Detection and characterization of methicillin-resistant Staphylococcus pseudintermedius in healthy dogs in La Rioja, Spain

The objective was to identify the methicillin-resistant coagulase-positive staphylococci (MRCoPS) nasal carriage rate of healthy dogs in La Rioja (Spain) and to characterize the recovered isolates by different molecular techniques. Nasal samples from 196 dogs were obtained (98 household-dogs, 98 pound-dogs). Isolates were identified and characterized by spa-, SCCmec- and MLST-typing, SmaI-PFGE, antimicrobial susceptibility, determination of antimicrobial resistance and toxin genes profiling. S. pseudintermedius was the only species recovered. Nine methicillin-resistant S. pseudintermedius (MRSP) were obtained from 9 of 196 sampled dogs (8% pound-dogs, 1% household-dogs). MRSP isolates were typed (MLST/PFGE/spa/SCCmec) as: ST71/A/t02/II–III (7 isolates), ST92/C/t06/V (1 isolate), and ST26/B/non-typable/non-typable (1 isolate). All MRSP were resistant to [resistance gene/number isolates]: β-lactams [mecA + blaZ/9], tetracycline [tet(K)/7, tet(M)/2], macrolides and lincosamides [erm(B)/9], aminoglycosides [aacA-aphD + aadE + aphA-3/9], and co-trimoxazol [dfr(G)/9]. Eight MRSP isolates showed also resistance to fluoroquinolones and amino acid changes in GyrA [Ser84Leu + Glu714Lys, 7 isolates; Ser84Leu, 1 isolate] and GrlA [Ser80Ile, 8 isolates] proteins were detected. The remaining isolate was chloramphenicol resistant and harboured cat_pC221 gene. All MRSP isolates harboured the aadE-sat4-aphA-3 multiresistance-gene-cluster linked to erm(B) gene as well as the siet, si-ent and lukS/F-I toxin genes. MRSP is a moderately common (4.6%) colonizer of healthy dogs in Spain. A major MRSP lineage (ST71) was detected and its future evolution should be tracked.     

High-elevation landforms limit the movement of invasive small mammal species

Landscape Ecology - Large-scale programs for eradication of pest mammals are confronted with the challenge of managing reinvasion. Exploiting high-elevation landscape features that naturally limit...     

Effect of Particle Size and Reused Organic Substrates on Tomato Crop Production

The bagasse of mezcal maguey and the fiber of coconut fruit are organic byproducts of the mezcal and copra agro-industries in Oaxaca, Mexico. The effects of different particle sizes and prior usage times as substrates on the production and quality of tomato (Lycopersicon esculentum Mill) were studied. Three independent and simultaneous experiments were conducted in multi-tunnel greenhouses. Three prior growing cycles of tomato crop, each 150 days in length days of use (DOU), were used for the usage time experiments with mezcal maguey bagasse as the growth medium. In the first experiment, tomato plants grown on substrate with 150 DOU produced the highest yields, the largest number of commercial quality fruits and the fewest non-commercial quality fruits. In the second experiment, the combination of fine particle size and maguey bagasse substrate with 150 DOU produced the highest yields. In the third experiment, fine and medium-sized particles of maguey bagasse and coconut fiber produced the highest yields. The data indicate that both coconut fiber and mezcal maguey bagasse can be used as substrates for tomato cultivation without affecting fruit quality; furthermore, the use of fine and medium-sized particles increases production. Maguey bagasse with up to 150 DOU as a substrate is best for culture, as prior usage beyond this length of time negatively affects production.     

Evolution of introduced Chinook salmon (Oncorhynchus tshawytscha) in Lake Huron: emergence of population genetic structure in less than 10 generations

Abstract – Population genetic structure was detected in Chinook salmon Oncorhynchus tshawytscha in their non‐native range of Lake Huron using microsatellite DNA. All Chinook salmon in this system descend from Green River, Washington cohorts, originally transplanted to Michigan hatcheries in the late 1960s. We tested for population genetic differentiation of age 0 fish collected from 13 rivers and two hatcheries in 2007. The amount of genetic differentiation among collection sites was low but statistically significant, with F_ST values ranging from 0.036 to 0.133 and R_ST values ranging from 0.008 to 0.157 for specific loci. Based on pairwise F_ST and R_ST values and Bayesian cluster analysis, the Maitland River population in the Main Basin of Lake Huron was genetically distinct from the remaining collection sites. Based on analysis of bycatch data from commercial gill net fisheries, Chinook salmon likely colonised the Main Basin by 1975 (10 generations ago) and the North Channel and southern Georgian Bay regions by 1980 (eight generations ago). Thus, population genetic structure has emerged in Lake Huron Chinook salmon in <10 generations.     

