[Online information system for -phytotherapy in animals]. / Online-Informationssystem für die Phytotherapie bei Tieren.

INTRODUCTION: Phytotherapy becomes increasingly popular in veterinary medicine. To fully exploit the therapeutic potential of medicinal plants and ensure their safe use, knowledge about the effective plant parts and preparations is required. Improper use and overdosage of medicinal plants can be toxic. With www.phytoarznei.ch, we provide an online decision support aid that allows for the retrieval of currently available information on medicinal plants and their use in domestic animals. This decision support system is based on the available literature in the field, which after critical evaluation has been incorporated into a structured database. For each medicinal plant or drug, we have listed therapeutic indications, different application types, organoleptic properties, plant ingredients, pharmacological effects, dosages, duration of treatment, toxicity, legal frame for use in livestock and relevance for doping. A user-friendly access to all data is achieved by means of two search programs, either by entering the plant name or name of the drug in a search field or by selecting the desired animal species and therapeutic application from respective drop-down lists. This database on medicinal plant applications in animals is linked to the poisonous plant database of the University of Zurich and, for marketed preparations, to the Swiss compendium of veterinary medicinal products as well as to an index of related veterinary products.

INTRODUCTION: En médecine vétérinaire aussi, la phytothérapie devient de plus en plus populaire. Exploiter le potentiel thérapeutique des plantes médicinales et assurer leur utilisation en toute sécurité nécessite toutefois une connaissance particulière des parties de plantes ou des préparations efficaces. Une utilisation inappropriée et un surdosage de plantes médicinales peuvent être toxiques. C'est pourquoi nous avons créé un outil de prise de décision en ligne, www.phytoarznei.ch, qui permet un accès rapide aux connaissances actuelles sur les plantes médicinales et leur utilisation sur les animaux. Ce système d'information est basé sur la littérature spécialisée disponible qui a été incorporée, après une évaluation critique, dans une base de données structurée. Les indications thérapeutiques, les modes d'applications, les propriétés organoleptiques, les composants, les effets pharmacologiques, doses, la durée du traitement, la toxicité, les réglementations juridiques chez les animaux de rente ainsi que la pertinence en matière de dopage sont répertoriés pour chaque plante médicinale ou médicament à base de plantes. Deux programmes de recherche fournissent un accès convivial, soit par la saisie du nom de la plante, du nom du médicament ou des ingrédients de la plante dans une zone de recherche, soit en sélectionnant les espèces d'animaux souhaitées ainsi que l'utilisation thérapeutique dans des menus déroulants correspondants. Cette base de données des plantes médicinales est liée avec base de plantes toxiques de l'Université de Zurich et, si des produits finis correspondants sont disponibles, au Compendium des médicaments vétérinaires suisse ainsi qu'à un répertoire de produits vétérinaires.

[AntibioticScout.ch: Decision support for the prudent use of antimicrobials: Application in cattle]. / AntibioticScout.ch: Entscheidungshilfe für den umsichtigen Einsatz von antimikrobiellen Wirkstoffen: Anwendung beim Rind.

INTRODUCTION: The administration of antibiotics in livestock has been criticized for many years, in particular because of an inappropriate use and the appearance of antibiotic residues in the environment, which can promote the emergence and spread of resistant bacteria. However, antibiotics are essential for the successful and sustainable control of bacterial pathogens. With the aim of optimizing the use of antibiotics in food animals and minimizing the prevalence of resistant bacteria, AntibioticScout. ch provides a decision aid for the prudent use of antimicrobial drugs. This approach emphasizes the importance of supportive therapy and the hallmarks of preventive concepts. Procedures to improve animal health and animal welfare in accordance with the principles of good veterinary practice are primary and effective tools to reduce the use of antimicrobial drugs. The necessary reduction in the use of antibiotics must, therefore, be accompanied by appropriate management strategies in animal husbandry. In particular, hygiene, animal welfare and biosecurity measures are crucial to ensure an optimal health status in farm animals.

