Determination of the effect of collars containing 10% w/w imidacloprid and 4.5% w/w flumethrin (Seresto®) on the incidence of Leishmania and other canine vector-borne pathogen infections in Greece

Background: The objective of this field study was to assess the effect of treating a considerable portion of a dog population naturally exposed to canine vector-borne pathogens (CVBPs) in endemic areas with a 10% w/w imidacloprid/4.5% w/w flumethrin collar (Seresto®) on the transmission of CVBPs and the resulting incidence of infection. Methods: A total of 479 dogs from two sites were enrolled in the study. Collars were placed on all dogs continuously for 21 months, with replacement of the collar every 7 months. All dogs were examined, including body weight and blood/conjunctival swab collections, every 7 months. Serum samples were analysed for the presence of antibodies against Leishmania infantum, Ehrlichia canis and Anaplasma phagocytophilum. PCR assays were also performed on blood samples and conjunctival swab collected from the dogs for the presence of L. infantum, and on blood samples only for the presence of Ehrlichia spp. and Anaplasma spp. Sand flies were collected, identified to species level and molecularly tested for L. infantum throughout two vector activity seasons. Results: The results showed that the Seresto collar was safe with continuous use. At study inclusion, 419, 370 and 453 dogs tested negative for L. infantum, Ehrlichia spp. and Anaplasma spp., respectively (353 dogs tested negative for any pathogen). Overall, 90.2% of the dogs were protected from L. infantum infection on both sites combined. The entomological survey confirmed the presence of competent vectors of L. infantum at all monitored locations, namely the sand flies Phlebotomus neglectus and Phlebotomus tobbi, both of which are regarded as the most important competent vectors in the Mediterranean basin. All captured sand flies tested negative for L. infantum. Protection against ticks and fleas was high, with only two dogs showing a low number of ticks and seven dogs having low numbers of fleas at single evaluation time points. Across the entire study population, a number of dogs became infected with tick-transmitted pathogens, but prevention of transmission was 93% for E. canis and 87.2% for Anaplasma spp. when all cases from both sites were combined. Conclusions: The Seresto® (10% w/w imidacloprid/4.5% w/w flumethrin) collar significantly reduced the risk of CVBP transmission when compared to previously observed incidences of CVBP infections in two highly endemic areas under field conditions

Defining the concept of ‘tick repellency’ in veterinary medicine

Although widely used, the term repellency needs to be employed with care when applied to ticks and other periodic or permanent ectoparasites. Repellency has classically been used to describe the effects of a substance that causes a flying arthropod to make oriented movements away from its source. However, for crawling arthropods such as ticks, the term commonly subsumes a range of effects that include arthropod irritation and consequent avoiding or leaving the host, failing to attach, to bite, or to feed. The objective of the present article is to highlight the need for clarity, to propose consensus descriptions and methods for the evaluation of various effects on ticks caused by chemical substances

Die Wahrnehmung verstehensfördernder Merkmale durch die Lernenden im physikbezogenen Unterricht der Primar- und Sekundarstufe:eine Längsschnittanalyse von der vierten bis zur siebten Klasse

Forschungsergebnisse belegen für die Wirksamkeit von Unterricht neben unterrichtlichen Lerngelegenheiten auch die Bedeutung von Mediationsprozessen auf Schülerseite. Die subjektive Schülerwahrnehmung von Unterricht ist damit ein wesentlicher Faktor z.B. für den Wissenserwerb. Sowohl bzgl. dieser Zielvariablen als auch bzgl. des Unterrichtsgeschehens weisen erste Studien auf Unterschiede zwischen der Primar- und Sekundarstufe hin. Inwieweit Lernende selber Veränderungen in ihrem Unterricht in der Phase des Schulstufenübergangs wahrnehmen und ob diese ggf. einen Einfluss auf den Aufbau ihrer kognitiven Kompetenzen haben, ist bislang wenig bekannt und wird in der vorliegenden Arbeit untersucht. Eingebettet in das Projekt PLUS-Längsschnitt wurden ca. 440 Lernende jährlich zu ihrem Unterricht befragt. Die Ergebnisse zeigen zumeist deutliche Rückgänge in der Wahrnehmung definierter Unterrichtsmerkmale von Klasse 4-7. In einer ergänzenden Interviewstudie wurden 20 Lernende zum Zusammenhang zwischen Unterrichtsmerkmalen und dem Verstehen von Unterrichtsinhalten befragt. Aus den Interviewdaten konnten Unterrichtsmerkmale hinsichtlich ihrer verstehensfördernden Wirkung eingeordnet werden