Bovine paramphistomosis in Galicia (Spain): Prevalence,intensity, aetiology and geospatial distribution of the infection

The present study explored various basic aspects of the epidemiology of paramphistomosis in Galicia, the main cattle producing region in Spain. In total, 589 cows from different farms located across the region were selected at random in the slaughterhouse for examination of the rumens and reticula for the presence of Paramphistomidae flukes. Paramphistomes were found in 111 of 589 necropsied cows (18.8%; 95% CI: 15.7–21.9%), with higher prevalences of infection in beef cows than in dairy cows (29.2% vs 13.9%). Although the number of flukes per animal was generally low (median = 266 flukes), some cows harboured large parasite burdens (up to 11,895 flukes), which may have harmful effects on their health or productivity. Cows with higher parasite burdens also excreted greater numbers of fluke eggs in their faeces, which suggests that heavily parasitized mature cows play an important role in the transmission of paramphistomosis. This role may be particularly important in Galicia, where the roe deer, which is the only wild ruminant in the study area, was found not to be a reservoir for the infection. The use of morpho-anatomical and molecular techniques applied to a large number of fluke specimens provided reliable confirmation that Calicophoron daubneyi is the only species of the family Paramphistomidae that parasitizes cattle in Galicia. The environmental data from the farms of origin of the necropsied cows were used in Bayesian geostatistical models to predict the probability of infection by C. daubneyi throughout the region. The results revealed the role of environmental risk factors in explaining the geographical heterogeneity in the probability of infection in beef and dairy cattle. These explanatory factors were used to construct predictive maps showing the areas with the highest predicted risk of infection as well as the uncertainty associated with the predictions.     

Efficiency and effectiveness in representative reserve design in Canada: The contribution of existing protected areas

To be effective, reserve networks should represent all target species in protected areas that are large enough to ensure species persistence. Given limited resources to set aside protected areas for biodiversity conservation, and competing land uses, a prime consideration for the design of reserve networks is efficiency (the maximum biodiversity represented in a minimum number of sites). However, to be effective, networks may sacrifice efficiency. We used reserve selection algorithms to determine whether collections of existing individual protected areas in Canada were efficient and/or effective in terms of representing the diversity of disturbance-sensitive mammals in Canada in comparison to (1) an optimal network of reserves, and (2) sites selected at random. Unlike previous studies, we restricted our analysis to individual protected areas that met a criterion for minimum reserve size, to address issues of representation and persistence simultaneously. We also tested for effectiveness and efficiency using historical and present-day data to see whether protected area efficiency and/or effectiveness varied over time. In general, existing protected areas did not effectively capture the full suite of mammalian species diversity, nor are most existing protected areas part of a near-optimal solution set. To be effective, Canada’s network of reserves will require at minimum 22 additional areas of >2700 km². This study shows that even when only those reserves large enough to be effective are considered, protected areas systems may not be representative, nor were they representative at the time of establishment.     

Developing and validating microsatellite markers in elephant grass (<Emphasis Type="Italic">Pennisetum purpureum</Emphasis> S.)

Elephant grass [Pennisetum purpureum S.; syn. Cenchrus purpureus (Schumach.) Morrone] is an important global forage crop and is recognized for high yields of herbage with good nutritive value. It also has high biomass potential to be utilized as a biofuel feedstock. Whereas several previous genetic studies adapted simple sequence repeat (SSR) markers from pearl millet [Pennisetum glaucum (L.) R.Br.] for investigations in elephant grass, the present study developed SSR markers from 3536 DNA sequences derived from 16 elephant grass entries. A total of 3866 SSRs were identified including 1028 monomeric, 2019 dimeric, 735 trimeric, 49 tetrameric, 20 pentameric and 15 hexameric repeat motifs. Three hundred and seven sequences contained more than one repeated motif, and 154 SSRs were present in compound formation. Susequenctly,  four elephant grass and two pearl millet genotypes were chosen to validate 727 SSR markers. Of these, 628 markers produced visually detectable amplification products, including 73 (11.6%) polymorphic ones across all six genotypes. Polymorphism between the four elephant grass genotypes was revealed by 316 (50.6%) markers with diversity index values ranging from 0.75 to 0.38. Dimeric SSRs had the highest polymorphic rate (48.7%). These validated SSR markers had 58.6% (368 of 628) transferability rate to pearl millet. The availability of these polymorphic SSR markers will support advanced genetic studies in P. purpureum and its relatives.