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1.
J Infect Dis ; 229(2): 558-566, 2024 Feb 14.
Article in English | MEDLINE | ID: mdl-37889572

ABSTRACT

Congenital toxoplasmosis in humans and in other mammalian species, such as small ruminants, is a well-known cause of abortion and fetal malformations. The calcium-dependent protein kinase 1 (CDPK1) inhibitor BKI-1748 has shown a promising safety profile for its use in humans and a good efficacy against Toxoplasma gondii infection in vitro and in mouse models. Ten doses of BKI-1748 given every other day orally in sheep at 15 mg/kg did not show systemic or pregnancy-related toxicity. In sheep experimentally infected at 90 days of pregnancy with 1000 TgShSp1 oocysts, the BKI-1748 treatment administered from 48 hours after infection led to complete protection against abortion and congenital infection. In addition, compared to infected/untreated sheep, treated sheep showed a drastically lower rectal temperature increase and none showed IgG seroconversion throughout the study. In conclusion, BKI-1748 treatment in pregnant sheep starting at 48 hours after infection was fully effective against congenital toxoplasmosis.


Subject(s)
Abortion, Spontaneous , Communicable Diseases , Toxoplasma , Toxoplasmosis, Congenital , Toxoplasmosis , Pregnancy , Humans , Female , Mice , Sheep , Animals , Toxoplasmosis, Congenital/drug therapy , Toxoplasmosis, Congenital/prevention & control , Mammals
2.
Mar Pollut Bull ; 185(Pt B): 114376, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36423566

ABSTRACT

Pinna nobilis is undergoing one of the most dramatic events suffered by an endangered species. An emerging disease has relegated its populations to coastal lagoons or estuaries with salinities beyond the 36.5-39.7 psu range. The Mar Menor is one of two such locations on the Spanish coastline. Poor environmental conditions and eutrophication and anoxia events, that became critical in 2016, 2019 and 2021, have reduced its population in >99 %. In this work, the spatial distribution of the species within the lagoon and the factors determining its survival along the successive crises of eutrophication are studied using a two-stage (presence/absence estimation and density modelling) Species Distribution Model. A potential area of 200.97 ha and an average density of 1.05 ind.100 m2 is estimated for 2020. The viability of the Mar Menor population depends on management actions designed both for the species and to improve the lagoon environmental state.


Subject(s)
Bivalvia , Animals , Uncertainty , Eutrophication , Endangered Species , Estuaries
3.
Animals (Basel) ; 11(3)2021 Mar 15.
Article in English | MEDLINE | ID: mdl-33804105

ABSTRACT

Natural service remains the main breeding method in extensively managed beef herds. Although the bull might be the most important factor in determining herd fertility, its importance has been largely overlooked, focusing instead on female fertility. Management of the bull is critical to maximize the opportunities for cow conception. Infectious bovine rhinotracheitis (IBR) and bovine viral diarrhea (BVD) are infections associated with reduced conception rates. This study aimed to determine the effect of both IBR and BVD infection, and bull: cow ratio on seminal parameters in the bull and herd fertility. The presence of antibodies to IBR and BVD, seminal parameters (volume, concentration, mass, and progressive motility), and herd fertility were analyzed in 158 extensively managed bulls. Sperm concentration and mass motility, as well as herd fertility, were significantly lower in BVD-positive bulls. No significant differences were found between IBR-positive and -negative bulls in any reproductive parameter. Sperm concentration was negatively affected by BVD infection in both Charolais and Limousin bulls, whereas mass motility and herd fertility were reduced in Limousin bulls only. No differences were observed in the cow: bull ratio between BVD+ and BVD- bulls. A significant negative correlation was detected between the number of cows per bull and herd fertility, which was negatively affected when herds had more than 40 cows per bull. In conclusion, BVD and bull overuse negatively affect the reproductive performance of the herd.

