Detection and molecular characterization of Actinomyces denticolens causing lymph node abscessation in horses.

Introduction: Abscessation of equine head lymph nodes can be caused by various bacteria, but Streptococcus equi subsp. equi is mainly involved. At our laboratory, samples of three unrelated horses with submandibular abscesses were found negative for S. equi, and further testing proved the presence of another genus. This raised the question for the exact identity of this pathogen and whether these isolates were epidemiologically related and it warranted further characterization with regards of virulence and resistance factors. Methods: Culture followed by identification using MALDI-TOF MS, MIC testing and whole genome sequencing (WGS) was performed to characterize the bacteria. Results: Bacterial culture and subsequent identification with MALDI-TOF MS resulted in the reliable identification of A. denticolens in two of the three cases. Final confirmation of A. denticolens for all three isolates was achieved by analysis of the WGS data, supported by multilocus sequence typing (MLST). The three isolates showed 95% nucleotide sequence identity. The number of single nucleotide polymorphisms (10,170 to 36,058) indicated that the isolates were not clonal, suggesting that these cases were epidemiologically unrelated. Only four known virulence related genes were detected. The absence of known antibiotic resistance genes was in line with the high susceptibility, as indicated by the susceptibility patterns obtained for two of the three isolates. Conclusion: We conclude that A. denticolens should be included in the differential diagnosis of (submandibular) lymph node abscessation in horses, especially if strangles cannot be confirmed with laboratory diagnostics. Furthermore, we report the first draft genome of A. denticolens isolated from horses.

Genetic mitigation strategies to tackle agricultural GHG emissions: The case for biological nitrification inhibition technology.

Accelerated soil-nitrifier activity and rapid nitrification are the cause of declining nitrogen-use efficiency (NUE) and enhanced nitrous oxide (N2O) emissions from farming. Biological nitrification inhibition (BNI) is the ability of certain plant roots to suppress soil-nitrifier activity, through production and release of nitrification inhibitors. The power of phytochemicals with BNI-function needs to be harnessed to control soil-nitrifier activity and improve nitrogen-cycling in agricultural systems. Transformative biological technologies designed for genetic mitigation are needed, so that BNI-enabled crop-livestock and cropping systems can rein in soil-nitrifier activity, to help reduce greenhouse gas (GHG) emissions and globally make farming nitrogen efficient and less harmful to environment. This will reinforce the adaptation or mitigation impact of other climate-smart agriculture technologies.

AMGET, an R-Based Postprocessing Tool for ADAPT 5.

ADAPT 5 is a powerful modeling software for population pharmacokinetic and pharmacodynamic systems analysis, but provides limited built-in functionality for creating pre- and post-analysis diagnostic plots. ADAPT 5 Model Evaluation Graphical Toolkit (AMGET), an external package written in the open source R programming language, was developed specifically to support efficient postprocessing of ADAPT 5 runs, as well as NONMEM and S-ADAPT runs. Using interactive navigational menus, users of AMGET are able to rapidly create informative diagnostic plots enriched by the display of numerical and graphical elements with a high degree of customization using a simple settings spreadsheet. This article describes each feature of the AMGET package and illustrates how it allows users to utilize the powerful numerical routines of the ADAPT 5 package in a more efficient manner through the use of a simulated dataset and a simple pharmacokinetic model optimized using the maximum likelihood expectation maximization (MLEM) algorithm of ADAPT 5.CPT: Pharmacometrics & Systems Pharmacology (2013) 2, e61; doi:10.1038/psp.2013.36; published online 31 July 2013.

Lawsonia intracellularis-associated proliferative enteritis in weanling foals in the Netherlands.

Equine proliferative enteropathy (EPE) is an emerging infectious enteric disease caused by the obligate intracellular gram-negative bacterium Lawsonia intracellularis. EPE was tentatively diagnosed in six weanling foals, aged between 5 and 7 months. Clinical signs included depression, anorexia, ventral oedema, and weight loss. Plasma biochemistry consistently revealed severe hypoproteinaemia. The ante-mortem diagnosis of EPE was based on clinical signs, hypoproteinaemia (6/6), the detection of moderate-to-high titres of L. intracellularis antibody (6/6), and severe thickening of the small intestinal wall on ultrasonography (2/2), or L. intracellularis detected in faeces by PCR (I/2). The first foal died despite treatment and at post-mortem examination the tentative diagnosis was EPE. Three foals from the same farm, which showed similar clinical symptoms were treated with azithromycin and rifampicin; two survived. Post-mortem examination of the foal that died confirmed the tentative clinical diagnosis of EPE on the basis of the lesions found and the detection of L. intracellularis--DNA in the ileum and jejunum. The fifth foal died despite intensive treatment and the post-mortem examination revealed lymphohistiocytic enteritis, typhlitis, and widespread thrombosis in several organs. The sixth foal recovered completely after treatment. This report confirms the presence of clinical L. intracellularis infection in weanling foals in the Netherlands and shows the difficulty in reaching a definitive ante-mortem diagnosis.

[Gastric ulceration in horses: etiology, diagnosis, and therapy: a review]. / Maagulcera bij paarden: etiologie, diagnostiek en therapie; een overzicht.

Since it has become possible to make an ante-mortem diagnosis of gastric ulceration in horses by means of endoscopy, interest in the presence and treatment of this syndrome has increased. Several endoscopic surveys have indicated that the frequency of gastric ulceration in Thoroughbreds in training is fairly high. Less is known about other breeds and horses that are kept under different (training) conditions. The equine stomach is covered by two different kinds of mucous membranes: squamous and glandular. These two areas differ from one another in the incidence and aetiology of ulceration and, therefore, the therapeutic approach is not similar. Clinical signs that typically are associated with gastric ulceration include recurrent colic, poor appetite, weight loss, and, in foals, diarrhoea. Often symptoms are less obvious (such as poor performance), or not even noticeable. Treatment is possible with, for example, H2-antagonists or proton pump inhibitors. Management measurements are important in preventing ulcer recurrence.

[Intoxication with propylene glycol in two horses]. / Een intoxicatie met propyleenglycol bij twee paarden.

Two horses were accidentally administered propylene glycol instead of mineral oil. After discovery of the mistake intensive medical therapy with intravenous fluids, etc. was started, and both animals recovered fully from their clinical symptoms. Veterinarians use propylene glycol as well as paraffin routinely for the treatment of their patients. Mistakes are likely to be made because both medicines and sometimes their packing have a similar appearance. Several incidents have been reported in other countries. A large amount of propylene glycol given to a horse, but also to other animals, can be dangerous and immediate adequate intervention is necessary. The major cause of the problems in case of a propylene glycol intoxication is the high concentration of D-lactate that arises. Clinically, this primarily results in a depression of the central nervous system and in metabolic acidosis. Furthermore colic, diarrhoea and respiratory problems may occur.