An Ibero-American inter-laboratory trial to evaluate serological tests for the detection of anti-<Emphasis Type="Italic">Neospora caninum</Emphasis> antibodies in cattle

We carried out an inter-laboratory trial to compare the serological tests commonly used for the detection of specific Neospora caninum antibodies in cattle in Ibero-American countries. A total of eight laboratories participated from the following countries: Argentina (n = 4), Brazil (n = 1), Peru (n = 1), Mexico (n = 1), and Spain (n = 1). A blind panel of well-characterized cattle sera (n = 143) and sera representative of the target population (n = 351) was tested by seven in-house indirect fluorescent antibody tests (IFATs 1–7) and three enzyme-linked immunosorbent assays (ELISAs 1–3; two in-house and one commercial). Diagnostic performance of the serological tests was calculated and compared according to the following criteria: (1) the “Pre-test information,” which uses previous epidemiological and serological data; (2) the “Majority of tests,” which classifies a serum as positive or negative according to the results obtained by most tests evaluated. Unexpectedly, six tests showed either sensitivity (Se) or specificity (Sp) values lower than 90%. In contrast, the best tests in terms of Se, Sp, and area under the ROC curve (AUC) values were IFAT 1 and optimized ELISA 1 and ELISA 2. We evaluated a high number of IFATs, which are the most widely used tests in Ibero-America. The significant discordances observed among the tests regardless of the criteria employed hinder control programs and urge the use of a common test or with similar performances to either the optimized IFAT 1 and ELISAs 1 and 2.     

Residues of methamidofos, malathion, and methiocarb in greenhouse crops

The diminution of methamidofos, malathion, and methiocarb in different crops grown in greenhouses has been studied, including the presence of metabolites such as malaoxon, methiocarb sulfoxide, and methiocarb sulfone. The analytical method is based on dichloromethane extraction and GC-PFPD analysis. It has been validated establishing performance parameters such as recovery rates, precision, linear ranges, and limits of detection and quantification, which are low enough for ensuring that their corresponding MLRs can be adequately quantified. Samples of treated cucumbers and peppers grown in greenhouses were collected and analyzed during a 15-day period for obtaining the diminution rates of methamidofos and malathion. The behavior of methiocarb in treated green beans and tomatoes has been studied using analysis of variance (ANOVA) as the statistical tool, for establishing the influence of crop, season, application dose, and greenhouse design.     

Effect of high-pressure treatment on the carotenoid composition and the radical scavenging activity of persimmon fruit purees

The carotenoid composition of persimmon fruit purees of two cultivars, cvs. Rojo Brillante and Sharon, grown in Spain was determined by HPLC to assess the effects of high-pressure processing on some sensory (carotenoids), nutritional (provitamin A value), and health-related (radical-scavenging capacity) parameters. Total carotenoid content was higher in untreated Rojo Brillante puree (22. 11 microg g(-)(1)) than in untreated Sharon puree (15.22 microg g(-)(1)). Purees of both untreated cultivars showed similar carotenoid patterns after saponification with beta-cryptoxanthin, beta-carotene, and zeaxanthin as the main pigments. A high content of lycopene was quantified in Rojo Brillante (5.34 microg g(-)(1)), whereas only traces were detected in Sharon. The provitamin A value, reported as retinol equivalents (RE), was in untreated Rojo Brillante puree (77 RE/100 g) similar to that of Sharon (75 RE/100 g). Scavenging free radical capacity, measured as antiradical efficiency (AE), showed in untreated Rojo Brillante puree a value (12.14 x 10(-)(3)) 8.5 times higher than that in untreated Sharon (1. 42 x 10(-)(3)). Nonuniform behavior of high-pressure treatment was detected. Pressure treatments at 50 and 300 MPa/15 min/25 degrees C for Rojo Brillante and at 50 and 400 MPa/15 min/25 degrees C for Sharon increased the amount of extractable carotenoids (9-27%), which are related with the increase of vitamin A value (75-87 RE/100 g). No correlation with the increase of AE (from 1.42 x 10(-)(3) to 16.73 x 10(-)(3) and 19.58 x 10(-)(3)) after some pressure treatments (150 and 300 MPa/15 min/25 degrees C) was found.     

