Multilocus sequence typing of Campylobacter jejuni from broilers

Campylobacter jejuni isolates from a national Swedish Campylobacter monitoring in broilers were characterized by multilocus sequencing typing (MLST) in order to study the genetic diversity of this bacterial population. Isolates were initially characterized by pulsed-field gel electrophoresis (PFGE). One hundred were chosen for MLST genotyping. PFGE identified 69 distinct types compared to 44 different sequence types (STs) identified with MLST. Eighteen STs had not been described previously, while the remaining 26 STs were assigned to previously known clonal complexes. The majority of isolates were of genotypes noted in broilers and in humans in earlier studies. However, three clonal complexes, ST-206 complex, ST-677 complex and ST-1034 complex, previously associated with wild bird and environmental samples, were among the genotypes found. This study shows that most of the Swedish broiler isolates were of genotypes noted as common in broilers. However, it also highlights the potential influence of environmental sources on the broiler C. jejuni genotypes.     

The effect of hypovitaminosis A on the pathogenesis of Pasteurella multocida in turkeys

It has been proposed that Pasteurella multocida can invade the host tissues via the mucous membrane. Vitamin A (VitA) deficiency has been associated with mucous membrane damage, such as squamous metaplasia. The objective of this study was to determine the early stages in the pathogenesis of P. multocida in VitA-deficient turkeys and clinically healthy turkeys. Fifteen-week-old VitA-deficient and clinically healthy turkeys were inoculated with P. multocida P-1059, a virulent strain, and the portal of entry, invasion, and localization of P. multocida were studied by microbial examination of the trachea, liver, and lung and histologic examinations of internal organs. Higher mortality was found in VitA-deficient turkeys. Pasteurella multocida was first reisolated from the trachea, secondarily from the liver and blood, and finally from the lung in both groups. Invasion of P. multocida into tissues occurred between 3 hr and 24 hr postinoculation in both groups. Our findings suggest that altered membrane integrity in VitA-deficient birds did not appear to change the time course of the systemic spread of P. multocida infection in turkeys and that the increased mortality seen in the VitA-deficient turkeys may be associated with immune system impairment.     

Peracute mortality in common cranes (Grus grus)

Out of a nonbreeding group of cranes, 10 birds died peracutely at the end of April 1998. The pathological investigation showed changes in the intestine, liver and kidneys caused probably by an intoxication; but corresponding analyses did not result in a specified poison. The proof of E. coli, Cl. perfringens and Campylobacter jejuni is to be interpreted as a subordinate result. 7 of 8 cranes had a low to high infestation with endoparasites (Porrocaeum spp., Eimeria pusilla, Echinostoma spp.). 5 of 8 birds showed leaness, possibly as a result of the migration exertion. Further on, the analysis results of a 9th crane found at another place are included in this paper.     

Variations in sheep serum conglutinating and haemolytic activity for sheep erythrocytes sensitized by rabbit antibody

Based on conglutinating and haemolytic reactions with sheep erythrocytes (E) sensitized by rabbit antibody (A), three types of sheep sera were encountered. Type 1 sera do not conglutinate or haemolyse sheep E-rabbit A. Type 2 sera failed to conglutinate, but are haemolytically active. Type 3 sera have both activities. Serum from one type 1 sheep still failed to conglutinate 5 days after venepuncture but was now haemolytically active (i.e., type 2). Some sheep that initially had type 2 sera had, five days after an intraperitoneal injection of yeast cells, sera with conglutinating activity (type 3 sera). Type 1, 2 and 3 sera all had haemolytic activity with human E-sheep A indicator cells.Pooled type 3 sera have the highest conglutinating titres with sheep E-rabbit A after 10 min incubation at 39 °C. At this stage, the haemolytic titres were very low. From 10 min, the conglutinating titres decreased whereas the haemolytic titres gradually increased until 80 min. Optimal conglutinating activity required less rabbit A to sensitize sheep E than did haemolytic activity.     

Changes in drug action in growing animals

Some results are given from a long-term study of possible changes in drug action in growing animals. It was found that the changes were of different character according to the drug studied, amongst other factors. A non-parallelity in changes of toxic effects and therapeutic effects of some drugs during aging appears to be important. The influence of age on effects in drug interactions is of great interest. All the findings show that it will be very difficult to correct for dose with respect to developmental changes in animals without further pharmacodynamic and pharmacokinetic studies in this field of pharmacology.