INTRODUCTION: On discute depuis des années de l'usage des antibiotiques dans l'élevage des animaux de rente, en particulier en ce qui concerne leur utilisation incorrecte et la charge environnementale liée à des résidus d'antibiotiques susceptibles de favoriser l'apparition et la propagation de résistances. Toutefois les antibiotiques sont essentiels pour assurer une lutte efficace et durable contre les maladies d'origine bactérienne. Dans le but d'optimiser l'usage des antibiotiques dans l'élevage des animaux de rente et, par conséquence, de réduire le développement de résistances, AntibioticScout.ch propose une aide à la décision pour un usage prudent de ces substances ("prudent use"). Parallèlement, on attire l'attention sur les traitements adjuvants et sur les mesures de prévention. Des mesures visant à améliorer la santé et le bien-être des animaux en tenant compte des fondements d'une bonne pratique vétérinaire sont des instruments efficaces pour réduire l'usage des antibiotiques. Cette réduction indispensable doit donc être combinée avec des mesures de gestion adéquates dans les élevages. Ce sont en particulier l'hygiène et les conditions d'élevage correctes ainsi que la mise en place de mesures de biosécurité qui sont décisives pour l'optimisation de la santé des troupeaux.

[AntibioticScout.ch: A decision supporting tool for antimicrobial stewardship: application to companion animal medicine]. / AntibioticScout.ch: Eine Entscheidungshilfe für den umsichtigen Einsatz von antimikrobiellen Wirkstoffen: Anwendung in der Kleintiermedizin.

INTRODUCTION: Bacterial resistances to antimicrobial drugs pose serious public health challenges. The observed increase of resistances is attributed to the uncontrolled, massive and often unnecessary administration of antibiotics both in human and veterinary medicine. To support the responsible use of antimicrobials in animals and help veterinarians selecting the most suitable antimicrobial drugs, we developed the AntibioticScout.ch as a comprehensive decision supporting tool providing online access to the current knowledge of rational antibiotic prescription practices. User-friendly search functions allow for the fast and efficient retrieval of information that is structured in this database by animal species, organ systems and therapeutic indications. In addition, an online form allows to report treatment failures in order to identify problematic cases as well as ensuing risks and take appropriate mitigation measures. The present report describes the workflow of this decision support system applied to the prudent use of antimicrobials in companion animal medicine.

INTRODUCTION: Les résistances bactériennes face aux substances antimicrobiennes placent le système de santé face à de grands défis. L'augmentation des résistances est attribuée à une utilisation mal dirigée, massive et souvent inutile d'antibiotiques tant en médecine humaine qu'en médecine vétérinaire. Afin d'encourager une utilisation responsable des substances antimicrobiennes en médecine vétérinaire et pour soutenir les vétérinaires lors du choix de l'antibiotique adapté, on a créé, avec AntibioticScout. ch, une aide à la décision de grande envergure qui permet de recourir à chaque instant aux principes de prescription reconnus de la médecine fondée sur les faits (Evidence Based Medicine). La banque de données est structurée par espèces animales, systèmes d'organes et indications et un moteur de recherche intuitif garantit de trouver rapidement et efficacement les informations. D'autre part un formulaire en ligne pour l'annonce d'une inefficacité est proposé afin de reconnaitre les cas à problèmes et les risques en vue d'améliorer l'aide au diagnostic. La présente contribution pour but de démontrer l'utilisation d'AntibioticScout pour un usage prudent des antibiotiques en médecine des petits animaux.

First Measurement of Electron Neutrino Appearance in NOvA.

We report results from the first search for ν_{µ}→ν_{e} transitions by the NOvA experiment. In an exposure equivalent to 2.74×10^{20} protons on target in the upgraded NuMI beam at Fermilab, we observe 6 events in the Far Detector, compared to a background expectation of 0.99±0.11(syst) events based on the Near Detector measurement. A secondary analysis observes 11 events with a background of 1.07±0.14(syst). The 3.3σ excess of events observed in the primary analysis disfavors 0.1π<δ_{CP}<0.5π in the inverted mass hierarchy at the 90% C.L.

