Suitability of inorganic and organic amendments for in situ immobilization of Cd,Cu, and Zn in a strongly contaminated Kastanozem of the Mashavera valley,SE Georgia. I. Effect of amendments on metal mobility and microbial activity in soil

The aim was to find an adequate, cost‐efficient in situ remediation technique for the Mashavera valley, a mining area in SE Georgia heavily contaminated with Cd, Cu, and Zn. A 12‐month experiment was conducted to test: iron grit, natural zeolite, biochar, and Divergan® (a scavenger) for soil melioration. The amendments were added in different concentrations to the topsoil of a Kastanozem. Mobile metal concentrations decreased with increasing concentrations of amendments in the sequence Divergan® >> iron grit ≈ natural zeolite > biochar. In the same order amendments enhanced activities of soil microbial respiration, alkaline phosphatase, and dehydrogenase; microbial C also followed this trend. A sequential extraction confirmed a shift from easily mobilized to heavily bound fractions. The addition of 2% (w/w) of Divergan® was sufficient to lower mobile trace metal concentrations below German thresholds by chemisorption, and soil microbial activity was significantly increased. The effects of all other treatments were at a much lower level and not found suitable due to needed application rates.     

Toward metrological traceability for DNA fragment ratios in GM quantification. 3. Suitability of DNA calibrants studied with a MON 810 corn model

The quantification of GMOs by real-time PCR relies on an external calibrant. In this paper the suitability of two DNA calibrants, genomic DNA from plant leaves and plasmidic DNA, was investigated. The PCR efficiencies, the correlation coefficients of the calibration curves, and the ratios between PCR efficiencies of transgenic and endogenous sequences were compared for both calibrants using 59 data sets produced by 43 laboratories. There were no significant differences between plasmidic and genomic DNA except for the PCR efficiencies of the calibration curves for the transgene of the construct-specific real-time PCR method. In the GM system investigated, PCR efficiencies of plasmidic calibrants were slightly closer to the PCR efficiencies observed for the unknowns than those of the genomic DNA calibrant. Therefore, plasmidic DNA was the more suitable calibrant for the PCR measurements on genomic DNA extracted from MON 810 seeds. It is shown that plasmidic DNA is an appropriate choice for the calibration of measurements of MON 810 corn with respect to the DNA copy number ratio.     

Assessment of serotonin in serum,plasma, and platelets of aggressive dogs

Canine aggression is the most common reason for the referral of dogs to behavior practices. In addition, dog bites represent an important problem for public health and animal welfare. The serotonergic system is believed to play an important role in modulating aggression. The aim of the present study was (1) to assess the suitability of different types of blood samples for measuring circulating serotonin in canine clinical studies, and (2) to investigate the relationship between the serotonergic system and canine aggression. The assessment of serotonin was simultaneously carried out in serum, plasma, and platelets of 28 aggressive and 10 nonaggressive dogs with an enzyme immunoassay technique. The mean serotonin concentration in aggressive dogs was significantly lower than in nonaggressive dogs in all the assayed samples. These findings suggest an inverse relationship between the activity of the serotonergic system and canine aggression. Considering the simplicity of the methodology, the authors propose sampling serum as the most suitable method for measuring circulating serotonin in dogs.     

Isolation and characterization of <Emphasis Type="Italic">Serratia rubidaea</Emphasis> from dark brown spots of tomato fruits

Bacterial contamination of fresh tomato fruits is of great concern. From naturally infected tomato fruits showing dark brown irregularly shaped spots, 36 bacterial isolates were recovered and identified on phenotypic characteristics and sequences of the gene encoding the 16S rRNA. Five isolates showing spots on tomato fruits in the pathogenicity test with healthy tomato fruits belong to the genus Serratia on the basis of phenotypic characteristics. One representative isolate of these has been further identified as a Serratia rubidaea by sequencing of the 16S rRNA gene. This is the first evidence showing that a S. rubidaea strain can cause spots on tomato fruits. Virulence of the S. rubidaea was also confirmed by the production and secretion of a large variety of enzymes capable of degrading the complex polysaccharides of the plant cell wall and membrane constituents. Nineteen bacterial isolates of the 36 did not induce any spot symptoms in a pathogenicity test on artificially infected tomato fruits although these are known as phytopathogenic bacteria. Five of these 19 bacterial isolates were identified as Ralstonia species on the basis of biochemical tests. Sequencing of the 16S ribosomal gene of one representative isolate revealed that the isolate is closely related to Ralstonia solanacearum. Six isolates of the 19 were related to Xanthomonas vesicatoria on the basis of biochemical tests and eight were related to the Enterobacteriaceae. One representative isolate of the Enterobacteriaceae could be identified by the 16S rRNA gene as Enterobacter cloacae subsp. dissolvens. The 12 other strains were related to Proteus mirabilis based on the 16S RNA gene sequence of one representative isolate. The isolates related to P. mirabilis did not produce any symptoms on artificially infected tomato fruits. The nucleotide sequences of S. rubidaea strain E9, E. cloacae strain E23, P. mirabilis strain E11, and R. solanacearum strain E15 have been deposited in the GenBank nucleotide sequence database under accession numbers HM585373 to HM585376.     

