Seroprevalence of Toxoplasma gondii among Nunavik Inuit (Canada)

As a result of their intimate contact with the land and their nutritional habits, the Inuit of Nunavik are considered to be at risk from zoonotic infections. To better understand the risk factors for Toxoplasma gondii infection, a serosurvey was conducted in Nunavik, Québec, in September 2004. A representative sample of the Inuit adult population of Nunavik participated in this cross-sectional study (n = 917). Antibodies (IgG) against T. gondii were detected by immunoassay. Information on sociodemographic characteristics, traditional activities, domestic environment and nutrition was gathered by questionnaire and explored as variables explanatory of seropositive results. Associations found to be statistically significant in univariate analyses were assessed by multivariable logistic regression to control for confounding factors. Almost two thirds (59.8%) of the Inuit of Nunavik were found to be seropositive for T. gondii. In multivariate analyses, risk factors for seropositivity were: increasing age, gender (women > men), lower level of education, consumption of potentially contaminated water (determined by an index of risk from waterborne infections), frequent cleaning of water reservoirs, and consumption of seal meat and feathered game. There was some variation in seroprevalence between the Ungava Bay coast (52.3%) and the Hudson Bay coast (65.6%), the two main regions of Nunavik, but this variation was not significant in the multivariable logistic regression model. This cross-sectional study demonstrated high T. gondii seroprevalence in the Inuit population and revealed that age, gender, schooling and community of residence all influence serostatus in this population. Variables related to drinking water and food choices may also influence the risk of infection. These results raise important questions about T. gondii transmission in Nunavik including possible links between terrestrial and marine cycles.     

Clay mineralogy differs qualitatively in aggregate‐size classes: clay‐mineral‐based evidence for aggregate hierarchy in temperate soils

Clay minerals have a major role in soil aggregation because of their large specific surface area and surface charges, which stimulate interactions with other mineral particles and organic matter. Soils usually contain a mixture of clay minerals with contrasting surface properties. Although these differences should result in different abilities of clay minerals regarding aggregate formation and stabilization, the role of different clay minerals in aggregation has been seldom evaluated. In this study, we took advantage of the intrinsic mineral heterogeneity of a temperate Luvisol to compare the role of clay minerals in aggregation. First, grassland and tilled soil samples were separated in water into aggregate‐size classes based on the aggregate hierarchy model. Then, clay mineralogy and organic C in the aggregate‐size classes were analysed. Interstratified minerals containing swelling phases accumulated in aggregated fractions compared with free clay fractions under the two land‐uses. The accumulation increased with decreasing aggregate size from large macroaggregates (> 500 µm) to microaggregates (50–250 µm). Carbon content and carbon‐to‐nitrogen ratio followed the opposite trend. This fully supports the aggregate hierarchy model, which postulates an increasing importance of mineral reactivity in smaller aggregates than in larger aggregates in which the cohesion relies mostly on physical enmeshment by fungal hyphae or small roots. Consequently, differences in the proportion of the different 2:1 clay minerals in soils can influence their structure development. Further research on the links between clay mineralogy and aggregation can improve our understanding of mechanisms of soil resistance to erosion and organic matter stabilization.     

Increasing circulation of Alaria alata mesocercaria in wild boar populations of the Rhine valley,France, 2007–2011

The presence of the mesocercarial stage of Alaria alata (Goeze, 1792) in wild boar meat represents a potential risk for human, but little is known about the circulation of mesocercaria in wild boar populations. Routine Trichinella inspection, mandatorily performed in wild boar in France, also allowed detecting mesocercaria. We analyzed the results of this detection in the carcasses of 27,582 wild boars hunted in 2007–2011, in 502 hunting areas of the Rhine valley. Prevalence was globally low (0.6%), but 12% of the hunting areas were affected. These were clustered in lowlands of the Rhine valley, and prevalence strongly decreased with increasing elevation. In the lowlands, prevalence doubled between 2007 and 2011. This time trend and the geographic aggregation of positive wild boars suggest risk management measures based on targeted surveillance, control and prevention.     

