Pseudomonas fluorescens contamination of a feline packed red blood cell unit and studies of canine units

Background: While screening programs have reduced the risk of infectious disease transmission by donors in human and veterinary blood banking, bacterial contamination of blood products has emerged as a major complication in human medicine. Objectives: To describe a Pseudomonas fluorescens (Pf)‐contaminated feline packed RBC (pRBC) unit and experimentally investigate Pf‐contaminated canine pRBCs. Methods: Canine pRBCs were inoculated with Pf‐rich pRBCs from the sentinel feline unit and stored at 4°C or 20°C for 72 hours. Aliquots from the pRBCs were serially evaluated by microscopy, culture, and a eubacterial 16S rRNA real‐time PCR assay. Results: One Pf‐contaminated feline unit turned black after 22 days of storage and was removed from the blood bank; a source was not found, and no other contaminated units were identified. Canine pRBCs spiked with 5 or 25 μL of the sentinel unit became culture‐ and/or 16S PCR‐positive at ≥8 hours at 20°C and 48 hours at 4°C and developed a color change at ≥24 hours. Sensitivity studies indicated that without incubation, inoculation of ≥100 μL Pf‐rich pRBCs was necessary for a positive 16S PCR test result. Conclusions: P. fluorescens grows in stored pRBCs slowly at 4°C and rapidly at 20°C. Screening of blood products for color change, estimating bacterial concentration with microscopy, and 16S PCR testing are simple and fast ways to detect bacteria in stored blood. Aseptic collection, temperature‐controlled storage, and regular visual monitoring of stored units is recommended. Discolored units should not be transfused, but examined for bacterial contamination or other blood product quality problems.     

A Comparison of Two Collectors for Monitoring Precipitation Chemistry

Comparison of event-based precipitation collected during 1 year showed that samples from a Yankee Environmental Systems collector had significantly higher volume, higher concentrations, and higher deposition of all ions analyzed except PO₄³⁻ and NH₄⁺ compared to samples collected simultaneously with an Aerochem Metrics collector.     

Uveodermatologic syndrome in a rat terrier

A 4 yr old intact male rat terrier presented with severe bilateral nonresponsive panuveitis. Bilateral uveitis, blepharospasm, conjunctival hyperemia, diffuse corneal edema, peripheral bullous retinal detachment, and secondary ocular hypertension were noted. Ocular lesions progressed despite aggressive medical treatment and were followed by cutaneous depigmentation and crusting along the nasal planum. Intensive oral and topical anti-inflammatory and topical antiglaucoma medications were administered, but the ocular disease progressed. A bilateral enucleation was performed. Uveodermatologic syndrome was diagnosed from histopathologic examination of a skin biopsy as well as histopathology of both globes after bilateral enucleation. To maintain control of the dermatologic lesions, oral azathioprine was initiated, but it was not well tolerated by this patient. Immunosuppressive doses of oral cyclosporine and anti-inflammatory doses of oral prednisone were used to control the depigmentation and crusting skin lesions.     

Concurrent nephrosplenic entrapment and acquired inguinal herniation of the jejunum in a Standardbred stallion

A stallion presenting for surgical correction of an acquired inguinal hernia was also diagnosed with a nephrosplenic entrapment (NSE) intraoperatively. Surgical intervention resulted in a successful outcome. To date, these conditions have not been reported to occur simultaneously.     

The left lateral projection is comparable to horizontal beam radiography for identifying experimental small volume pneumoperitoneum in the canine abdomen

Nontraumatic spontaneous pneumoperitoneum suggests the presence of gastrointestinal perforation; early detection can be lifesaving. Horizontal beam projections have been reported to be more sensitive than standard radiographic views for detecting small volumes of free peritoneal gas. This prospective, experimental, analytical study compared both left lateral (LL) and ventrodorsal (VD) standard views to horizontal beam projections for detecting small volumes of artificially induced pneumoperitoneum in live dogs. The effect of radiology training on accurate detection of small amounts of free peritoneal air was also assessed. Fourteen dogs had four radiographic projections taken after injection of 0, 2.5, 5, and 10 mL of cumulative air into their abdominal cavities. Radiographs were interpreted individually by three American College of Veterinary Radiology‐certified radiologists and three small animal internship‐trained veterinarians who were blinded to the air volume injected. At 2.5 and 10 mL of air injected, the LL projection had highest odds of an accurate response (odds ratio [OR] = 2.4 and 99.0 when compared to VD horizontal and VD projections, respectively). At 5 mL of air injected, the lateral horizontal (LH) projection had the highest odds of an accurate response (OR = 3.2 compared to VD horizontal). The LL projection was not significantly different from the LH projection at all volumes of air injected. Board certification led to higher odds of accurate responses at volumes of 5 (OR = 2.2) and 10 mL (OR = 3.6), as compared to nonspecialist veterinarians. Overall, LH and standard LL appeared to be the most useful radiographic projections for detection of small amounts of free peritoneal gas.     

