Ultrastructural features of Tritrichomonas mobilensis and comparison with Tritrichomonas foetus

Tritrichomonas mobilensis is an intestinal parasite of squirrel monkeys. There are few reports concerning the morphological aspects of this parasite. In addition, the taxonomic relationship between T. mobilensis and Tritrichomonas foetus, a serious pathogen that causes bovine and feline trichomonosis, has been questioned. For this reason, in the present study, we examined and compared both tritrichomonads with regard to their morphology, ultrastructure, endocytic activity and cytotoxicity when in the presence of host cells. Electron microscopy demonstrated consistent morphological differences between the hydrogenosomes of both parasites. Moreover, T. mobilensis and T. foetus had striking differences in their endocytic behavior. Thus, this work provides additional data that support the hypothesis that T. mobilensis is a distinct species from T. foetus.     

Epidemiology, control and management of an EBHS outbreak in captive hares

Here we describe an outbreak of European brown hare syndrome (EBHS) in a captive hare population. The EBHS outbreak occurred in March 2009, at the beginning of the breeding season. Overall mortality was 53% out of an original population of 61 animals. Animals between five and eleven months showed a significantly higher mortality rate than other age classes. Pregnant females either aborted their foetuses and survived or died pregnant. All foetuses (n=10) of the pregnant hares were PCR positive for EBHSV. Only one offspring born during the outbreak survived. Shortly after the outbreak, the surviving hares developed a specific anti-EBHSV titre between 1:80 and 1:2560, which dropped to 1:10-1:160 nine months later. Hares between one and three years of age developed a significantly higher titre than hares younger than one year or older than four years. Offspring born after the outbreak showed a lower titre of 1:10, indicating passive antibody transfer via placenta and milk. After two months, the titre was not detectable any longer. In December 2009, the captive population was vaccinated against EBHS virus with inactivated virus prepared from the organs of infected hares. The titres after the first vaccination ranged from 1:10 to 1:640, and after the second vaccination from 1:10 to 1:320. To estimate the effect of EBHS on reproduction, we compared the breeding seasons 2008 and 2009. Several possible sources of infection of the colony are discussed, but the definite cause could not be determined.     

Bovine herpesvirus 4 immediate early 2 (Rta) gene is an essential gene and is duplicated in bovine herpesvirus 4 isolate U

The ORF50/Rta gene has been shown to be an essential gene for many gammaherpesviruses. Although the BoHV-4 ORF50/Rta homolog, immediate early gene 2 (IE2), has been shown to activate several BoHV-4 early and late promoters in cotransfection assays, there is no direct proof of its indispensability for progression of the virus to the lytic replication cycle in the context of the viral genome. In the present communication, replication defective BoHV-4-V.test IE2 mutants were efficiently rescued, with respect to production of infectious virus and DNA replication, upon the expression of BoHV-4 ORF50/Rta in trans. Surprisingly, in the course of our studies, we discovered that the IE2 gene is duplicated in the genome of BoHV-4-U.     

Campylobacter jejuni, Campylobacter coli, and cytolethal distending toxin genes in laying hens

As no data are available on the prevalence of cytolethal distending toxin (cdt) genes carried by Campylobacter spp. in laying hens, this study was conducted with the aim to evaluate the prevalence of both Campylobacter spp. and cdt genes in 1680 laying hens from four different farms. The samples were analyzed by culture methods and by polymerase chain reaction. Campylobacter spp. were isolated from 1097/1680 cloacal swabs. Among the isolates, 913 were identified as Campylobacter jejuni whereas 345 were identified as Campylobacter coli. All isolates carried cdt genes. The results presented here confirm the very common occurrence of C. jejuni and C. coli in laying hens and underline that the cdt genes may also be frequently present in both C. jejuni and C. coli isolates from laying hens.     

Holding power of three different pin designs in the femur and ulna of the common buzzard (Buteo buteo)

External skeletal fixation is generally considered the best stabilization technique for immobilizing avian long bone fractures, but one of its major complications is the failure of bone-fixation pin interface or the loss of holding power. Consequently, this study is aimed at elucidating which pin design offers more pull-out strength in certain bones of the common buzzard (Buteo buteo). To achieve this objective, three pin designs (a smooth design and two negative profile threaded designs, with different thread pitch) were placed in five positions along the femur and ulna of the common buzzard. The pin pull-out strength was measured with the purpose of comparing medullary and pneumatic bones, insertion sites, and pin designs. Threaded pins with negative profile showed greater holding power than smooth pins (P < 0.05). When comparing holding power between the ulna and femur, no differences were found for smooth pins, whereas threaded pins showed more pull-out strength in the ulna than in the femur (P < 0.05). There were no differences observed related to pin location along the same bone when considering the same pin type. These results suggest that negative profile threaded pins have more holding power than smooth pins and that pneumatic bones provide less pull-out strength to negative profile threaded pins than medullary bones.     

