Comparison of invasive and non-invasive isolates of Neisseria meningitidis by whole genome sequencing, Czech Republic, 2005-2021.

AIM: Whole genome sequencing (WGS) analysis of candidate virulence genes of epidemiologically and/or clinically related invasive and non-invasive isolates of Neisseria meningitidis from 2005-2021. MATERIAL AND METHODS: Seventy-nine isolates were selected for analysis from three different categories: cases of invasive meningococcal disease (IMD) and their healthy contacts, different clinical specimens from the same IMD case, and different clinical specimens from the same IMD case and their healthy contacts. WGS was used to analyse sequence variability in candidate N. meningitidis virulence factor genes, with more than 250 loci studied. RESULTS: The frequency of sequence changes in the candidate N. meningitidis virulence factor genes of invasive and non-invasive isolates varied widely. The highest level of variability was observed in the pilus genes, especially pilE and pglA. Our study detected variability in the opacity protein A (opaA) gene in more than half of the isolates analysed, with the frequency of opaA gene changes reaching almost 70% in MenC isolates. Higher frequency of changes were also observed in the genes for capsule production, especially in those of the D+D' capsular region. CONCLUSIONS: The results obtained support the hypothesis that serogroup-specific genetic mechanisms are also involved in the pathogenicity of N. meningitidis. These data add to the body of knowledge necessary for the development of new effective IMD vaccines.

Analysis of meningococcal vaccine uptake in patients with invasive meningococcal disease, Czech Republic, 2006-2022.

In 2006-2022, 958 cases of invasive meningococcal disease (IMD) were reported to the surveillance programme in the Czech Republic, of which 21 (2.19%) had a history of vaccination with one of the meningococcal vaccines. Data analysis shows that these vaccines provide a very good protection against IMD. It was found that vaccinated patients with IMD either were not vaccinated against the causative serogroup and/or did not receive a booster dose. The results of this analysis show the benefit of both vaccines available in the Czech Republic: recombinant vaccine containing meningococcal serogroup B antigens (MenB vaccine) and tetravalent conjugate vaccine containing antigens of four meningococcal serogroups A, C, W, Y (A, C, W, Y conjugate vaccine). The results also show the benefit of meningococcal vaccine booster doses and the need for giving MenB vaccine to young children as early as possible.

Analysis of epidemiological and molecular data from invasive meningococcal disease surveillance in the Czech Republic, 1993-2020.

AIM: An analysis is presented of epidemiological and molecular data from invasive meningococcal disease (IMD) surveillance in the Czech Republic (CR) for 1993-2020, comparing trends in four seven-year periods: 1993-1999, 2000-2006, 2007-2013, and 2014-2020. MATERIAL AND METHODS: IMD surveillance data are generated by linking National Reference Laboratory for Meningococcal Diseases data and epidemiological data routinely reported to the infectious diseases information systems, with duplicate data removal. Whole genome sequencing (WGS) was used for analysis of selected isolates from IMD cases. In this study, WGS data are analysed on 323 isolates recovered from IMD cases in the Czech Republic between 1993-2020. RESULTS: Over the entire study period 1993-2020, 2,674 cases were recorded in the IMD surveillance programme, of which 272 were fatal. In the first seven-year period, the highest incidence rate of 2.2/100,000 population was reported in 1995, a gradual decline from 0.8 to 0.6/100,000 was observed in the third period, and in the last period, this decline continued until 2020, achieving a low of 0.2/100,000. In all four study periods, the age group 0-11 months was the most affected, followed by 1-4-year-olds and 15-19-year-olds. Serogroup B caused the highest number of cases (43.6%), followed by serogroups C (34.9%), Y (1.8%), and W (1.5%). Serogroup X was only found in three cases. The overall case fatality rate in the entire study period was 10.2%, with no decline seen in the four periods. The highest case fatality rate was associated with serogroup Y (14.6%), followed by serogroups W (12.5%), C (12.0%), and B (8.1%). In terms of age, the highest case fatality rate was observed in people aged 65+ (24.7%). The WGS data for 323 IMD isolates from 1993-2020 showed the highest representation of eight clonal complexes: cc11, cc44/41, cc32, cc267, cc23, cc18, cc35, and cc865. Isolates of serogroup C, cc11, from the last study period form two genetically distinct populations with distinct phenotypes that are genetically distant from the lineage of cc11 isolates from the first two periods. The study population included a unique Czech subpopulation of serogroup W isolates (ST-3342, cc865), recorded only in the last two periods (2007-2020), whose position in the phylogenetic network supports the theory that the serogroup W population in the Czech Republic originated from serogroup B isolates as a result of serogroup switch (capsule switch). Clonal complexes cc41/44, cc32, cc267, cc18, and cc35 are predominantly composed of serogroup B isolates, while cc23 includes exclusively serogroup Y isolates. CONCLUSIONS: The analysis of surveillance data over a 28-year period confirms that the vaccination strategy currently used in the Czech Republic, i.e., vaccination of young children and adolescents with a combination of MenB vaccine and quadrivalent conjugate ACWY vaccine, appears to be the most appropriate in the context of the long-term epidemiological situation of IMD in the CR.