High mortality in egg layers as a result of necrotic enteritis

A new facility was designed to hold 1.8 million birds in 10 houses; chickens were placed in five of the houses, and the remaining five houses were under construction when this outbreak occurred. An increase in mortality was reported in five houses; however, mortality in house 7 was quite high. Well-fleshed birds were suddenly found dead without a significant drop in egg production. The middle and distal intestines were distended with gas, congested, thin walled, atonic, and bluish or pale in color with sloughed mucosa in some places. Necrotic enteritis was diagnosed as the cause of increased mortality. The ingesta in the crop occasionally contained flies. The 4-wk mortality in house 7 was 6.55% with a loss of 10,898 chickens. The 4-wk mortality rate in the other houses ranged from 0.54% to 1.98%. The houses affected with necrotic enteritis were treated for coccidiosis with amprolium because low numbers of the oocysts were present in the intestinal specimens of some of the chickens. Household bleach was added to the water at a dilution of one part bleach to 1040 parts water to control bacterial contamination. The fly (Musca domestica) population was out of control. Clostridium perfringens was isolated from the alcohol-washed macerated flies caught from houses 4 and 7. Dead flies were often seen in the feed troughs. The chickens may possibly have had C. perfringens infection as a result of consumption of dead flies or their secretions/excretions. The alcohol-washed, macerated, clarified fly extract from the affected houses caused death in 11 inoculated mice and paralysis in one mouse. Similarly, illness and mortality were present in four mice inoculated with clarified intestinal contents. The bacterium isolated on anaerobic culture was identified as C. perfringens by polymerase chain reaction. The disease was brought under control after straw was added and mixed in with the litter. As a result, the litter temperature increased, causing a decrease in the fly population. This study suggests that flies in the poultry houses acted as mechanical transmitters of C. perfringens and that the development of necrotic enteritis was by ingestion of bacteria present in the flies and their secretions/excretions.     

Antimicrobial resistance in generic Escherichia coli isolated from swine fecal samples in 90 Alberta finishing farms

The objective of this study was to determine the prevalence of antimicrobial resistance in generic Escherichia coli isolates obtained from 90 Alberta finisher swine farms. Up to 5 isolates were obtained from each of 269 pooled fecal samples and were classified as susceptible or resistant according to Clinical and Laboratory Standards Institute guidelines. Of the 1322 isolates, 166 (12.6%) were susceptible to all 15 antimicrobials. No resistance to amikacin, ceftiofur, ceftriaxone, or ciprofloxacin, antimicrobials of importance in human medicine, was observed. Relatively low frequencies of resistance were observed to gentamicin (1.1%), amoxicillin/clavulanic acid (0.7%), and cefoxitin (0.7%). Higher frequencies of resistance were observed for tetracycline (78.9%), sulfisoxazole (49.9%), streptomycin (49.6%), ampicillin (30.6%), chloramphenicol (17.6%), kanamycin (10%), and trimethoprim/ sulfamethoxazole (6.4%). Among the isolates resistant to > or = 2 antimicrobial classes, 20.8%, 20.6%, 18.2%, 7.0%, 1.8%, 0.2%, and 0.2% were resistant to 2, 3, 4, 5, 6, 7, and 8 antimicrobials, respectively. The most common multidrug-resistance patterns (resistance to > or = 2 antimicrobial classes) were streptomycin-tetracycline (9.4%), streptomycin-sulfisoxazole-tetracycline (6.2%), and ampicillin-streptomycin-sulfisoxazole-tetracycline (6.1%). More clustering (higher intra-class correlation coefficients) in antimicrobial resistance was observed for isolates at the same visit than for isolates from different visits in the same farm, indicating that sampling more farms, testing fewer isolates per visits, and taking longer periods between visits may be appropriate and more efficient for a better understanding of potential shifts in resistance over time.