Degradation of Cry1Ab protein from genetically modified maize in the bovine gastrointestinal tract

Immunoblotting assays using commercial antibodies were established to investigate the unexpected persistence of the immunoactive Cry1Ab protein in the bovine gastrointestinal tract (GIT) previously suggested by enzyme-linked immunosorbent assay (ELISA). Samples of two different feeding experiments in cattle were analyzed with both ELISA and immunoblotting methods. Whereas results obtained by ELISA suggested that the concentration of the Cry1Ab protein increased during the GIT passage, the immunoblotting assays revealed a significant degradation of the protein in the bovine GIT. Samples showing a positive signal in the ELISA consisted of fragmented Cry1Ab protein of approximately 17 and 34 kDa size. Two independent sets of gastrointestinal samples revealed the apparent discrepancy between the results obtained by ELISA and immunoblotting, suggesting that the antibody used in the ELISA reacts with fragmented yet immunoactive epitopes of the Cry1Ab protein. It was concluded that Cry1Ab protein is degraded during digestion in cattle. To avoid misinterpretation, samples tested positive for Cry1Ab protein by ELISA should be reassessed by another technique.     

Epidemiological enquiries in two Q fever outbreaks in a community of Baden-Württemberg during 2008 and 2009

In 2008 and 2009, two consecutive outbreaks of Q fever in humans were recorded in the district of Freudenstadt, northern Black Forrest, Baden-Württemberg, Germany. In 2008, a total of 41 persons from a single local community fell ill and were found infected with Coxiella burnetii. Although comprehensive diagnostic and epidemiological outbreak investigations were conducted and control measures taken which included vaccination of ruminants at risk in three parts of the affected community, re-occurrence of the disease in 2009 with further 29 confirmed human Q fever cases could not be prevented. While the origin of infection of the first outbreak was probably a flock of 550 sheep moved in the surrounding of the affected villages, the source of infection for the consecutive outbreak in 2009 could not be identified. It seems possible that meadows contaminated with infectious placenta or birth fluids represented the sources of infection.     

Salmonella Montevideo outbreak in military kennel dogs caused by contaminated commercial feed, which was only recognized through monitoring

A large outbreak of canine salmonellosis in military watch dogs due to Salmonella Montevideo and/or Salmonella Give was only recognized through a monitoring program, implemented by the military forces. In 51 out of 80 exposed dogs (63.8%) from four kennels Salmonella was isolated from fecal samples. The prevalence per sampling day ranged from 5.6 to 77.8%. Clinical disease with mild diarrhea but without fever appeared only in nine dogs (11.3% of study population, 16.9% of cases) from one kennel (***P < 0.001). Risk analysis identified "dog food A" (odds ratio 3.33 [1.12 < OR < 10.06] *P < 0.05) and "dog food C" (odds ratio 3.40 [1.07 < OR < 11.22] *P < 0.05), two commercial dehydrated dog feeds, as suspected infectious sources. Feeding "dog food C" alone or together with "dog food A" was significantly associated with clinical disease (***P < 0.001). S. Montevideo and S. Give with similar plasmid profiles and PFGE-restriction patterns were isolated from the suspected dog feeds and fecal samples. This outbreak demonstrates not only that Salmonella infections in dogs occur without clinical symptoms but also that large outbreaks occur after feeding dehydrated dog feeds. Especially in households with known risk group patients this finding demonstrates a particular risk for their owners, as they often live in close contact with their animals.     