Evolution of the peripheral blood lymphocyte populations in multiparous rabbit does with two reproductive management rhythms

The emergence of epizootic rabbit enteropathy is leading to changes in weaning protocols in commercial rabbitries. Traditional weaning protocols are being replaced with late weaning, beyond 35 days postpartum (dpp). The main objectives of this study were to compare the peripheral blood lymphocyte populations of multiparous rabbit does under two reproductive rhythms (insemination at 11 dpp and weaning at 28 dpp, insemination at 25 dpp and weaning at 42 dpp), and to assess the influence on those of kits. Samples of peripheral blood were taken in 22 adult females and 44 of their kits at different critical times, and several lymphocytic populations were evaluated by flow cytometry. Additionally, the perirenal fat thickness of does was also measured at partum and weaning to observe if body condition correlates with lymphocyte populations. During whole lactation, counts of total, CD5(+), CD4(+) and CD8(+) lymphocytes of females were generally lower with weaning at 42 dpp compared to 28 dpp. Moreover, counts of total, B and CD5(+) lymphocytes in rabbit does weaned at 42 dpp correlated to their body condition (+0.60 to 0.82; P<0.05), contrary to that observed in rabbit does weaned at 28 dpp. Some correlations between lymphocyte counts in both groups of does and weaning rabbits were observed. At weaning, those young rabbits weaned at 42 dpp had a significantly lower number of CD4(+) lymphocytes than those weaned at 28 dpp (P<0.01). In conclusion, the 42 ddp rabbit does presented a lower number of total lymphocytes and lymphocytic subpopulations during lactation and at weaning, as well as lesser capacity of adjustment during the gestation-lactation cycle.     

Experimental inoculation of Neospora caninum in pregnant water buffalo

The aim of this study was to characterize the pathogenesis of Neospora caninum in experimentally inoculated pregnant water buffalo (Bubalus bubalis). Twelve Mediterranean female water buffaloes ranging in age from 4 to 14 years old and seronegative to N. caninum by indirect fluorescent antibody test (IFAT) were involved. Ten females were intravenously inoculated with 10(8) tachyzoites of NC-1 strain at 70 (n=3) or 90 (n=7) days of pregnancy (dp). Two control animals were inoculated with placebo at 70 and 90 dp, respectively. Serum samples were obtained weekly following inoculation to the end of the experiment. Three animals inoculated at 70 dp were slaughtered at 28 days post inoculation (dpi), three animals inoculated at 90 dp were slaughtered at 28 dpi and the remaining four animals inoculated at 90 dp were slaughtered at 42 dpi. Fetal fluids from cavities and tissue samples were recovered for IFAT and histopathology, immunohistochemistry and PCR, respectively. Genomic DNA from fetal tissues was used for parasite DNA detection and microsatellite genotyping in order to confirm the NC-1 specific-infection. Dams developed specific antibodies one week after the inoculation and serological titers did not decrease significantly to the end of the experiment. No abortions were recorded during the experimental time; however, one fetus from a dam inoculated at 70 dp was not viable at necropsy. Specific antibodies were detected in only two fetuses from dams inoculated at 90 dp that were slaughtered at 42 dpi. No macroscopic changes in the placentas and organs of viable fetuses were observed. Nonsuppurative placentitis was a common microscopic observation in Neospora-inoculated specimens. Microscopic fetal lesions included nonsuppurative peribronchiolar interstitial pneumonia, epicarditis and myocarditis, interstitial nephritis, myositis and periportal hepatitis. Positive IHC results were obtained in two fetuses from dams inoculated at 70 dp and slaughtered at 28 dpi. N. caninum DNA was detected in placentas and fetuses from all inoculated animals. The pattern of amplified microsatellites from placental and fetal tissues resembled the NC-1 strain. Water buffaloes, like cattle, are susceptible to experimental inoculation with N. caninum at early pregnancy.