The effect of the hibernation on the larval development of Troglostrongylus brevior in the land snail Cornu aspersum

Troglostrongylus brevior, a lungworm affecting wild felids, has been increasingly reported in domestic cats from Europe. Troglostrongylosis is a relevant disease that may result in a potentially life-threatening bronchopneumonia, especially in kittens. The life cycle of T. brevior is indirect with terrestrial gastropods acting as intermediate host. The widely distributed spread land snail Cornu aspersum (former Helix aspersa) is competent for T. brevior development and may transmit the nematode in natural conditions. The present study evaluated the larval development of T. brevior in C. aspersum at two different environmental temperature conditions, with a focus on the effect of hibernation. One hundred and seventy snails were infected with 500 first stage larvae (L1) of T. brevior and kept in vivaria at 25 ± 2 °C. Fifteen days post infection (p.i.), 20 specimens were digested to evaluate the overall larval developmental rate from L1 to L3 (2.5 % on days 15 p.i.) and then the snails were divided in two groups, i.e. G1 kept at 25 ± 2 °C and G2 that were hibernated at 4 ± 2 °C. The developmental rate of T. brevior was evaluated in these groups on 30 and 60 days p.i. by snail digestion at each time-point. An additional batch of 40 snails (G2-1) was hibernated on D15 and digested on D60. Larvae recovered were morphologically and morphometrically examined. The infective third larval stage (L3) was detected in the muscular foot of C. aspersum at different rates depending on the environmental temperature. In particular, T. brevior showed a higher developmental rate in hibernated snails (G2: 6.9 % and 14.1 % on days 30 and 60 p.i; G2-1: 4%; G2 + G2-1 overall mean percentage: 9%) compared to non-hibernated snails (G1: 4% and 5.2 % on days 30 and 60 p.i.), indicating that lower temperatures may positively influence the developmental in C. aspersum. These data are suggestive for a seasonal pattern of T. brevior infections under field conditions, with snails containing higher parasitic burdens after their natural hibernation occurring in winter. Studies on the larval development of T. brevior in other mollusc species in field surveys evaluating differences in developmental rates and transmission patterns in different seasons are warranted

Disrupted function of lactate transporter MCT1, but not MCT4, in Schwann cells affects the maintenance of motor end-plate innervation.

Recent studies in neuron-glial metabolic coupling have shown that, in the CNS, astrocytes and oligodendrocytes support neurons with energy-rich lactate/pyruvate via monocarboxylate transporters (MCTs). The presence of such transporters in the PNS, in both Schwann cells and neurons, has prompted us to question if a similar interaction may be present. Here we describe the generation and characterization of conditional knockout mouse models where MCT1 or MCT4 is specifically deleted in Schwann cells (named MCT1 and MCT4 cKO). We show that MCT1 cKO and MCT4 cKO mice develop normally and that myelin in the PNS is preserved. However, MCT1 expressed by Schwann cells is necessary for long-term maintenance of motor end-plate integrity as revealed by disrupted neuromuscular innervation in mutant mice, while MCT4 appears largely dispensable for the support of motor neurons. Concomitant to detected structural alterations, lumbar motor neurons from MCT1 cKO mice show transcriptional changes affecting cytoskeletal components, transcriptional regulators, and mitochondria related transcripts, among others. Together, our data indicate that MCT1 plays a role in Schwann cell-mediated maintenance of motor end-plate innervation thus providing further insight into the emerging picture of the biology of the axon-glia metabolic crosstalk