Rickettsial infection in farmed Atlantic salmon in eastern Canada

The cause of death in a postsmolt, Atlantic salmon population with elevated levels of mortalities was investigated. Diagnosis of a rickettsia-like organism was based on gross pathology, histopathology, differential staining, electron microscopy and fluorescent antibody tests. The course of the infection and response to treatment are discussed. This is the first reported occurrence of salmon rickettsias in the Atlantic coast of North or South America.     

Plasma glucose-insulin relationship in chicken lines selected for high or low fasting glycaemia

1. Selected Fat or Lean chickens differ in their plasma glucose insulin relationship: in the fed or fasted state, Fat chickens have a lower glycaemia associated with normal or higher insulinaemia, depending upon the difference in glycaemia. 2. Conversely, chickens selected for low fasting glycaemia (LG) are fattier than their counterparts selected for high fasting glycaemia (HG), although the divergence in fat content is lower than in the Fat-Lean model. 3. The plasma glucose insulin relationship has been investigated in males of the HG and LG lines in the F4 and F5 generations. 4. A difference in glycaemia is suggested during embryonic development and was present at hatching and later on in the fasted or the fed state; insulinaemia did not differ. 5. During refeeding after an overnight fast, glycaemia differed between lines (except at intermediate times); cumulative food intake and insulinaemia were similar. 6. During a glucose tolerance test, glucose disposal rate and insulinaemia were rather similar. 7. Exogenous insulin exerted a very similar hypoglycaemic effect in both lines. 8. Other variables (body temperature, plasma concentrations of potassium and alpha NH2-non protein nitrogen) did not differ between HG and LG chickens. 9. In conclusion, HG and LG chickens do not exhibit any differences in glucose disposal rate, insulinaemia (in various nutritional conditions) or sensitivity to exogenous insulin, which contrasts with Fat or Lean chickens and may explain why HG and LG chickens have diverged to a lesser extent in fat content.     

Development and evaluation of an indirect enzyme-linked immunosorbent assay for detection of foot-and-mouth disease virus nonstructural protein antibody using a chemically synthesized 2B peptide as antigen.

Forty peptides were synthesized corresponding to hydrophilic clusters of amino acids within the sequences of foot-and-mouth disease virus (FMDV) nonstructural proteins (NSP). Six peptides were studied in more detail and the most promising, a 2B peptide, was evaluated in enzyme-linked immunosorbent assay (ELISA) using sera from naive, vaccinated, and vaccinated-and-challenged cattle as well as bovine sera from field outbreaks. The performance of the new NSP peptide ELISA was compared to that of 4 commercial NSP ELISA kits. Antibody to 2B was detectable from the end of the first week to the second week after infection in most of the nonvaccinated animals and by the second to third week in vaccinated-and-challenged animals. The sensitivity of the 2B peptide ELISA was comparable to the 3ABC Ceditest (Ceditest FMDV-NS, Cedi Diagnostics B.V.; Chung et al., 2002). With some modification and further validation, this 2B test could be useful as a screening or conformational NSP test in postvaccination surveillance for FMD.     

Bill impaction in a group of captive Caribbean flamingos (Phoenicopterus ruber ruber).

Flamingos are filter feeders that only rarely ingest larger food items. Their bill anatomy is adapted to the suction, filtration, and ejection of a fluid medium. This case report documents a rare case of bill impaction in a group of Caribbean flamingos (Phoenicopterus ruber) that were kept in a mixed exhibit together with roseate spoonbills (Platalea ajaja) and scarlet ibis (Eudocimus ruber). The latter species received fatty minced meat as part of their diet, which was also accessible to the flamingos. Weakness and poor body condition of one flamingo were noted. On clinical examination, the animal was emaciated, hypoglycemic, and showed a severe impaction of the bill with a mixture of lard, mud, and sand. This mixture had compressed the tongue and eventually had most likely prevented further food intake. In five additional flamingos, a bulging of the gular area, similar to the extension of this area during the tongue-retraction stage of the feeding cycle, was noted and interpreted as a sign of tongue displacement by similar masses in their bills. All animals were caught and the masses removed. All animals resumed food intake immediately, and the emaciated animal rapidly improved in condition. Food presentation was changed so that the trays for the other species were no longer accessible to the flamingos, and no similar problems have been observed since that time.     

