Detection of Borrelia burgdorferi sensu-lato-Specific Antibodies in Sera of Canine and Equine Origin—A Comparative Study with Two Line Immunoassays

Lyme borreliosis is a vector-borne disease in humans and animals caused by bacteria from the Borrelia burgdorferi sensu lato complex (Bbsl). The possible transmission of Bbsl from companion animals to humans via ticks makes this disease important in terms of One Health approaches. Thus, early and accurate diagnosis and treatment are of utmost importance. Today’s standard for the detection of specific antibodies against Bbsl is a two-tiered test system based on an ELISA for screening combined with a line immunoassay (LIA) for confirmation. In this study, 200 canine and 200 equine serum samples with known antibody status were tested with two different LIAs (A and B). Results were compared regarding sensitivity, specificity, the diagnostic outcome for dogs and horses, as well as operability of the test. The results for canine serum samples corresponded to 94.0%, making both LIAs a good choice for LB diagnostic in dogs. For equine serum samples, the agreement of both tests was 65.5%, displaying the challenge equine samples still provide in LB diagnostic. Major concerns were the interpretation of the OspA antigen (AG) signal and the use of unspecific (i.e., p100/p83) or too sensitive signals on the LIA. The operability of both LIAs was equally user-friendly. Regarding the tests’ evaluation, the scanning process provided by LIA A was a major advantage considering the comparability of the tests

Exposure to Leptospira spp. and associated risk factors in the human, cattle and dog populations in Bhutan

Leptospirosis is a neglected worldwide zoonotic bacterial disease with a high prevalence in subtropical and tropical countries. The prevalence of Leptospira spp. in humans, cattle and dogs is unknown in Bhutan. Therefore, we sought to find out whether humans, cattle or dogs had been infected in the past with leptospires by measuring antibodies in the serum. We therefore collected blood from 864 humans >/=13 years of age, 130 bovines and 84 dogs from different rural and urban areas in Bhutan and tested the serum for antibodies specific for leptospires with a screening of enzyme-linked immunosorbent assays (ELISA) and a confirmatory microscopic agglutination test (MAT). In humans, 17.6% were seropositive by ELISA and 1.6% by MAT. The seropositivity was stronger in bovines (36.9%) and dogs (47.6%). "Having had a fever recently" (OR 5.2, p = 0.004), "working for the military" (OR 26.6, p = 0.028) and "being unemployed" (OR 12.9, p = 0.041) (reference category = housemaker) were statistically significantly associated with seropositivity when controlled for the effects of other risk factors. However, due to the small number of positive test results, the findings on risk factors should be interpreted with caution. Based on the serogroups found in the three species, dogs could be a source of infection for humans, or dogs and humans are exposed to the same environmental risk factors Clinical leptospirosis in humans and domestic animals should be investigated by testing blood and urine for the presence of leptospires by molecular methods (qPCR)

Experimental assessment of pre-turbo aftertreatment configurations in a single stage turbocharged diesel engine. Part 1: Steady-state operation

Diesel oxidation catalysts and diesel particulate filters are standard aftertreatment systems in Diesel engines which are traditionally placed downstream of the turbine. However, pre-turbo aftertreatment configurations are being approached as a way to improve the aftertreatment performance in terms of light-off and passive regeneration. This exhaust line architecture can also benefit fuel economy. The objective of this work is to analyse experimentally how the pre-turbo aftertreatment placement impacts on the performance of a single stage turbocharged Diesel engine. The work has been divided into two parts focused on steady-state and transient engine operation separately. The first part comprises the analysis of the experimental results corresponding to steady-state operating conditions. The range of operation covers different engine loads and speeds. The engine response with pre-turbo aftertreatment placement is mainly affected by the change in the pumping work caused by the aftertreatment pressure drop reduction and its new location, which avoids the multiplicative effect of the turbine expansion ratio when setting the engine back-pressure. These effects become more significant as the engine load increases benefiting fuel consumption from low to high loads. Concerning aftertreatment performance, the results evidence noticeable benefits in DPF passive regeneration and CO/HC emissions reduction at low engine load.This work has been partially supported by the Vicerrectorado de Investigacion de la Universitat Politenica de Valencia through grant number SP20120340-UPPTE/2012/96 and by the Conselleria de Educacio, Cultura i Esport of the Generalitat Valenciana through grant number GV/2013/043.Luján, JM.; Bermúdez, V.; Piqueras, P.; García Afonso, Ó. (2015). Experimental assessment of pre-turbo aftertreatment configurations in a single stage turbocharged diesel engine. Part 1: Steady-state operation. Energy. 80:599-613. https://doi.org/10.1016/j.energy.2014.05.048S5996138

Experimental assessment of a pre-turbo aftertreatment configuration in a single stage turbocharged diesel engine. Part 2: Transient operation