[AntibioticScout: Online tool for antimicrobial stewardship in veterinary medicine]. / AntibioticScout: Online-Entscheidungshilfe für den umsichtigen Einsatz von antimikrobiellen Wirkstoffen.

INTRODUCTION: Resistances to antimicrobials pose serious public health challenges. This issue concerns both human and veterinary medicine and can only be solved by a multidisciplinary approach. A comprehensive concept is, therefore, being worked out within the StAR (strategy antibiotic resistance) program in order to preserve the effectiveness of antibiotics for humans as well as animals. In this context, the AntibioticScout (www.AntibioticScout. ch) offers a new online tool for the prudent use of antibiotics in veterinary medicine. By involving all stakeholders, the guidelines included in the AntibioticScout will result in a nationwide accepted standard for the treatment of bacterial infections in animals. An additional system for the rapid reporting of cases of suspected lack of efficacy of antimicrobials is integrated to allow early detection of emerging resistance and the immediate launch of risk mitigation measures. A first version of the AntibioticScout for the treatment of dogs, cats and horses is available by the end of 2016. All stakeholders are now invited to contribute to the development of the AntibioticScout decision support.

INTRODUCTION: Les résistances face aux substances antimicrobiennes placent le système de santé face à de grands défis. Ce problème touche aussi bien la médecine humaine que vétérinaire et ne peut être réglé que de façon transversale. C'est pour cette raison qu'a été développé, avec le programme StAR (Strategie Antibiotikaresistenzen), un concept global pour assurer à long terme l'efficacité des antibiotiques aussi bien chez les hommes que chez les animaux. Dans ce contexte, nous mettons à disposition, avec le développement d'AntibioticScout (www.AntibioticScout. ch), un nouvel outil en ligne pour soutenir un usage responsable des antibiotiques en médecine vétérinaire. Avec le concours de représentants de tous les milieux intéressés, il s'agit de développer les lignes directrices d'un standard accepté au plan national pour le traitement des infections bactériennes chez les animaux et de le mettre à disposition dans AntibioticScout. En outre un système d'annonce immédiate en cas d'inefficacité sera mis en place, afin de repérer précocement les risques et de prendre les mesures correspondantes. Une première version d'AntibioticScout pour le traitement des chiens, chats et chevaux est disponible dès fin 2016. Tous les cercles intéressés sont dès maintenant invités à contribuer au développement d'Antibiotic Scout.

Evaluation of the effectiveness of liraglutide and sitagliptin in type 2 diabetes: a retrospective study in UK primary care.

OBJECTIVE: Type 2 diabetes is a chronic condition that continues to increase in prevalence in the UK. Incretin-based therapies, including liraglutide and sitagliptin, provide adequate blood glucose control. Clinical trials have shown that liraglutide offers greater glycaemic control and body weight reduction in comparison to sitagliptin. We aimed to assess the effectiveness of liraglutide and sitagliptin in routine clinical practice. MATERIALS AND METHODS: We designed and conducted a retrospective database analysis in primary care using the Clinical Practice Research Datalink in the UK. Patients aged ≥ 18 years, diagnosed with type 2 diabetes and prescribed liraglutide or sitagliptin between July 2009 and July 2012, were included in the study. Glycaemic and weight control were investigated 6 months after treatment initiation. RESULTS: A total of 287 liraglutide and 2781 sitagliptin patients were identified. Compared with sitagliptin, liraglutide recipients had greater reductions in HbA1c (%) (-0.90 vs. -0.57, p < 0.01), weight (kg) (-3.78 vs. -1.12, p < 0.001), BMI (kg/m(2) ) (-1.30 vs. -0.39, p < 0.001) and systolic blood pressure (mmHg) (-3.91 vs. -0.39, p < 0.001) after 6 months of treatment. When controlling for potential confounders, liraglutide was more likely than sitagliptin to achieve an HbA1c reduction ≥ 1% (OR = 2.29, 95% CI 1.62-3.25), an HbA1c reduction ≥ 1% and a weight reduction ≥ 3% (OR = 2.99; 95% CI 2.00-4.48) and a target HbA1c < 7% (OR = 2.11; 95% CI 1.45-3.07) after 6 months of treatment. CONCLUSIONS: Clinical trials show superior glycaemic control and weight reduction with liraglutide compared with sitagliptin. This finding is reflected in routine clinical practice in the UK.

