Cryptosporidiosis in two alpaca (Lama pacos) holdings in the South-West of England

Cryptosporidiosis was investigated on two alpaca (Lama pacos) holdings in the South-West of England. Diagnosis was initially confirmed in a cria with diarrhoea from each holding. Cohort faeces samples were subsequently collected and examined for presence of Cryptosporidium oocysts by immunofluorescence microscopy. On the first holding, 30 samples (24 adults, 6 crias) were tested, and oocysts were detected in three of the cria samples but in none of the adults. On the second holding, 14 floor faeces samples representing apparently healthy crias and one faeces sample from a cria with diarrhoea were collected. Oocysts were detected in four of the "healthy" faeces samples and the sample of diarrhoeic faeces. All isolates were confirmed as Cryptosporidium parvum using polymerase chain reaction restriction fragment length polymorphism of the cryptosporidium oocyst wall protein (COWP) and ssu rRNA genes. Sequence analysis of a 741bp region of ssu rDNA was carried out on nine of these and revealed high sequence homology with previously reported C. parvum isolates. This investigation highlights the possibility of alpaca crias subclinically shedding oocysts, which has implications for epidemiology and transmission in animals as well as raising zoonotic concerns for human contacts. Gene sequencing of UK isolates from South American camelids is also described for the first time.     

Root system plasticity to drought influences grain yield in bread wheat

Crop productivity in semiarid regions is mainly limited by water availability. Root characteristics and plasticity to drought may reduce the negative impact of drought on crop yield. A set of near-isogenic wheat-rye translocation lines was used to test the hypothesis that root system plasticity to drought influences grain yield in wheat. Bread wheat Pavon 76 and 1RS translocation lines, namely Pavon 1RS.1AL, Pavon 1RS.1BL, and Pavon 1RS.1DL were evaluated for root allocation and plasticity in sand-tube experiments under well-watered and droughted conditions across 2 years using factorial treatments in a randomized complete block design with four replicates. The 1RS translocation lines had greater root biomass per plant ranging from 7.37 to 8.6 compared to 5.81 g for Pavon 76. Only Pavon 76 showed a positive response to drought by producing more shallow roots (roots developed between 0 and 30 cm) and deep roots (roots developed below 30 cm) in droughted conditions than in well-watered conditions. Thus at drought intensity of 19% (measured as overall reduction in grain yield), grain yield in Pavon 76 was reduced only by 11% compared to the other genotypes with yield reductions ranging from 18 to 24%. However, at drought intensity of 36%, grain yield in Pavon 76 showed maximum reduction indicating that greater root production under drought is advantageous only when plant-available water is enough to support grain production. Grain yield was positively correlated with shallow and deep root weight and root biomass under terminal drought. Correlation coefficients between root system components (shallow and deep root weight and root biomass) and phenological periods were not significant. Our study indicated that genes influencing adaptive phenotypic plasticity of the root system to drought in Pavon 76 are located on chromosome 1BS.     

Seawater transmission and infection dynamics of pilchard orthomyxovirus (POMV) in Atlantic salmon (Salmo salar)

The Tasmanian salmon industry had remained relatively free of major viral diseases until the emergence of pilchard orthomyxovirus (POMV). Originally isolated from wild pilchards, POMV is of concern to the industry as it can cause high mortality in farmed salmon (Salmo salar). Field observations suggest the virus can spread from pen to pen and between farms, but evidence of passive transmission in sea water was unclear. Our aim was to establish whether direct contact between infected and naïve fish was required for transmission, and to examine viral infection dynamics. Atlantic salmon post‐smolts were challenged with POMV by either direct exposure via cohabitation or indirect exposure via virus‐contaminated sea water. POMV was transmissible in sea water and direct contact between fish was not required for infection. Head kidney and heart presented the highest viral loads in early stages of infection. POMV survivors presented low viral loads in most tissues, but these remained relatively high in gills. A consistent feature was the infiltration of viral‐infected melanomacrophages in different tissues, suggesting an important role of these in the immune response to POMV. Understanding POMV transmission and host–pathogen interactions is key for the development of improved surveillance tools, transmission models and ultimately for disease prevention.     

Cefquinome Concentrations in Endometrium after Intrauterine Treatment of Cobactan 4.5%® in Mares and Inflammatory Response of the Endometrium to this Treatment

This study was conducted to measure the concentration of cefquinome in the endometrium of mares after intrauterine treatment and to evaluate associated inflammation. Mares (n = 14) were randomly assigned to one of the following groups: (i) control (n = 4) were either not treated (n = 2) or received (n = 2) lactated Ringer's intrauterine for 1 or 3 days; (ii) treated mares (n = 10) received intrauterine cefquinome for 1 or 3 days. After at least 10 days had passed following the last treatment and ovulation, mares were given Prostaglandin F2α (PGF2α) and were randomly assigned to an alternate treatment. Endometrial biopsy samples were taken at 2, 8, 24 and 48 h, or at 4, 12 and 36 h, after the last treatment. Biopsy samples were taken at the same time points from control mares (n = 2) and lactated Ringer-treated mares (n = 2). Cefquinome concentrations were quantified using a high-performance liquid chromatography (HPLC) assay and inflammation was assessed using haematoxylin and eosin (H&E)-stained sections. Concentrations of cefquinome [559 (1 day) and 595 μg/g (3 days) at 2 h, and 403 (1 day) and 370 μg/g (3 days) at 4 h] were similar between treatment groups at 2 and 4 h after treatment (p > 0.05). At 8 h, as well as at 24 and 48 h, concentrations were greater in the 3-day group (17 vs 301 μg/g, 3 vs 80 μg/g and 0.1 vs 0.2 μg/g, respectively) (p < 0.05). No significant differences (p > 0.05) in the inflammatory response at 2–48 h after treatment were found between groups.     

