Molecular survey of Cytauxzoon spp. and Hepatozoon spp. in felids using a novel real-time PCR approach

Tick-transmitted apicomplexans of the genera Cytauxzoon and Hepatozoon affect a wide range of felids worldwide, but little is known about them. Recently, several studies addressed the species circulating in Europe, their distribution, and their hosts. Molecular assays are the method of choice for their detection. Unfortunately, conventional PCRs already described are time- and cost-consuming and specific for either Hepatozoon or Cytauxzoon detection. This study was developed to evaluate (i) the occurrence of Cytauxzoon and Hepatozoon in felids using a fast and cost-saving real-time PCR capable of detecting both protozoa simultaneously, (ii) the distribution of Cytauxzoon and Hepatozoon species in north-eastern Italy, and (iii) the involvement of other susceptible felid hosts in the same area. An SYBR^® Green-based real-time PCR with primers targeting the 18S-rRNA was validated and applied to 237 felid samples, i.e., whole blood from 206 domestic cats and 12 captive exotic felids, and tissues from 19 wildcats. Positive results were obtained by melting temperature curve analysis due to the specific melting peak (i.e., 81°C Cytauxzoon spp.; 78-78.5°C Hepatozoon spp.). Positive samples were subjected to conventional PCR, followed by sequencing for species identification. Phylogenetic analyses were performed to assess relatedness among European isolates. Data on domestic cats (age class, sex, origin, management, and lifestyle) were recorded, and statistical analyses were performed to identify potential risk factors. A total of 31 (15%) domestic cats were positive for Hepatozoon spp. (i.e., 12 for H. felis, 19 for H. silvestris), while six (2.9%) for C. europaeus. The prevalence of Hepatozoon felis was significantly (p < 0.05) higher in domestic cats, while H. silvestris was higher in strays and animals from the Eastern region (i.e., Friuli-Venezia Giulia). Cytauxzoon europaeus was detected only in stray cats from Friuli-Venezia Giulia (province of Trieste). Among captive felids, one tiger was infected with H. felis and another with H. silvestris; eight out of 19 (42%) wildcats were positive for Hepatozoon spp. (i.e., six with H. felis, two with H. silvestris) and four out of 19 (21%) for Cytauxzoon europaeus. Outdoor lifestyle and origin (i.e., Friuli-Venezia Giulia region) were the most relevant risk factors for H. silvestris and C. europeus infections. Conversely, H. felis was most frequently isolated from domestic cats, suggesting different modes of transmission.

Red mark syndrome of trout (Oncorhynchus mykiss; Walbaum, 1792): Histopathological scoring and correlation with gross lesions

Red mark syndrome (RMS) is a skin disorder affecting rainbow trout (Oncorhynchus mykiss). The present work aimed to correlate the gross skin lesions affecting 46 fish sampled from farms surveyed for RMS with their microscopic features, identifying histological parameters that may be suggestive of disease progression. Skin lesions were grossly included in one of three categories (types I, II and III) according to the progressive degree of severity. Histological parameters and anti-proliferating cell nuclear antigen (PCNA) tissue immunoreactivity were semi-quantitatively assessed. In the dermis, PCNA-positive lymphocytes, fibroblasts and endothelial cells were indicative of active phlogosis. A significant increase in PCNA-immunoreactive lymphocytes, from gross type I to type III cases, was found only in the hypodermis. The histological parameters significantly associated with the gross lesion severity were progressive loss of the epithelium and scales, recruitment of inflammatory cells in the stratum compactum, loss of architecture of the stratum compactum, perivascular and perineural granulomatous inflammation and increase in lymphocyte infiltration of the muscular layer. In the type II and type III categories, inflammation in the hypodermis and muscle displayed a granulomatous pattern, reinforcing the hypothesis of an immunopathological mechanism. The morphological diagnosis of "deep chronic dermatitis associated to panniculitis and myositis, characterised by lympho-histiocytic and granulomatous reaction" is suggested.

Red mark syndrome (RMS) in farmed rainbow trout: First report of outbreaks in Bosnia and Herzegovina

Red mark syndrome (RMS) is a non-lethal inflammatory skin disorder spreading in farmed adult rainbow trout (Oncorhynchus mykiss) and reported worldwide. The aetiology is still uncertain, but positive correlation was found between Midichloria-like organism and RMS-affected fish. Here, we describe the first cases of RMS in Bosnia and Herzegovina. The outbreaks under study occurred in two intensive farms during the late winter and spring of 2020. Affected fish showed signs of disease ascribable to RMS, confirmed by pathological and molecular examination.

