A rapid chronometric assay of peroxidase activity in citrus leaf discs

A rapid peroxidase assay is proposed, using 3-mm diameter leaf discs, and based on the chronometric measurement of the oxidation of ascorbic acid, which is detected by means of the appearance of the blue colour of the benzidine-coupled reaction.The proposed method is adequately reproducible and sensitive for the diagnosis of iron deficiency in citrus.     

Closing wedge ostectomy and medial distal tibia plate application for treatment of severe bilateral angular limb deformities in the hindlimbs of an 8-month-old foal

This case report describes the evaluation, surgical approach and outcome of an 8-month-old foal with severe angular limb deformities of both metatarsophalangeal joints (MTPJ). Radiography and computed tomography (CT) were used to diagnose a windswept deformity of the hindlimbs with associated bilateral physitis. The orthopaedic surgery was planned and rehearsed using three-dimensional (3D) bone models. A bilateral closing wedge ostectomy was performed on the distal MtIII, and 3.5 mm LCP^® medial distal tibia plates were used bilaterally for osteosynthesis. Even though convalescence was prolonged and complicated by partial unilateral implant failure and osteoarthritis (OA), reduction of the deformities was successful and resulted in a sound foal.     

Relationship between root growth potential and field performance in Aleppo pine

Commercial stocks of Aleppo pine in Spain vary in quality, but there is no accepted standard for evaluating quality. A RGP test was applied to six commercial seedling stocklots at two dates (November, February) and under two test conditions (growth-chamber, greenhouse). The RGP’s predictive ability was evaluated on two contrasting sites. There was a considerable variation in the RGP depending on application date, test conditions and stock factors. The RGP results for November were correlated with each other but they did not explain outplanting performance. The February results in the growth-chamber correlated well with survival at both sites. Regression models explained survival both in the lower (R ² = 97%) and in the higher (R ² = 92%) quality sites. RGP has a valid predictive ability for this species although it is sensitive to the test conditions. In this sense, a shorter and more intensive test performed right before planting may be more reliable.     

First report of Enterocytozoon bieneusi from dairy cattle in Argentina

Fecal specimens were obtained from a total of 70 dairy calves less than two months old on 11 municipalities in Buenos Aires, Argentina. After removal of fecal debris by sieving and sucrose flotation, specimens were subjected to PCR to detect the presence of Enterocytozoon bieneusi. PCR revealed a 14.3% of prevalence for E. bieneusi with 10 positive calves from 7 municipalities. Gene sequence analysis conducted in all samples positives by PCR revealed the presence of six genotypes; four previously reported in cattle as well as humans (D, I, J, and BEB4), one never reported in cattle before but previously reported in humans (EbpC), and one novel genotype (BEB10). These results constitute the first molecular characterization of E. bieneusi in Argentina, and suggest a potential risk of zoonotic transmission in this area.     

Amoebic meningoencephalitis caused by Balamuthia mandrillaris in an orang utan

Objective
To describe a case of meningoencephalitis caused by Balamuthia mandrillaris in an orang utan.
Design
A pathological case report.
Animal
A 20 years old male orang utan (Pongo pygmaeus).
Procedure
The disease process was investigated by clinical pathology, necropsy, histopathology and immunofluorescence labelling.
Results
The orang utan developed sudden onset of depression, lethargy, inappetence and apparent head pain. The condition was considered to be related to a 2 year history of upper and lower respiratory disease, and the animal was placed on antibiotics after extensive testing. By the seventh day the animal had become ataxic and disoriented and a brain abscess was suspected. He died on the ninth day of illness. At necropsy, and subsequent sectioning, the brain showed multiple circular, soft, white to grey brown areas of varying size, the largest being in the left temporal (3.5 cm diameter) and right occipital (2.5 cm diameter) regions of the cerebrum. Histological examination of these regions revealed many amoebic trophozoites and occasional cysts associated with areas of haemorrhage and inflammatory necrosis. The trophozoites were packed in perivascular spaces and their nuclei often contained two or more prominent nucleoli. Immunofluorescent labelling of histological sections suggested that the agent was B mandrillaris.
Clinical implications
This report provides further evidence that B mandrillaris , a free living amoeba, can act as a pathogen in animals as well as people, and cause fatal meningoencephalitis. Along with Naegleria and Acanthamoeba spp, B mandrillaris should be considered amongst the causes of acute onset meningoencephalitis in animals.     