4.
Vet Parasitol ; 277: 109012, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31884316

ABSTRACT

Early in vivo diagnosis of bovine besnoitiosis is crucial for the success of control programmes. However, diagnosis in acutely infected animals is hindered by the low sensitivity of the available serological tools. In this study, a novel ELISA to detect specific anti-Besnoitia besnoiti IgM antibodies was developed. The usefulness of this tool together with an avidity ELISA were studied with a well-coded sera panel from experimentally and naturally infected cattle. First, the kinetics of specific IgM levels were determined in experimentally infected calves during the acute and chronic infection. Next, IgM levels were determined in naturally infected cattle with either acute or chronic infection. Finally, the IgG avidity index was monitored in both experimentally and naturally infected cattle. Specific IgM antibodies were detected prior to specific IgG antibodies (7-19 days vs. 17-26 days post-infection). A prompt IgM response was associated with the end of the febrile stage in experimentally infected calves. Naturally and experimentally infected animals with acute clinical signs tested IgM-positive but IgG-negative, followed by IgG seroconversion 2-3 weeks later. Chronically infected cattle developed both IgM and IgG specific antibodies. Moreover, a progressive increase in the avidity index (AI) was observed in all experimentally infected calves during the course of the experimental trials. However, a low AI coincided with visible tissue cysts. Low avidity values were also detected when naturally infected cattle with acute clinical signs seroconverted, in contrast to a high AI detected in chronically infected cattle. In summary, IgM and avidity ELISAs improved the early in vivo diagnosis of bovine besnoitiosis. IgM-positive but IgG-negative results were indicative of an acute infection, whereas IgG positive results accompanied by low avidity values confirmed a recent infection.


Subject(s)
Cattle Diseases/diagnosis , Coccidiosis/veterinary , Acute Disease , Animals , Antibodies, Protozoan/blood , Cattle , Coccidiosis/diagnosis , Enzyme-Linked Immunosorbent Assay/veterinary , Immunoglobulin M/blood
5.
Vet Res ; 50(1): 72, 2019 Sep 24.
Article in English | MEDLINE | ID: mdl-31551079

ABSTRACT

Early Neospora caninum infection dynamics were investigated in pregnant heifers intravenously inoculated with PBS (G-Control) or 107 tachyzoites of high (G-NcSpain7)- or low (G-NcSpain1H)-virulence isolates at 110 days of gestation. Serial culling at 10 and 20 days post-infection (dpi) was performed. Fever was detected at 1 dpi in both infected groups (P < 0.0001), and a second peak was detected at 3 dpi only in G-NcSpain7 (P < 0.0001). At 10 dpi, Nc-Spain7 was detected in placental samples from one animal related to focal necrosis, and Nc-Spain7 transmission was observed, although no foetal lesions were associated with this finding. The presence of Nc-Spain1H in the placenta or foetuses, as well as lesions, were not detected at 10 dpi. At 20 dpi, G-NcSpain7 animals showed almost 100% positive placental tissues and severe focal necrosis as well as 100% transmission. Remarkably, foetal mortality was detected in two G-NcSpain7 heifers. Only one animal from G-NcSpain1H presented positive placental samples. No foetal mortality was detected, and lesions and parasite transmission to the foetus were not observed in this group. Finally, 100% of G-NcSpain7 heifers at 20 dpi presented specific antibodies, while only 60% of G-NcSpain1H animals presented specific antibodies at 20 dpi. In addition, earlier seroconversion in G-Nc-Spain7 was observed. In conclusion, tachyzoites from Nc-Spain7 reached the placenta earlier and multiplied, leading to lesion development, transmission to the foetus and foetal mortality, whereas Nc-Spain1H showed delayed infection of the placenta and no lesional development or transmission during early infection.


Subject(s)
Cattle Diseases/immunology , Coccidiosis/veterinary , Fetus/parasitology , Neospora/pathogenicity , Placenta/parasitology , Pregnancy Complications, Parasitic/veterinary , Animals , Cattle , Cattle Diseases/parasitology , Coccidiosis/immunology , Coccidiosis/parasitology , Female , Gestational Age , Neospora/physiology , Pregnancy , Pregnancy Complications, Parasitic/immunology , Pregnancy Complications, Parasitic/parasitology , Vaccination/veterinary , Virulence/genetics
6.
BMC Pulm Med ; 19(1): 109, 2019 Jun 20.
Article in English | MEDLINE | ID: mdl-31221129