White spots on the mucosal surface of the duodenum in dogs with lymphocytic plasmacytic enteritis

Distended lacteals, described as expanded white villi in duodenum, are strongly indicative of primary intestinal lymphangiectasia. In the present study, we evaluated the significance of white spots present in the duodenal mucosa of dogs with lymphocytic plasmacytic enteritis (LPE). Fifty dogs with LPE were included in this study, and white spots were detected in the duodenal mucosa in 22 dogs during endoscopy. Hypoproteinemia was more frequent in dogs with white spots than in dogs without spots (p = 0.02). Serum protein and albumin concentration were significantly lower in LPE dogs with white spots (p = 0.038) compared to LPE dogs without white spots (p = 0.039). There was a significant correlation between white spots density and lymphatic dilatation histological scores (p = 0.023; ρ = 0.481). These results suggest that the presence of white spots in the duodenal mucosa of dogs is not a finding exclusive for intestinal lymphangiectasia. Low serum protein and albumin concentrations together with lymphatic dilatation seem to be related to the presence of white spots in the duodenal mucosa of LPE dogs.     

Improved water-use efficiency by deficit-irrigation programmes: Implications for saving water in citrus orchards

Water efficiency is a key concept to solve water-shortage problems in semiarid areas. Deficit irrigation (DI) in many crops has frequently proved to be an efficient tool to optimise water-use efficiency. Three different DI strategies were studied for commercial orchards of mature sweet orange (Citrus sinensis L. Osbeck, cv. Salustiana and cv. Navelina) from 2006 to 2008: sustained deficit irrigation (SDI), regulated deficit irrigation (RDI), and low-frequency deficit irrigation (LFDI) all defined physiologically with stem-water potential thresholds. The experimental research plots were located in the Guadalquivir river basin, SW Spain. The effects of DI treatments on the fruit yield and on the crop-water status, by the integrated stem-water potential (Ψ_int) were analysed. Also, the benefits of DI in terms of agricultural water-use efficiency (WUE_agr) and financial water-use efficiency (WUE_f) were estimated for each irrigation strategy. Different relationships were estimated between these parameters and irrigation and total water applied, in order to establish the best irrigation strategy for different irrigation regimes. Yield and Ψ_int showed significant differences consistent with the water amounts applied, although the crop response was influenced by other parameters such as crop variety and irrigation strategy. In this sense, treatments with similar irrigation rates and Ψ_int resulted in different yield values, evidencing the importance of these factors. Regarding the crop variety, the results showed that cv. Salustiana responded better than cv. Navelina to DI, from the physiological and agricultural perspectives. In terms of water savings, the RDI and LFDI reduced water use by between 1000 and 1250 m³ ha⁻¹, respectively, with similar yields in comparison to the fully irrigated treatment, significantly improving the WUE. Consequently, the WUE_f, and WUE_agr were more strongly affected by deficit-irrigation strategy rather than the total water supplied. Thus, the amount of irrigation water would have a relative importance but other variables such as the irrigation strategy, would decidedly influence prudent water management in semiarid areas.     

Molecular identification and mycotoxin production of <Emphasis Type="Italic">Lilium longiflorum</Emphasis>-associated fusaria isolated from two geographic locations in the United States

Fusarium diseases of Liliaceae crops cause significant losses worldwide. Yet some Fusarium species are found in planta without causing disease or even in a symbiotic relationship with its host. In this study we identified and characterized the Fusarium species isolated from soil, and from healthy and diseased bulbs of Lilium longiflorum grown in New Jersey and Oregon in the United States. The predominant Fusarium species from the Oregon location were F. solani (74%) and F. oxysporum (20%), whereas F. concentricum (43%) and F. proliferatum (26%), both belonging to the Gibberella fujikuroi species complex (GFSC), were the most commonly isolated species from New Jersey. To our knowledge, this is the first report of F. concentricum associated with Liliaceae. All of the isolates were characterized with sequences of the internal transcribed spacer and translation elongation factor 1-alpha genes. The 24 GFSC isolates were further characterized with mating type, mating population, and mycotoxin analysis. Results showed that all GFSC isolates were MAT-2, suggesting that the populations may be asexually reproducing in the region examined. The majority of the GFSC isolates produced beauvericin. Enniatin A, B, B₁ and fusaproliferin were produced by a few isolates. Enniatin A₁ and fumonisins were not detected in any of the isolates. Although F. oxysporum and F. solani are well-known bulb pathogens, many isolates of F. oxysporum and F. solani, and all of the F. concentricum and F. proliferatum were isolated from asymptomatic bulbs, suggesting their endophytic association with lilies.     

Botrytone, a new naphthalenone pentaketide produced by Botrytis fabae, the causal agent of chocolate spot disease on Vicia faba

A strain of Botrytis fabae isolated from faba bean (Vicia faba L.) plants displaying clear chocolate spot disease symptoms produced phytotoxic metabolites in vitro. The phytotoxins isolated from the culture filtrate organic extract were characterized by spectroscopic and optical methods. A new naphthalenone pentaketide, named botrytone, was isolated and characterized as (4R)-3,4-dihydro-4,5,8-trihydroxy-1(2H)-naphthalenone together with other well-known closely related naphthalenones such as regiolone and cis- and trans-3,4-dihydro-2,4,8-trihydroxynaphthalen-1(2H)-ones. When tested on leaves of the host plant, with the cis- and trans-3,4-dihydro-2,4,8-trihydroxynaphthalen-1(2H)-ones assayed in mixture, regiolone demonstrated the highest level of phytotoxicity together with cis- and trans-3,4-dihydro-2,4,8-trihydroxynaphthalen-1(2H)-ones. Botrytone showed moderate phytotoxic activity at 1 mg/mL and was still phytotoxic at 0.5 mg/mL.