Susanne Jacobsson

Prevalence and sequence variations of the genes encoding the five antigens included in the novel 5CVMB vaccine covering group B meningococcal disease

During the recent years, projects are in progress for designing broad-range non-capsular-based meningococcal vaccines, covering also serogroup B isolates. We have examined three genes encoding antigens (NadA, GNA1030 and GNA2091) included in a novel vaccine, i.e. the 5 Component Vaccine against Meningococcus B (5CVMB), in terms of gene prevalence and sequence variations. These data were combined with the results from a similar study, examining the two additional antigens included in the 5CVMB (fHbp and GNA2132). nadA and fHbp v. 1 were present in 38% (n=36), respectively 71% (n=67) of the isolates, whereas gna2132, gna1030 and gna2091 were present in all the Neisseria meningitidis isolates tested (n=95). The level of amino acid conservation was relatively high in GNA1030 (93%), GNA2091 (92%), and within the main variants of NadA and fHbp. GNA2132 (54% of the amino acids conserved) appeared to be the most diversified antigen. Consequently, the theoretical coverage of the 5CVMB antigens and the feasibility to use these in a broad-range meningococcal vaccine is appealing.

Direct and Rapid Identification and Genogrouping of Meningococci and porA Amplification by LightCycler PCR

ABSTRACT Invasive meningococcal infections are usually diagnosed by culture. This approach is far from optimal due to, e.g., treatment with precollection antibiotics. Molecular-genetics methods are therefore recognized as important tools for optimal laboratory confirmation of meningococcal infections as well as characterization of meningococci (Mc). The aims of the present study were to develop real-time PCRs for identification and genogrouping (A, B, C, Y, and W-135) of Mc and porA amplification that further can be used for subsequent genosubtyping. In a first run Mc were identified. In a second run they were genogrouped and porA genes were amplified. All the Mc isolates (n = 71) but one and cerebrospinal fluid samples (n = 11) tested gave the expected positive results. The specificity, inter- and intra-assay variations, and effects of different amounts of DNA on the melting temperatures were also explored. The LightCycler PCR system was found to effectively detect and characterize Mc in a few hours. This testing, including the DNA sequencing of the porA gene to reveal the genosubtype, does not take more than a working day, and the results can be compared to those from culturing with phenotypic analysis, which takes at least a few days.

Alterations of the pilQ gene in Neisseria gonorrhoeae are unlikely contributors to decreased susceptibility to ceftriaxone and cefixime in clinical gonococcal strains

OBJECTIVES Gonorrhoea remains a global public health problem and the treatment options are diminishing through the emergence of gonococci resistant to most antimicrobials. Previous in vitro studies have indicated a role for Neisseria gonorrhoeae pilQ alterations in conferring resistance to antimicrobials, including penicillin. In this study, we investigated whether pilQ polymorphisms were associated with decreased susceptibility to extended-spectrum cephalosporins (ESCs) in clinical gonococcal strains. METHODS Full-length pilQ nucleotide and PilQ amino acid sequences from geographically and temporally diverse gonococcal clinical isolates (n = 63), including the 2008 WHO reference strains, representing a range of ceftriaxone and cefixime MICs (≤0.008-0.25 and <0.016-0.5 mg/L, respectively) and 38 N. gonorrhoeae multiantigen sequence types, were examined. Previously described alterations associated with decreased ESC susceptibility (mosaic penA, mtrR and penB alterations) were also examined. RESULTS Fifteen different pilQ nucleotide sequence types and nine different PilQ amino acid sequence types were observed, with two PilQ types accounting for 53 (84%) of the isolates. Independent of other genetic resistance determinants (penA mosaic, mtrR promoter deletion and penB), only one pilQ alteration, a D526N substitution, provided a statistically significant association with ceftriaxone (P < 0.01) and cefixime (P < 0.05) MICs. However, the two isolates exhibiting D526N lacked all three previously described alterations associated with decreased ESC susceptibility, thereby providing an alternative basis for the low MICs (≤0.008 mg/L) observed for these strains. The previously described E666K (pilQ2) and F595L (pilQ1) mutations were absent in all 63 isolates. CONCLUSIONS pilQ polymorphisms are unlikely contributors to decreased susceptibility to ESCs in clinical gonococcal strains.

An international invasive meningococcal disease outbreak due to a novel and rapidly expanding serogroup W strain, Scotland and Sweden, July to August 2015.

The 23rd World Scout Jamboree in 2015 took place in Japan and included over 33,000 scouts from 162 countries. Within nine days of the meeting ending, six cases of laboratory-confirmed invasive serogroup W meningococcal disease occurred among scouts and their close contacts in Scotland and Sweden. The isolates responsible were identical to one-another by routine typing and, where known (4 isolates), belonged to the ST-11 clonal complex (cc11) which is associated with large outbreaks and high case fatality rates. Recent studies have demonstrated the need for high-resolution genomic typing schemes to assign serogroup W cc11 isolates to several distinct strains circulating globally over the past two decades. Here we used such schemes to confirm that the Jamboree-associated cases constituted a genuine outbreak and that this was due to a novel and rapidly expanding strain descended from the strain that has recently expanded in South America and the United Kingdom. We also identify the genetic differences that define the novel strain including four point mutations and three putative recombination events involving the horizontal exchange of 17, six and two genes, respectively. Noteworthy outcomes of these changes were antigenic shifts and the disruption of a transcriptional regulator.

