Usefulness of serological examinations in the analysis of Salmonella infections in pig herds

The development of the antibody concentration against lipopolysaccharide (LPS) of S. Typhimurium und S. Choleraesuis in rearing pigs during the fattening period and in breeding sows of the corresponding age was recorded. The studies revealed the following results. Antibodies of isotypes IgG1 and IgG2 revealed a more pronounced specificity against the according Salmonella serovar than IgM antibodies. The calculated "antibody percent value" based on the total amount of Salmonella antibodies is mainly determined by the IgM antibodies in sera and meat juice, respectively. In fattening pigs a significant increase of antibodies against IgM and total Ig was observed between week 3 and 10 after beginning of the rearing period. In breeding pigs this increase was detectable already earlier. In only 3 out of 10 groups an increase of IgG1 and IgG2 was also seen. The detected significant increase of total Ig and IgM in the other groups might be the result of a less intensive exposure to salmonellas or it might be due to an increase of unspecific antibodies induced by other antigens. Serological investigations represent a valuable tool to record the intensity and development in time of the Salmonella exposure in pigs farms. Examination of total Ig is an appropriate method to detect pig herds with a high level of Salmonella exposure, for detailed epidemiological studies in pig farms the examination of antibody isotypes will give more comprehensive information.     

The effect of treatment with eprinomectin on lungworms at early patency on the development of immunity in young cattle

An experiment was carried out to study the effect of topical application of eprinomectin at early patency on the build up of infection and development of protection against Dictyocaulus viviparus in young cattle. Three groups of six calves were used and parasitological and blood variables were monitored at weekly intervals throughout the trial. At the start of the experiment calves in groups A and B were experimentally inoculated with 100 D. viviparus infective third-stage larvae (L3) for five consecutive days, whereas calves in group C served as uninfected controls. The calves in group A were each treated with eprinomectin (0.5mg/kg bodyweight) in a pour-on formulation at early patency at day 24 post the first inoculation, whereas the calves in groups B and C were left untreated. Seven weeks following anthelmintic treatment all groups were challenged with 1500 L3. Another 4 weeks later the animals were sacrificed and established worms in the lungs were counted. Moderate transient signs of lungworm disease occurred both in groups A and B. However, group B calves were found to be about 8 times more resistant than those in group A, whereas the naive infection controls in Group C was found to be about 35 times more susceptible to infection. Also the ELISA values showed that the course of infection was different between experimental groups. The eosinophil counts prior to and at the time of slaughter indicate that immunity was involved in the protection and the response was correlated with previous exposure and worm load. Weight gains differed significantly, but only between groups A and C and between groups B and C that on an average were approximately 13kg heavier at the termination of the experiment. It was concluded that eprinomectin was effective against established adult lungworms. However, the untreated calves (group B) developed a more marked resistance to lungworms compared to those that were subjected to anthelmintic treatment at early patency (group A). On the other hand, the cumulative number of excreted larvae was on an average 43 times higher in group B as compared to group A. Consequently, infected calves that remain out on pasture should be treated. This will restrain transmission of the parasite despite the fact that immunity is deteriorated.     

A new furovirus infecting barley in France closely related to the Japanese soil-borne wheat mosaic virus

In April 2001, stunted barley plants bearing mosaic symptoms were observed in a field in France (Marne Department, 51). Rod-shaped and flexuous particles were visualized by electron microscopy and positive serological reactions were detected by ELISA with Barley yellow mosaic virus (BaYMV) and Soil-borne cereal mosaic virus (SBCMV) polyclonal antisera. The tubular virus which was soil transmissible to barley cv. Esterel was separated from BaYMV by serial mechanical inoculations to barley cv. Esterel. This furo-like virus, in contrast to a French isolate of SBCMV, could be transmitted to Hordeum vulgare, Avena sativa, Beta vulgaris and Datura stramonium. RT-PCR was used to amplify the 3′-terminal 1500 nucleotides of RNA1 and the almost complete sequence of RNA2. Nucleotide and amino acid sequence analyses revealed that the French virus infecting barley is closely related to a Japanese isolate of Soil-borne wheat mosaic virus (SBWMV-JT) which was originally isolated from barley. This French isolate was named SBWMV-Mar. The 3′ UTRs of both RNAs can be folded into tRNA-like structures which are preceded by a predicted upstream pseudoknot domain with seven and four pseudoknots for RNA1 and RNA2, respectively. The four pseudoknots strongly conserved in RNAs 1 and 2 of SBWMV-Mar show strong similarities to those described earlier in SBWMV RNA2 and were also found in the 3′ UTR of Oat golden stripe virus RNAs 1 and 2 and Chinese wheat mosaic virus RNA2. Sequence analyses revealed that the RNAs 2 of SBWMV-Mar and -JT are likely to be the product of a recombination event between the 3′ UTRs of the RNAs 2 of SBWMV and SBCMV. This is the first report of the occurrence of an isolate closely related to SBWMV-JT outside of Japan.     

