Suppression of Babesia microti infection in mice concurrently infected with Schistosoma mansoni

Blood cell panasitaemias of Babesai microti and associated haematological changes were studied in mice concurrently infected with Schistosoma mansoni and in controls with no schistosome infections. In comparison to the controls B. microti parasit-aemias were suppressed markedly in mice harbouring 6 and 8 weeks old patent S. mansoni infections at the time of infection with B. microti. The suppression was accompanied by an alleviation/annulment of the B. microti induced reductions in haemoglobin and haematocrit levels and in its erythropoetic stimulation. The suppressive effect of patent S. mansoni infections on B. microti is suggested to be at least partly attributable to non-specific immunological factors although the altered erythrocyte kinetic state induced by the schistosoma infection in combination with the preference of B. microti for mature (old) erythrocytes might also play a role in the suppression. In mice harbouring 2 weeks old prepatent S. mansoni infections B. microti was not suppressed.     

Age-related functional changes in the follicle-associated epithelium of the bursa of Fabricius in Shaver cockerels

A study of the age-related functions of immunologically important components of the bursa of Fabricius in Shaver cockerels showed that endocytosis of carbon particles by the specialised follicle-associated epithelium was at a high level from hatching until 5 weeks of age and thereafter declined until at 18 weeks it could no longer be detected. The follicle-associated epithelium had marked non-specific esterase activity during the first 15 weeks of life as determined by a standard acid alpha-naphthyl acetate esterase method. The absolute weight of the bursa was at a maximum at 9 to 10 weeks. Involution began before 14 weeks and was complete by 22 weeks. The results indicate that the critical period for the bursa in regard to acquiring immunity from either local vaccination or environmental challenge is likely to be within the first five weeks of life.     

Megabacteriosis in a flock of budgerigars

Megabacteriosis was diagnosed as the cause of depression and wasting in a flock of breeding budgerigars in the Manawatu. Large numbers of megabacteria were detected in direct smears from mucosal scrapings of the proventriculus of two birds and in the faeces of live birds. The diagnosis was confirmed by demonstrating a chronic proventriculitis histologically associated with megabacterial organisms. Treatment of seven individuals with amphotericin B resulted in clinically sustained weight gain over a 10-week period. Treatment of the whole flock resulted in the resumption of normal condition, behaviour and activity.     

Habitat Preferences of Clethrionomys Rufocanus in Boreal Sweden

A long-term decline of vole populations in boreal Sweden, especially of the grey-sided vole (Clethrionomys rufocanus Sund.), has been revealed by snap-trapping in 1971–2004. We identified important habitats for the grey-sided vole by mapping the distribution of cumulated number of reproductive females in 1971–1978, prior to the major decline in the 1980s. Mean abundance of C. rufocanus was higher in the western (inland) than eastern (coastland) part of the study area. As the inland appeared to represent the most, as far as we know, pristine, abundant part of the population, we based identification of high quality habitats on inland data only. Four habitats were more important than others and yielded nearly 86% of the reproductive females in spring: (1) forests of dry, (2) moist and (3) wet/hydric dwarf-shrub type, in addition to (4) forest/swamp complexes rich in dwarf-shrubs. The latter three habitats were used more frequently than expected from their occurrence in the landscape. Still, the variation in density of reproductive females within patches of the same habitat was frequently high. This suggested that habitat composition in the surrounding landscape, perhaps may have affected local vole density at the patch scale. Clear-cut sampling plots appeared to be low-frequently used by reproductive females, but also by males and immatures. In conclusion, our study indicated the importance of also studying habitat at a larger scale than that of the patch to get a deeper understanding on how habitat influences local and regional densities and population dynamics of C. rufocanus.     

Comparative molecular epidemiological investigation on different bovine herpes viruses

Eight Bulgarian bovine herpes viruses, two Hungarian herpes viruses 1A, 3A, calves isolate named Mramor, buffalo isolate 723 and two referents BHV 1 strains were investigated by restrictase fragment pattern analysis. Migration profile of viral DNA by using different restrictase enzymes Hpa I, BamH I and Hind III were compared. Clearly differences among two Hungarian strains, calves isolate Mramor, buffalo isolate 723 and 8 Bulgarian and two referents BHV 1 strain was observed. The strain Sartze was determined as a genital type BHV 1, whereas Ozet, Tch.voda, Slivnitza, B. Budinov, Ptcelarovo, Vrana and Podgumer as a respiratory type. Hungarian strains 1A, 3A, calves isolate Mramor and buffalo isolate 723 had similar migration profile as swine herpes viruses. Hybridisation between the K 22 fragment and 8 bovine herpes viruses after Southern blotting were observed. That is evidence for genetic relation of these strains. Such hybridisation with Hungarian 1A, 3A, Mramor and buffaloes 723 strains were not observed. This fact allowed us to conclude that these strains are genetically different from BHV 1.

