Antimicrobial use and antimicrobial resistance monitoring in pig production in the United States of America.

Monitoring antimicrobial use (AMU) and antimicrobial resistance (AMR) on farms is recognised as an important component of antimicrobial stewardship, yet the process can be resource intensive. This paper describes a subset of findings from the first year of a collaboration across government, academia and a private sector veterinary practice focused on swine production in the Midwestern United States. The work is supported by participating farmers and the greater swine industry. Twice-annual collection of samples from pigs along with AMU monitoring occurred on 138 swine farms. Detection and resistance of Escherichia coli from pig tissues was assessed, and associations between AMU and AMR were evaluated. This paper describes the methods utilised and the first-year E. coli-related results from this project. Higher minimum inhibitory concentrations (MIC) for enrofloxacin and danofloxacin in E. coli from swine tissues were associated with the purchase of fluoroquinolones. There were no other significant associations between MIC and AMU combinations in E. coli isolated from pig tissues. This project represents one of the first attempts to monitor AMU as well as AMR in E. coli in a large-scale commercial swine system in the United States of America.

Alors même que la surveillance exercée sur l'utilisation des agents antimicrobiens (UAM) et sur la résistance aux agents antimicrobiens (RAM) dans les élevages est une composante majeure reconnue de la gestion des antimicrobiens, le processus en lui-même exige une mobilisation intensive de ressources. Les auteurs décrivent un sous-ensemble de résultats obtenus au cours de la première année d'une collaboration entre les pouvoirs publics, les universités et une clinique vétérinaire privée, axée sur la production porcine dans le Midwest des états-Unis d'Amérique. Ce travail est soutenu par les éleveurs participants et par le secteur porcin au sens large. Une collecte d'échantillons porcins a été effectuée deux fois par an, parallèlement à la surveillance de l'UAM dans 138 élevages. Il a été procédé à une recherche des Escherichia coli présents dans les tissus porcins prélevés puis à la détermination de la résistance aux antimicrobiens chez les microorganismes détectés ; les corrélations éventuelles entre l'UAM et la RAM ont ensuite été évaluées. Les auteurs décrivent les méthodes utilisées dans la cadre de ce projet ainsi que les résultats en lien avec les E. coli obtenus au cours de la première année. Une corrélation a été constatée entre l'augmentation des concentrations minimales inhibitrices (CMI) recueillies pour l'enrofloxacine et la danofloxacine vis-à-vis d'E. coli dans les tissus porcins analysés, d'une part, et l'achat de fluoroquinolones, d'autre part. Aucune autre corrélation significative n'a été décelée entre les CMI recueillies et les profils d'UAM concernant les E. coli isolés à partir des tissus porcins. Ce projet représente l'une des premières tentatives conduites aux états-Unis d'Amérique pour surveiller parallèlement l'UAM et la RAM chez les E. coli dans un système commercial de production porcine à grande échelle.

Aunque se tiene por sabido que la vigilancia en las explotaciones del uso de agentes antimicrobianos (UAM) y de la resistencia a los antimicrobianos (RAM) es un importante componente de la gestión de estos fármacos, no es menos cierto que el proceso puede consumir cuantiosos recursos. Los autores exponen un ubconjunto de observaciones realizadas durante el primer año de un proyecto de colaboración entre la administración pública, el mundo universitario y una clínica veterinaria privada que tenía por objeto de estudio la producción porcina en la zona del medio oeste de los Estados Unidos de América. Respaldaban el proyecto los productores que participaban en él y el sector de la industria porcina en general. Dos veces al año se obtuvieron muestras en 138 explotaciones porcinas, en las que también se seguía de cerca el UAM. Tras realizar pruebas de detección de Escherichia coli en tejidos porcinos y analizar la resistencia de esos microorganismos a antimicrobianos, se buscaron correlaciones entre el uso de estos fármacos y la presencia de eventuales resistencias. Los autores describen los métodos empleados y los resultados obtenidos el primer año del proyecto en relación con E. coli. Se observó una correlación entre la compra de fluoroquinolonas y el aumento de la concentración inhibitoria mínima (MIC) de enrofloxacina y de danofloxacina en los E. coli analizados. No se constató ninguna otra asociación significativa entre las MIC y el uso de diferentes antimicrobianos en los E. coli aislados a partir de tejido porcino. Este proyecto constituye una de las primeras tentativas de hacer seguimiento y balance del uso de agentes antimicrobianos y de la resistencia de E. coli a estos fármacos en el sistema de producción porcina industrial de los Estados Unidos de América.