Detailed molecular characterization of Neisseria meningitidis isolates by whole genome sequencing (WGS), Czech Republic, 2010-2019.

AIM: Presentation of the first results of the analysis of Neisseria meningitidis isolates from invasive meningococcal disease and from clinically and/or epidemiologically linked cases from 2010-2019. Whole genome sequencing (WGS) was used for the study. MATERIAL AND METHODS: The study set included 59 isolates of N. meningitidis from 2010-2019. Serogrouping was done by conventional serological methods and confirmed by RT-PCR. WGS was used for detailed molecular characterization, covering not only basic genes but also ribosomal and capsular genes, antibiotic resistance gene penA, and outer membrane protein gene porA. RESULTS: WGS analysis of N. meningitidis isolates resulted in a detailed molecular characterization. In a large part of the genes analysed, new mutated allelic variants were found. They were submitted to the PubMLST database and subsequently annotated by the curator. All 59 study isolates were assigned to BAST types, characterized by a unique combination of allelic variants of N. meningitidis B vaccine (MenB vaccine) antigen genes. Overall, 32 different BAST types were identified, and 10 isolates either carried an unknown combination of BAST loci or a new allelic variant in some of the BAST loci. Furthermore, the MenDeVAR index, which provides information on the functional effect of MenB vaccines on a given isolate, was determined. CONCLUSIONS: The results obtained add to the body of knowledge of the transmission of invasive and non-invasive strains of N. meningitidis in the population. The WGS analysis provided detailed data on the coverage of these strains by new MenB vaccines.

Surveillance of invasive meningococcal disease based on whole genome sequencing (WGS), Czech Republic, 2015.

AIM: To test the potential of whole genome sequencing (WGS) for molecular surveillance of invasive meningococcal disease in the Czech Republic. To check the success of the new method in the identification of gene and protein variants and to compare the outcomes between WGS and conventional sequencing methods. MATERIAL AND METHODS: WGS was carried out in a set of 20 N. meningitidis isolates from invasive meningococcal disease cases in the Czech Republic in 2015. WGS was performed using the Illumina MiSeq platform. The WGS data were processed by the Velvet de novo Assembler software, and the resultant genome contigs were submitted to the Neisseria PubMLST web database containing allelic and genomic data on strains of the genus Neisseria. The genomes were analysed and compared using the BIGSdb Genome Comparator, which is part of the PubMLST database. WGS data were compared at several levels of resolution: MLST (Multi Locus Sequence Typing), rMLST (ribosomal MLST), cgMLST (core genome MLST), and "all loci", i.e. all genes of N. meningitidis defined in the PubMLST database by 6 November 2017 (3028 loci). The WGS method was used to characterise in detail the genes of antigens involved in vaccines against N. meningitidis B. RESULTS: The new WGS method provided detailed characteristics of N. meningitidis isolates, which improved the results obtained previously by conventional sequencing methods. High quality WGS data made it possible to identify novel alleles and novel sequence types that could not be recognized by conventional sequencing methods. The analysis of genetic diversity confirmed closer relatedness between isolates belonging to the same clonal complex. The most accurate information on genetic diversity of isolates was obtained by the comparison of WGS data at the cgMLST and "all loci" levels. Distant relatedness of three clonal complexes (cc32, cc35, and cc269) was found. WGS data also provided more accurate information on the coverage of isolates by MenB vaccines in comparison with conventional sequencing data. CONCLUSIONS: The WGS method showed a higher discrimination potential and allowed a more accurate determination of genetic characteristics of N. meningitidis. The integration of the WGS method in routine molecular surveillance of invasive meningococcal disease in the Czech Republic is desirable.

