Nicola Jones

Multilocus Sequence Typing System for Group B Streptococcus

ABSTRACT A multilocus sequence typing (MLST) system was developed for group B streptococcus (GBS). The system was used to characterize a collection (n = 152) of globally and ecologically diverse human strains of GBS that included representatives of capsular serotypes Ia, Ib, II, III, V, VI, and VIII. Fragments (459 to 519 bp) of seven housekeeping genes were amplified by PCR for each strain and sequenced. The combination of alleles at the seven loci provided an allelic profile or sequence type (ST) for each strain. A subset of the strains were characterized by restriction digest patterning, and these results were highly congruent with those obtained with MLST. There were 29 STs, but 66% of isolates were assigned to four major STs. ST-1 and ST-19 were significantly associated with asymptomatic carriage, whereas ST-23 included both carried and invasive strains. All 44 isolates of ST-17 were serotype III clones, and this ST appeared to define a homogeneous clone that was strongly associated with neonatal invasive infections. The finding that isolates with different capsular serotypes had the same ST suggests that recombination occurs at the capsular locus. A web site for GBS MLST was set up and can be accessed at http://sagalactiae.mlst.net. The GBS MLST system offers investigators a valuable typing tool that will promote further investigation of the population biology of this organism.

Hyperinvasive Neonatal Group B Streptococcus Has Arisen from a Bovine Ancestor

ABSTRACT The genetic relatedness and evolutionary relationships between group B streptococcus (GBS) isolates from humans and those from bovines were investigated by phylogenetic analysis of multilocus sequence typing data. The collection of isolates consisted of 111 GBS isolates from cows with mastitis and a diverse global collection of GBS isolates from patients with invasive disease (n = 83) and carriers (n = 69). Cluster analysis showed that the majority of the bovine isolates (93%) grouped into one phylogenetic cluster. The human isolates showed greater diversity and clustered separately from the bovine population. However, the homogeneous human sequence type 17 (ST-17) complex, known to be significantly associated with invasive neonatal disease, was the only human lineage found to be clustered within the bovine population and was distinct from all the other human lineages. Split decomposition analysis revealed that the human isolate ST-17 complex, the major hyperinvasive neonatal clone, has recently arisen from a bovine lineage.

User involvement in the development of a research bid: barriers, enablers and impacts.

Objective  To involve users in the development of a research bid to examine parents’ experiences of having a pre‐term baby, and to examine the barriers, enablers and impacts of user involvement.

Multilocus Sequence Typing of Serotype III Group B Streptococcus and Correlation with Pathogenic Potential

Serotype III group B streptococcus (GBS) causes more invasive disease in infants than do other serotypes in North America. We used multilocus sequence typing to identify clones within 28 invasive serotype III GBS isolates identified from a population-based study and 55 serotype III GBS colonizing isolates from a cohort of women from the same population. Ten allelic sequence types (STs) were identified and primarily involved 2 profiles: ST-19 (57.1% of invasive isolates and 58.2% of colonizing isolates) and ST-17 (32.1% of invasive isolates and 29.1% of colonizing isolates). On concatenation, the 10 allelic profiles converged into 3 groups. Group 1 consisted of ST-19 complex, ST-36, and ST-1, and was closely related to reference genome 2603V/R (serotype V). Group 2 consisted of ST-17 complex. Group 3 consisted of ST-23 complex and was closely related to the serotype III genome strain NEM 316. Neither of the major sequence types or groups was more commonly associated with invasion (P=.61) or with lower levels of maternal capsular polysaccharide-specific IgG (0.89 microg/mL and 0.39 microg/mL, respectively) for ST-19 and ST-17 (P=.86). The close association of genomic strain 2603V/R (serotype V) with ST-19 suggests that the phenomenon of capsule switching may have occurred.

A systematic mapping review of effective interventions for communicating with, supporting and providing information to parents of preterm infants

Background and objective The birth of a preterm infant can be an overwhelming experience of guilt, fear and helplessness for parents. Provision of interventions to support and engage parents in the care of their infant may improve outcomes for both the parents and the infant. The objective of this systematic review is to identify and map out effective interventions for communication with, supporting and providing information for parents of preterm infants. Design Systematic searches were conducted in the electronic databases Medline, Embase, PsychINFO, the Cochrane library, the Cumulative Index to Nursing and Allied Health Literature, Midwives Information and Resource Service, Health Management Information Consortium, and Health Management and Information Service. Hand-searching of reference lists and journals was conducted. Studies were included if they provided parent-reported outcomes of interventions relating to information, communication and/or support for parents of preterm infants prior to the birth, during care at the neonatal intensive care unit and after going home with their preterm infant. Titles and abstracts were read for relevance, and papers judged to meet inclusion criteria were included. Papers were data-extracted, their quality was assessed, and a narrative summary was conducted in line with the York Centre for Reviews and Dissemination guidelines. Studies reviewed Of the 72 papers identified, 19 papers were randomised controlled trials, 16 were cohort or quasi-experimental studies, and 37 were non-intervention studies. Results Interventions for supporting, communicating with, and providing information to parents that have had a premature infant are reported. Parents report feeling supported through individualised developmental and behavioural care programmes, through being taught behavioural assessment scales, and through breastfeeding, kangaroo-care and baby-massage programmes. Parents also felt supported through organised support groups and through provision of an environment where parents can meet and support each other. Parental stress may be reduced through individual developmental care programmes, psychotherapy, interventions that teach emotional coping skills and active problem-solving, and journal writing. Evidence reports the importance of preparing parents for the neonatal unit through the neonatal tour, and the importance of good communication throughout the infant admission phase and after discharge home. Providing individual web-based information about the infant, recording doctor–patient consultations and provision of an information binder may also improve communication with parents. The importance of thorough discharge planning throughout the infants admission phase and the importance of home-support programmes are also reported. Conclusion The paper reports evidence of interventions that help support, communicate with and inform parents who have had a premature infant throughout the admission phase of the infant, discharge and return home. The level of evidence reported is mixed, and this should be taken into account when developing policy. A summary of interventions from the available evidence is reported.

