Landscape‐mediated variation in diet is associated with egg size and maculation in a generalist forager

Human impacts alter landscapes with consequences for the distribution and availability of high‐quality food resources to populations inhabiting those landscapes, which may impact on the reproductive output of individuals in those populations. Sensitivity of wild populations to changes in food resources may vary among stages of the annual cycle. For example, in birds, effects are likely to be greater during costly stages such as egg production. Here we compare assimilated diet (from stable isotope analysis of chick feathers) and egg traits (egg size, shape, eggshell colour and maculation, using pattern‐analysis software) in Herring Gulls Larus argentatus, across seven colonies in southwest Scotland and Northern Ireland

Molecular basis of rifampicin resistance in methicillin-resistant Staphylococcus pseudintermedius isolates from dogs

Background: Methicillin-resistant Staphylococcus pseudintermedius (MRSP) often display resistance to almost all classes of antimicrobial agents used in veterinary medicine. In the present study, we investigated the emergence of rifampicin resistance in MRSP, the persistence of these isolates and identified the corresponding mutations in the rpoB gene. Methods: In addition to two rifampicin-resistant MRSP isolates from a multicentre study, consecutive MRSP isolates collected prior to and after rifampicin therapy from nine dogs at five Dutch veterinary hospitals were included in this study. The isolates were tested for resistance to rifampicin and other antimicrobial agents. The rifampicin resistance-determining region (RRDR) within the rpoB gene of the rifampicin-resistant and -susceptible isolates was amplified by PCR and sequenced. PFGE served to determine the genetic relationships of the MRSP isolates. Results: Two MRSP isolates of the multicentre study showed mutations at position 513 or 522 in the RRDR of the rpoB gene. In contrast to the rifampicin-susceptible isolates, all rifampicin-resistant MRSP isolates showed mutations at one or two of the amino acid positions 508, 509, 513, 516, 522, 526 and 531. In most strains, a single amino acid exchange was observed. PFGE analysis confirmed that the rifampicin-resistant MRSP isolates were indistinguishable from or closely related to the rifampicin-susceptible isolate obtained from the same dog prior to rifampicin application. Conclusions: Therapy of MRSP infections with rifampicin results in the rapid emergence of rifampicin resistance and these isolates can persist for months. As a consequence, single therapy with rifampicin is not recommended

Molecular basis of rifampicin resistance in methicillin-resistant Staphylococcus pseudintermedius isolates from dogs

Background: Methicillin-resistant Staphylococcus pseudintermedius (MRSP) often display resistance to almost all classes of antimicrobial agents used in veterinary medicine. In the present study, we investigated the emergence of rifampicin resistance in MRSP, the persistence of these isolates and identified the corresponding mutations in the rpoB gene. Methods: In addition to two rifampicin-resistant MRSP isolates from a multicentre study, consecutive MRSP isolates collected prior to and after rifampicin therapy from nine dogs at five Dutch veterinary hospitals were included in this study. The isolates were tested for resistance to rifampicin and other antimicrobial agents. The rifampicin resistance-determining region (RRDR) within the rpoB gene of the rifampicin-resistant and -susceptible isolates was amplified by PCR and sequenced. PFGE served to determine the genetic relationships of the MRSP isolates. Results: Two MRSP isolates of the multicentre study showed mutations at position 513 or 522 in the RRDR of the rpoB gene. In contrast to the rifampicin-susceptible isolates, all rifampicin-resistant MRSP isolates showed mutations at one or two of the amino acid positions 508, 509, 513, 516, 522, 526 and 531. In most strains, a single amino acid exchange was observed. PFGE analysis confirmed that the rifampicin-resistant MRSP isolates were indistinguishable from or closely related to the rifampicin-susceptible isolate obtained from the same dog prior to rifampicin application. Conclusions: Therapy of MRSP infections with rifampicin results in the rapid emergence of rifampicin resistance and these isolates can persist for months. As a consequence, single therapy with rifampicin is not recommended

Clonal spread of methicillin-resistant Staphylococcus pseudintermedius in Europe and North America: an international multicentre study

Objectives: The aim of this study was to determine the phenotypic and genotypic resistance profiles of methicillin-resistant Staphylococcus pseudintermedius (MRSP) and to examine the clonal distribution in Europe and North America. Methods: A total of 103 MRSP isolates from dogs isolated from several countries in Europe, the USA and Canada were characterized. Isolates were identified by PCR-restriction fragment length polymorphism (RFLP), antimicrobial susceptibility was determined by broth dilution or gradient diffusion, and antimicrobial resistance genes were detected using a microarray. Genetic diversity was assessed by multilocus sequence typing (MLST), PFGE and spa typing. Staphylococcal cassette chromosome mec (SCCmec) elements were characterized by multiplex PCR. Results: Thirteen different sequence types (STs), 18 PFGE types and 8 spa types were detected. The hybrid SCCmec element II-III described in a MRSP isolate was present in 75 (72.8%) isolates. The remaining isolates either had SCCmec type III (n=2), IV (n=6), V (n=14) or VII-241 (n=4) or were non-typeable (n=2). The most common genotypes were ST71(MLST)-J(PFGE)-t02(spa)-II-III(SCCmec) (56.3%) and ST68-C-t06-V (12.6%). In addition to mecA-mediated beta-lactam resistance, isolates showed resistance to trimethoprim [dfr(G)] (90.3%), gentamicin/kanamycin [aac(6')-Ie-aph(2')-Ia] (88.3%), kanamycin [aph(3')-III] (90.3%), streptomycin [ant(6')-Ia] (90.3%), streptothricin (sat4) (90.3%), macrolides and/or lincosamides [erm(B), lnu(A)] (89.3%), fluoroquinolones (87.4%), tetracycline [tet(M) and/or tet(K)] (69.9%), chloramphenicol (cat(pC221)) (57.3%) and rifampicin (1.9%). Conclusions: Two major clonal MRSP lineages have disseminated in Europe (ST71-J-t02-II-III) and North America (ST68-C-t06-V). Regardless of their geographical or clonal origin, the isolates displayed resistance to the major classes of antibiotics used in veterinary medicine and thus infections caused by MRSP isolates represent a serious therapeutic challenge