Seasonality and anatomical location of human tick bites in the United Kingdom

Tick bites on humans can occur in a variety of habitats and may result in the transmission of tick‐borne pathogens, such as the causative agent of Lyme borreliosis (LB), Borrelia burgdorferi sensu lato. As the risk of transmission of this pathogen to the host increases with the duration of tick feeding, the recognition and removal of ticks as soon as possible following attachment is important for reducing the risk of infection. Performing a thorough body examination for ticks following potential exposure is recommended by tick awareness campaigns. Knowledge of where on the body feeding ticks are frequently found, and at which times of year peak tick exposure occurs, provides important information for public health messaging and may aid those bitten by ticks to engage more effectively with tick‐checking behaviour. This paper summarizes human tick bites in the United Kingdom (UK) during 2013–2018 reported to Public Health England's passive Tick Surveillance Scheme and further examines the anatomical location and seasonality of bites from the most commonly encountered tick and LB vector Ixodes ricinus. A total of 1,328 tick records from humans were received of which 93% were I. ricinus. Humans were most commonly bitten by I. ricinus nymphs (70% bites). Tick bites were recorded on all parts of the body, but there were significant differences in their anatomical location on adults and children. Most tick bites on adults occurred on the legs (50%), whereas on children tick bites were mostly on the head and neck (43%). Bites from I. ricinus were recorded throughout the year but were most numerous during May to August. This study adds to the body of research on the seasonality and anatomical location of human tick bites in temperate Europe and highlights the importance of data collected through passive surveillance in addition to research and epidemiological studies.     

Recurrent maternal half-sib selection improves resistance to foliar late blight in a diploid hybridSolanum phureja-solanum stenotomum population

Foliar late blight, caused byPhytophthora infestans, is a devastating disease of potatoes worldwide. In 1996 we initiated a breeding strategy to improve the levels of resistance to late blight in a diploid hybrid population ofSolanum phureja-Solanum stenotomum. The purpose of this study was to determine if resistance to late blight in this diploid potato population could be improved by recurrent maternal half-sib selection. Four clones from each of 72 maternal half-sib families were evaluated for late blight resistance in replicated field trials in Pennsylvania in 1996 and 1997 (cycle 1) and in 2003 and 2004 (cycle 2). ‘Atlantic’ was included as a check cultivar at all sites. Percentage of infected foliage was recorded three times towards the end of the growing season each year and was used to compute area under the disease progress curve (AUDPC). Mean AUDPC for Atlantic in cycle 1 and 2 was 863 and 854, respectively. Mean AUDPC of the cycle 1 and cycle 2 diploid clones was 652 and 556, respectively. Narrowsense heritability for resistance in cycle 1 and cycle 2 was estimated as 0.78 and 0.77, respectively; additive genetic variance was estimated as 10960 and 12636, respectively; phenotypic variance was estimated as 14088 and 16375, respectively. Predicted and realized genetic gain from cycle 1 to cycle 2 was ?80 and ?96, respectively. Recurrent maternal half-sib selection is an effective way to improve resistance to late blight in this population and to maintain adequate genetic diversity for further enhancement efforts.     

A conservation-tillage, cover-cropping strategy and economic analysis for creamer potato production

A two-year experiment was conducted at the Beltsville Agricultural Research Center (BARC), MD, and Virginia Polytechnic Institute and State University Kentland Agricultural Research Farm (KARF), VA, to evaluate potato (Solanum tuberosum L.) production of 32- to 57-mm-size-range tubers (referred to hereafter as creamers) in a conservation-tillage, cover-cropping strategy. The experiments used a split-plot design in which the main-plots were cover crop treatments and the sub-plots were different potato selections. Main plot treatments included rye (Secale cereale L.), crimson clover (Trifolium incarnatum L.), Austrian winter pea (Pisum sativum L.), rape (Brassica napus L.), oat (Avena sativa L.), rye/crimson clover mixture, rape/crimson clover mixture, bare soil/raised beds, and bare soil/flat beds (control). Potato selections tested were B1145-2, B1491-5, and B1492-12 in 2000 and B1145-2, B1102-3, and B0811-4 in 2001. Yields in the conservation-tillage treatments were equal to or better than those in the bare soil/flat bed control with few exceptions. Large-sized tubers (<57 mm) in almost all cases remained below 6% of total marketable yield even when the tubers were harvested late. Delayed harvest did not reduce creamer-sized yields nor did it increase yield of large-sized tubers. Economic analysis shows that net returns from some conservation-tillage treatments are equal to or higher than the conventional-tillage strategy and confirms the viability of the conservation-tillage, cover-cropping strategy. Furthermore, the conservation-tillage strategy in many cases allows timely planting using machinery in the wet soils of Maryland and Virginia during the narrow window of spring potato planting time, whereas the conventional tillage strategy does not offer this advantage.     

Male fertility of derived tetraploids ofSolanum tuberosum from groups tubersosum x phureja-stenotomum

Four plants of each of 15 derived tetraploids from a cross of B0749-2F (2n=4×=48) and DM91-5 (2n=2×=24) were planted in the greenhouse at Beltsville, Maryland, in January 1992. The female tetraploid parent is a late blight resistant selection from theTuberosum germplasm base. The male diploid parent is a high dry matter selection from the GroupPhureja-Stenotomum germplasm base. For each derived tetraploid, the percent normal, abnormal, and total pollen germinationin vitro were determined on 2–4 flowers per derived tetraploid harvested 3–4 times during a three-week period in April. The percent normal, abnormal, and total pollen germination ranged from 0.6 to 27.5, 0.1 to 7.6, and 1.4 to 36.6, respectively. Pollen tube growth, measured 2 hours from initiation of germination, ranged from 22 to 130 nm. Four general types of abnormalities in the pollen were identified: a) stunted and curly pollen tubes; b) damaged membranes allowing leakage of cytoplasmic contents; c) pollen grains with two or more pollen tubes; and d) split pollen tubes. In hybridizations with Atlantic as the female parent, 11 out of 15 of these derived tetraploids produced viable seeds. All 15 derived tetraploids were female fertile. These results suggest that utilizing derived tetraploids from theTuberosum andPhureja-Stenotomum germplasm bases in future breeding efforts should not present any great difficulty. However, hybridizations involving these derived tetraploids were more successful when the derived tetraploids were the female parent.