Histological and immunohistochemical characterization of 17 gonadal tumours in koi carp (Cyprinus carpio koi)

Reports on abdominal tumours in koi carp are scarce and most are from the gonads. Their histological diagnosis is challenging due to the occurrence of mixed populations of neoplastic cells and the few availability of cross-reactive antibodies in fish tissues. The present study aims to provide a histopathological characterization of seventeen gonadal tumours, enriched by a wide antibody panel (vimentin, CD117, placental alkaline phosphatase-PLAP, AE1/AE3 cytokeratin, E-cadherin, proliferating cell nuclear antigen-PCNA, müllerian-inhibiting substance-MIS, GATA4 and Inhibin-α) applied on whole and tissue microarray (TMA) sections. Abdominal enlargement was associated with tumours filling 30%-80% of the abdominal cavity; frequently, the gonads had been completely replaced by neoplastic tissue. Twelve cases were characterized as sex cord-stromal tumours (SCSTs), three as germ cell tumours (GCTs), one as mixed germ cell sex cord-stromal tumour (MGCSCST) and one as carcinoma. By immunohistochemistry, PLAP enabled confirmation of GCTs, ovarian carcinoma and the objective identification of a further cell component in 8 out of the 12 SCSTs that were reclassified as mixed tumours. The use of an immunohistochemical panel can help in refining the histological diagnosis, but the morphological diagnosis still represents the main tool for the characterization of these tumours in koi carp.

Innate immune-gene expression during experimental amyloodiniosis in European seabass (Dicentrarchus labrax)

The ectoparasite protozoan Amyloodinium ocellatum (AO) is the causative agent of amyloodiniosis in European seabass (ESB, Dicentrarchus labrax). There is a lack of information about basic molecular immune response mechanisms of ESB during AO infestation. Therefore, to compare gene expression between experimental AO-infested ESB tissues and uninfested ESB tissues (gills and head kidney) RNA-seq was adopted. The RNA-seq revealed multiple differentially expressed genes (DEG), namely 679 upregulated genes and 360 downregulated genes in the gills, and 206 upregulated genes and 170 downregulated genes in head kidney. In gills, genes related to the immune system (perforin, CC1) and protein binding were upregulated. Several genes involved in IFN related pathways were upregulated in the head kidney. Subsequently, to validate the DEG from amyloodiniosis, 26 ESB (mean weight 14 g) per tank in triplicate were bath challenged for 2 h with AO (3.5 × 10⁶/tank; 70 dinospores/mL) under controlled conditions (26-28 °C and 34‰ salinity). As a control group (non-infested), 26 ESB per tank in triplicate were also used. Changes in the expression of innate immune genes in gills and head kidney at 2, 3, 5, 7 and 23 dpi were analysed using real-time PCR. The results indicated that the expression of cytokines (CC1, IL-8) and antimicrobial peptide (Hep) were strongly stimulated and reached a peak at 5 dpi in the early infestation stage, followed by a gradual reduction in the recovery stage (23 dpi). Noticeably, the immunoglobulin (IgM) expression was higher at 23 dpi compared to 7 dpi. Furthermore, in-situ hybridization showed positive signals of CC1 mRNA in AO infested gills compared to the control group. Altogether, chemokines were involved in the immune process under AO infestation and this evidence allows a better understanding of the immune response in European seabass during amyloodiniosis.

Transcriptome Analysis of Amyloodinium ocellatum Tomonts Revealed Basic Information on the Major Potential Virulence Factors

The ectoparasite protozoan Amyloodinium ocellatum (AO) is the etiological agent of amyloodiniosis in European seabass (Dicentrarchus labrax) (ESB). There is a lack of information about basic molecular data on AO biology and its interaction with the host. Therefore, de novo transcriptome sequencing of AO tomonts was performed. AO trophonts were detached from infested ESB gills, and quickly becoming early tomonts were purified by Percoll^® density gradient. Tomont total RNA was processed and quality was assessed immediately. cDNA libraries were constructed using TruSeq^® Stranded mRNA kit and sequenced using Illumina sequencer. CLC assembly was used to generate the Transcriptome assembly of AO tomonts. Out of 48,188 contigs, 56.12% belong to dinophyceae wherein Symbiodinium microadriaticum had 94.61% similarity among dinophyceae. Functional annotations of contigs indicated that 12,677 had associated GO term, 9005 with KEGG term. The contigs belonging to dinophyceae resulted in the detection of several peptidases. A BLAST search for known virulent factors from the virulence database resulted in hits to Rab proteins, AP120, Ribosomal phosphoprotein, Heat-shock protein70, Casein kinases, Plasmepsin IV, and Brucipain. Hsp70 and casein kinase II alpha were characterized in-silico. Altogether, these results provide a reference database in understanding AO molecular biology, aiding to the development of novel diagnostics and future vaccines.