High in-vitro activity of the novel spiropyrimidinetrione AZD0914, a DNA gyrase inhibitor, against multidrug resistant Neisseria gonorrhoeae isolates suggests a new effective option for oral treatment of gonorrhea

ABSTRACT We evaluated the activity of the novel spiropyrimidinetrione AZD0914 (DNA gyrase inhibitor) against clinical gonococcal isolates and international reference strains (n = 250), including strains with diverse multidrug resistance and extensive drug resistance. The AZD0914 MICs were substantially lower than those of most other currently or previously recommended antimicrobials. AZD0914 should be further evaluated, including in vitro selection, in vivo emergence and mechanisms of resistance, pharmacokinetics/pharmacodynamics in humans, optimal dosing, and performance, in appropriate randomized and controlled clinical trials.

Meningococcal serogroup Y emergence in Europe: update 2011.

Neisseria meningitidis is differentiated into 12 distinct serogroups, of which A, B, C, W-135, X, and Y are medically most important and represent an important health problem in different parts of the world. The epidemiology of N. meningitidis is unpredictable over time and across geographic regions. Recent epidemiological surveillance has indicated an increase of serogroup Y invasive meningococcal disease in some parts of Europe as shown in the epidemiological data for 2010 from various European countries previously published in this journal.1 Here, data is reported indicating that the emergence of serogroup Y continued in 2011 in various regions of Europe. The average age of persons affected by N. meningitidis serogroup Y seems to have decreased in some countries in comparison to the previous decade.

Decreased susceptibility to chlorhexidine and prevalence of disinfectant resistance genes among clinical isolates of Staphylococcus epidermidis

Staphylococcus epidermidis is a versatile agent, being both a commensal and a nosocomial pathogen usually with an opportunistic role in association with implanted foreign body materials. Pre‐operative antiseptic preparation is an important strategy for reducing the risk of complications such as surgical site infection (SSI). Currently, the most widely used antiseptics are alcohols, quaternary ammonium compounds (QACs), and the bisbiguanide chlorhexidine. Occurrence of resistance to the latter agent has drawn increasing attention. The aim of this study was to investigate if decreased susceptibility to chlorhexidine among S. epidermidis was present in our setting, a Swedish university hospital. Staphylococcus epidermidis (n = 143), retrospectively collected, were obtained from prosthetic joint infections (PJI) (n = 61), post‐operative infections after cardiac surgery (n = 31), and the skin of the chest after routine disinfection prior to cardiac surgery (n = 27). In addition, 24 commensal isolates were included. Minimum inhibitory concentration (MIC) of chlorhexidine was determined on Mueller Hinton agar plates supplemented with serial dilutions of chlorhexidine. Five QAC resistance genes, qacA/B, smr, qacH, qacJ, and qacG, were detected using PCR. Decreased susceptibility to chlorhexidine was found in 54% of PJI isolates, 68% of cardiac isolates, 21% of commensal isolates, and 7% of skin isolates from cardiac patients, respectively. The qacA/B gene was present in 62/143 isolates (43%), smr in 8/143 (6%), and qacH in one isolate (0.7%). The qacA/B gene was found in 52% of PJI isolates, 61% of cardiac isolates, 25% of commensal isolates, and 19% of the skin isolates. In conclusion, decreased susceptibility to chlorhexidine, as well as QAC resistance genes, were prevalent among S. epidermidis isolates associated with deep SSIs.

Staphylococcus epidermidis surface protein I (SesI): a marker of the invasive capacity of S. epidermidis?

Staphylococcus epidermidis surface protein I (SesI) : a marker of the invasive capacity of S. epidermidis?

Meningococcal serogroup Y disease in Europe: Continuation of high importance in some European regions in 2013

Neisseria meningitidis or meningococcus is divided into 12 distinct serogroups of which A, B, C, W, X, and Y are medically most important and cause health problems in different parts of the world. The epidemiology of N. meningitidis is unpredictable over time and across geographic regions. Globally, serogoup A has been prevalent in the African “meningitis belt” whereas serogroup B and C have predominated in Europe. In a paper published earlier in this journal1, an increase in serogroup Y invasive meningococcal disease (IMD) in some European countries was reported based on the epidemiological data for 2010, 2011 and 2012. Here, we report additional data from 30 European countries indicating that high or increased serogroup Y disease levels have continued in 2013 in certain regions of Europe. In the Western and Central Europe, there were no major changes in the proportion of serogroup Y IMD cases in 2013 compared to 2012. In the Scandinavian countries, proportion of serogroup Y disease remained high, ranging from 26% to 51% in 2013. This was in contrast to Baltic, Eastern and most Southern European countries, where the proportion of serogroup Y IMD was low similarly to previous years. For the last 2 decades, the mean age of patients affected by serogroup Y was 41 y for 7 countries from which data was available and 50% of cases were in patients aged 45 to 88 y. The age distribution of serogroup Y was bimodal and did not change significantly despite the increase of the total number and the proportion of serogroup Y IMD in some European regions.

Increase of meningococcal serogroup Y cases in Europe: a reason for concern?

Neisseria meningitidis is differentiated into 12 distinct serogroups of which A, B, C, W-135, X and Y are medically most important and represent a major health problem in one or more parts of the world. The epidemiology of N. meningitidis is unpredictable over time and across geographic regions. A sudden increase or decrease of IMD or meningococcal carriage may occur anywhere at any time. Recent epidemiological surveillance indicates an increase of serogroup Y IMD in some parts of Europe and data from various European countries are presented.