This paper corresponds to the second part of a work devoted to analyse the impact of the pre-turbo aftertreatment configuration on the performance of a single stage turbocharged Diesel engine. This second part focuses on the analysis of the engine response under transient operating conditions. To address the causes and effects of the change in engine response several types of transient processes consisting of driving cycles and load transient tests have been evaluated as starting point of the analysis. These tests make possible to account for the influence of the aftertreatment thermal inertia and how it affects the engine and aftertreatment performance obtained during driving cycles and under highly demanding transient operation. The pre-turbo aftertreatment placement also provides advantages in terms of faster aftertreatment warm-up. Therefore, the benefits on DPF (diesel particulate filter) passive regeneration as well as DOC (diesel oxidation catalyst) light-off leading to lower gas emissions have been assessed. The results have been compared against baseline emissions measured during experiments with post-turbo aftertreatment placement. Finally the influence of the thermal inertia on driveability in sudden accelerations as a function of the wall temperature along the exhaust line and boosting architecture is assessed combining the analysis of experimental and modelled data.This work has been partially supported by the Spanish Ministry of Economy and Competitiveness through Grant No. TRA2013-40853-R.Lujan Martinez, JM.; Serrano Cruz, JR.; Piqueras Cabrera, P.; García Afonso, Ó. (2015). Experimental assessment of a pre-turbo aftertreatment configuration in a single stage turbocharged diesel engine. Part 2: Transient operation. Energy. 80:614-627. https://doi.org/10.1016/j.energy.2014.12.017S6146278

Variable Geometry Turbocharger Technologies for Exhaust Energy Recovery and Boosting-A Review

As emissions regulations become increasingly demanding, higher power density engine (downsized/downspeeded and increasingly right-sized) requirements are driving the development of turbocharging systems. Variable geometry turbocharging (VGT) at its most basic level is the first step up from standard fixed geometry turbocharger systems. Currently, VGTs offer significant alternative options or complementarity vis-à-vis more advanced turbocharging options. This review details the range of prominent variable geometry technologies that are commercially available or openly under development, for both turbines and compressors and discusses the relative merits of each. Along with prominent diesel-engine boosting systems, attention is given to the control schemes employed and the actuation systems required to operate variable geometry devices, and the specific challenges associated with turbines designed for gasoline engines

A Retrospective Study with a Commercial Vaccine against Lyme Borreliosis in Dogs Using Two Different Vaccination Schedules: Characterization of the Humoral Immune Response

Lyme borreliosis, a multisystemic disease caused by spirochetes of the genus Borrelia, is the most common tick-borne disease in the northern hemisphere. Differently from human medicine, several vaccines are available for dogs. To provide the best protection possible, vaccination schemes should be adapted regularly to meet the needs resulting from an increased tick exposure risk due to an inescapable climate change. In this retrospective study, a total of 183 vaccinations were performed with a commercial, multivalent vaccine against Lyme borreliosis, and vaccinated dogs were monitored over an observation period of 13 months. Dogs were either vaccinated on days 0 and 21 and a booster on day 365 (standard vaccination schedule), or with an additional booster vaccination on day 180. Canine serum samples were then tested for their borrelia-specific antibody levels using a two-tiered test system consisting of a kinetic ELISA followed by a line immunoassay. Dogs vaccinated with the standard vaccination schedule displayed decreasing antibody levels between days 120 and 360, which is probably insufficient to prevent an infection with borreliae. In contrast, the additional booster vaccination received on day 180 intercepts this decline in antibody levels between days 225 and 360, providing a sufficient immunity to prevent infection. The results from this retrospective study allow us to recommend a basic vaccination schedule with an additional booster vaccination on day 180 to ensure the best possible protection for dogs against Lyme borreliosis

Revealing the Tick Microbiome: Insights into Midgut and Salivary Gland Microbiota of Female <i>Ixodes ricinus</i> Ticks

The ectoparasite Ixodes ricinus is an important vector for many tick-borne diseases (TBD) in the northern hemisphere, such as Lyme borreliosis, rickettsiosis, human granulocytic anaplasmosis, or tick-borne encephalitis virus. As climate change will lead to rising temperatures in the next years, we expect an increase in tick activity, tick population, and thus in the spread of TBD. Consequently, it has never been more critical to understand relationships within the microbial communities in ticks that might contribute to the tick’s fitness and the occurrence of TBD. Therefore, we analyzed the microbiota in different tick tissues such as midgut, salivary glands, and residual tick material, as well as the microbiota in complete Ixodes ricinus ticks using 16S rRNA gene amplicon sequencing. By using a newly developed DNA extraction protocol for tick tissue samples and a self-designed mock community, we were able to detect endosymbionts and pathogens that have been described in the literature previously. Further, this study displayed the usefulness of including a mock community during bioinformatic analysis to identify essential bacteria within the tick