Detection of Ureaplasma diversum in the upper airways of Australian feedlot cattle

Bovine respiratory disease (BRD) exerts a major impact on the beef cattle industry nationally and worldwide, with a range of aetiological factors impacting its pathogenesis. Previous research has focussed on an increasing number of bacteria and viruses that have been shown to play a role in eliciting disease. Recently, additional agents have been emerging as potential contributors to BRD, including the opportunistic pathogen Ureaplasma diversum. To determine if U. diversum was present in Australian feedlot cattle and if that presence was linked to BRD, nasal swabs were collected from a cohort of 34 hospital pen animals and compared to 216 apparently healthy animals sampled contemporaneously at feedlot induction and again after 14 days on feed at an Australian feedlot. All samples were subjected to a de novo polymerase chain reaction (PCR) assay targeting U. diversum in combination with other BRD agents. U. diversum was detected at a low prevalence in cattle at induction (Day 0: 6.9%, Day 14: 9.7%), but in a significantly greater proportion of cattle sampled from the hospital pen (58.8%). When considering the presence of other BRD-associated agents, co-detection of U. diversum and Mycoplasma bovis was most common in hospital pen animals receiving treatment for BRD. These findings suggest that U. diversum may be an opportunistic pathogen involved in the aetiology of BRD in Australian feedlot cattle, in combination with other agents, with further studies are warranted to identify if a causal relationship exists.     

Infestation of sheep with the stored product mite Sancassania berlesei (Acaridae)

A sheep reared outdoors in Victoria was found to be heavily infested with a stored product mite, Sancassania berlesei (Acaridae), apparently subsequent to an earlier flystrike. Laboratory observation revealed the infestation to be self-sustaining. Shearing rapidly resolved the infestation but treatment with diazinon was ineffective. The infestation could be transferred to other sheep only in the presence of moisture; once established it caused an extensive skin lesion with considerable fluid loss, apparently contributing to the death of one animal. This lesion was extremely attractive to blowflies. Animals infested with mites showed few signs of irritation.     

Metronidazole for the treatment of bovine pyometra

Metronidazole, an antibiotic with specific activity against anaerobic bacteria, was assessed as a treatment for bovine pyometra. A preliminary experiment with metronidazole-neomycin was followed by an experiment in which metronidazole-ampicillin was compared with povidone iodine. Each treatment was given as a single intrauterine infusion. The success of therapy was judged by clinical examination, bacteriological examination before and after treatment and, in the second experiment, by post treatment reproductive performance. Before treatment 45 of the 84 cows in both experiments were infected with a mixture of anaerobic and aerobic bacteria, 23 cows were infected with aerobes alone and significant bacteria were not isolated from 16 cows. Complete bacteriological and clinical cures were achieved in 23 of 32 cows treated with metronidazole-neomycin, 15 of 32 cows treated with metronidazole-ampicillin and 1 of 20 cows treated with iodine. When only those cows with mixed anaerobe/aerobe infections were considered, complete cures occurred in 12 of 17 cows treated with metronidazole-neomycin, and 11 of 16 cows treated with metronidazole-ampicillin, but none of the 12 cows treated with iodine. Twenty-two of 29 cows treated with metronidazole-ampicillin conceived after treatment (mean 51.4 days), while 9 of 18 cows treated with iodine conceived (mean 58.7 days). Statistically, metronidazole-ampicillin treatment produced significantly better clinical and bacteriological cure rates than iodine treatment (P less than 0.05), but the differences in reproductive parameters were not significant.