Enzyme activities and diuron persistence in soil amended with vermicompost derived from spent grape marc and treated with urea

Mineral fertilizers, organic amendments, and pesticides are inputs commonly used in conventional farming practices. The aim of this study was to evaluate the effects of single or combined applications of spent grape marc-vermicompost, urea, and/or diuron on soil-enzyme activities and the persistence of this herbicide in soils with low organic carbon content. The application of vermicompost enhanced dehydrogenase (DHase) enzyme activity over time but altered soil urease activity to a very limited extent. The reduction in diuron concentrations and the increase in DHase activity indicated that the soil microorganisms were capable of degrading the ureic herbicide. Treatment with vermicompost and diuron had a stimulatory effect on soil microbial activity. On the whole, the application of diuron and urea to the vermicompost-amended soil raised DHase and urease activity to maximum levels (>3 μg INTF g^?1 h^?1 and >47 μg NH₄⁺ g^?1 h^?1, respectively). The application of urea to the unamended and vermicompost-amended soil decreased diuron persistence from 18.8 and 33 d to 12.5 and 15 d, respectively. Our findings show that although vermicompost additions reduce diuron availability, this boosts diuron degradation when combined with urea. These additions, under different soil management conditions, minimize the bioavailability and persistence of diuron and consequently the risk of leaching and seepage into aquifers. Compared with untreated soils, these types of treated soils could also improve agricultural sustainability and the quality of the environment.     

Progeny Production of the Copepods Pseudodiaptomus euryhalinus and Tisbe monozota in Monospecific and Mixed Cultures

The objective of this research was to culture the calanoid copepod Pseudodiaptomus euryhalinus, Johnson 1939, and the harpacticoid Tisbe monozota, Bowman, 1962, in monospecific and combined cultures (P. euryhalinus : T. monozota at 1:1, 2:1, and 1:2 starting ratios), and to compare the nauplii, copepodite, and adult production. Mean total production ranged from 740.3 ± 137.5 organisms/L (P. euryhalinus) to 884.3 ± 489.7 organisms/L (T. monozota) for monospecific cultures. The 1:1 ratio mixed cultures gave 780.4 ± 155.8 organisms/L, those with the 2:1 and 1:2 P. euryhalinus and T. monozota starting ratios produced 710.1 ± 195.2 and 799.7 ± 232.5 organisms/L, respectively, and there were no significant difference among treatments. All mixed cultures gave significantly lower copepodite productions than the monocultures of each species. In addition, the tendency to a decreased progeny production of the initial females of T. monozota indicates that the outcome of long‐term mixed cultures would production either a high dominance of P. euryhalinus, or monocultures of this species .     

Regeneration in mouse skeletal muscle injured by Trichinella larvae

During the infection caused by Trichinella pseudospiralis serious damage to muscles is partly compensated with regeneration process. Short, thin fibrillae with central position of the nuclei--regenerating myotubes originate 20--40th day post infection in endomysial tubes remaining after damaged muscle fibres, left by migrating larva. On the 10th day post infection in the vicinity of moving larva activation of nuclei and increased origin of satellite cells under basal membrane occur. With development of the infection endothelia in the vicinity of altered fibrillae are increasing in number but there is small inflammatory and fibroproductive reaction only. During the infection caused by Trichinella spiralis and T. nativa, alteration of muscle fibres is accompanied by early inflammatory and fibroproductive reaction towards immediate surroundings of larvae. In a changed segment of muscle fibre with the larva--in pseudocyst there is altered basal lamina as well, built in increased glycocalyx and in the course of 20 days encased by connective tissue. Revascularisation and regeneration in a short damaged segment does not occur even during long-lasting infection because of separation by capsule.     

The effect of age on the fertility of males of Culex molestus (Diptera, Culicidae)

Older males of C. molestus have a markedly lowered fertility (even by 50%) and the image productivity of their progeny is much lower than that of freshly hatched males (more than 6X). This fact may hinder the population explosion particularly in those species whose individual generations coincide in the course of a year or are much diffused.     

Serotyping of Haemophilus paragallinarum isolates from Mexico by the Kume hemagglutinin scheme

A total of 42 isolates of Haemophilus paragallinarum from Mexico were serotyped by the Kume hemagglutinin scheme. Serovars A-1, A-2, B-1, and C-2 were recognized among 11 (26.2%), 7 (16.6%), 4 (9.5%), and 14 (33.3%) isolates, respectively. A further six isolates (14.3%) showed hemagglutinating activity but could not be classified into any serovar. Commercial vaccines containing Kume serovars A-1, A-2, B-1, and C-2 may provide better protection than those bi- or trivalent infectious coryza vaccines currently used in Mexico.     