Effects of past, present and future atmospheric CO2 concentrations on soil organic matter dynamics in a chaparral ecosystem

Owing to the continuously increasing concentration of atmospheric CO₂, it has become a priority to understand if soil organic matter (SOM) will behave as a sink or a source of CO₂ under future environmental changes. Although many studies have addressed this question, a clear understanding is still missing, particularly with respect to long-term responses. In this study, we quantified soil C stores and dynamics in relationship to soil aggregation and pool composition in a Californian chaparral ecosystem exposed for 6 years to a gradient of atmospheric CO₂ concentrations, ranging from pre-industrial levels 250 to 750 μl l⁻¹ CO₂. Fossil fuel-derived CO₂ depleted in ¹³C was used for the fumigation, thus providing a tracer of C input from the vegetation to the soil.Long-term CO₂ exposure invariably affected soil aggregation, with a significant decrease in the macroaggregate fraction at highest CO₂ levels relative to the other two size fractions (i.e. microaggregates and silt and clay). This soil structural change most likely reduced the stability and protection of SOM, and C content generally decreased in most fractions over the CO₂ treatments, and induced faster turnover of recently fixed C at high CO₂ levels. The strongest response was found in the C content of the microaggregates, which decreased significantly (P<0.05) with rising levels of CO₂. We conclude that increasing atmospheric CO₂ concentrations will decrease soil C in chaparral ecosystems, and that the microaggregate fraction is the most responsive to increasing concentrations of atmospheric CO₂.     

Evidence for widespread Leishmania infantum infection among wild carnivores in L. infantum periendemic northern Spain

Leishmania spp. infection was investigated in tissue samples of wild carnivores from the Spanish Basque Country (BC), by PCR and DNA sequencing. The region is at the northern periphery of Leishmania infantum endemic Iberian Peninsula and infection in the dog (reservoir) or other species has not been previously reported. Leishmania kinetoplast DNA was detected by real-time PCR (rtPCR) in 28% (44/156) of animals. Specifically, in 26% of Eurasian badgers (n = 53), 29% of foxes (n = 48), 29% of stone martens (n = 21) and in 25–50% of less numerous species including genets, wild cats, pole cats, European mink and weasels. Infected animals particularly badgers, were most prevalent in the southernmost province of the BC (Araba) in areas dominated by arable land. Subsequent amplification and sequencing of a fragment of the rRNA internal transcribed spacer 2 (ITS2) from a subset of rtPCR positives samples confirmed the species as L. infantum, showing a high sequence homogeneity with ITS2 sequences of L. infantum from dogs and humans from southern Spain. In summary, this study reports for the first time L. infantum infection in wild carnivores from the BC including in stone martens, pole cats and minks in which infection has not been previously described. It supports the need to study infection in dogs and people in this region and is an example of the value of infection surveillance in wildlife to assess potential risks in the domestic environment and their role in spreading infections in non-endemic areas.     

Efficacy of formic acid in gel for Varroa control in Apis mellifera L.: importance of the dispenser position inside the hive

The efficacy of formic acid in a gel matrix was evaluated in two groups of honeybee colonies. In Group 1, a dispenser with 120 g of formic acid (70%) in gel was placed on the brood combs and another dispenser with the same dose was located on the hive bottom (total dose, 240 g). Group 2 received two doses of 240 g of formic acid (70%) in gel and each application was applied in two dispensers containing 120 g of the formic acid solution each and they were located over the brood chamber (total dose, 480 g). In Group 2, the period between both applications was 15 days, and the efficacies after the first and both applications were calculated. Significant differences were registered for final efficacy between both groups. When final efficacy of Group 1 was compared with efficacy after first application of Group 2, significant differences were found (P=0.0005). Same doses in different positions within the hive have different final efficacy. The higher efficacy was registered when the dispensers were placed over brood combs and on the hive bottom. It is suggested that efficacy is related to dispenser position within the hive.     

Field trial of a staphylococcal mastitis vaccine in dairy herds: clinical, subclinical and microbiological assessments

Objective To assess the efficacy of a new staphylococcal mastitis vaccine under commercial dairying conditions.
Design A field trial involving 1819 cows and heifers conducted on seven dairy herds in Victoria. The trial was done 'blind'; approximately half the animals were vaccinated and the remainder were untreated controls.
Procedure The vaccine was given twice during the last 10 weeks of pregnancy. Effects of vaccination were assessed, during the ensuing lactation, on the basis of clinical and sub-clinical mastitis and microbiological investigations of the milk.
Results A total of 273 cases of clinical mastitis were recorded. Staphylococcus aureus was isolated from 112 of these, 45 cases in vaccinates and 67 cases in controls; the difference was not statistically significant. One herd was notable in having a high incidence of clinical staphylococcal mastitis. This herd accounted for 15.8% of the animals in the field trial but 54.5% of cases of clinical staphylococcal mastitis. For this herd, vaccinated animals had significantly lower incidence of clinical staphylococcal mastitis and prevalence of subclinical mastitis, relative to controls. An unexpected feature of the trial as a whole was the low incidence of clinical mastitis from which S aureus was isolated in pure culture (26.3% of cases) and the high incidence of clinical Streptococcus uberis mastitis (22.7% of cases).
Conclusions The trial showed that the vaccine was efficacious in reducing the incidence of clinical mastitis and prevalence of subclinical mastitis in a herd that had a serious staphylococcal mastitis problem.