Adherence and outcomes of patients prescribed dabigatran (Pradaxa) in routine clinical practice.

AIM: To explore and detail clinical experiences of dabigatran, a novel anticoagulant, after it became available in New Zealand in July 2011. METHODS: A cohort of patients was recruited from Hutt Hospital and the two largest primary care practices in the Hutt Valley region. They were included if they took at least one dose of dabigatran between July 2011 and April 2012. Participants undertook a questionnaire 3-12 months after starting dabigatran assessing adherence, perceived side-effects and complications. Those presenting due to an adverse event were analysed separately. RESULTS: Of 102 patients identified, 92 were recruited to this study. At a median of 8 months, 70% of participants were still taking dabigatran, significantly lower than in the RE-LY trial at 12 months (P = 0.0002). The commonest reason given for discontinuation was gastrointestinal (GI) side-effects. Rates of serious adverse outcomes on dabigatran therapy were relatively low. Patients expressed polarised comments, both positive and negative, regarding their experiences of dabigatran. CONCLUSIONS: A high rate of discontinuation of dabigatran, mainly due to GI symptoms, was observed. There does not appear to be any specific predictor of dabigatran tolerance. When prescribed according to guidelines, rates of serious adverse events associated with dabigatran appear to be low.

Alteration of striatal dopaminergic neurotransmission in a mouse model of DYT11 myoclonus-dystonia.

BACKGROUND: DYT11 myoclonus-dystonia (M-D) syndrome is a neurological movement disorder characterized by myoclonic jerks and dystonic postures or movement that can be alleviated by alcohol. It is caused by mutations in SGCE encoding ε-sarcoglycan (ε-SG); the mouse homolog of this gene is Sgce. Paternally-inherited Sgce heterozygous knockout (Sgce KO) mice exhibit myoclonus, motor impairment and anxiety- and depression-like behaviors, modeling several clinical symptoms observed in DYT11 M-D patients. The behavioral deficits are accompanied by abnormally high levels of dopamine and its metabolites in the striatum of Sgce KO mice. Neuroimaging studies of DYT11 M-D patients show reduced dopamine D2 receptor (D2R) availability, although the possibility of increased endogenous dopamine, and consequently, competitive D2R occupancy cannot be ruled out. METHODOLOGY/PRINCIPAL FINDINGS: The protein levels of striatal D2R, dopamine transporter (DAT), and dopamine D1 receptor (D1R) in Sgce KO mice were analyzed by Western blot. The striatal dopamine release after amphetamine injection in Sgce KO mice were analyzed by microdialysis in vivo. The striatal D2R was significantly decreased in Sgce KO mice without altering DAT and D1R. Sgce KO mice also exhibited a significant increase of dopamine release after amphetamine injection in comparison to wild-type (WT) littermates. CONCLUSION/SIGNIFICANCE: The results suggest ε-SG may have a role in the regulation of D2R expression. The loss of ε-SG results in decreased striatal D2R, and subsequently leads to increased discharge of dopamine which could contribute to the behavioral impairment observed in DYT11 dystonia patients and in Sgce KO mice. The results suggest that reduction of striatal D2R and enhanced striatal dopamine release may contribute to the pathophysiology of DYT11 M-D patients.

Reaction rate constants and mechanistic detail of the Ni+ + butanone reaction.

The unimolecular decomposition kinetics of the jet-cooled Ni(+)-butanone cluster ion has been monitored over a range of internal energies (16000-18800 cm⁻¹). First-order rate constants are acquired for the precursor ion dissociation into three product channels. The temporal growth of each fragment ion is selectively monitored in a custom instrument and yields similar valued rate constants at a common ion internal energy. The decomposition reaction is proposed to proceed along two parallel reaction coordinates. Each dissociative pathway is rate-limited by the initial Ni(+) oxidative addition into either the C-CH3 or C-C2H5 σ-bond in the butanone molecule. Ratios of integrated product ion intensities as well as the measured rate constants are used to determine values for each σ-bond activation rate constant. The lowest energy measurement presented in this study occurs when the binary complex ion possesses an internal energy of 16000 cm⁻¹. Under this condition, the Ni(+) assisted decomposition of the butanone molecule is rate limited by k(act)(C-C2H5) = (0.92 ± 0.08) × 105 s⁻¹ and k(act)(C-CH3) = (0.37 ± 0.03) × 105 s⁻¹. The relative magnitudes of the two rate constants reflect the greater probability for reaction to occur along the C-C2H5 σ-bond insertion pathway, consistent with thermodynamic arguments. DFT calculations at the B3LYP/6-311++G(d,p) level of theory suggest the most likely geometries and relative energies of the reactants, intermediates, and products.