Host-Parasite Interaction between Parasitic Cymothoid Ceratothoa oestroides and Its Host, Farmed European Sea Bass (Dicentrarchus labrax)

Parasitic isopod Ceratothoa oestroides (Cymothoidea, Isopoda) is a common and generalist buccal cavity-dweller in marine fish, recognised for its detrimental effect in fingerling and juvenile farmed European sea bass (Dicentrarchus labrax). Although distributed throughout the Mediterranean, the isopod provokes acute outbreaks mainly limited to particular endemic areas in Croatia (Adriatic Sea) and Greece (Aegean Sea). While numerous studies have previously evidenced its gross effect on farmed fish (i.e. decreased condition index, slower growth rate, lethargy and mortality), details on the host-parasite interaction are still lacking. Therefore, using a multimethodological approach, we closely examined the structure and appearance of isopod body parts acting in the attachment and feeding (stereomicroscopy, scanning and transmission electron microscopy), and the extent of host tissues damage (histology, immunohistochemistry, micro-computational tomography) induced by parasitation. Interestingly, while hematophagous nature of the parasite has been previously postulated we found no unambiguous data to support this; we observed host tissues fragmentation and extensive hyperplasia at the parasitation site, and no structures indicative of heme detoxifying mechanisms in the parasite gut, or other traces of a blood meal. The bacterial biofilm covering C. oestroides mouthparts and pereopods suggests that the isopod may play a role in conveying secondary pathogens to the infected host, or alternatively, it serves the parasite in normal interaction with its environment.

Comparative Therapeutic Effects of Natural Compounds Against Saprolegnia spp. (Oomycota) and Amyloodinium ocellatum (Dinophyceae)

The fish parasites Saprolegnia spp. (Oomycota) and Amyloodinium ocellatum (Dinophyceae) cause important losses in freshwater and marine aquaculture industry, respectively. The possible adverse effects of compounds used to control these parasites in aquaculture resulted in increased interest on the search for natural products with antiparasitic activity. In this work, eighteen plant-derived compounds (2′,4′-Dihydroxychalcone; 7-Hydroxyflavone; Artemisinin; Camphor (1R); Diallyl sulfide; Esculetin; Eucalyptol; Garlicin 80%; Harmalol hydrochloride dihydrate; Palmatine chloride; Piperine; Plumbagin; Resveratrol; Rosmarinic acid; Sclareolide; Tomatine, Umbelliferone, and Usnic Acid) have been tested in vitro. Sixteen of these were used to determine their effects on the gill cell line G1B (ATCC®CRL-2536™) and on the motility of viable dinospores of Amyloodinium ocellatum, and thirteen were screened for inhibitory activity against Saprolegnia spp. The cytotoxicity results on G1B cells determined that only two compounds (2′,4′-Dihydroxychalcone and Tomatine) exhibited dose-dependent toxic effects. The highest surveyed concentrations (0.1 and 0.01 mM) reduced cell viability by 80%. Upon lowering the compound concentration the percentage of dead cells was lower than 20%. The same two compounds revealed to be potential antiparasitics by reducing in a dose-dependent manner the motility of A. ocellatum dinospores up to 100%. With respect to Saprolegnia, a Minimum Inhibitory Concentration was found for Tomatine (0.1 mM), Piperine and Plumbagin (0.25 mM), while 2′,4′-Dihydroxychalcone considerably slowed down mycelial growth for 24 h at a concentration of 0.1 mM. Therefore, this research allowed to identify two compounds, Tomatine and 2′,4′-Dihydroxychalcone, effective against both parasites. These compounds could represent promising candidates for the treatment of amyloodiniosis and saprolegniosis in aquaculture. Nevertheless, further in vitro and in vivo tests are required in order to determine concentrations that are effective against the considered pathogens but at the same time safe for hosts, environment and consumers.