ABSTRACT

BACKGROUND: Evaluating severity of illness of patients with prolonged mechanical ventilation (PMV) is important to adopt the best appropriate care management for each individual. Yet, no severity-of-illness scoring system has been specifically designed for this type of patients. The aim of this study was to develop and validate a new instrument, the Multi-INdependence Dimensions (MIND) questionnaire designed to comprehensively measure the severity of illness of patients under PMV. METHODS: The validation of the MIND questionnaire was performed during a longitudinal observational study conducted with PMV subjects in weaning facilities in three countries (Argentina, Colombia and Germany). The questionnaire validity was tested in 3 stages: 1) Specification of components, with description of item responses, inter-item and Cronbach alpha correlations; 2) Creation of the composite scores; 3) Measurement properties determination including test-retest reliability after 30 days, clinical validity (Medical Research Council (MRC) muscle strength score, Sepsis-related Organ Failure Assessment (SOFA), Glasgow Coma Scale (GCS), Dependence Nursing Scale and EuroQol-5 Dimension evaluated at inclusion), and ability to detect change. RESULTS: A total of 128 subjects participated in the validation study. Eleven component scores and four composite scores were created. MIND scores significantly correlated with MRC muscle strength, SOFA, DNS, GCS and EQ-5D, supporting the validity of the new scores. Intraclass Correlation Coefficient greater than 0.82 were observed for all composite scores, indicating good test-retest reliability. MIND scores were able to detect improvement in subject severity of illness. CONCLUSION: The MIND questionnaire is a valid and reliable instrument for measuring comprehensively the multiple dimensions characterizing the severity of illness of PMV patients. TRIAL REGISTRATION: NCT02255058 .


Subject(s)
Critical Illness/therapy , Psychometrics/instrumentation , Respiration, Artificial/methods , Surveys and Questionnaires , Adult , Aged , Argentina , Colombia , Female , Germany , Health Status , Humans , Longitudinal Studies , Male , Middle Aged , Multivariate Analysis , Prospective Studies , Regression Analysis , Reproducibility of Results , Severity of Illness Index
7.
Transbound Emerg Dis ; 65(6): 1979-1990, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30101497

ABSTRACT

Bovine besnoitiosis is continuing to spread in Europe. Therefore, the development of ruminant animal models of infection is urgently needed to evaluate therapeutic and prophylactic tools. Herein, we studied the effect of parasite dose and host age on the infection dynamics with Besnoitia besnoiti tachyzoites in cattle in two independent experimental infections. In experiment A, twelve 3-month-old male calves were inoculated intravenously with either three different doses of tachyzoites (G1: 108 ; G2: 107 ; G3: 106 ) or with PBS (G4). In experiment B, six 14-month-old bulls were inoculated with 106 tachyzoites based on results obtained in experiment A. In both trials, clinical signs compatible with acute and chronic besnoitiosis were monitored daily; blood and skin samples were collected regularly for 70-115 days post-infection (pi). Finally, animals were killed, and tissues were collected for lesion and parasite detections. Infected animals developed mild-moderate signs compatible with acute besnoitiosis. Lymphadenopathy and fever were observed in both calves (from 12 hr until 7 days pi) and bulls (from 6 days until 9 days pi). Seroconversion was detected at 16-19 days pi, and antibody levels remained high. Infected animals did not developed characteristic clinical signs and macroscopic lesions of chronic besnoitiosis. However, successfully, parasite-DNA was detected in a reduced number of target tissues: conjunctiva, ocular sclera, epididymis, skin of the scrotum and carpus in calves (n = 10, 6 of which belonged to G3), and pampiniform plexus and testicular parenchyma in bulls. Remarkably, one tissue cyst and mild microscopic lesions were also detected. In summary, inoculated animals developed the acute besnoitiosis and chronic infection was evidenced by microscopic findings. However, our results suggest that tachyzoite dose and host age are not key variables for inducing clinical signs and macroscopic lesions characteristic of chronic besnoitiosis. Thus, a further refinement of this model should evaluate other parasite- and host-dependent variables.