Serotype III Streptococcus agalactiae from bovine milk and human neonatal infections

Although largely unrelated, many bovine type III GBS appear to share a common ancestor with an important human clone.

Increasing burden of community-acquired pneumonia leading to hospitalisation, 1998-2014.

Background Community-acquired pneumonia (CAP) is a major cause of mortality and morbidity in many countries but few recent large-scale studies have examined trends in its incidence. Methods Incidence of CAP leading to hospitalisation in one UK region (Oxfordshire) was calculated over calendar time using routinely collected diagnostic codes, and modelled using piecewise-linear Poisson regression. Further models considered other related diagnoses, typical administrative outcomes, and blood and microbiology test results at admission to determine whether CAP trends could be explained by changes in case-mix, coding practices or admission procedures. Results CAP increased by 4.2%/year (95% CI 3.6 to 4.8) from 1998 to 2008, and subsequently much faster at 8.8%/year (95% CI 7.8 to 9.7) from 2009 to 2014. Pneumonia-related conditions also increased significantly over this period. Length of stay and 30-day mortality decreased slightly in later years, but the proportions with abnormal neutrophils, urea and C reactive protein (CRP) did not change (p>0.2). The proportion with severely abnormal CRP (>100 mg/L) decreased slightly in later years. Trends were similar in all age groups. Streptococcus pneumoniae was the most common causative organism found; however other organisms, particularly Enterobacteriaceae, increased in incidence over the study period (p<0.001). Conclusions Hospitalisations for CAP have been increasing rapidly in Oxfordshire, particularly since 2008. There is little evidence that this is due only to changes in pneumonia coding, an ageing population or patients with substantially less severe disease being admitted more frequently. Healthcare planning to address potential further increases in admissions and consequent antibiotic prescribing should be a priority.

Genetic islands of Streptococcus agalactiae strains NEM316 and 2603VR and their presence in other Group B Streptococcal strains

BackgroundStreptococcus agalactiae (Group B Streptococcus; GBS) is a major contributor to obstetric and neonatal bacterial sepsis. Serotype III strains cause the majority of late-onset sepsis and meningitis in babies, and thus appear to have an enhanced invasive capacity compared with the other serotypes that cause disease predominantly in immunocompromised pregnant women. We compared the serotype III and V whole genome sequences, strains NEM316 and 2603VR respectively, in an attempt to identify genetic attributes of strain NEM316 that might explain the propensity of strain NEM316 to cause late-onset disease in babies. Fourteen putative pathogenicity islands were described in the strain NEM316 whole genome sequence. Using PCR- and targeted microarray- strategies, the presence of these islands were assessed in a diverse strain collection including 18 colonizing isolates from healthy pregnant women, and 13 and 8 invasive isolates from infants with early- and late-onset sepsis, respectively.ResultsSide-by-side comparison of the strain NEM316 and strain 2603VR genomes revealed that they are extremely similar, with the only major difference being the capsulation loci and mobile genetic elements. PCR and Comparative Genome Hybridization (CGH) were used to define the presence of each island in 39 GBS isolates. Only islands I, VI, XII, and possibly X, met criteria of a true pathogenicity island, but no significant correlation was found between the presence of any of the fourteen islands and whether the strains were invasive or colonizing. Possible associations were seen between the presence of island VI and late-onset sepsis, and island X and early-onset sepsis, which warrant further investigation.ConclusionThe NEM316 and 2603VR strains are remarkable in that their whole genome sequences are so similar, suggesting that the capsulation loci or other genetic differences, such as pathogenicity islands, are the main determinants of the propensity of serotype III strains to cause late-onset disease. This study supports the notion that GBS strain NEM316 has four putative pathogenicity islands, but none is absolutely necessary for disease causation, whether early- or late-onset sepsis. Mobile genetic elements are a common feature of GBS isolates, with each strain having its own peculiar burden of transposons, phages, integrases and integrated plasmids. The majority of these are unlikely to influence the disease capacity of an isolate. Serotype associated disease phenotypes may thus be solely related to differences in the capsulation loci.

The amino acid requirements of Staphylococcus aureus isolated from cases of bovine mastitis.

The amino acid requirements of seven strains of Staphylococcus aureus isolated from cases of bovine mastitis were determined. Arginine, cystine, glycine, leucine, proline and valine were essential for the growth of all isolates. In addition, all isolates required one or more of the following: glutamic acid, histidine, isoleucine, lysine, methionine, phenylalanine, tryptophan and tyrosine.

Capsular Typing Method for Streptococcus agalactiae Using Whole-Genome Sequence Data

ABSTRACT Group B streptococcus (GBS) capsular serotypes are major determinants of virulence and affect potential vaccine coverage. Here we report a whole-genome-sequencing-based method for GBS serotype assignment. This method shows strong agreement (kappa of 0.92) with conventional methods and increased serotype assignment (100%) to all 10 capsular types.