Summer drought stress: differential effects on cane anatomy and non-structural carbohydrate content in overwintering Cabernet Sauvignon and Syrah vines

Grapevines store non-structural carbohydrates (NSC) during late summer to sustain plant development at the onset of the following spring’s growth. Starch is the main stored carbohydrate, found in the wood-ray parenchyma of roots and canes. Although the relationship between hydraulic and plant photosynthetic performance is well-recognized, little research has been done on the long-term effects of drought in grapevines adopting different strategies to cope with water stress (i.e. isohydric and anisohydric). We performed our study by exposing two different grape cultivars (Syrah and Cabernet Sauvignon) to a short but severe drought stress, at two stages of the growing season (July and September). No marked differences in the physiological and hydraulic responses of the two varieties were found, probably due to our experimental conditions. However, anatomical and biochemical characterization of overwintering canes pointed out several interesting outcomes. We found a significant and parallel increase of starch and medullar ray number in both cultivars exposed to early water stress. We hypothesize that stressed vines limited their carbon allocation to growth, while shifting it to starch accumulation, with a most evident effect in the period of intense photosynthetic activity. We also speculate that a different aptitude to osmotic adjustment may underlay variation in starch increase and the specific involvement of bark NSC in the two cultivars.

Expression of infection-related immune response in European sea bass (Dicentrarchus labrax) during a natural outbreak from a unique dinoflagellate Amyloodinium ocellatum

In the Mediterranean area, amyloodiniosis represents a major hindrance for marine aquaculture, causing high mortalities in lagoon-type based rearing sites during warm seasons. Amyloodinium ocellatum (AO) is the most common and important dinoflagellate parasitizing fish, and is one of the few fish parasites that can infest several fish species living within its ecological range. In the present study, A. ocellatum was recorded and collected from infected European sea bass (Dicentrarchus labrax) during a summer 2017 outbreak in north east Italy. Histological observation of infected ESB gill samples emphasized the presence of round or pear-shaped trophonts anchored to the oro-pharingeal cavity. Molecular analysis for small subunit (SSU) rDNA of A. ocellatum from gill genomic DNA amplified consistently and yielded 248 bp specific amplicon of A. ocellatum, that was also confirmed using sequencing and NCBI Blast analysis. Histological sections of ESB gill samples were addressed to immunohistochemical procedure for the labelling of ESB igm, inos, tlr2, tlr4, pcna and cytokeratin. Infected gills resulted positive for igm, inos, pcna and cytokeratin but negative to tlr-2 and tlr-4. Furthermore, ESB immune related gene response (innate immunity, adaptive immunity, and stress) in the course of A. ocellatum infection using quantitative polymerase chain reaction (qpcr) for infected gills and head kidney was analysed. Among the twenty three immune related gene molecules tested, cc1, il-8, il-10, hep, cox-2, cla, cat, casp9, and igt were significantly expressed in diseased fish. Altogether, these data on parasite identification and expression of host immune-related genes will allow for a better understanding of immune response in European sea bass against A. ocellatum and could promote the development of effective control measures.

Shrub growth and plant diversity along an elevation gradient: Evidence of indirect effects of climate on alpine ecosystems

Enhanced shrub growth and expansion are widespread responses to climate warming in many arctic and alpine ecosystems. Warmer temperatures and shrub expansion could cause major changes in plant community structure, affecting both species composition and diversity. To improve our understanding of the ongoing changes in plant communities in alpine tundra, we studied interrelations among climate, shrub growth, shrub cover and plant diversity, using an elevation gradient as a proxy for climate conditions. Specifically, we analyzed growth of bilberry (Vaccinium myrtillus L.) and its associated plant communities along an elevation gradient of ca. 600 vertical meters in the eastern European Alps. We assessed the ramet age, ring width and shoot length of V. myrtillus, and the shrub cover and plant diversity of the community. At higher elevation, ramets of V. myrtillus were younger, with shorter shoots and narrower growth rings. Shoot length was positively related to shrub cover, but shrub cover did not show a direct relationship with elevation. A greater shrub cover had a negative effect on species richness, also affecting species composition (beta-diversity), but these variables were not influenced by elevation. Our findings suggest that changes in plant diversity are driven directly by shrub cover and only indirectly by climate, here represented by changes in elevation.