Subject(s)
Coccidiosis/parasitology , Age Factors , Animals , Cattle , Cattle Diseases/parasitology , Coccidiosis/veterinary , Disease Models, Animal
8.
Vet Res ; 49(1): 42, 2018 05 08.
Article in English | MEDLINE | ID: mdl-29739449

ABSTRACT

Experimental infections in pregnant sheep have been focused on studying the effect of the time of challenge on the outcome of N. caninum infection, whereas the impact of the dose and route of challenge has not been studied in depth. Therefore, clinical outcome, immune responses, parasite detection and burden, and lesion severity in placental tissues and foetal brains were investigated in 90-day-pregnant sheep inoculated intravenously with 105 (G1), 104 (G2), 103 (G3), or 102 (G4) tachyzoites or subcutaneously with 104 (G5) tachyzoites of the virulent Nc-Spain7 isolate and an uninfected group (G6). Comparing challenge doses, G1 was the only group that had 100% abortion. Likewise, IFNγ levels in G1 increased earlier than those in other intravenously infected groups, and IgG levels on day 21 post-infection (pi) were higher in G1 than those in other intravenously infected groups. Concerning vertical transmission, G1 shows a higher parasite burden in the foetal brain than did G2 and G3. Comparing routes of administration, no differences in foetal survival rate or parasite load in the foetal brain were found. Although G2 had higher IFNγ levels than G5 on day 10 pi, no differences were found in humoral immune responses. Because the outcome after intravenous infection with 105 tachyzoites was similar to that observed after intravenous infection with 106 tachyzoites used in a previous work (100% abortion and vertical transmission), we conclude that it may be reasonable to use 105 tachyzoites administered by the intravenous route in further experiments when assessing drugs or vaccine candidates.


Subject(s)
Coccidiosis/veterinary , Neospora/physiology , Pregnancy Complications, Parasitic/veterinary , Sheep Diseases/immunology , Sheep Diseases/pathology , Animals , Coccidiosis/immunology , Coccidiosis/parasitology , Coccidiosis/pathology , Female , Fetus/parasitology , Immunity, Cellular , Immunity, Humoral , Parasite Load/veterinary , Placenta/parasitology , Pregnancy , Pregnancy Complications, Parasitic/immunology , Pregnancy Complications, Parasitic/parasitology , Pregnancy Complications, Parasitic/pathology , Sheep , Sheep Diseases/parasitology
9.
Int J Parasitol Drugs Drug Resist ; 8(1): 112-124, 2018 04.
Article in English | MEDLINE | ID: mdl-29501973

ABSTRACT

Neospora caninum is one of the main causes of abortion in cattle, and recent studies have highlighted its relevance as an abortifacient in small ruminants. Vaccines or drugs for the control of neosporosis are lacking. Bumped kinase inhibitors (BKIs), which are ATP-competitive inhibitors of calcium dependent protein kinase 1 (CDPK1), were shown to be highly efficacious against several apicomplexan parasites in vitro and in laboratory animal models. We here present the pharmacokinetics, safety and efficacy of BKI-1553 in pregnant ewes and foetuses using a pregnant sheep model of N. caninum infection. BKI-1553 showed exposure in pregnant ewes with trough concentrations of approximately 4 µM, and of 1  µM in foetuses. Subcutaneous BKI-1553 administration increased rectal temperatures shortly after treatment, and resulted in dermal nodules triggering a slight monocytosis after repeated doses at short intervals. BKI-1553 treatment decreased fever in infected pregnant ewes already after two applications, resulted in a 37-50% reduction in foetal mortality, and modulated immune responses; IFNγ levels were increased early after infection and IgG levels were reduced subsequently. N. caninum was abundantly found in placental tissues; however, parasite detection in foetal brain tissue decreased from 94% in the infected/untreated group to 69-71% in the treated groups. In summary, BKI-1553 confers partial protection against abortion in a ruminant experimental model of N. caninum infection during pregnancy. In addition, reduced parasite detection, parasite load and lesions in foetal brains were observed.