Cotton response to short-term waterlogging imposed with a water-table gradient facility

Waterlogging of field-grown plants can occur either when the surface of slowly permeable soils is inundated or when the water-table rises so that part or all of the root zone is saturated. The effects of short-term waterlogging on field crop growth and yield have not been well quantified. To study these effects, a sloping, repacked slab of soil underlain by an impermeable membrane was constructed. The sloping plot (45 m long × 6 m wide × 0.6 m deep) was flooded by introducing water through a drainage network and gravel bed so that a gradient of water-table depth ranging from 0.1 m above to 0.66 m below the soil surface was obtained. Cotton (Gossypium hirsutum cv. Deltapine 61) was grown in the facility and the responses of plants to two periods of flooding were monitored. Soil matric potential and oxygen partial pressure data indicated that plants were subjected to a continuum of conditions ranging from complete inundation to no water-table within the root zone.The first flooding event began 82 days after sowing just prior to the main flowering period. Plants with more than 55% of their root system below the water table showed decreased leaf growth about 3–4 days after the flooding started with visible wilt symptoms and decreased leaf water potential observed on days 7 and 8 of flooding. In the second flooding event (131 days after sowing), plants showed no signs of waterlogging stress apart from reduced leaf growth despite 16 days of flooding. Plant growth response was probably more the result of reduced nutrient status (mostly nitrate) rather than a water deficit stress effect with some plant acclimatization between the first and second flooding event. Seed cotton yield data indicated that the observed stress during the first flooding event may have promoted reproductive growth in plants where the short-term water-table was greater than 0.2 m below the soil surface.     

Low Mw-lignin fractions together with vegetable oils as available oligomers for novel paper-coating applications as hydrophobic barrier

Lignin residues are available in large amounts as kraft lignin from chemical pulping processes. This lignin is mainly incinerated in recovery boilers. The recovery boilers are often the bottle-necks in the overall pulping process when pulp production increases are desired. Through cross-flow nano-filtration of the black liquor from kraft pulping, a low-molecular weight lignin fraction can be removed thus decreasing the organic load on the recovery boilers. The low-molecular weight lignin fraction furthermore exhibit different characteristics compared to other commercial kraft lignins and represents a new raw material source in novel applications.The low-molecular weight lignin was used together with a vegetable oil to produce a new hydrophobic lignin derivative similar to suberin. The lignin and the lignin derivative was analysed with FT-IR, UV–vis and SEC. The ability of the product to make paper surfaces hydrophobic was also evaluated.The results demonstrate the possibility to make a suberin-like lignin derivative that is potentially of interest in paper-coating applications due to its capability to interact well with wood fibres and make paper hydrophobic.     

Untersuchungen über Maikäfer und Engerlinge

Ohne Zusammenfassung     

Disease patterns in the Detroit Zoo: a study of reptilian and amphibian populations from 1973 through 1983

A retrospective study was conducted to determine disease patterns in reptilian and amphibian populations at the Detroit Zoo from 1973 through 1983. In the reptilian population (mean +/- SD = 285.2 +/- 28), overall annual mortality rates were 1% to 40%. Mortality rates were highest in the fall months (20%) and lowest in the winter months (6%). The most frequently affected reptiles were iguana (Iguana iguana), reticulated python (Python reticulatus), rattlesnakes (Crotalus spp), common boa (Constrictor constrictor), and lizards (various genera of suborder Lacertilia). Of the 1,300 reptilian deaths from 1973 through 1983, 36.6% were caused by microbial agents, 12% by parasites, 11.6% by trauma, and 9.3% by nutritional deficiencies. The main microbial organisms that caused death were Aeromonas spp, Salmonella spp, Pseudomonas spp, Proteus spp, and Edwardsiella spp. The main parasites that caused death were Entamoeba spp and lungworms. Among amphibians, frogs and toads were the most frequently affected, and starvation and trauma were the most frequent causes of death.     

Disease patterns in the Detroit Zoo: a study of the mammalian population from 1973 through 1983

A retrospective study was conducted to evaluate disease patterns in the mammals at the Detroit Zoo from 1973 through 1983. The reindeer (Rangifer tarandus), common eland (Taurotragus oryx), rednecked Wallaby (Protemnodon rufogrisea), sitatunga (Tragelaphus spekii), and kangaroo (Macropus spp)- were the most frequently affected mammalian species. Parasitic agents (80% of which were internal parasites) caused morbidity in 60.2% of the mammals evaluated (n = 2,475) and microbial agents caused morbidity in 20.8% of the animals. Strongyloides spp, Trichostrongylus spp, coccidian species, Diphyllobothrium spp, and Trichuris spp were the internal parasites most frequently found. Overall annual mortality rate was 14% to 34%, with microbiological agents causing the highest mortality (26.5%). Pasteurella spp, beta-hemolytic Streptococcus spp, pathogenic Escherichia coli, Corynebacterium spp, and Klebsiella pneumoniae were the most frequent microbial causes of death. Cause of mortality could not be determined in 21.5% of the animals evaluated. The percentage of animals successfully treated increased from 1973 through 1983. Generally, however, the percentage of successfully treated animals was low (21% to 39%).