Human tularaemia associated with exposure to domestic dogs—United States, 2006–2016

Dogs have been implicated in the zoonotic transmission of numerous pathogens. Whereas cats are known to transmit Francisella tularensis to humans via bite and other routes, the role of dogs in facilitating infection is much less understood. We reviewed tularaemia case investigation records collected through national surveillance during 2006–2016 to summarize those with dog involvement, characterize the nature of dog‐related exposure and describe associated clinical characteristics. Among 1,814 human tularaemia cases, 735 (41%) supplemental case investigation records were available for review; and of those, 24 (3.3%) were classified as dog‐related. Median age of patients was 51 years (range: 1–82); 54% were female. Two thirds (67%) of cases presented with ulceroglandular/glandular tularaemia; pneumonic (13%) and oropharyngeal (13%) illness occurred less frequently. Dog‐related exposures were classified as follows: direct contact via bite, scratch or face snuggling/licking (n = 12; 50%); direct contact with dead animals retrieved by domestic dogs (n = 8; 33%); and contact with infected ticks acquired from domestic dogs (n = 4; 17%). Prevention of dog‐related tularaemia necessitates enhanced tularaemia awareness and tick avoidance among pet owners, veterinarians, health care providers and the general public.     

Evaluating the risk of tick‐borne relapsing fever among occupational cavers—Austin,TX, 2017

Tick‐borne relapsing fever (TBRF) is a potentially serious spirochetal infection caused by certain species of Borrelia and acquired through the bite of Ornithodoros ticks. In 2017, Austin Public Health, Austin, TX, identified five cases of febrile illness among employees who worked in caves. A cross‐sectional serosurvey and interview were conducted for 44 employees at eight organizations that conduct cave‐related work. Antibodies against TBRF‐causing Borrelia were detected in the serum of five participants, four of whom reported recent illness. Seropositive employees entered significantly more caves (Median 25 [SD: 15] versus Median 4 [SD: 16], p = 0.04) than seronegative employees. Six caves were entered more frequently by seropositive employees posing a potentially high risk. Several of these caves were in public use areas and were opened for tours. Education of area healthcare providers about TBRF and prevention recommendations for cavers and the public are advised.     

Simultaneous application of the vascular endothelial growth factor (VEGF) receptor inhibitor PTK787/ZK 222584 and ionizing radiation does not further reduce the growth of canine oral melanoma xenografts in nude mice

PTK787/ZK 222584 is an inhibitor of the vascular endothelial growth factor (VEGF) receptor tyrosine kinases. In this study, the effectiveness of PTK787/ZK 222584 and radiation on canine oral melanoma xenografts was assessed. Xenografts were treated with radiotherapy (4x6Gy), or with PTK787/ZK 222584, or with a combination of both. Treatment efficacy was assessed using a tumour growth delay assay, serial power Doppler and pO(2) measurements during and after therapy. There was a significant growth delay for the group treated with radiation alone and for the combined treatment group. However, tumour growth delay was similar in both groups. Tumours were hypoxic before irradiation and no significant re-oxygenation occurred during therapy. In all tumours, vascularity and perfusion were significantly lower at the end of the study but no significant differences in perfusion, vascularity and oxygenation status were observed between and within treatment groups. The combination of PTK787/ZK 222584 and radiotherapy did not perform better than radiotherapy alone in this model.     