Subject(s)
Coccidiosis/drug therapy , Life Cycle Stages/drug effects , Neospora/drug effects , Pyrazoles/adverse effects , Pyrazoles/therapeutic use , Pyrimidines/adverse effects , Pyrimidines/therapeutic use , Abortion, Veterinary/prevention & control , Animals , Brain/drug effects , Brain/parasitology , Coccidiosis/immunology , Coccidiosis/parasitology , Female , Fetus/drug effects , Fever/chemically induced , Immunoglobulin G/blood , Interferon-gamma/blood , Neospora/immunology , Neospora/isolation & purification , Parasite Load , Pregnancy , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/adverse effects , Protein Kinase Inhibitors/pharmacokinetics , Protein Kinase Inhibitors/therapeutic use , Pyrazoles/administration & dosage , Pyrazoles/pharmacokinetics , Pyrimidines/administration & dosage , Pyrimidines/pharmacokinetics , Sheep
10.
Am J Vet Res ; 77(11): 1187-1193, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27805442

ABSTRACT

OBJECTIVE To compare the effectiveness of an ultrasound-guided paravertebral nerve blockade technique (UGPNB) with distal and proximal paravertebral nerve blockade techniques without ultrasound guidance (DPNB and PPNB, respectively) in calves. ANIMALS 4 calf cadavers and 7 healthy calves. PROCEDURES A suitable acoustic window was identified to facilitate access to the T13, L1, and L2 spinal nerves in cadavers and live calves. In cadavers, nerves were injected with dye under ultrasound guidance. In calves, the UGPNB, DPNB, and PPNB were performed in random order at 10-day intervals by injection of an anesthetic solution containing 2% lidocaine hydrochloride. Nociceptive withdrawal responses were assessed to determine the effects of the blockades. RESULTS In cadavers, nerve staining success rates (ie, ≥ 2-cm-long dye path) achieved with ultrasound guidance were 88% (T13 [ventral branch]), 75% (T13 and L1 [dorsal branches] and L1 and L2 [ventral branches]), and 38% (L2 [dorsal branch]). The nerves were each identified as a hyperechoic band in a longitudinal plane. In calves, the UGPNB, DPNB, and PPNB reduced the withdrawal response to the noxious stimulus, mainly in the dorsal-cranial, dorsal-caudal, and ventral-cranial areas of the flank. Overall, the UGPNB resulted in a better nociceptive cumulative score, administering only one half of the local anaesthetic dose, compared with findings for the DPNB and PPNB. However, time to perform the UGPNB was longer. CONCLUSIONS AND CLINICAL RELEVANCE The UGPNB evaluated may be an improved alternative to the DPNB and PPNB for provision of anesthesia for flank surgery in calves. However, effectiveness of the UGPNB should be evaluated in a clinical setting and in adult cattle.


Subject(s)
Cattle , Nerve Block/veterinary , Anesthesia, Local/veterinary , Anesthetics, Local/administration & dosage , Animals , Spinal Nerves , Ultrasonography/veterinary
11.
Eur J Pediatr Surg ; 26(1): 7-12, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26378482

ABSTRACT

OBJECTIVE: The mesoportal shunt (MPS) and liver transplantation (LT) have changed the scenario of extrahepatic portal vein obstruction (EHPVO) since the MPS, the only "curative" technique, can now be offered in asymptomatic patients and also thrombotic complications of LT have increased the incidence of EHPVO. MATERIAL AND METHODS: A retrospective study of patients undergoing surgery for EHPVO was conducted between 1990 and 2015. An analysis was done for the shunt permeability and clinical evolution over time. RESULTS: Of the 73 children with EHPVO, 39 were operated (12 posttransplant and 27 idiopathic). The median age at surgery was 9.36 years (range, 1.60-17.42 years). The MPS was the technique of choice; it was offered in 21 patients but eventually could be performed in only 18 (9 posttransplant and 9 idiopathic). The results of MPS were better in idiopathic (just one thrombosis successfully converted into mesocaval bypass). In the MPS after LT (n = 9), six shunts are permeable, two became thrombotic (one patient requiring retransplantation), and one late thrombosis occurred and the patient died eventually because of gastrointestinal bleeding. In the remaining patients (21 out of the 39), MPS was not performed because of intrahepatic cavernoma, portal vein hypoplasia, or insufficient length of vascular graft (especially in left lateral segment graft LT, since the portal vein is usually located in the right upper quadrant). They underwent 10 distal splenorenal shunts (DSRS) (1 posttransplant and 9 idiopathic), 5 proximal splenorenal shunts (PSRS) (1/4), 6 mesocaval shunts (1/5), and 1 modified Sugiura procedure. The results with DSRS have been favorable (one thrombosis, converted into mesocaval bypass). In the PSRS no thrombosis was identified and in the mesocaval shunt one early thrombosis occurred. Posttransplantation group had higher risk of shunt thrombosis, regardless of the surgical technique (chi-square, 0.021). The total increase of platelets after 6 months was not different in MPS as compared with other surgical techniques (analysis of variance, 0.110). CONCLUSIONS: The MPS is the technique of choice in EHPVO for idiopathic thrombosis as well as secondary to LT. Not all cases are favorable for MPS, so the surgeon must consider the possibility of alternative techniques for EHPVO. The results in terms of shunt patency are much better in idiopathic cavernoma that posttransplant patients.