Ultrastructural and biomolecular detection of Rickettsiales-like organisms in tissues of rainbow trout with Red Mark Syndrome

Red mark syndrome (RMS) and US strawberry disease (US SD) are skin disorders affecting rainbow trout farmed in Europe and USA. The disease etiology has not yet been established. In spite of specific investigations, identifying Rickettsia-like organism (RLO)- and Midichloria-like organism (MLO)-related DNA in affected individuals, these pathogens have never been observed. We performed histological, ultrastructural and biomolecular analysis on skin and spleen samples of trout with RMS. Examination by TEM revealed the presence of intracytoplasmic microorganisms resembling Rickettsiales within macrophages, fibroblasts and erythrocytes. The microorganisms were oval or short rod shaped (400-800 nm in length and 100-200 nm in width) and often showed a cell wall similar to Gram-negative bacteria. PCR analysis for Rickettsiales supported these findings: 53% of affected trout were positive by both PCR and TEM The primers RiFCfw-RiFCrev were used to anneal both the RLO 16S DNA sequence and the MLO 16S DNA sequence. For this reason, and in agreement with previous studies confirming the presence of Rickettsiales-related DNA in trout with RMS, we assume that TEM detected microorganisms morphologically consistent with bacteria belonging to Rickettsiales order and could be considered as possible causative agents of RMS.

Evaluation of the physicochemical properties of gluten-free pasta enriched with resistant starch

BACKGROUND

The objective was to examine the potential use of resistant starch (RS) as a fibre-enriching ingredient in gluten-free pasta. Pasta was enriched with commercial RS type II (Hi-Maize™ 260) at 100-200 g kg^-1 substitution of rice flour. The effects on the rheological properties of dough and pasta quality as a result of RS addition and the loss in RS due to the process were evaluated.

RESULTS

Dough water absorption was not influenced by the addition of RS. The cooking loss (CL) of RS-enriched samples was 30% lower than reference without fibre. The addition of RS significantly increased firmness of cooked pasta, and above 100 g kg^-1 RS level of substitution samples showed a lower stickiness value. Dynamic rheological tests on pasta dough showed a higher storage modulus for fibre samples, indicating a higher number of elastically physical interactions. Loss in RS in uncooked pasta was about 31% compared with the initial amount added to the product.

CONCLUSIONS

The addition of RS improved the quality of gluten-free pasta owing to its ability to increase the firmness and decrease the CL and stickiness of cooked pasta. The product enriched with 200 g kg^-1 RS can be considered a source of DF. © 2016 Society of Chemical Industry.

First detection of Cytauxzoon spp. infection in European wildcats (Felis silvestris silvestris) of Italy

Cytauxzoonosis is an emerging, tick-transmitted, protozoan disease affecting domestic and wild felids and caused by Cytauxzoon felis, Cytauxzoon manul and Cytauxzoon spp. This study aimed to determine the presence of infection with Cytauxzoon spp. in Felis silvestris silvestris in Italy, in order to enhance the comprehension of its pattern distribution among domestic cat populations. In addition, wildcats were tested for other endemic vector-borne pathogens in Italy. The carcasses of 21 F. s. silvestris were collected from central and northern regions of Italy. All the animals were submitted to necropsy and samples of the spleens were collected. Cytauxzoon infection was surveyed by a conventional PCR amplifying a portion of the SSU-rDNA of species of Piroplasmida. The samples were also screened for Anaplasma spp., Ehrlichia spp., Rickettsia spp., Babesia spp., Theileria spp., and Leishmania spp. using SYBR Green Real-Time PCR (rPCR) assays. Four animals (19%) were positive for Piroplasmida-PCR assay and three sequenced amplicons were obtained (14.3%), clustering with the Italian, Spanish, French and Romanian Cytauxzoon spp. isolates and with C. manul found in Mongolia. The samples were negative for the other pathogens screened. The present results showed that Cytauxzoon spp. may infect both F. s. silvestris and F. s. catus.