Antimicrobial susceptibility of Klebsiella spp. and Proteus spp. from various organ systems of horses, dogs and cats as determined in the BfT-GermVet monitoring program 2004-2006

A total of 120 isolates of Klebsiella spp. and Proteus spp. collected from horses and small animals (dogs and cats) were screened for their susceptibility to 24 different antimicrobial agents. Klebsiella spp. were included from infections of the genital tract (GT) of horses (36 isolates) and the urinary/genital tract (UGT) from dogs and cats (17 isolates), while Proteus spp. were from small animal (dogs and cats) infections of the UGT (37 strains) and the skin (incl. ear/mouth) (30 isolates). In Klebsiella spp. resistance appeared most frequently to ampicillin (53-67%), sulfamethoxazole (19-29%) and potentiated sulfonamides (trimethoprim/sulfamethoxazole 1/19 combination) (19-24%). A further 29% of enrofloxacin resistant Klebsiella isolates were observed for the UGT of small animals. From the GT of horses for this antimicrobial agent there was no isolate detected with a comparably high minimum inhibitory concentration (MIC) value. In Proteus spp. highest percentages of resistance occurred against tetracycline (90-92%). Due to drug efflux proteins, high MIC values against this antimicrobial agent have been frequently reported in literature. In Proteus spp. relevant resistance percentages also occurred for potentiated sulfonamides (27-37%), sulfamethoxazole (24-37%) and chloramphenicol (24-37%).     

Assessing arbuscular mycorrhizal plant metal uptake and soil metal bioavailability among ‘dwarf’ sunflowers in a stratified compartmental growth environment

Using the micronutrient zinc (Zn) as a metal contaminant, a stratified compartmental pot greenhouse experiment involving ‘dwarf’ sunflowers and an arbuscular mycorrhizal (AM) fungus was designed to assess the role of AM symbiosis toward plant growth and metal uptake, and to differentiate its impact toward edaphic parameters across different soil strata. Consistent with previous hypotheses, AM plants contained up to 40% lower metal concentrations in their shoots than non-AM plants, particularly at the highest soil Zn levels (200 and 400 mg Zn kg^?1 dry soil); this, corresponding with an enhanced growth status among AM plants. Upon assessing the soil Zn concentrations and pH, AM treatments also tended to have higher soil Zn levels and more alkaline conditions compared to non-AM treatments. This was found especially in the topmost soil stratum where AM root colonization was deemed most active as evidenced by a higher frequency of extraradical hyphae, vesicles, and arbuscules. Together, these effects were putatively linked to the AM-induced mechanism of metal biosorption known to modulate soil nutrient bioavailability and even delay the onset of metal toxicity.     

Möglichkeiten zur komplexen steigerung der abiotischen stresstoleranz bei winterraps∗

Auf Basis von Hydrokultur‐ und Feldversuchen wurden Ursachen für die im Winterraps vorhandenen Variabilitäten der N‐Effizienz ‐ getrennt nach ihren Komponenten N‐Aneignung und N‐Verwertung ‐ ermittelt. Als Versuchsmaterial dienten die Verbundhybride “Synergy”;, die Normalrapssorte “Sollux”; und zwei DH‐Linien mit unter‐schiedlcher N‐Effizienz. Es zeigte sich, daß die N‐Aneignungseffizienz sehr stark durch die Wurzelsaugkraft und die N‐Verwertungseffizienz durch das N‐Translokationsvermögen beeninflußt wird. Beide Komponenten fördern die Gesamt‐N‐Effizienz und zusätzlich die Trockentoleranz. Die gewonnenen Erkenntnisse sind in einem Selektionsprogramm zur Steigerung der abiotischen Streßtoleranz zusammengefaßt worden.     

Long‐term tillage effects on the distribution of phosphorus fractions of loess soils in Germany