Subject(s)
Hypertension, Portal/surgery , Liver Transplantation , Portal Vein/surgery , Portasystemic Shunt, Surgical/methods , Postoperative Complications/surgery , Venous Thrombosis/surgery , Adolescent , Child , Child, Preschool , Female , Follow-Up Studies , Humans , Hypertension, Portal/etiology , Infant , Male , Retrospective Studies , Venous Thrombosis/etiology
12.
Vet J ; 200(3): 434-9, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24797105

ABSTRACT

This study aimed to describe a suitable acoustic window to facilitate access to the sciatic and femoral nerves in calves and to study the effects of their blockade with local anaesthetics. The neuroanatomical and ultrasound (US) study was performed on the cadavers of 10 calves, and the effects of 2% lidocaine with epinephrine (0.2 mL/kg) were determined in five healthy calves. The sciatic nerve in the cadavers was easily visualised as a hyperechoic band distal to the femoral greater trochanter and caudal to the femoral shaft. The femoral nerve in the cadavers was not easily identified, and was visualised as a hyperechoic oval structure situated immediately medial to the psoas major muscle and lateral to the femoral artery. The sciatic nerve was stained by methylene blue, injected under US guidance, in 9/10 cases, and the femoral nerve was stained in 6/10 cases. Sciatic nerve blockade under US guidance produced adduction of the limb with metatarsophalangeal joint flexion, while the femoral nerve blockade produced reduced weight bearing. The sciatic nerve blockade produced a reduced response to the noxious stimulus, mainly in the phalanges, proximal and distal metatarsus, tarsus and tibia and, following the femoral nerve blockade, in the medial subarea of the femur. However, femoral nerve blockade produced a more variable degree of blockade. In conclusion, US -guided anaesthetic blockade of the sciatic nerve in calves may be considered for surgery in the distal pelvic limb, although further studies are necessary to determine its clinical application.


Subject(s)
Femoral Nerve/surgery , Injections, Subcutaneous/veterinary , Nerve Block/veterinary , Sciatic Nerve/surgery , Ultrasonography, Interventional/veterinary , Anesthesia, Local/veterinary , Anesthetics, Local/administration & dosage , Animals , Cadaver , Cattle , Coloring Agents , Femoral Nerve/diagnostic imaging , Hindlimb/diagnostic imaging , Methylene Blue , Sciatic Nerve/diagnostic imaging
13.
Vet Res ; 44: 106, 2013 Nov 01.
Article in English | MEDLINE | ID: mdl-24180373