Long term improvement in the treatment of canine leishmaniosis using an antimony liposomal formulation

Pharmacokinetic and clinical effectiveness of liposome-encapsulated N-methylglucamine antimoniate (LMA) was performed in dogs suffering from experimental leishmaniosis. LMA was compared with N-methylglucamine antimoniate (MGA), the same drug in its free form. Sb plasma concentrations for LMA were always higher than those for MGA. Mean residence time (MRT), half-life time (t(1/2)) and clearance (Cl) showed that Sb was eliminated slower after liposome administration. The high volume of distribution (Vd) obtained with LMA suggests that Sb could achieve therapeutic concentrations in parasite-infected tissues. Average plasma concentration at steady state (Css(ave)) shows that Sb body concentrations after LMA treatment (9.8 mg/kg Sb, each 24h) would be effective in Leishmania infantum canine infection. Comparing LMA with MGA in a 1-year follow-up we observed no relapses for LMA and total protein and gammaglobulin concentrations were within normal range, while for MGA both began to rise 3 months after treatment. Use of antimonial liposomal formulations may restore effectiveness to an existing drug and reduce toxicity.     

Pneumatosis cystoides intestinalis in a rabbit doe (Oryctolagus cuniculus).

Pneumatosis cystoides intestinalis (PCI) is an infrequent condition of animals characterized by the existence of numerous thin-walled, gas-filled cystic structures within the intestinal wall and adjacent lymph nodes. Microscopically, the cystic structures appear to be dilated lymphatics located in the lamina propria, submucosa, muscularis, subserosa, mesentery, and mesenteric lymph nodes. This report describes a case of pneumatosis cystoides intestinalis in a rabbit doe from an organic farm where 20 rabbit does were fed ad libitum with a natural diet consisting of whole barley, pea beans, alfalfa hay, and a pelleted vitamin-mineral blend. A combination of nutritional, bacterial, and other factors are hypothesized as possible predisposing factors in the development of PCI.     

Use of avidity enzyme-linked immunosorbent assay and avidity Western blot to discriminate between acute and chronic Neospora caninum infection in cattle.

Avidity serological tests (avidity enzyme-linked immunosorbent assay [ELISA] and avidity Western blot) were developed and used to differentiate between acute (primary infection, reinfection, and recrudescence) and chronic Neospora caninum infection in cattle. In addition, the pattern of immunoglobulin G (IgG) avidity maturation against different specific antigens of N. caninum tachyzoites was studied. Sequential serum samples were collected from cattle naturally and experimentally infected with N. caninum. Four groups of experimentally infected cattle were included in the study and were representative of primary infection, reinfection, chronic infection, and noninfection. Serum samples were also collected from naturally infected cattle classified into nonaborting and aborting cows on the basis of clinical findings and serological profiles, and a third group composed of seronegative cows that seroconverted during the course of the experiment. All samples were tested by avidity ELISA and avidity Western blot. The IgG avidity ELISA allowed the discrimination between primary and chronic infection because all experimentally primary-infection cows showed low avidity indexes at week 4 postinfection (p.i.) compared with the high avidity values found at week 20 postinfection. However, this test did not allow the discrimination of reinfection or recrudescence from chronic infection. Regarding IgG avidity Western blot results, no antigenic markers correlating with acute (primary infection, recrudescence, and reinfection) or chronic infection were recognized. However, the 17-kD immunodominant antigen was mostly responsible for high avidity values obtained by avidity ELISA because it was intensively recognized by high-avidity antibodies in all chronically infected animals after urea treatment.     

Isolation of equine herpesvirus-2 from the lung of an aborted fetus.

This study describes the isolation of equine herpesvirus-2 (EHV-2) from the lung of an aborted equine fetus in Argentina. The isolated virus was confirmed as EHV-2 by indirect immunofluorescence using a rabbit anti-EHV-2 polyclonal antiserum and by virus-neutralization test using an equine polyclonal antibody against EHV-2. Restriction endonuclease DNA fingerprinting with BamHI also confirmed the identity of the virus as EHV-2. Furthermore, viral nucleic acid was detected by polymerase chain reaction from the original lung sample and from the DNA obtained from cells infected with the virus isolate. This work constitutes the first reported isolation of EHV-2 from an aborted equine fetus. The presence of EHV-2 in the lung of the aborted fetus would indicate that this virus is capable of crossing the placental barrier. However, no cause-effect relationship was established between the EHV-2 isolate and the abortion.