Identification and characterization of methicillin-resistant Staphylococcus aureus (MRSA) from Austrian companion animals and horses

The aim of this study was to investigate the antimicrobial resistance, resistance gene patterns and genetic relatedness of a collection of Austrian methicillin-resistant Staphylococcus aureus (MRSA) isolates from companion animals and horses.A total of 89 non-repetitive MRSA isolates collected during routine veterinary microbiological examinations from April 2004 to the end of 2012, and one isolate from 2013 were used for this study. The presence of mecA and other resistance genes was confirmed by PCR. Isolates were genotyped by spa typing, two multiple-locus variable-number tandem repeat analyses (MLVA) analyses, SCCmec typing and multilocus sequence typing (MLST). PCR targeting Panton-Valentine leukocidin (PVL) and detection of staphylococcal enterotoxins (SE), toxic shock syndrome toxin (TSST) was performed using PCR assays. Antimicrobial susceptibility testing was performed.Five sequence types (STs—ST398, ST254, ST22, ST5 and ST1), SCCmec types II, IVa, V, and non-type-abele, 8 spa-types (t003, t011, t036, t127, t386, t1348, and t4450), and two isolates could not be assigned, 21 MLVA-14Orsay types Multiplex-PCR MLVA (mMLVA) displayed 17 different MLVA types.The present study is the most comprehensive dealing with MRSA from Austrian companion animals and horses. The results confirm that MRSA ST398 is present in a wide range of animal species and is predominant especially in horses. In other companion animals it is unclear whether the infections with the different MRSA isolates investigated in the present study truly represents a rare phenomenon or may be an emerging problem in companion animals.     

Hierarchical faunal filters: an approach to assessing effects of habitat and nonnative species on native fishes

Abstract –  Understanding factors related to the occurrence of species across multiple spatial and temporal scales is critical to the conservation and management of native fishes, especially for those species at the edge of their natural distribution. We used the concept of hierarchical faunal filters to provide a framework for investigating the influence of habitat characteristics and nonnative piscivores on the occurrence of 10 native fishes in streams of the North Platte River watershed in Wyoming. Three faunal filters were developed for each species: (i) large-scale biogeographic, (ii) local abiotic, and (iii) biotic. The large-scale biogeographic filter, composed of elevation and stream-size thresholds, was used to determine the boundaries within which each species might be expected to occur. Then, a local abiotic filter (i.e., habitat associations), developed using binary logistic-regression analysis, estimated the probability of occurrence of each species from features such as maximum depth, substrate composition, submergent aquatic vegetation, woody debris, and channel morphology (e.g., amount of pool habitat). Lastly, a biotic faunal filter was developed using binary logistic regression to estimate the probability of occurrence of each species relative to the abundance of nonnative piscivores in a reach. Conceptualising fish assemblages within a framework of hierarchical faunal filters is simple and logical, helps direct conservation and management activities, and provides important information on the ecology of fishes in the western Great Plains of North America.     

Phenotypic and genotypic background underlying variations in fatty acid composition and sensory parameters in European bovine breeds

Background

Consuming moderate amounts of lean red meat as part of a balanced diet valuably contributes to intakes of essential nutrients. In this study, we merged phenotypic and genotypic information to characterize the variation in lipid profile and sensory parameters and to represent the diversity among 15 cattle populations. Correlations between fat content, organoleptic characteristics and lipid profiles were also investigated.

Methods

A sample of 436 largely unrelated purebred bulls belonging to 15 breeds and reared under comparable management conditions was analyzed. Phenotypic data -including fatness score, fat percentage, individual fatty acids (FA) profiles and sensory panel tests- and genotypic information from 11 polymorphisms was used.

Results

The correlation coefficients between muscle total lipid measurements and absolute vs. relative amounts of polyunsaturated FA (PUFA) were in opposite directions. Increasing carcass fat leads to an increasing amount of FAs in triglycerides, but at the same time the relative amount of PUFAs is decreasing, which is in concordance with the negative correlation obtained here between the percentage of PUFA and fat measurements, as well as the weaker correlation between total phospholipids and total lipid muscle content compared with neutral lipids. Concerning organoleptic characteristics, a negative correlation between flavour scores and the percentage of total PUFA, particularly to n-6 fraction, was found. The correlation between juiciness and texture is higher than with flavour scores. The distribution of SNPs plotted by principal components analysis (PCA) mainly reflects their known trait associations, although influenced by their specific breed allele frequencies.

Conclusions

The results presented here help to understand the phenotypic and genotypic background underlying variations in FA composition and sensory parameters between breeds. The wide range of traits and breeds studied, along with the genotypic information on polymorphisms previously associated with different lipid traits, provide a broad characterization of beef meat, which allows giving a better response to the variety of consumers’ preferences. Also, the development and implementation of low-density SNP panels with predictive value for economically important traits, such as those summarized here, may be used to improve production efficiency and meat quality in the beef industry.     

