Isolation of Succinivibrionaceae implicated in low methane emissions from Tammar wallabies

The Tammar wallaby (Macropus eugenii) harbors unique gut bacteria and produces only one-fifth the amount of methane produced by ruminants per unit of digestible energy intake. We have isolated a dominant bacterial species (WG-1) from the wallaby microbiota affiliated with the family Succinivibrionaceae and implicated in lower methane emissions from starch-containing diets. This was achieved by using a partial reconstruction of the bacterium's metabolism from binned metagenomic data (nitrogen and carbohydrate utilization pathways and antibiotic resistance) to devise cultivation-based strategies that produced axenic WG-1 cultures. Pure-culture studies confirm that the bacterium is capnophilic and produces succinate, further explaining a microbiological basis for lower methane emissions from macropodids. This knowledge also provides new strategic targets for redirecting fermentation and reducing methane production in livestock.     

Treatment of Theileria annulata infection in calves with parvaquone

Fifteen calves were infected by the injection of stabilate of a suspension of Hyalomma anatolicum anatolicum ticks infected with the Ankara strain of Theileria annulata. Three were kept untreated, as controls, and they all died of theileriosis. Three groups of four calves were treated intramuscularly with parvaquone (Clexon; Wellcome) when early signs of theileriosis were clinically apparent. One group received 20 mg (kg bodyweight)-1 of parvaquone 10 days after infection. Two of these calves were clinically cured and two died of theileriosis. The remaining two groups of four calves received two doses of parvaquone, each of 10 mg (kg bodyweight)-1, either on days 10 and 11 or days 10 and 12. Three calves in each group were clinically cured while one in each group died of theileriosis. Total parasitological cure was not achieved in any of the calves. No symptoms of toxicity due to parvaquone treatment were observed.     

Efficacy, toxicity and metabolism of imidocarb dipropionate in the treatment of Babesia ovis infection in sheep

An intramuscular dose of 1.2 mg kg-1 of imidocarb dipropionate (IMDP) was effective in controlling fatal infections with Babesia ovis in sheep. The sheep were infected by the intravenous injection of sheep blood containing B ovis. A severe recrudescence of infection occurred in most sheep 10 to 14 days after therapy but this could be controlled by a second dose of 1.2 mg kg-1 IMDP. Studies on the toxicology, residues and metabolism of IMDP showed this to be a safe dosage regimen. Transient or mild signs of toxicity were seen at 2.4 and 4.8 mg kg-1 IMDP. Severe toxicity was observed in sheep treated with 9.6 mg kg-1.     

Treatment of East Coast Fever of Cattle with a Combination of Parvaquone and Frusemide

Pulmonary oedema is a common sign of East Coast fever (ECF, Theileria parva infection) of cattle. A trial was conducted on farms in Uganda to compare a product containing both the antitheilerial compound parvaquone and the diuretic compound frusemide with one containing only parvaquone, in the treatment of ECF. The trial involved 40 clinical cases of ECF, some of them complicated by other infections, in cattle of all ages and on several farms. Confirmed cases were treated with either parvaquone+frusemide (P+F) or parvaquone alone (P). Survival after treatment with P+F was 77% compared with 71% with P. Five of the 10 fatalities were complicated cases. The cure rate for severe but uncomplicated ECF was 89% with P+F and 40% with P. Pulmonary signs were resolved within 24-48 h after treatment with P+F and clinical recovery was noticeably more rapid than with P. The antiparasitic effect of the two treatments was similar. P+F could be particularly useful when reporting, diagnosis or laboratory confirmation of ECF is delayed, because advanced cases are more likely to be encountered under these circumstances.     

Elimination ofTheileria buffeli infections from cattle by concurrent treatment with buparvaquone and primaquine phosphate

Attempts (some successful) were made to eliminate Theileria buffeli infections from 23 naturally or experimentally infected, splenectomised calves. The anti-theilerial hydroxynaphthoquinone derivative buparvaquone was used either alone or in combination with primaquine phosphate. After treatment the calves were monitored for infection for up to 26 weeks. Blood films were examined for piroplasms and serum antibody levels were measured using an immunofluorescence technique. Buparvaquone alone failed to eliminate infections. Infections were eliminated from 11 of 16 calves treated twice with buparvaquone and three or six times with primaquine phosphate. Theilerial parasites were not subsequently seen in these 11 calves nor were antibodies detected beyond the eighth week after treatment.     

Serological responses to bovine anaplasmosis following treatment with gloxazone

Groups of unsplenectomised steers and calves were infected with either the Onderstepoort or Sukari 1 strain of Anaplasma marginale by the injection of infected blood. The infections were treated with gloxazone (2.5 – 25 mg/kg). The serological response of the animals was monitored by the complement fixation (CF) and capillary tube agglutination (CA) tests, using antigens prepared from the Onderstepoort strain. CF antibody responses were alike in both strains. The titre rose rapidly from four days after infection to a peak around the time of the initial crisis. These high titres were maintained, and generally did not rise further at the time of recrudescence of parasitaemia. CA antibody appeared 7–10 days after infection and reached a peak shortly after the initial crisis. Titres fell as parasitaemia was reduced following gloxazone treatment, then rose as parasitaemia recrudesced. There was a close correlation between the effectiveness of gloxazone treatment and changes in CA antibody titre.     

Clinical efficacy and plasma concentrations of two formulations of buparvaquone in cattle infected with East Coast fever (Theileria parva infection)

East Coast fever, caused by the protozoan parasite Theileria parva, kills about 600,000 cattle annually in Africa. The hydroxynaphthoquinone compound buparvaquone (BPQ) is curative. Sixteen calves were infected with T. parva. On manifestation of disease symptoms, eight were injected with the original (pioneer) BPQ product and eight with a test product containing BPQ. All 16 calves were cured by one injection of 2.5 mg BPQ/kg bodyweight. The concentration of BPQ in blood plasma was monitored by HPLC. The mean observed C(max) of BPQ was 0.229 and 0.253 microg/mL of plasma, the mean observed time to reach this concentration (T(max)) was 2.62 and 2.12 h and the AUC (area under curve) was 4.785 and 4.156 microg h/mL, respectively, for the pioneer and test product. Considerable variations occurred in the plasma concentration of BPQ within each group. They showed no relationship with either clinical or parasitological parameters following treatment.