Partial sequences of the 16s ribosomal RNA genes of eleven autotrophic ammonia-oxidizing bacteria were determined by PCR amplification from small amounts of heat-lysed biomass followed by direct sequencing of PCR products. The sequences were aligned with those of representative Proteobacteria and phylogenetic trees inferred using both parsimony and distance matrix methods. This confirmed that the autotrophic ammonia-oxidizers comprise two major lines of descent within the Proteobacteria. Nitrosomonas spp., Nitrosococcus mobilis, and strains of Nitrosovibrio, Nitrosospira and Nitrosolobus were located in the beta-subdivision. The recovery of Nitrosococcus oceanus strains as a deep branch in the gamma-subdivision supported the RNA catalogue data which had indicated that the genus Nitrosococcus is polyphyletic. The autotrophic ammonia-oxidizing bacteria of the beta-Proteobacteria formed a coherent group which is interpreted as representing a single family. Within this clade, the genera Nitrosovibrio, Nitrosospira and Nitrosolobus exhibited very high levels of homology in their 16s ribosomal RNA gene sequences and can be accommodated within a single genus. Separation of these genera is currently based entirely on gross morphological differences and these can now be considered more appropriate for the identification of species within this group. It is therefore proposed that Nitrosolobus, Nitrosovibrio and Nitrosospira strains be reclassified in a single genus for which the name Nitrosospira has priority.

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The bacterial load and degree of antibiotic resistance present in untreated and antibiotic-treated semen samples were investigated in five bulls standing at a cattle-breeding centre. Bacterial load was determined by colony counts from semen samples cultured on brain heart infusion and nutrient agar plates. Antibiotic resistance in these bacteria was assessed by measuring the diameter of bacterial growth inhibition zones around discs containing different concentrations of antibiotics. Representative antibiotic-resistant bacterial isolates were selected for identification. Untreated semen contained few culturable bacteria, and all were completely sensitive to gentamycin, spectinomycin and lincomycin: six of the isolates showed some resistance to tylosin. In semen to which antibiotics had been added as part of the routine production process, two isolates were sensitive to all of the antibiotics tested, and the remainder were resistant to all. Resistant Gram-negative isolates that were identified included Pseudomonas and Stenotrophomonas spp. both in the class Gammaproteobacteria and a Sphingomonas sp. which is in the class Alphaproteobacteria.

Background/AimsData are limited on the frequency of ‘consensus’ between sub-specialists attending a neurovascular multidisciplinary meeting (MDM) regarding management of patients with extracranial carotid/vertebral stenoses, and post-MDM ‘adherence’ to advice. This prospective audit/quality improve- ment project collated data at a Neurovascular/Stroke Centre.MethodsData from a weekly MDM were prospectively-recorded to document the proportion of extrac- ranial carotid/vertebral stenosis patients in whom ‘consensus management decisions’ were reached by Neurologists/Vascular Surgeons/Stroke Physicians-Geriatricians. Adherence to MDM advice was analysed in patients with asymptomatic, symptomatic and ‘indeterminate symptomatic status [ISS]’ stenoses, including intervals between symptom onset-MDM discussion +/- intervention.Results115 patients were discussed (September/2017-February/2020). Consensus regarding manage- ment was 96.5% (111/115) overall; 100% (29/29) with asymptomatic carotid stenosis [ACS], 96.5% (55/57) with symptomatic carotid stenosis [SCS], and 93.1% (27/29) with ISS. Overall adherence to MDM advice was 93% (107/115); 100% (29/29) with ACS, 89.5% (51/57) with SCS, 93.1% (27/29) with ISS. Median interval from index TIA/stroke to intervention was 12.5 days (IQR:9-18d), and MDM discussion-to-intervention was 5.5d (IQR:1-7d) in patients with 50-99% SCS.ConclusionsHigh-frequency inter-specialty consensus regarding management/adherence to proposed treatment supports a collaborative, multidisciplinary model-of-care in patients with extracranial arterial stenosis. Service development should shorten intervals between symptoms-MDT discussion-intervention to optimise secondary prevention.