ABSTRACT

Live vaccines have emerged as one of the most potentially cost-effective measures for the control of bovine neosporosis. Previous studies have shown that Nc-Spain 1H is a naturally attenuated isolate of Neospora caninum and that immunisation with live Nc-Spain 1H tachyzoites generated a protective immune response in mice. The aim of this study was to evaluate the safety and efficacy of immunisation in cattle. N. caninum-seronegative heifers were immunised subcutaneously twice with 107 live Nc-Spain 1H tachyzoites prior to artificial insemination. No adverse reactions or negative effects on reproductive parameters were recorded following immunisation. In immunised and non-challenged heifers, no foetal deaths were observed, and none of the calves was congenitally infected. The efficacy against N. caninum-associated foetal death and vertical transmission was determined after challenge with high doses of the Nc-1 isolate at 70 and 135 days of gestation, respectively. After the challenge in early gestation, the immunisation induced a protection of 50% against foetal death. In addition, the microsatellite analysis performed in PCR-positive tissue samples from foetuses that died after challenge infection showed that the profiles corresponded to the challenge isolate Nc-1. A degree of protection against vertical transmission was observed after challenge at mid-gestation; calves from immunised heifers showed significantly lower pre-colostral Neospora-specific antibody titres than calves from the non-immunised/challenge group (P < 0.05). Strong antibody and interferon gamma responses were induced in the immunised heifers. This study indicates that the immunisation before pregnancy with the Nc-Spain 1H vaccine isolate appeared to be safe and reduced the occurrence of N. caninum-associated abortion and vertical transmission in experimentally infected cattle. In light of these encouraging results, the next step for testing this live attenuated candidate should be the assessment of its efficacy and safety in naturally infected cattle.


Subject(s)
Cattle Diseases/prevention & control , Coccidiosis/veterinary , Infectious Disease Transmission, Vertical/veterinary , Neospora/immunology , Protozoan Vaccines/immunology , Animals , Antibodies, Protozoan/blood , Cattle , Cattle Diseases/immunology , Coccidiosis/immunology , Coccidiosis/prevention & control , Female , Infectious Disease Transmission, Vertical/prevention & control , Interferon-gamma/genetics , Interferon-gamma/metabolism , Microsatellite Repeats , Neospora/genetics , Neospora/pathogenicity , Polymerase Chain Reaction/veterinary , Pregnancy , Protozoan Vaccines/administration & dosage , Spain , Vaccines, Attenuated/administration & dosage , Vaccines, Attenuated/immunology
14.
Vet Res ; 40(5): 49, 2009.
Article in English | MEDLINE | ID: mdl-19497257

ABSTRACT

The Nc-Spain 1H isolate of Neospora caninum, which was newly obtained from the brain of a congenitally asymptomatic infected calf, demonstrated a reduced in vitro tachyzoite yield and viability rate, as well as low virulence in mouse models. The objective of the present study was to determine the ability of this isolate to induce foetal death in a pregnant bovine model. For this purpose, 13 naïve pregnant heifers were divided into three groups and were experimentally challenged with either 10(7) tachyzoites of Nc-1 (group 1, n=5), Nc-Spain 1H (group 2, n=5) isolates or phosphate-buffered saline (group 3, n=3) intravenously at 70 days of gestation. After inoculation, pregnancy was monitored and dams were sacrificed when foetal death was detected. The remaining animals were slaughtered at 45 days post-infection. Maternal and foetal samples were collected for examination by histology and parasite DNA detection. Parasitaemia, specific anti- N. caninum IgG and interferon gamma responses were also studied. At 3-4 weeks after infection, foetal death was detected in 3 out of 5 Nc-1-infected dams. However, no evidence of foetal death was observed in either Nc-Spain 1H-infected or control groups during the period studied. The most severe histopathological lesions were observed in the placenta and foetal organs from Nc-1-infected cattle that exhibited foetal death. It was in these animals that N. caninum DNA was more frequently detected. Parasitaemia was observed in all Nc-1-infected dams and in only 3 out of 5 Nc-Spain 1H-infected animals. The magnitude of the immune response was significantly higher in the Nc-1-inoculated group than in the group inoculated with the Nc-Spain 1H isolate. These data reveal the reduced virulence of the Nc-Spain 1H isolate in cattle.