Résumé

On a examiné par l'analyse de la restrictase huit souches bulgares de virus herpès bovins, deux souches hongroises de virus herpès (1A et 3A), l'une isolée d'un buffle 723, l'autre isolée d'un veau nommé ‘Mramor’ et deux souches de virus de référence BHVI. Le profil migratoire des virus a été comparé à l'aide d'enzymes restrictase Hpa I, BamH I, Hind III. Une nette différence a été constatée entre les deux souches hongroises, la souche isolée du veau ‘Mramor’, celle isolée du buffle 723 et les huit souches bulgares. La souche Sartze a été déterminéee comme type génital, alors que Ozet, Tch.voda, Slivnitza, B. Budinov, Ptcelarovo, Vrana, Podgumer sont des types respiratoires. Le deux virus hongrois 1A et 3A, la souche isolée du veau ‘Mramor’, et celle isolée du buffle 723 ont un profil migratoire comparable à celui des virus herpès du porc. Après Soutchern blotting, une hybridation entre fragment K 22 et les huit virus herpès bovins a été constatée. Il y a une liaison génétique entre ces souches. Il n'y a pas d'hybridation entre les souches hongroises 1A et 3A, celle isolée du veau Mramor et celle isoléee du buffle 723. Cette observation nous permet de conclure que les souches sont génétiquement différentes de BHV 1.     

Comparison between microscopic and automated differential leukocyte counts in the silver fox (Vulpes vulpes) and the blue fox (Alopex lagopus)

Differential leukocyte (WBC) counts in blood from clinically healthy silver foxes (n=32) and blue foxes (n=37) obtained from an automated hematology analyzer (Technicon H*1 Hematology System) with canine software were compared with microscopic differential WBC counts (M-diff). There was good agreement between the automated differential cell count (A-diff) and the M-diff for neutrophil and lymphocyte percentages. The correlation was lower for monocyte percentages and variable for eosinophil percentages. There was no significant difference between the A-diff and M-diff in either fox species. The A-diff counts were very precise, and may be a good alternative to the traditional M-diff for screening populations of clinically healthy foxes or for studies on stress and animal welfare. Intercept values, however, indicated a constant bias that must be taken into account before interpreting results based on different methods of analysis     

Water pollution and the ulcer syndrome in the cod (Gadus morhua)

One and a half-2 1/2 year old cold living in Danish coastal waters suffer from a specific ulcer syndrome, which occurs only in waters polluted with town sewage or effluents from sugar and cellulose plants. Although the etiology of the primary lesions is unknown (virus?, stress?), the development of ulcers depends upon a bacterial infection.Vibrio anguillarum was the most common bacterium involved in both local and generalized infections in these cod. The prevalence ofVibrio anguillarum was greater in polluted than in unpolluted areas, and the response to an outlet of wastewater from a sugar plant was an immediate increase in the number ofVibrio anguillarum in water and sediment. There was, however, no simple relationship between the prevalence ofVibrio anguillarum and the frequency of the ulcer syndrome. The observed heterogeneity among strains ofVibrio anguillarum from different localities requires a more intensive study of the taxonomy and serology of these strains. In the future the ulcer syndrome in cod and the prevalence ofVibrio anguillarum (and other Vibrios) might be important measurements in programmes for monitoring marine pollution.     

Grain yield and crop N offtake in response to residual fertilizer N in long‐term field experiments

Organic inputs [e.g. animal manure (AM) and plant residues] contribute directly to the soil organic N pool, whereas mineral N fertilizer contributes indirectly by increasing the return of the crop residues and by microbial immobilization. To evaluate the residual effect of N treatments established in four long‐term (>35 yr) field experiments, we measured the response of barley (grain yield and N offtake at crop maturity) to six rates (0, 30, 60, 90, 120 and 150 kg N/ha) of mineral fertilizer N (N_new) applied in subplots replacing the customary long‐term plot treatments of fertilizer inputs (N_prev). Rates of N_prev above 50–100 kg N/ha had no consistent effect on the soil N content, but this was up to 20% greater than that in unfertilized treatments. Long‐term unfertilized plots should not be used as control to test the residual value of N in modern agriculture with large production potentials. Although the effect of mineral N_prev on grain yield and N offtake could be substituted by N_new within a range of previous inputs, the value of N_prev was not eliminated irrespective of N_new rate. Provided a sufficient supply of plant nutrients other than N, the use‐efficiency of N_new did not change significantly with previous mineral N fertilizer rate. The residual effect of mineral N fertilizer was negligible compared with the residual effect of N from AM and catch crop residues.