Respiratory nematodes in cat populations of Italy

The occurrence of common respiratory parasites of domestic cats (the metastrongyloid "cat lungworm" Aelurostrongylus abstrusus and the trichuroid Capillaria aerophila) and of neglected respiratory nematodes of felids (Troglostrongylus brevior, Angiostrongylus chabaudi and Oslerus rostratus) was here evaluated in two and three geographical sites of Northern and Central Italy, respectively. In 2014-2015, individual fecal samples of 868 domestic cats were examined microscopically and genetically, and epidemiological data related to parasitic infections were evaluated as possible risk factors by binary logistic regression models. The most common parasite was A. abstrusus in both mono- and poli-specific infections, followed by T. brevior and C. aerophila, while cats scored negative for other parasites. Cats positive for A. abstrusus (1.9-17 % infection rate) and C. aerophila (0.9-4.8 % infection rate) were found in all examined sites, while cats scored positive for T. brevior (1-14.3 % infection rate) in four sites. Also, T. brevior was here found for the first time in a domestic cat from a mountainous area of Northern Italy. The occurrence of lungworms was statistically related to the presence of respiratory signs and more significant in cats with mixed infection by other lungworms and/or intestinal parasites. Cats living in site C of Central Italy resulted statistically more at risk of infection for lungworms than cats living in the other study sites, while animals ageing less than 1 year were at more risk for troglostrongylosis. Finally, the presence of lungworms was more significant in cats with mixed infection by other lungworms and/or intestinal parasites. These results are discussed under epidemiological and clinical points of views.

Cryopreservation of roe deer abomasal nematodes for morphological identification

Conventional methods to preserve adult nematodes for taxonomic purposes involve the use of fixative or clearing solutions (alcohol, formaldehyde, AFA and lactophenol), which cause morphological alterations and are toxic. The aim of this study is to propose an alternative method based on glycerol-cryopreservation of nematodes for their subsequent identification. Adults of trichostrongylid nematodes from the abomasum of roe deer (Capreolus capreolus Linnaeus) were glycerol-cryopreserved and compared with those fixed in formaldehyde, fresh and frozen without cryoprotectans. Morphology, transparency and elasticity of the anterior and posterior portion of male nematodes were compared, especially the caudal cuticular bursa and genital accessories. The method presented is quick and easy to use, and the quality of nematode specimens is better than that of nematodes fixed by previously used fixatives. Moreover, glycerol cryopreserved nematodes can be stored for a long time at -20 degrees C in perfect condition and they could be suitable for further analyses, such as histological or ultrastructural examinations.

Recovery of opercular anomalies in gilthead sea bream, Sparus aurata L.: morphological and morphometric analysis

Opercular anomalies are very frequent in reared gilthead sea bream and these can negatively influence the product value. Field observations have suggested that opercular malformations can recover over time. In order to verify this hypothesis, 140-day-old gilthead sea bream with monolateral opercular anomalies were divided into three groups, according to the type and increasing seriousness of the opercular malformations, and another group was composed of fish with bilateral opercular anomalies. All groups were monitored for 16 months. In the group with monolateral anomalies, the opercular recovery process was documented by morphological (stereomicroscope) and morphometric analysis. For the latter analysis, two relevant areas, A and T, were identified in the cephalic region. The ratio (T - A)/T, tending to 1, represents the recovery index (RI) of anatomical integrity and quantifies the recovery level of opercular complex anomalies. Results suggested that the recovery process was considerable over the 16 months of investigation but should not be considered complete. At the end of the study, 61% of the gilthead sea bream population with monolateral opercular defects recovered external integrity, whereas the population with bilateral defects showed a poorer recovery capability.

Faecal Cyathostomin Egg Count distribution and efficacy of anthelmintics against cyathostomins in Italy: a matter of geography?

BACKGROUND

In the framework of a trial carried out in 2008 in Europe to evaluate the efficacy of major parasiticides against horse cyathostomins, pre- and/or post-treatment Faecal Egg Counts (FEC) were evaluated in a total of 84 yards and 2105 horses from nine different regions from the South, the Center, the North-Center and North-East of Italy. Specifically, on the basis of FECs of the horses present in each property, 60 out of the 84 yards were enrolled for a Faecal Egg Count Reduction Test (FECRT) using fenbendazole, pyrantel, ivermectin and moxidectin.

RESULTS

Of the 1646 horses bred in the 60 recruited yards, 416 animals had a FEC between 50 and 150 Eggs Per Gram (EPG) of faeces and 694 a FEC >150 EPG (i.e. with total of 1110 positive animals). Of the 1110 positive animals, those with the highest FECs (i.e. 988) were included in the FECRT. The FECRT for four anthelmintic compounds showed remarkable differences in terms of prevalence of reduced and equivocal efficacy against cyathostomins in the different areas of Italy. Administration of fenbendazole and pyrantel resulted in resistance present or suspected in about half of the yards examined while resistance to ivermectin was found in one yard from central Italy and suspected resistance was detected in three more yards, one in each the North, the Center and the South. Treatment with moxidectin was 100% effective in all yards examined.