Phytophthora bilorbang sp. nov., a new species associated with the decline of Rubus anglocandicans (European blackberry) in Western Australia

A new homothallic Phytophthora species, isolated from rhizosphere soil and roots of declining or dead Rubus anglocandicans (European blackberry) in south-west Western Australia, is described as Phytophthora bilorbang sp. nov. It produces non-papillate sporangia, smooth-walled oogonia containing thick-walled oospores, and paragynous antheridia. Although morphologically similar to several species within ITS Clade 6 and sub-clade II, namely P. gibbosa, P. gregata and P. megasperma, phylogenetic analyses of the ITS, cox1, HSP90, BT and NADH gene regions demonstrate that P. bilorbang sp. nov. is a distinct species. Additionally, P. bilorbang differs from these species in its growth and colony morphology on several media. Pathogenicity tests indicate that P. bilorbang could be responsible for the decline syndrome of blackberry within the Warren and Donnelly River catchments in the south-west of Western Australia.     

A new large scale soil DNA extraction procedure and real-time PCR assay for the detection of Sclerotium cepivorum in soil

A real-time PCR assay specific for Sclerotium cepivorum, the causal agent of white rot in onions, was developed for use with a new DNA extraction method capable of processing up to 1?kg of soil in weight. The assay was specific for S. cepivorum when tested against 24 isolates representative of 14 closely related species and other pathogens of onion. The assay was highly sensitive when used with soil DNA extracted using the new DNA extraction procedure. In three different field soils tested, a good relationship between cycle threshold (Ct) and number of sclerotia was observed (R2?=?0.89). Twenty-nine soil samples from onion and leek crops were obtained and the pathogen was detected in four samples. All four positive samples were associated with current or past outbreaks of white rot of onion. Additional assays were also used on the 29 field soil samples, Botrytis aclada and Rhizoctonia solani AG8 were also detected, in one soil sample each. Rhizoctonia solani AG2-1 was more widespread and was detected in eight different soil samples. The method is therefore suitable to quantify levels of S. cepivorum in soil samples, with the added advantage that the technique allows other soil pathogens of interest to be assayed from the same DNA sample. The bulk soil DNA extraction method described here has the potential to be used to detect soil-borne pests and pathogens for other crops in a wide range of soil types.     

Quantitative Risk Assessment for Zoonotic Transmission of Cryptosporidium parvum Infection Attributable to Recreational Use of Farmland

Cryptosporidiosis caused by Cryptosporidium parvum infection is a major cause of enteric illness in man and there is a significant reservoir in animals, particularly young ruminant species. To preliminary assess the magnitude of the risk posed by contact with faeces produced by infected livestock, two microbiological risk assessments have been developed: one for the risk of human infection with C. parvum while camping on contaminated land recently grazed by infected suckler cattle and a comparable risk assessment for camping on land recently spread with contaminated cattle slurry. Using a worst‐case scenario approach, the upper level of risk was estimated to be one infection in every 6211 person‐visits for a camping event on land recently grazed by infected cattle. Translated into camping events of 100 persons, this risk estimate would most likely lead to zero (98% likelihood) or one infection (1% likelihood). The results for cattle slurry model are similar despite different pathways. Sensitivity analysis was conducted for the grazing cattle model only. This suggested that the time between grazing and camping was the most important control strategy, but increasing hand‐washing frequency and the removal of cattle faeces before camping would also be beneficial. If the upper level of risk were to be judged unacceptable then further data would be required to more accurately estimate the risk of infection through these scenarios. Further research would also be required to assess the fraction of cases attributable to camping and/or environmental contact with Cryptosporidium oocysts.     

Efficacy of danofloxacin 18% injectable solution in the treatment of Escherichia coli diarrhoea in young calves in Europe

The efficacy of danofloxacin 18% against naturally occurring Escherichia coli diarrhoea was investigated in calves at seven European sites. Treatment commenced on day 0, with either a single subcutaneous injection of danofloxacin 18% (n=267) at 6 mg/kg repeated on day 2 if required, or reference product containing baquiloprim/sulphadimidine (n=37) or gentamicin (n=98) administered as recommended. E. coli was isolated from 90% to 100% of calves pre-treatment, and the prevalence of serotypes K99 and F41 was 8-46% and 46-92%, respectively. In both treatments, the majority of calves (93.2-93.9%) showed clinical improvement and completed the studies. There were significant reductions for both treatments, in severity of clinical signs on days 4 and 10 compared to day 0 (P<0.0001), and between days 4 and 10 (P<0.05), but no significant differences between treatments (P>0.05). Danofloxacin 18% was clinically safe, and as effective as the reference products in the treatment of E. coli diarrhoea in calves.