[New causes of animal poisoning in Switzerland]. / Neue Ursachen von Tiervergiftungen in der Schweiz.

This retrospective study evaluated the frequency, etiology, therapy and prognosis of animal poisoning registered from 2003 to 2012. The relevant cases reported to the Swiss Toxicological Information Center (STIC) were compared with those from previously examined periods. Human medicines not approved for animals and pesticides represented the most common causes of poisoning in dogs. Novel cases occurred as a consequence of the exposure of dogs to ricinus fertilizers, grape residues from wineries, pepper lachrymatory spray and dry bouillon. Cats are still freequently poisoned by pyrethroid drugs that should be administered only to dogs. Agrochmical products are the main source of toxicities in farm animals. Most poisonings in horses and exotic animals took place due to toxic plants. In addition, two tigers died of a secondary poisoning after ingestion of meat from euthanized calves.

Reasons for nonuse of antiviral treatment in patients with chronic hepatitis C infection and thrombocytopaenia: a retrospective chart review from five European countries.

Antiviral therapy has been shown to reduce the risk of disease progression, liver damage and death in patients with chronic hepatitis C virus (HCV) infection. While interferon labels recommend that patients with platelet counts below 50 × 10(3) /µL not receive interferon-based therapy, it is unknown to what extent thrombocytopaenia influences treatment decisions in practice. This study profiles the reasons for withholding antiviral treatment in HCV patients with thrombocytopaenia in five European countries. Medical records of 466 patients who had HCV infection and thrombocytopaenia (platelet count <100 × 10(3) /µL) in 2006 were retrospectively reviewed for clinical characteristics. Collected data included use of antiviral therapy and reasons for withholding therapy. In total 184 of 466 patients (39.5%) did not receive interferon-based therapy during the study period, with treatment withheld most frequently due to multiple clinical characteristics including hepatic cirrhosis (16.3%), thrombocytopaenia (16.3%) and age >60 years (10.9%). The reasons for lack of treatment varied among countries, with thrombocytopaenia as a reason being more common in Italy (10.9%) and Spain (20.0%), and less common in France, Germany and the UK (3.2-7.1%). Overall, thrombocytopaenia was reported as the only reason for withholding treatment in 4.9% of untreated patients. This study demonstrates that thrombocytopaenia is one of many factors, indicative of the poor clinical state of the patient, that contributes to withholding antiviral treatment. In 4.9% of untreated patients, thrombocytopaenia can be considered as a modifiable factor to enable more HCV patients to receive guideline-recommended therapy and thus improved clinical outcomes.

[Pharmacogenetics: relevant aspects for the practicing veterinarian]. / Pharmakogenetik: Relevante Aspekte für den praktizierenden Tierarzt.

Pharmacogenetics is the study of genetic determinants of different responses to drug therapy and deals with differences in metabolic pathways and therapeutic effects as well as adverse reactions. A common genetic defect found in veterinary medicine is the MDR1 mutation occurring in Collies and related breeds that leads to an altered P-glycoprotein. Genetic mutations of enzymes (cytochrome P450, thiopurine s-methyltransferase, n-acetyltransferase, UDP-glucuronyltransferase, plasma esterase or sulfotransferase), which are responsible for the metabolism of drugs, are found as well. A decreased functional level of these enzymes can lead to an increased plasma concentration of the drug with a consequent relative overdose.