CONCLUSION

Cyathostomin populations in the South and the Center of Italy were more susceptible to fenbendazole and pyrantel than the populations present in the Center-North and North-Eastern areas of Italy. Fenbendazole and/or pyrantel were ineffective in almost all properties from the North of Italy. The reasons for such a difference among the Italian regions in terms of FECs and efficacy of antiparasitic drugs are discussed, together with the role that veterinarians, and horse owners and managers should have for effective worm control programs in this country.

Effects of worm control practices examined by a combined faecal egg count and questionnaire survey on horse farms in Germany, Italy and the UK

Background

For the control of worm infections, the strategic use of anthelmintics, often accompanied by additional farm and/or pasture management procedures, is currently applied on most horse farms in industrialized countries. However, the particular effects of the specific worm control procedures are often unclear and have only been investigated to a limited extent. We examined faecal egg count (FEC), faecal egg count reduction (FECR) and questionnaire data on farm and pasture management procedures. The aim of this study was to determine whether specific worm control practices reported to be applied in European horse farms affect worm prevalence.

Results

This study involved 20 German, 26 Italian and 16 UK horse farms for each of which FEC were performed on a minimum of 16 horses. In total, 2029 horse faecal samples were quantitatively analysed for helminth eggs, resulting in 56.3% of the faecal samples being positive for strongylid eggs. The prevalence in the 742 German horse samples (48.1%) was significantly lower than that in the 737 Italian (61.1%) and the 550 UK (60.9%) samples. As expected, a significant effect of horse age on the infection prevalence was observed, with adult horses showing lower prevalences and lower mean FEC than foals and yearlings. The majority of the participating farms were stud farms (n = 29), followed by riding stables (n = 27) and racehorse stables (n = 6). The prevalence of strongyle infection by farm type differed between countries. While in Germany, horses on riding farms were significantly less often strongyle positive, in the UK horses on stud farms showed the lowest strongyle prevalences, whereas in Italy, no significant difference between farm types were seen. On all farms, horses received routine/preventive anthelmintic treatment. An effect of treatment frequency on strongyle prevalence was only encountered with adult horses. On farms performing more than one annual treatment, faecal samples were significantly less often positive. Furthermore, by comparing the FECR results of individual horses with their pre-treatment FEC, it was found that high pre-treatment FEC were associated with a significantly higher probability for a FECR below 90%.

Conclusion

Overall, age-dependent strongyle infection patterns and general worm control approaches were found to be similar on horse farms in the three countries. Also, a negative association of pre-treatment FEC and treatment efficacy was consistently found in all countries. However, mean strongyle prevalences and frequencies of anthelmintic treatments were considerably different. In addition to the age-dependent prevalence patterns, the finding of a possible negative association between high FEC and reduced FECR might argue for a focus on horses showing high pre-treatment FEC when monitoring anthelmintic treatment efficacy in the field.

Anthelmintic resistance in cyathostomin populations from horse yards in Italy, United Kingdom and Germany

BACKGROUND

A large survey was carried out in 2008 in Europe to evaluate the efficacy of fenbendazole (FBZ), pyrantel (PYR), ivermectin (IVM) and moxidectin (MOX), i.e. the major anthelmintic molecules used in current practice against cyathostomins affecting horses. A total of 102 yards and 1704 horses was studied in three countries: 60 yards and 988 horses from Italy, 22 and 396 from the UK, 20 and 320 from Germany. The survey consisted of Faecal Egg Count Reduction Tests (FECRTs) with a faecal egg count reduction (FECR) categorization of (I) resistance present if FECR <90% and the lower 95% confidence limit (LCL) <90%, (II) resistance suspected if FECR >/= 90% and/or LCL <90% and (III) no resistance if FECR >/= 90% and LCL >90%. The calculation of FECR data was performed employing bootstrap analysis of group arithmetic means.

RESULTS

The testing of FBZ on a total of 80 yards resulted in resistance present on more than 80% of the UK and German yards and on significantly fewer in Italy, i.e. in 38% (p < 0.01). PYR, IVM and MOX were tested on a total of 102 yards. For PYR resistance present was found in 25% of the yards with no significant differences between countries. For IVM resistance present was encountered in one Italian and two UK yards (3%), resistance present to MOX was not found in any yard in any country.

