Biomedical subjects

R Ure

Publications and source records attributed to R Ure.

5 recordsLinked to original sources

PubMed2023

Exploiting Real-Time Genomic Surveillance Data To Assess 4CMenB Meningococcal Vaccine Performance in Scotland, 2015 to 2022.

The United Kingdom implemented the first national infant immunization schedule for the meningococcal vaccine 4CMenB (Bexsero) in September 2015, targeting serogroup B invasive meningococcal disease (IMD). Bexsero contains four variable subcapsular proteins, and postimplementation IMD surveillance was necessary, as nonhomologous protein variants can evade Bexsero-elicited protection. We investigated postimplementation IMD cases reported in Scotland from 1 September 2015 to 30 June 2022. Patient demographics and vaccination status were combined with genotypic data from the causative meningococci, which were used to assess vaccine coverage with the meningococcal deduced vaccine antigen reactivity (MenDeVAR) index. Eighty-two serogroup B IMD cases occurred in children >5 years of age, 48 (58.5%) of which were in unvaccinated children and 34 (41%) of which were in children who had received ≥1 Bexsero dose. Fifteen of the 34 vaccinated children had received one dose, 17 had received two doses, and two had received three doses. For 39 cases, meningococcal sequence data were available, enabling MenDeVAR index deductions of vaccine-preventable (M-VP) and non-vaccine-preventable (M-NVP) meningococci. Notably, none of the 19 of the children immunized ≥2 times had IMD caused by M-VP meningococci, with 2 cases of NVP meningococci, and no deduction possible for 17. Among the 15 children partially vaccinated according to schedule (1 dose), 7 were infected by M-VP meningococci and 2 with M-NVP meningococci, with 6 for which deductions were not possible. Of the unvaccinated children with IMD, 40/48 were ineligible for vaccination and 20/48 had IMD caused by M-VP meningococci, with deductions not being possible for 14 meningococci. IMPORTANCE This study demonstrates the value of postimplementation genomic surveillance of vaccine-preventable pathogens in providing information on real-world vaccine performance. The data are consistent with 2 and 3 doses of Bexsero, delivered according to schedule, providing good protection against invasive disease caused by meningococci deduced from genomic data to be vaccine preventable. Single doses provide poorer protection to infants. In practical terms, these data can provide public health reassurance when vaccinated individuals develop IMD with non-vaccine-preventable variants. They further indicate that additional testing is needed on variants for which no immunological data exist to improve estimates of protection, although these data suggest that the uncharacterized variants are unlikely to be covered by Bexsero. Finally, the confirmation that incomplete or absent doses in infancy lead to reduced protection supports public health and general practitioners in promoting vaccination according to schedule.

Infant↗

PubMed2003

Reference isolates for the clonal complexes of Campylobacter jejuni.

AIMS: To identify and make available through the National Collection of Type Cultures (NCTC) a set of reference isolates for the clonal complexes of Campylobacter jejuni. METHODS AND RESULTS: The development of a multilocus sequence typing scheme for C. jejuni enabled the genetic characterization of a large number of isolates (n = 814) from cases of human disease, animals, birds and their food products. The nucleotide sequence data were used to assign each isolate an allelic profile or sequence type (ST) and examine the C. jejuni population structure in terms of clonal complexes. The clonal complexes consisted of an abundant central or founder genotype (ST), after which the complex was named, together with very closely related, generally less abundant genotypes differing from the founder at one, two or three loci. The clonal complex is an informative unit for the study C. jejuni epidemiology. It provides data which enabled the choice of 13 C. jejuni founder isolates for submission to the NCTC as a representative cross-section of the C. jejuni population. CONCLUSIONS: These 13 isolates provide a defined resource for further research into aspects of C. jejuni biology such as genomic diversity, virulence and adaptation to particular hosts or environmental survival. SIGNIFICANCE AND IMPACT OF STUDY: This isolate collection is available through the NCTC and provides a resource for further research.

Alleles↗

PubMed2001

Multilocus sequence typing system for Campylobacter jejuni.

The gram-negative bacterium Campylobacter jejuni has extensive reservoirs in livestock and the environment and is a frequent cause of gastroenteritis in humans. To date, the lack of (i) methods suitable for population genetic analysis and (ii) a universally accepted nomenclature has hindered studies of the epidemiology and population biology of this organism. Here, a multilocus sequence typing (MLST) system for this organism is described, which exploits the genetic variation present in seven housekeeping loci to determine the genetic relationships among isolates. The MLST system was established using 194 C. jejuni isolates of diverse origins, from humans, animals, and the environment. The allelic profiles, or sequence types (STs), of these isolates were deposited on the Internet (http://mlst.zoo.ox.ac.uk), forming a virtual isolate collection which could be continually expanded. These data indicated that C. jejuni is genetically diverse, with a weakly clonal population structure, and that intra- and interspecies horizontal genetic exchange was common. Of the 155 STs observed, 51 (26% of the isolate collection) were unique, with the remainder of the collection being categorized into 11 lineages or clonal complexes of related STs with between 2 and 56 members. In some cases membership in a given lineage or ST correlated with the possession of a particular Penner HS serotype. Application of this approach to further isolate collections will enable an integrated global picture of C. jejuni epidemiology to be established and will permit more detailed studies of the population genetics of this organism.

Alleles↗

PubMed1998

The phenotype enhancement method identifies the Xcp outer membrane secretion machinery from Pseudomonas alcaligenes as a bottleneck for lipase production.

Pseudomonas alcaligenes M-1 has been selected from an intensive screening for micro-organisms that can naturally produce a lipase active in detergent formulations. The lipase expression has been increased to allow high level secretion from Pseudomonas alcaligenes, via the introduction of multi-copy plasmids. In order to improve the lipase yield further, the phenotype enhancement method has been developed. This idea comprises the reintroduction of a cosmid library with random chromosomal fragments in a P. alcaligenes strain with already high lipase productivity. One of the strains which showed an enhanced lipase production appeared to contain a cosmid encoding the outer membrane secretion genes. These xcp-genes are clustered in two divergently transcribed operons similar to the situation in Pseudomonas aeruginosa. Remarkably and dissimilar to P. aeruginosa, in between the two xcp gene clusters, two reading frames of unknown function--OrfV and OrfX--are present. For OrfX no equivalent can be found in the known protein data bases. On the other hand, OrfV shows homology to the regulatory proteins MalT and AcoK. Some evidence is provided that suggests that OrfV acts as a regulator of the xcp operons. A model is proposed for the regulation of the secretion system from P. alcaligenes.

Amino Acid Sequence↗

PubMed1990

Flumazenil: a twelve-month survey of use in a New Zealand public hospital.

As part of a program of postmarketing surveillance, the use of flumazenil was monitored prospectively in a New Zealand public hospital for a period of twelve months. A questionnaire on usage, efficacy and side-effects was completed by clinicians for 118 patients receiving the drug. Our conclusions are these: 1. Flumazenil was used most frequently after anaesthesia and in the initial management of intentional drug overdose. 2. In two-thirds of cases, flumazenil was used to antagonise benzodiazepines in the presence of non-benzodiazepine drugs and its efficacy was primarily determined by the presence of these latter drugs. 3. The complications of flumazenil are mild although important complications may arise from interaction with other drugs and unmasking of conditions such as postoperative pain. 4. Resedation was common (24%), although rarely a problem unless large doses of benzodiazepine agonist had been administered or if other hypnosedatives were given subsequently.

Adult↗