Cryopreservation of trochophore larvae from the hard clam Mercenaria mercenaria: Evaluation of the cryoprotectant toxicity,cooling rate and thawing temperature

Aquaculture of hard clams Mercenaria mercenaria is a $65 million industry along the east coast and Gulf of Mexico coast in the United States. The goal of this study was to develop a preliminary protocol to cryopreserve trochophore larvae of hard clams. The objectives were to evaluate the: 1) toxicity of cryoprotectants, including dimethyl sulfoxide (DMSO), propylene glycol, ethylene glycol and glycerol, at 5, 10, 15 and 20% for exposure time of 1, 15, 30, 45, 60 and 75 min; 2) effects of cooling rates (5, 10, 20 and 30°C/min for the first trial; and 1, 3 and 5°C/min for second trial from 4 to ?80°C), thawing temperature (30, 40 and 50°C) and their interactions on post‐thaw viability. A basic protocol was concluded as: 15‐hr trochophore larvae mixed with DMSO or propylene glycol (5, 10%), equilibrated for 15 min, cooled in a programmable freezer from 4 to ?80°C at a cooling rate of 5°C/min and thawed at 50°C for 6 s. With this protocol, the immediate post‐thaw trochophore survival was 23 ± 14%, and survival to D‐stage was 27 ± 14%. This is the first report on larval cryopreservation in the hard clam and would have application for genetic breeding and seed production.     

Comparison of remote sensing indices for monitoring of desert cienegas

This research considers the applicability of different vegetation indices at 30 m resolution for mapping and monitoring desert wetland (cienega) health and spatial extent through time at Cienega Creek in southeastern Arizona, USA. Multiple stressors including the risk of decadal-scale drought, the effects of current and predicted global warming, and continued anthropogenic pressures threaten aquatic habitats in the southwest and cienegas are recognized as important sites for conservation and restoration efforts. However, cienegas present a challenge to satellite-imagery based analysis due to their small size and mixed surface cover of open water, exposed soils, and vegetation. We created time series of five well-known vegetation indices using annual Landsat Thematic Mapper (TM) images retrieved during the April–June dry season, from 1984 to 2011 to map landscape-level distribution of wetlands and monitor the temporal dynamics of individual sites. Indices included the Normalized Difference Vegetation Index (NDVI), the Soil-Adjusted Vegetation Index (SAVI), the Normalized Difference Water Index (NDWI), and the Normalized Difference Infrared Index (NDII). One topographic index, the Topographic Wetness Index (TWI), was analyzed to examine the utility of topography in mapping distribution of cienegas. Our results indicate that the NDII, calculated using Landsat TM band 5, outperforms the other indices at differentiating cienegas from riparian and upland sites, and was the best means to analyze change. As such, it offers a critical baseline for future studies that seek to extend the analysis of cienegas to other regions and time scales, and has broader applicability to the remote sensing of wetland features in arid landscapes.     

Profiling of the Molecular Weight and Structural Isomer Abundance of Macroalgae-Derived Phlorotannins

Phlorotannins are a group of complex polymers of phloroglucinol (1,3,5-trihydroxybenzene) unique to macroalgae. These phenolic compounds are integral structural components of the cell wall in brown algae, but also play many secondary ecological roles such as protection from UV radiation and defense against grazing. This study employed Ultra Performance Liquid Chromatography (UPLC) with tandem mass spectrometry to investigate isomeric complexity and observed differences in phlorotannins derived from macroalgae harvested off the Irish coast (Fucus serratus, Fucus vesiculosus, Himanthalia elongata and Cystoseira nodicaulis). Antioxidant activity and total phenolic content assays were used as an index for producing phlorotannin fractions, enriched using molecular weight cut-off dialysis with subsequent flash chromatography to profile phlorotannin isomers in these macroalgae. These fractions were profiled using UPLC-MS with multiple reaction monitoring (MRM) and the level of isomerization for specific molecular weight phlorotannins between 3 and 16 monomers were determined. The majority of the low molecular weight (LMW) phlorotannins were found to have a molecular weight range equivalent to 4–12 monomers of phloroglucinol. The level of isomerization within the individual macroalgal species differed, resulting in substantially different numbers of phlorotannin isomers for particular molecular weights. F. vesiculosus had the highest number of isomers of 61 at one specific molecular mass, corresponding to 12 phloroglucinol units (PGUs). These results highlight the complex nature of these extracts and emphasize the challenges involved in structural elucidation of these compounds.