Detection of TNF alpha receptors on ovine leucocytes by flow cytofluorimetry.

Tumour necrosis factor receptor activity was detected on sheep leucocytes using flow cytofluorimetry and commercially available fluorescent human tumour necrosis factor. The density of receptors per cell and the proportion of cells expressing TNF receptor activity was found to be in the following rank order: monocytes greater than granulocytes greater than lymphocytes.     

The efficacy of a combined oral formulation of derquantel-abamectin against anthelmintic resistant gastro-intestinal nematodes of sheep in the UK

The objective of the present studies was to evaluate the efficacy of a combined formulation (Startect(?) Dual Active Oral Solution for Sheep, Pfizer Animal Health) of derquantel (DQL) and abamectin (ABA) for the treatment of: (1) sheep experimentally infected with a moxidectin (MOX)-resistant isolate of Teladorsagia circumcincta, and (2) multi-drug resistant gastrointestinal nematode parasites under UK field conditions. In the first study, a total of 40 animals were allocated into 4 treatment groups, and were either left untreated or treated with DQL+ABA, MOX or ABA. Faecal samples were collected on days 1-5 and on day 7 after treatment to examine the reduction in faecal egg excretion and to evaluate the egg viability. On day 14 post treatment all animals were euthanised for abomasal worm counts. There was a 100% reduction in geometric mean worm counts for the DQL+ABA treated animals compared to the untreated control animals (P<0.0001), whereas the percentage reduction in worm counts for the MOX- (P>0.05) and ABA-treated (P=0.0004) animals was 12.4% and 71.8%, respectively. The data from the egg hatch assay (EHA) indicated that in the MOX-treated and the ABA-treated animals, the majority of the eggs hatched after treatment. In the field study, performed on four farms, animals were allocated into 6 groups of 11-15 animals each in order to conduct a faecal egg count reduction test (FECRT), based on arithmetic mean egg counts. One group of animals remained untreated, whereas the other animals were treated with DQL+ABA, MOX, fenbendazole (FBZ), levamisole (LV) or ivermectin (IVM). On each of the farms the reduction in egg excretion after treatment with FBZ, LV or IVM was below 95.0%, indicating anthelmintic resistance. The efficacy of DQL+ABA ranged from 99.1 to 100%, yielding significantly lower egg counts compared to the untreated control group (P≤0.003). For MOX the egg counts were significantly (P≤0.003) lower compared to the untreated group at each farm, with reductions varying from 98.2 to 100%. The post-treatment copro-cultures for larva identification indicated that T. circumcincta was the most abundant worm species after treatment (52-99% of the larvae). The results of these studies confirm the high efficacy of the DQL+ABA combination formulation against anthelmintic resistant nematodes in the UK.     

Haematology and serum biochemistry in the racing greyhound following intraperitoneal povidone-iodine

Povidone-iodine caused peritonitis with neutrophilic leukocytosis and a minimal left shift at the dosage rate of 3.5 ml/kg body weight. A dosage rate of 2 ml/kg only caused slight neutrophilic leukocytosis. There was a significant increase in the levels of creatinine (p=0.049) and BUN (p=0.020) in dogs that received the higher dose rate. Two dogs died from povidone-iodine toxicity with a marked increase in ALT, AP, SDH and conjugated bilirubin. It is concluded that povidone-iodine is unsafe for use in the peritoneal cavity of dogs.     

Bioassay of bovine interleukin-1-like activity

A bioassay for bovine interleukin-1 (IL1) activity is described. The assay is based on the IL1-stimulated proliferation of a mouse T-lymphocyte cell line, D10(N4)M. Bovine mononuclear cells stimulated with lipopolysaccharide produce an interleukin-1-like activity which stimulated the growth of the D10(N4)M cell line in a dose-dependent manner. The stimulatory activity was neutralised by a combination of both anti-human IL1 alpha and anti-human IL1 beta sera. The quantity of IL1-like activity released from the mononuclear cells increased asymptotically with increasing lipopolysaccharide dose.     

Replication,molecular biology,and genetic engineering of granulosis viruses

Baculoviruses of subgroup B, the granulosis viruses, show particular promise as control agents for several horticultural pests. Recent studies have concentrated particularly onCydia pomonella granulosis virus, which provides very good control of the codling moth, a major world-wide pest of apples, pears and walnuts. The viral genome has been mapped and the granulin gene has been located and sequenced. Transfer vectors for insertion of foreign genes into the virus have been constructed. Cell cultures which support viral replication have been obtained and have been transfected with viral DNA.     

Detection of type III secretion system genes in animal isolates of Bordetella bronchiseptica

A cosmid clone bank of Bordetella bronchiseptica genomic DNA was screened for the presence of type III secretion (TTS) genes using a probe derived from the TTS system genes of Ralstonia solanacearum. A 3.35kb PstI fragment, sub-cloned from a hybridising cosmid clone, was sequenced and found to contain a 97bp overlap with the previously reported B. bronchiseptica bscIJKLNO TTS gene cluster. DNA and predicted protein homology analysis suggests that a bscPQRST cluster lies immediately downstream of bscIJKLNO. A PCR amplification assay indicated that the bscT locus was present in 27 B. bronchiseptica animal isolates tested (100%). Dot-blot DNA hybridisation using probes for bscT and bscP confirmed the presence of these loci in six canine isolates associated with a variety of clinical signs. Although TTS has been implicated in the pathogenicity of B. bronchiseptica, it is likely that different clinical manifestations may be due to variations in gene expression or host factors, rather than the absence or presence of TTS genes.