Ineffectiveness of pruning to control citrus huanglongbing caused by <Emphasis Type="Italic">Candidatus</Emphasis> Liberibacter americanus

The huanglongbing (HLB) disease of citrus trees, caused by Candidatus Liberibacter asiaticus and Ca. Liberibacter americanus, was first reported in Brazil in March, 2004. The presence of the disease has caused serious concerns among growers. Pruning experiments were conducted to determine if removal of symptomatic branches or the entire canopy (decapitation) would eliminate infected tissues and save HLB-affected trees. Pruning was done in five blocks on a total of 592 3- to 16 year-old ‘Valência’, ‘Hamlin’ or ‘Pêra’ sweet orange trees showing no symptoms or with two levels of symptom severity. Ten decapitated trees per block were caged and all trees were treated with insecticides to control the psyllid vector, Diaphorina citri. Mottled leaves reappeared on most symptomatic (69.2%) as well on some asymptomatic (7.6%) pruned trees, regardless of age, variety, and pruning procedure. Presence of the pathogen (Ca. Liberibacter americanus) in all symptomatic trees was confirmed by PCR. In general, the greater the symptom severity before pruning the lower the percentage of trees that remained asymptomatic after pruning.     

The viability ofCampylobacter jenuni on refrigerated chicken drumsticks

Radappertized chicken drumsticks were experimentally contaminated with suspensions ofCampylobacter jejuni in two trials. Qualitative analysis on drumsticks with an initial level of contamination of 4.8×10³ CFU/cm² showed that viability was retained for at least 10 days of storage at either 9° or –12°C.In a second quantitative trial, the level of contamination declined from 9.9×10² CFU/cm² to 4.5×10¹ CFU/cm² after 7 days at –20°C. Thereafter,C. jejuni persisted at levels ranging from 1.8×10¹ to 0.2×10¹ CFU/cm² through the 26th week of storage. Drumsticks held at 4°C showed a significant decline in count from 9.9×10² CFU/cm² to 1.8×10² CFU/cm² on day 7.It is concluded that the viability ofC. jejuni on chicken parts is maintained under both refrigerated and freezing conditions which approximate commercial storage. This is of significance to the meat industry and consumers.     

Toxic elements in the sex organs of the cow and their relationship to fertility

The content of heavy metals (Cd, Hg, Pb, Cr, Cu and Zn) has been determined by atomic absorption spectrophotometry in parts of genital organs of cows with and without reproductive disorders, in blood, in placenta, in colostrum, and in the calf blood. The samples were collected in an industrially polluted area and in a relatively non-polluted area. It has been proven in the group of 99 cows that the biological quality of the oestrous cervical mucus is also influenced by toxic elements. The best conception rate after the artificial insemination (80.0%) has been found in cows with the cervical mucus without spermiotoxic properties. The genital organs of 49 cows culled because of reproductive disorders were examined. No significant differences in the content of heavy metals have been found in the separate parts of genital organs. There were also no differences between the cows with and without reproductive disorders. Toxic elements in blood have been found in cows after parturition and in newborn calves both in the polluted and the non-polluted areas. However, significant differences (p less than 0.01) were determined only in the content of Cd and Zn. The average content of all determined toxic elements in the samples of placenta in pluriparous and primiparous cows from the polluted and non-polluted areas was approximately at the same level. The content of Zn was 4.3 times higher than the hygienic standard in the colostrum of cows from the polluted area. The content of Zn exceeded the hygienic standard also in the non-polluted area, and the content of Cd and Hg was close to the hygienic standard there.