[The reclassification assistant: Drug reclassification made easy]. / Umwidmungs-Assistent: Arzneimittelumwidmung leicht gemacht.

INTRODUCTION: In Switzerland, just over 700 veterinary medicinal products are authorized. Nevertheless, in practice veterinarians are often confronted with extraordinary situations in which a suitable veterinary medicinal product is not authorized, unavailable or otherwise not applicable. For livestock and horses in particular, this poses a challenge for pharmacotherapy due to food safety regulations. In these cases, the reclassification assistant can be used to determine whether and how a medicinal product containing the appropriate drug can be reclassified and correctly applied in food-producing animals. The users will be guided step by step with selectable options through the online assistant. If the desired reclassification is permitted in the legal framework, information on the withdrawal periods to be observed for the chosen medicinal product will be provided. This online assistant follows an algorithm based on the reclassification cascade and applicable food safety regulations.

INTRODUCTION: En Suisse, un peu plus de 700 médicaments vétérinaires sont autorisés. Néanmoins, dans la pratique, les vétérinaires sont souvent confrontés à des situations extraordinaires dans lesquelles un médicament vétérinaire approprié n'est ni autorisé, ni disponible, ni utilisable pour d'autres raisons. En particulier pour le bétail et les chevaux, cela pose un défi pour la pharmacothérapie en raison de la réglementation sur la sécurité alimentaire. Dans ces cas, l'assistant de reconversion peut être utilisé pour déterminer si et comment un médicament contenant le principe actif approprié peut être reconverti et correctement appliqué. Les utilisateurs seront guidés pas à pas avec des options sélectionnables via l'assistant en ligne. Si la reconversion souhaitée est autorisée dans le cadre légal, des informations sur les délais d'attente à respecter pour le médicament choisi seront fournies. Cet assistant en ligne suit un algorithme basé sur la cascade de reconversion les réglementations applicables en matière de sécurité alimentaire.

Identification and functional characterization of type II toxin/antitoxin systems in Aggregatibacter actinomycetemcomitans.

Type II toxin/antitoxin (TA) systems contribute to the formation of persister cells and biofilm formation for many organisms. Aggregatibacter actinomycetemcomitans thrives in the complex oral microbial community subjected to continual environmental flux. Little is known regarding the presence and function of type II TA systems in this organism or their contribution to adaptation and persistence in the biofilm. We identified 11 TA systems that are conserved across all seven serotypes of A. actinomycetemcomitans and represent the RelBE, MazEF and HipAB families of type II TA systems. The systems selectively responded to various environmental conditions that exist in the oral cavity. Two putative RelBE-like TA systems, D11S_1194-1195 and D11S_1718-1719 were induced in response to low pH and deletion of D11S_1718-1719 significantly reduced metabolic activity of stationary phase A. actinomycetemcomitans cells upon prolonged exposure to acidic conditions. The deletion mutant also exhibited reduced biofilm biomass when cultured under acidic conditions. The D11S_1194 and D11S_1718 toxin proteins inhibited in vitro translation of dihydrofolate reductase (DHFR) and degraded ribosome-associated, but not free, MS2 virus RNA. In contrast, the corresponding antitoxins (D11S_1195 and D11S_1719), or equimolar mixtures of toxin and antitoxin, had no effect on DHFR production or RNA degradation. Together, these results suggest that D11S_1194-1195 and D11S_1718-1719 are RelBE-like type II TA systems that are activated under acidic conditions and may function to cleave ribosome-associated mRNA to inhibit translation in A. actinomycetemcomitans. In vivo, these systems may facilitate A. actinomycetemcomitans adaptation and persistence in acidic local environments in the dental biofilm.

[Reported adverse reactions due to veterinary drugs in 2006]. / Gemeldete unerwünschte Wirkungen von Tierarzneimitteln im Jahr 2006.