Evaluation of Actinobacillus pleuropneumoniae diagnostic tests using samples derived from experimentally infected pigs.

New serological tests have recently been introduced for Actinobacillus pleuropneumoniae diagnosis. No information is currently available on how these tests compare regarding the detection of antibodies from subclinically infected pigs. To answer this question, 80 pigs were randomly assigned to experimental groups infected with A. pleuropneumoniae serovars 1, 3, 5, 7, 10, 12, 15 and a non-inoculated control group. Blood samples and oropharyngeal swabs were collected prior to infection and for 7 consecutive weeks thereafter. Serum samples were tested using the Swinecheck(®) APP ELISA and the Multi-APP ELISA (University of Montreal). All pigs were euthanized at 49 days post-inoculation. Tonsil and lung samples were cultured for isolation and tested by PCR. The Multi-APP ELISA detected seroconversion 1 week earlier than the Swinecheck(®) APP ELISA with the earliest seroconversion detected at 1 week post-infection (serovar 10) and the latest at 3 weeks post-infection (serovar 1). Seroconversion at day 49 was serovar-dependent and varied from 4 (44%) positives detected in the serovar 10 group to 9 positives (100%) detected in the serovar 15 group. Thirty-one pigs were serologically positive for A. pleuropneumoniae at 49 days post-infection and only 15 still carried A. pleuropneumoniae on their tonsils based on PCR results. No cross-reactions were observed when serum samples were cross-tested using the Swinecheck(®) APP ELISA. A. pleuropneumoniae was successfully isolated from the lung of 2 pigs that developed pleuropneumonia, but was not isolated from tonsils due to heavy contamination by the resident flora. This study offers a comprehensive evaluation of the diagnostic tools currently available for detection of A. pleuropneumoniae subclinical infection.

Low-energy reaction rate constants for the Ni+-assisted decomposition of acetaldehyde: observation of C-H and C-C activation.

Rate constants for the low-energy Ni(+)-assisted dissociative reaction of acetaldehyde have been measured under jet-cooled conditions in the gas phase. The rate constants are acquired through monitoring the time dependence of fragment Ni(+)CO formation. The decomposition of the precursor Ni(+)-acetaldehyde cluster ion proceeds via consecutive, parallel reaction coordinates that originate with the Ni(+)-assisted cleavage of either a C-C or an aldehyde C-H bond. The energies used to initiate these reactions are well below that required to cleave sigma-bonds in the isolated acetaldehyde molecule. Direct measurement of the reaction kinetics over a range of energies indicates that the rate-limiting step in the dissociative mechanism changes at cluster ion internal energies = 17,200 +/- 400 cm(-1). Arguments are presented that this energy marks the closure of the dissociative coordinate that initiates with C-H sigma-bond activation and thus provides a measure of the activation energy of this dissociative pathway.

Rate-limiting step in the low-energy unimolecular decomposition reaction of Ni+* acetone into Ni+CO + ethane.

Rate constants for the low-energy Ni(+)-assisted C-C bond cleavage reaction of deuterium-labeled acetone have been acquired under jet-cooled conditions in the gas phase. The energies used to initiate the dissociative reactions of the precursor complex ion Ni(+)(d(6)-Ac) are well below that required to cleave C-C sigma-bonds in isolated organic molecules. The rate constants are compared to those acquired previously for the lighter Ni(+)(h(6)-Ac) isotope and result in a substantial kinetic isotope effect (k(H)/k(D) approximately 5.5). Arguments are made that implicate isomerization leading to C-C bond coupling as the rate-limiting step (not C-C sigma-bond activation) in the dissociative reaction.

The low-energy unimolecular reaction rate constants for the gas phase, Ni+-mediated dissociation of the C-C sigma bond in acetone.

The time dependence of the gaseous unimolecular decomposition of the jet-cooled adduct ion, Ni+-OC(CH3)2, was monitored through selective detection of the Ni+CO fragment ion. Various resolved amounts of energy in the range 15600-18800 cm(-1) were supplied to initiate the dissociation reaction through absorption of laser photons by the title molecular complex. First-order rate constants, k(E), ranged from 113000 to 55000 s(-1) and decreased with decreasing amounts of internal excitation. The energy used to initiate the reaction is well below that required to fragment C-C sigma bonds and indicates the necessity of the Ni+ cation to induce bond activation and fragmentation. These measurements are carried out in a unique apparatus and represent the first direct kinetic study of such catalytic type reactions.