CONCLUSION

The results indicate that single and/or multiple drug resistance in equine cyathostomins is present in the three countries, is widespread particularly for FBZ and/or PYR and in one UK yard multiple resistance present was detected to FBZ, PYR and IVM. Macrocylic lactones proved to be the most effective drugs, with some evidence of resistance to IVM and highest activity of MOX, despite a single case of reduced efficacy in Germany. These data call for the development and implementation, among practitioners, owners and managers, of further plans to reduce the expansion of the anthelmintic resistant populations and to use those anthelmintics that remain effective in a manner that preserves their efficacy as long as possible.

[Selective dorsal T1-T6 fusion of the thoracic spine and effects on thorax growth: experimental study in prepuberal New Zealand White rabbits]

PURPOSE OF THE STUDY

The purpose of this study is to assess the consequences brought by selective dorsal arthrodesis of thoracic spine (T1-T6) to the growth of spine and thoracic volume in operated and sham-operated New Zealand White rabbits, between prepubertal age and the end of somatic growth, through the study of computerised tomography (CT) scans periodically carried out on them after arthrodesis surgery.

MATERIAL AND METHODS

Nine female rabbits were subjected to surgery for selective dorsal arthrodesis of the upper thoracic spine and three were sham-operated. Surgery was performed at age nine weeks, before the onset of puberty. Two "C"-shaped titanium bars were placed beside the spinous processes of the thoracic vertebrae to obtain a selective posterior arthrodesis of the first six thoracic vertebrae. Under general anesthesia, three CT scans were performed, 10 (t1), 55 (t2) and 139 (t3) days after surgery. Measures were obtained by Myrian Pro software for three different groups: group 1 with complete fusion, group 2 with incomplete fusion, group 3 sham-operated.

RESULTS

The total dorsal and ventral lengths of thoracic vertebral bodies in the spinal segment T1-T6 was smaller in group 1 and group 2 than in group 3, whereas no differences were observed between the three groups in the T7-T12 segment. The average of the dorsoventral/laterolateral thoracic diameter ratio at fused levels was less than 1 in group 1 as well as in group 2; on the contrary, in group 3 it was greater than 1. The sternum and lung volume grow less.

CONCLUSIONS

Vertebral arthrodesis in the treatment of progressive idiopathic scoliosis in prepubertal patients is not ideal, but is still a choice in treating major deformities of the spine. Postoperative assessment of spinal deformity is essential, feasible and recordable through CT scans. Dorsal arthrodesis in prepubertal rabbits changes thoracic growth patterns. In operated rabbits, the dorsoventral thoracic diameter grows more slowly than the laterolateral thoracic diameter. The sternum, the total lengths of thoracic vertebral bodies in the spinal segment T1-T6 and lungs grow less. The Crankshaft phenomenon is evident at the fused vertebral levels where there is a reduction of thoracic kyphosis.

Forced oscillation technique to evaluate tracheostenosis in patients with neurologic injury

STUDY OBJECTIVES

To determine the utility of forced oscillation technique (FOT) for measuring pulmonary resistance and reactance in patients with central nervous system injuries, for detection and follow-up of posttracheostomy tracheal stenosis.

DESIGN

Case series.

SETTING

A rehabilitation hospital, Brasilia, Distrito Federal, Brazil.

PATIENTS

Ten consecutive neurologically impaired patients, who had previously undergone tracheostomies, with tracheostenosis without current tracheostomy or other tracheal lesion.

INTERVENTIONS AND MEASUREMENTS

FOT evaluations were compared to tracheal diameter before and after bronchoscopic tracheostenosis dilatation procedures. Forced spirometry examinations were also obtained and compared.

RESULTS

Tracheal stenotic lesions were characterized by marked increase in resistance and reduction in reactance at low frequency and a marked increase in resonance frequency (Rf). Consistent reversal of this pattern with large reductions in total impedance of the respiratory system (Zresp) Rf and resistance at 5 Hz (R 5 Hz) were noted in all patients after each successful dilatation. Diameter of the stenosis was strongly correlated with Rf, Zresp, and R 5 Hz. The change in diameter before and after dilatation was similarly correlated with the changes in FOT values of Rf and Zresp. Spirometry values did not correlate well with the diameter of the tracheal stenosis.

CONCLUSION

The strong correlation of Rf, Zresp, and R 5 Hz to diameter of tracheostenosis suggests a previously unappreciated role for FOT in the noninvasive detection and follow-up of airway stenosis. This may be especially useful for patients with concomitant neurologic disabilities who are at risk of airway stenosis.