Different tillage systems may affect P dynamics in soils due to differently distributed plant residues, different aggregate dynamics and erosion losses, but quantitative data are scarce. Objectives were to investigate the effect of tillage on the availability of P in a long‐term field trial on loess soils (Phaeozems and Luvisols) initiated from 1990 to 1997. Four research sites in E and S Germany were established with a crop rotation consisting of two times winter wheat followed by sugar beet. The treatments were no‐till (NT) without cultivation, except for seedbed preparation to a depth of 5 cm before sugar beet was sown and conventional tillage (CT) with mouldboard plowing down to 25–30 cm. Soil P was divided into different pools by a sequential extraction method, and total P (P_t) in the single P fractions was extracted by digesting the extracts of the fractionation to calculate the contents of organic P. The P_t content (792 mg [kg soil]^–1) in the topsoil (0–5 cm) of NT was 15% higher compared to CT, while with increasing depth the P_t content decreased more under NT than under CT. This was also true for the other P fractions except for residual P. The higher P contents in the topsoil of NT presumably resulted from the shallower incorporation of harvest residues and fertilizer P compared to CT, whereas estimated soil losses and thus also P losses due to water erosion were only small for both treatments. Contents of oxalate‐extractable Fe and organic C were positively related to the labile fractions of inorganic P, while there was a high correlation of the stable fractions with the clay contents and pH. Multiple regression analyses explained 50% of the variability of these P fractions. Overall, only small differences in the P fractions and availability were observed between the long‐term tillage treatments.     

Inheritance of field resistance to Septoria tritici blotch in the wheat doubled-haploid population Solitär × Mazurka

Breeding for field resistance to Septoria tritici blotch (STB), caused by Mycosphaerella graminicola (anamorph: Septoria tritici), is the most suitable strategy for controlling this important disease of wheat. Although many Stb genes for resistance to single pathogen isolates have been identified in wheat, knowledge of their efficiency against natural fungal populations is lacking. In a quantitative-trait-locus (QTL) mapping approach in six environments and four locations, field resistance to STB was studied in a doubled-haploid population derived from a cross between the field-resistant cultivar Solitär and the susceptible cultivar Mazurka. After plant height as a disease escape trait was accounted for, five QTL with effects on STB response on chromosomes 5A, 6D and 7D explained 20 % of the genotypic variance; QTL × environment interactions were minor. Field resistance was conferred exclusively by alleles from Solitär, which was previously shown to carry the isolate-specific genes Stb6 and Stb11 as well as minor QTL detected with seven fungal isolates. Surprisingly, neither the Stb6 nor Stb11 isolate-specific genes nor minor QTL previously detected in Solitär were found to be involved in its field resistance. The study suggests that resistance breeding for STB should not rest solely on the deployment of Stb genes. Field tests are indispensable to show their efficacy and durability and to identify genes conferring partial field resistance to STB.     

Factors associated with seroprevalence of Neospora caninum in dairy cattle in southeastern Brazil

Neosporosis is an infectious disease caused by Neospora caninum, an obligate intracellular cyst-forming protozoan considered a major cause of miscarriage in dairy cattle in many parts of the world. This cross-sectional study evaluated the relationship between reproductive abnormalities and seropositivity to N. caninum in 1,204 dairy cows from 40 farms located in the state of Minas Gerais, southeastern Brazil. Producers were interviewed, and blood samples were collected to perform indirect immunofluorescence tests (IFAT 1:200). Association between reproductive abnormalities and seropositivity in cattle was evaluated with generalized estimating equations. The true herd-level seroprevalence of N. caninum was 95 % (83.3–99.1), while the individual-level true seroprevalence was 21.6 % (19.2–24.2). Several reproductive abnormalities were significantly associated with seropositivity to N. caninum: occurrence of repeated estrus (p?=?0.02; OR?=?3.84; 95 % CI?=?1.239–11.893), repeated miscarriages (p?=?0.001; OR?=?2.54; 95 % CI?=?1.423–5.402), and temporary anestrus (p?=?0.001; OR?=?3.44; 95 % CI?=?1.976–5.994). Furthermore, loose dogs (p?=?0.041; OR?=?2.20; 95 % CI?=?1.033–4.672) when fed raw meat (p?=?0.001; OR?=?1.91; 95 % CI?=?1.443–2.519) are risk factors for N. caninum infection. We observed that seropositivity to N. caninum in cattle increases risk of miscarriage by almost twice throughout the reproductive life of cows (p?=?0.004; OR?=?1.978; 95 % CI?=?1.249–3.131). Serologic evidence in this study indicates that N. caninum infection is widely distributed among dairy herds and significantly associated with reproductive disorders, especially miscarriage, repeated estrus, and temporary anestrus.