Copper binding components of blood plasma and organs, and their responses to influx of large doses of (65)Cu, in the mouse.

To establish for the first time how mice might differ from rats and humans in terms of copper transport, excretion, and copper binding proteins, plasma and organ cytosols from adult female C57CL6 mice were fractionated and analyzed by directly coupled size exclusion HPLC-ICP-MS, before and after i.p. injection of large doses of (65)Cu. Plasma from untreated mice had different proportions of Cu associated with transcuprein/macroglobulin, ceruloplasmin and albumin than in humans and rats, and two previously undetected copper peaks (Mr 700 k and 15 k) were observed. Cytosols had Cu peaks seen previously in rat liver (Mr > 1,000 k, 45 k and 11 k) plus one of 110 kDa. (65)Cu (141 microg) administered over 14 h, initially loaded plasma albumin and mainly entered liver and kidney (especially 28 kDa and 11 kDa components). Components of other organs were less (but still significantly) enriched. (63)Cu/(65)Cu ratios returned almost to normal by 14 days, indicating a robust system for excreting excess copper. We conclude that there are significant differences but also strong similarities in copper metabolism between mice, rats and humans; that the liver is able to buffer enormous changes in copper status; and that a large number of mammalian copper proteins remain to be identified.

Infection dynamics of porcine reproductive and respiratory syndrome virus in a continuous-flow population of pigs also infected with Mycoplasma hyopneumoniae.

Twenty-eight 10-week-old pigs were inoculated intratracheally with 1 x 10(5) colour-changing units/ml Mycoplasma hyopneumoniae strain 232, and another 32 pigs were not inoculated but were divided into 12 direct-contact pigs and 20 indirect-contact pigs. Thirty-five days later, the inoculated pigs were inoculated intranasally with 1 x 10(2.4) tcid50 of porcine reproductive and respiratory syndrome virus (PRRSV) strain mn 30-100. Viraemia, seroconversion and the transmission of PRRSV in the M hyopneumoniae-infected pigs were then assessed for four months. Three groups of 10 age-matched gilts were introduced as sentinels into the experimental barn on days 28, 56 and 84 after the PRRSV infection. The persistence of PRRSV was evaluated in both the experimentally and naturally infected pigs, which were slaughtered 120, 135 and 150 days after the infection. The period of viraemia and the extent of seroconversion were similar to those observed in studies of pigs infected only with PRRSV, suggesting that under the conditions of the study M hyopneumoniae did not affect these features of the disease. A delayed pattern in the seroconversion and proportion of pcr-positive pigs was observed in the direct and indirect contact groups, and the persistence of PRRSV in tissues was confirmed by pcr at 120 and 150 days after infection only in the directly inoculated pigs and not in the direct- or indirect-contact groups of pigs.

Evaluation of the aerosol transmission of a mixed infection of Mycoplasma hyopneumoniae and porcine reproductive and respiratory syndrome virus.

To evaluate the transmission of Mycoplasma hyopneumoniae and porcine reproductive and respiratory syndrome virus (PRRSV) by aerosol as either a single or mixed infection, 28 pigs were inoculated intratracheally with M hyopneumoniae on day 0 and infected intranasally with PRRSV on day 35; they were housed together in a barn. To assess the aerosol transmission of M hyopneumoniae as a single infection, one trailer (A) containing 10 five-week-old sentinel pigs was placed along the south side of the infected barn (1 m from the fans) on day 28. To assess the mixed infection, two trailers (B and C), each containing 10 five-week-old sentinel pigs, were placed along each side of the barn on day 42. The sentinel pigs in the three trailers were exposed to the exhaust from the fans for seven days. No M hyopneumoniae infection was detected in the sentinel pigs in trailer A, but it was detected in the sentinel pigs in trailers B and C. No PRRSV was detected in any of the sentinel pigs.

Pro- and anti-apoptotic evidence for cholinergic denervation and hippocampal sympathetic ingrowth in rat dorsal hippocampus.