Subject(s)
Cattle Diseases/parasitology , Coccidiosis/veterinary , Neospora/pathogenicity , Pregnancy Complications, Parasitic/veterinary , Animals , Cattle , Coccidiosis/parasitology , DNA, Protozoan/genetics , Female , Immunoglobulin G/blood , Interferon-gamma/blood , Polymerase Chain Reaction , Pregnancy , Pregnancy Complications, Parasitic/parasitology , Virulence
15.
Vet Parasitol ; 159(1): 7-16, 2009 Jan 22.
Article in English | MEDLINE | ID: mdl-19027235

ABSTRACT

Neospora caninum tachyzoites were isolated from the brain of an asymptomatic naturally infected calf with precolostral-specific antibodies. The new isolate, named Nc-Spain 1H, was identified as a member of the N. caninum species based on its internal transcribed spacer 1 (ITS-1) sequence and was genetically characterized using microsatellite markers. Multilocus analysis showed that Nc-Spain 1H was genetically different from other N. caninum isolates. We compared the in vitro tachyzoite yield and viability rate of the Nc-Spain 1H and Nc-1 isolates in a plaque assay. The lower tachyzoite yields displayed by Nc-Spain 1H were complemented with a significantly lower viability rate. Moreover, in an in vitro tachyzoite-bradyzoite stage conversion assay, the percentage of Nc-Spain 1H bradyzoite conversion was similar to that of the cystogenic isolate Nc-Liv, with the exception that Nc-Spain 1H produced only intermediate bradyzoites. The pathogenicity of Nc-Spain 1H was examined in BALB/c mice, and the results demonstrated that Nc-Spain 1H failed to induce clinical signs or mortality and that no parasite DNA was detected in the brain during the chronic stage of infection. In a pregnant mouse model, Nc-1 infection resulted in high transplacental transmission, leading to a high neonatal mortality rate over time. In contrast, the offspring survival rate from Nc-Spain 1H-infected dams was almost 100%, and N. caninum DNA was detected in only one pup. These data show that Nc-Spain 1H appears to be a low virulence isolate and may be a suitable candidate for live vaccine development.


Subject(s)
Antibodies, Protozoan/immunology , Cattle Diseases/parasitology , Coccidiosis/veterinary , Neospora/isolation & purification , Neospora/pathogenicity , Analysis of Variance , Animals , Antibodies, Protozoan/genetics , Cattle , Coccidiosis/parasitology , Female , Mice , Mice, Inbred BALB C , Mice, Nude , Microsatellite Repeats , Neospora/genetics , Polymerase Chain Reaction/veterinary , Statistics, Nonparametric , Viral Plaque Assay , Virulence/genetics , Virulence/immunology
16.
Cir. Esp. (Ed. impr.) ; 73(4): 244-251, abr. 2003. tab
Article in Es | IBECS | ID: ibc-21390

ABSTRACT

La bipartición hepática representa en la actualidad un procedimiento de elección para el trasplante hepático de donante cadáver. La escasez del número de donantes existentes y el constante incremento en el número de receptores avalan este hecho. La realización de este procedimiento obliga a un riguroso protocolo de selección del donante, a una cuidadosa logística en la donación con el objetivo de no prolongar los tiempos de isquemia y al establecimiento de un consenso entre los dos equipos que van a realizar los dos implantes, a efectos de atender sus necesidades en función de la situación del receptor y las características anatómicas, y poder realizar una lógica repartición de los pedículos vasculobiliares. Dos procedimientos técnicos han sido descritos: procedimiento ex vivo e in situ. Este último está asociado con una menor incidencia de complicaciones quirúrgicas, hemorragia postoperatoria, trombosis de las reconstrucciones vasculares realizadas, complicaciones biliares y necrosis de áreas hepáticas. Si bien la bipartición hepática para un receptor adulto y otro pediátrico está claramente justificada, más dificultades existen para su realización con dos receptores adultos. Sólo debe plantearse ser efectuado con dos adultos de bajo peso, en donde el volumen hepático a implantar sea el adecuado. Los resultados obtenidos con la bipartición hepática confirman el gran beneficio para los programas pediátricos en función de la reducción de su lista de espera y las mínimas consecuencias en términos de complicaciones postoperatorias o pérdidas de injertos para los programas de adultos. (AU)


Subject(s)
Adult , Female , Male , Child , Humans , Tissue Donors/supply & distribution , Liver Transplantation/methods , Postoperative Complications/epidemiology , Treatment Outcome , Spain/epidemiology , Survival Rate/trends , Liver Transplantation/trends
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