We received 190 reports of suspected adverse events (SARs) following the use of veterinary drugs for the year 2006: 118 declarations for veterinary drugs and 72 declarations following the application of immunolgical medicinal products. Most of the 118 declarations relate to the use of antiparasitic drugs (48%) and every second declaration to drug use in dogs. Other drug classes concerned were, in decreasing order, antiinfectives (20%) and drugs used off-label (12%; other target species or other indication). For the vaccines, most of the reactions occurred in dogs (62%) followed by horses (11%) and cattle (10%). The most frequently reported reactions concerned the use of a vaccine against piroplasmosis. Another 349 requests for information were processed by the Swiss Toxicological Information center. We also present a case of a serious adverse reaction in form of a Stevens-Johnson syndrome in a cat as well as a case of ketamine abuse. We note the growing interest of practicing veterinarians with pleasure and are currently working on further adaptations to the system.

[Reported adverse reactions of veterinary drugs and vaccines in 2005]. / Gemeldete unerwünschte Wirkungen von Tierarzneimitteln im Jahr 2005.

We received 105 reports of suspected adverse events (SARs) following the use of veterinary drugs for the year 2005. This corresponds to a 35% increase compared to 2004. Practicing veterinarians sent most of these declarations. 73% of these concerned drugs used on companion animals. Antiparasitic drugs approved for topical use were the most frequently represented group with 48%, followed by drugs used to treat gastrointestinal disorders (11%) and drugs used off-label (14%; other target species or other indication). For the first time 2 declarations concerning the application of permethrin containing spot-on preparations used by mistake on cats were received. An overview of 20 declarations about adverse reactions following application of different vaccines is also presented with emphasis on the problem of fibrosarcoma in cats. We are pleased by the growing interest shown by practicing veterinarians for the vigilance system and hope to further develop this collaboration in the future.

[Swiss veterinary drug compendium as a tool for reconversions]. / Das Tierarzneimittelkompendium als Umwidmungshilfe.

The new Swiss ordinance on veterinary drugs poses a new challenge to the veterinarians, specially those working with farm animals. A complete overview about the registered veterinary drugs and immunobiologicals is absolutely necessary to cope with these new tasks: the internet version of the Swiss Veterinary Drug Compendium is a versatile tool to satisfy this needs (http://www.tierarzneimittel.ch). Due to the frequent updates and powerful search possibilities, this database is a reliable and comprehensive information system regarding Swiss veterinary drugs. We will demonstrate how this system can be used as a valuable help in the case of reconversions of drugs (e.g. use of small animal drugs in farm animals).

QseBC, a two-component bacterial adrenergic receptor and global regulator of virulence in Enterobacteriaceae and Pasteurellaceae.

The QseBC two-component system (TCS) is associated with quorum sensing and functions as a global regulator of virulence. Based on sequence similarity within the sensor domain and conservation of an acidic motif essential for signal recognition, QseBC is primarily distributed in the Enterobacteriaceae and Pasteurellaceae. In Escherichia coli, QseC responds to autoinducer-3 and/or epinephrine/norepinephrine. Binding of epinephrine/norepinephrine is inhibited by adrenergic antagonists; hence QseC functions as a bacterial adrenergic receptor. Aggregatibacter actinomycetemcomitans QseC is activated by a combination of epinephrine/norepinephrine and iron, whereas only iron activates the Haemophilus influenzae sensor. QseC phosphorylates QseB but there is growing evidence that QseB is activated by non-cognate sensors and regulated by dephosphorylation via QseC. Interestingly, the QseBC signaling cascades and regulons differ significantly. In enterohemorrhagic E. coli, QseC induces expression of a second adrenergic TCS and phosphorylates two non-cognate response regulators, each of which induces specific sets of virulence genes. This signaling pathway integrates with other regulatory mechanisms mediated by transcriptional regulators QseA and QseD and a fucose-sensing TCS and likely controls the level and timing of virulence gene expression. In contrast, A. actinomycetemcomitans QseC signals through QseB to regulate genes involved in anaerobic metabolism and energy production, which may prime cellular metabolism for growth in an anaerobic host niche. QseC represents a novel target for therapeutic intervention and small molecule inhibitors already show promise as broad-spectrum antimicrobials. Further characterization of QseBC signaling may identify additional differences in QseBC function and inform further development of new therapeutics to control microbial infections.