In rat, injection of the specific cholinotoxin, 192 IgG-saporin, into the medial septum results not only in a selective cholinergic denervation of hippocampus, but in an ingrowth of peripheral sympathetic fibers, originating from the superior cervical ganglion, into the hippocampus. A similar process, in which peripheral noradrenergic axons invade hippocampus, may also occur in Alzheimer's disease. Since apoptotic cell death has been demonstrated in the selective neuronal loss found in Alzheimer's disease, the aim of this study was to measure apoptotic protein expression and DNA fragmentation in hippocampal sympathetic ingrowth and cholinergic denervation. Western blot, TdT-mediated dUTP nick end labeling, and oligo ligation techniques were used. Choline acetyltransferase activity and norepinephrine concentrations were also measured. As seen in our previous results, an increase in apoptotic markers was induced by cholinergic denervation alone (medial septum lesion + ganglionectomy), while hippocampal sympathetic ingrowth (medial septum + sham ganglionectomy) reduced or normalized apoptotic effects to control group levels. A decrease in choline acetyltransferase activity was also found in the dorsal hippocampus of hippocampal sympathetic ingrowth and cholinergic denervation groups. An increase in norepinephrine concentration was found in hippocampal sympathetic ingrowth but not in cholinergic denervation group. Results of this study suggest that cholinergic denervation is responsible for most of the proapoptotic responses, while hippocampal sympathetic ingrowth produces a protective effect in the process of programmed cell death in rat dorsal hippocampus. This effect may be a secondary to an altered relationship between norepinephrine-acetylcholine.

Laboratory model to evaluate the role of aerosols in the transport of porcine reproductive and respiratory syndrome virus.

The aim of this study was to develop a model to evaluate the aerosol transmission of porcine reproductive and respiratory disease virus (PRRSV). PRRSV (MN 30-100 strain, total dose 3 x 10(6) virus particles) was aerosolised and transported up to 150 m and a portable air sampler was used to collect air samples at 1, 30, 60, 90, 120 and 150 m (five replicates at each distance) and the air samples were tested by TaqMan PCR and virus isolation. The infectivity of the aerosolised PRRSV was tested by exposing six PRRSV-naive pigs for three hours to aerosolised virus that had been transported 150 m. PRRSV RNA was detected in all five replicate air samples collected at 1, 30, 60 and 90 m, in four of the five collected at 120 m, and in three of the five collected at 150 m. Infectious PRRSV was detected by virus isolation at 1 and 30 m (all five replicates), 60, 90 and 120 m (three of the five) and 150 m (two of the five). There was a 50 per cent reduction in the log concentration of PRRSV RNA every 33 m. Three of the six pigs exposed to PRRSV-positive aerosols became infected, and PRRSV RNA was detected in air samples and on swab samples collected from the interior of the chambers that housed the infected pigs while they were being exposed.

The effect of central cholinergic and noradrenergic denervation on hippocampal sympathetic ingrowth and apoptosis-like reactivity in the rat.

In this study, the effect of intraseptal injection of specific cholinotoxin 192-IgG saporin (SAP) +/- intraperitoneal injection of N-[chloroethyl]-N-ethyl-2-bromobenzylamine (DSP-4) (noradrenergic fiber neurotoxin) was examined in rat hippocampus. Medial septal lesions resulted not only in selective cholinergic denervation of hippocampus (Medial septal lesion + ganglionectomy; SAP + Gx) but also in hippocampal sympathetic ingrowth (IG) of adrenergic fibers (Medial septal lesion + sham ganglionectomy; SAP + IG). Saporin-induced septal lesions produced a significant reduction in hippocampal choline acetyltransferase activity in all tested groups (SAP + IG +/- DSP-4 and SAP + Gx +/- DSP-4), and an increase in noradrenaline concentration in the SAP + IG group. Visualization of noradrenergic fibers by histofluorescence revealed a mixture of fine and thick varicosities in the SAP + IG but only fine fibers in control and SAP + Gx animals. SAP + IG + DSP-4 lesions produced significant reduction in noradrenaline concentration in all groups with a concomitant decrease in visualization of central noradrenergic fibers in dorsal and ventral hippocampus. Treatment of SAP + IG animals with DSP-4 left mostly thick fibers, probably derived from peripheral sympathetic ingrowth. No fluorescence was seen in either the control + DSP-4 or SAP + Gx + DSP-4 animals. Apoptotic-like changes, using in situ oligonucleotide ligation techniques, were also assessed. Proapoptotic changes were seen in the SAP + Gx +/- DSP-4 group as compared to CON +/- DSP-4 groups. SAP + IG regardless of DSP-4 treatment protected hippocampal cells from apoptotic cell death when compared to positive control and SAP + Gx +/- DSP-4 groups. In summary, elevated noradrenaline concentration following specific cholinergic denervation probably reflects compensatory hippocampal ingrowth originating from the peripheral sympathetic system which may be responsible for neuroprotective effects, i.e., antiapoptosis-like effect. Since cholinergic and noradrenergic systems are known to be involved in Alzheimer's disease and related cognitive function, knowing how these neurotransmitters work after specific lesions may be of importance as an animal model of Alzheimer's disease and as a potential target for Alzheimer's disease drug therapies.