP concentration was significantly lower in pigs with PRDC than in PMWS affected pigs (P<0.001). CRP and SAA levels increased with the lymphoid depletion score, presenting statistical differences between pigs with no depletion and pigs with low, moderate or severe lymphoid depletion (P<0.05, P<0.05 and P<0.001 for CRP and P<0.01, P<0.01 and P<0.01 for SAA, respectively). Hp was higher in pigs with no or low depletion compared with the pigs suffering severe lymphoid depletion (P<0.001 and P<0.05, respectively).     

Gurltia paralysans (Wolffhügel, 1933): description of adults and additional case reports of neurological diseases in three domestic cats from southern Chile

Adults of Gurltia paralysans were obtained from veins of the spinal cord subarachnoid space from three domestic cats presenting with chronic paraparesis/paraplegia from rural areas of southern Chile. Four adult nematodes were collected (2 males and 2 females) were recovered from cat 1, 14 adult nematodes (12 females and 2 males) from cat 2, and 12 nematodes (10 females and 2 males) were collected from cat 3. Parasite induced lesions that compromised subarachnoid vein microvasculature at the thoracic, lumbar, sacral spinal cord segments extending to conus medularis. Female nematodes measured 25 mm long (range=25-30 mm) and 0.1mm wide. Male measured a mean of 16 mm length (range=13-18 mm) with a body diameter of 0.1mm (range=0.08-0.15 mm). The present study described structural features of G. paralysans, a rare parasite first reported in the 1930s, and provides additional reports on associated clinical and pathological findings in naturally infected domestic cats.     

Anti-predator behaviour of adult red-legged partridge (Alectoris rufa) tutors improves the defensive responses of farm-reared broods

1. The aim of this work was to improve natural anti-predator behaviour of farm-reared gamebirds.

2. We evaluated the anti-predator behaviour of reared red-legged partridge Alectoris rufa chicks kept in brooder houses in large groups (>350 chicks), trained and not trained by parent red-legged partridges acting as experienced tutors.

3. The experiment consisted of two conditioned tests (a raptor model and a human) and two control tests, which were conducted during three consecutive phases of life (1–4, 15–17 and 30–32 d after hatching). The motor anti-predator behaviour, its duration, the intensity of response in chicks and alarm calls elicited by adults were recorded.

4. Tutors elicited aerial alarm calls (76% of tests) and showed prolonged crouching (59% of tests) in response to the raptor model whereas uttering the ground alarm call (73% of tests) and showing vigilance behaviour (78% of tests) was the main pattern during the human test.

5. Trained and not trained chicks showed similar motor behaviour in response to the raptor model (crouching) and the human test (escaping), but frequency of strong responses (all chicks responding) from chicks trained with tutors was double that of chicks trained without them, and chicks trained with tutors showed a higher frequency of long responses (41–60 s).

6. This study indicates that anti-predator training programmes before release may improve behaviour of farm-reared partridges which may confer benefits to survival of birds.