[Suspected adverse drug reactions in 2004]. / Meldungen zu unerwünschten Wirkungen von Tierarzneimitteln im Jahr 2004.

We received 62 reports of suspected adverse events (SARs) for the year 2004. Their number and repartition according to affected animals and active substances were comparable with the previous year. The distributors or manufacturers submitted most of the declarations, but the proportion submitted by practicing veterinarians is slowly growing. 72% of the declarations dealt with adverse reactions in small animals (cats and dogs), followed by cattle and horses. Antiparasitics, anti-inflammatory drugs and immunologicals were the most frequently mentioned therapeutic classes, which are listed here according to the international ATCvet classification. A report from abroad about a fatality following injection of an antibiotic preparation for cattle prompted Swissmedic to review the security of this medication also sold on the Swiss market. It was decided to modify the package insert to warn about the danger of inadvertent self-injection in humans, to reduce the risk of similar accidents in Switzerland. We hope that the pharmacovigilance system will enjoy an increasing awareness by the practicing veterinarians.

Aggregatibacter actinomycetemcomitans QseBC is activated by catecholamines and iron and regulates genes encoding proteins associated with anaerobic respiration and metabolism.

Aggregatibacter actinomycetemcomitans QseBC regulates its own expression and is essential for biofilm growth and virulence. However, the signal that activates the QseC sensor has not been identified and the qseBC regulon has not been defined. In this study, we show that QseC is activated by catecholamine hormones and iron but not by either component alone. Activation of QseC requires an EYRDD motif in the periplasmic domain of the sensor and site-specific mutations in EYRDD or the deletion of the periplasmic domain inhibits catecholamine/iron-dependent induction of the ygiW-qseBC operon. Catecholamine/iron-dependent induction of transcription also requires interaction of the QseB response regulator with its binding site in the ygiW-qseBC promoter. Whole genome microarrays were used to compare gene expression profiles of A. actinomycetemcomitans grown in a chemically defined medium with and without catecholamine and iron supplementation. Approximately 11.5% of the A. actinomycetemcomitans genome was differentially expressed by at least two-fold upon exposure to catecholamines and iron. The expression of ferritin was strongly induced, suggesting that intracellular iron storage capacity is increased upon QseBC activation. Consistent with this, genes encoding iron binding and transport proteins were down-regulated by QseBC. Strikingly, 57% of the QseBC up-regulated genes (56/99) encode proteins associated with anaerobic metabolism and respiration. Most of these up-regulated genes were recently reported to be induced during in vivo growth of A. actinomycetemcomitans. These results suggest that detection of catecholamines and iron by QseBC may alter the cellular metabolism of A. actinomycetemcomitans for increased fitness and growth in an anaerobic host environment.

Construction of pYGK, an Actinobacillus actinomycetemcomitans-Escherichia coli shuttle vector.

A shuttle vector that is capable of replicating in Actinobacillus actinomycetemcomitans (Aa) and Escherichia coli (Ec) was constructed by modifying the Actinobacillus pleuropneumoniae (Ap) plasmid pYG53. A DNA fragment containing the KmR gene was inserted into pYG53 to generate pYGK, which confers resistance to kanamycin in both Aa and Ec. By electroporation, Ec DH5alpha and 17 strains of Aa were transformed with pYGK with efficiencies ranging from 0.5 to 3 X 10(6) colonies per microgram of DNA. Plasmid pYGK exists at approx. 3-4 copies per cell in Ec. This plasmid will facilitate the genetic manipulation of Aa strains and the molecular analysis of virulence factors expressed by this organism.