Antimicrobial susceptibility and molecular characterization of avian pathogenic Escherichia coli isolates

Ninety-five avian pathogenic Escherichia coli (APEC) isolates recovered from diagnosed cases of avian colibacillosis from North Georgia between 1996 and 2000 were serotyped and examined for typical virulence-factors, susceptibility to antimicrobials of human and veterinary significance, and genetic relatedness. Twenty different serotypes were identified, with O78 being the most common (12%). The majority of the avian E. coli isolates (60%), however, were non-typeable with standard O antisera. Eighty-four percent of isolates were PCR positive for the temperature-sensitive hemagglutinin (tsh) gene and 86% positive for the increased serum survival (iss) gene. Multiple antimicrobial-resistant phenotypes (> or =3 antimicrobials) were observed in 92% of E. coli isolates, with the majority of isolates displaying resistance to sulfamethoxazole (93%), tetracycline (87%), streptomycin (86%), gentamicin (69%), and nalidixic acid (59%). Fifty-six E. coli isolates displaying resistance to nalidixic acid were co-resistant to difloxacin (57%), enrofloxacin (16%), gatifloxacin (2%), and levofloxacin (2%). DNA sequencing revealed point mutations in gyrA (Ser83-Leu, Asp87-Tyr, Asp87-Gly, Asp87-Ala), gyrB (Glu466-Asp, Asp426-Thr), and parC (Ser80-Ile, Ser80-Arg). No mutations were observed in parE. Twelve of the quinolone-resistant E. coli isolates were tolerant to cyclohexane, a marker for upregulation of the acrAB multi-drug resistance efflux pump. Quinolone-resistant isolates were further genetically characterized via ribotyping. Twenty-two distinct ribogroups were identified, with 61% of isolates clustering into four major ribogroups, indicating that quinolone resistance has emerged among multiple avian pathogenic E. coli serogroups and chromosomal backgrounds.     

An in vitro biomechanical comparison of a 5.5 mm limited-contact dynamic compression plate fixation with a 4.5 mm limited-contact dynamic compression plate fixation of osteotomized equine third metacarpal bones

Objectives— To compare monotonic biomechanical properties and fatigue life of a 5.5 mm broad limited‐contact dynamic compression plate (5.5‐LC‐DCP) fixation with a 4.5 mm broad LC‐DCP (4.5‐LC‐DCP) fixation to repair osteotomized equine third metacarpal (MC3) bones. Study Design— In vitro biomechanical testing of paired cadaveric equine MC3 with a mid‐diaphyseal osteotomy, stabilized by 1 of 2 methods for fracture fixation. Sample Population— Adult equine cadaveric MC3 bones (n=18 pair). Methods— MC3 were divided into 3 test groups (6 pairs each) for: (1) 4‐point bending single cycle to failure testing; (2) 4‐point bending cyclic fatigue testing; and (3) torsional single cycle to failure testing. The 8‐hole, 5.5 mm broad LC‐DCP (5.5‐LC‐DCP) was applied to the dorsal surface of 1 randomly selected bone from each pair. One 8‐hole, 4.5 mm broad LC‐DCP (4.5‐LC‐DCP) was applied dorsally to the contralateral bone from each pair. Plates and screws were applied using standard ASIF techniques. All MC3 bones had mid‐diaphyseal osteotomies. Mean test variable values for each method were compared using a paired t–test within each group. Significance was set at P<.05. Results— Mean yield load, yield bending moment, composite rigidity, failure load and failure bending moment under 4‐point bending, single cycle to failure, of the 5.5‐LC‐DCP fixation were significantly greater (P<.024) than those of the 4.5‐LC‐DCP fixation. Mean cycles to failure for 4‐point bending was significantly (P<.05) greater for the 4.5‐LC‐DCP fixation compared with the 5.5‐LC‐DCP fixation. Mean yield load, mean composite rigidity, and mean failure load in torsion for the 5.5‐LC‐DCP fixation was not significantly different (P>.05) than those with the 4.5‐LC‐DCP fixation. Conclusion— 5.5‐LC‐DCP fixation was superior to 4.5‐LC‐DCP fixation in resisting the static overload forces under palmarodorsal 4‐point bending. There was no significant difference between 5.5‐LC‐DCP fixation and 4.5‐LC‐DCP fixation in resisting static overload forces under torsion; however, the 5.5‐LC‐DCP offers significantly less stability (80% of that of the 4.5‐LC‐DCP) in cyclic fatigue testing. Clinical Relevance— The results of this in vitro study may provide information to aid in the selection of a biological plate for long bone fracture repair in horses.