[The possibilities for the implementation of whole genome sequencing (WGS) of Neisseria meningitidis in molecular surveillance of invasive meningococcal disease in the Czech Republic]. / Moznosti implementace sekvenace celého genomu (WGS) Neisseria meningitidis do molekulární surveillance invazivního meningokokového onemocnení v Ceské republice.

The implementation of the surveillance of invasive meningococcal disease is recommended worldwide. The Whole Genome Sequencing (WGS) method increasingly comes to the fore, which provides the possibilities for further detailed characterization of Neisseria meningitidis and makes it possible to integrate all conventional sequencing approaches into one method. Six N. meningitidis isolates from 2013 and 2015, characterized previously by Sanger amplicon sequencing, were selected to be studied by the novel WGS method. WGS data analysis has confirmed the accuracy of this method in determining epidemiological markers. The aim of this communication is to point out the possibility for the implementation of WGS into molecular surveillance of invasive meningococcal disease in the Czech Republic. The National Reference Laboratory for Meningococcal Infections (NRL/MEN) will continue to use WGS for molecular characterization of selected isolates of N. meningitidis and for the improvement of molecular surveillance of invasive meningococcal disease in the country.

[Multiple-locus variable number tandem repeat analysis of Bordetella pertussis strains collected in the Czech Republic in 1967-2015: spread of a variant adapted to the population with a high vaccination coverage]. / Multiple-locus variable number tandem repeat analýza souboru kmenu Bordetella pertussis v CR z období 1967-2015: rozsírení varianty adaptované na proockovanou populaci.

AIM: To perform multiple-locus variable number tandem repeat analysis (MLVA) of B. pertussis strains from the collection of the National Reference Laboratory for Diphtheria and Pertussis (NRL/DIPE), National Institute of Public Health (NIPH), Prague. The study strains were isolated from clinical specimens collected mostly in the Czech Republic over a nearly 50-year period from 1967 to 2015 (June). The isolates from three periods characterized by different vaccination strategies and trends in pertussis are compared for genetic diversity and distribution of MLVA types (MT). Based on the results obtained, the suitability for use of MLVA in the analysis of epidemic outbreaks of B. pertussis in the Czech Republic is considered. MATERIAL AND METHODS: DNA samples extracted from B. pertussis strains included in the present study were examined by MLVA using the standard protocol. Data were processed by means of the eBURST algorithm and the calculation of the Simpson diversity index (DI) was used for the statistical analysis. Data were analyzed as a whole and also separately for strains from the three periods: 1967-1980, 1990-2007, and 2008-2015 (June). RESULTS: Fourteen different MT were detected in the study strains, with three of them not being reported before. The most common MTs were MT27 and MT29. MT29 was predominant in 1967-1980 while MT27 was the most prevalent in 1990-2007 and 2008-2015 (June). The DI was the lowest (0.49) in 2008-2015 (June), and comparably higher DIs were calculated for the two previous periods (i.e. 0.667 for 1967-1980 and 0.654 for 1990-2007). CONCLUSION: MLVA revealed a decrease in genetic diversity and shifts in MT distribution of B. pertussis strains isolated from clinical specimens in the Czech Republic from 1967 to 2015 (June). These shifts in the Czech Republic can be characterized as a progressive increase in global MTs at the expense of the locally unique ones. The most common MT, similarly to other geographical areas with long-term high vaccination coverage, is MT27. The results of MLVA of 136 B. pertussis strains can provide a background for using this method in molecular epidemiological analysis of smaller groups of strains.

[Antigenic variability of Bordetella pertussis strains isolated in 1967-2010 in the Czech Republic--possible explanation for the rise in cases of pertussis?]. / Antigenní variabilita kmenu Bordetella pertussis izolovaných v letech 1967-2010 v Ceské republice--mozné vysvetlení vzestupu nemocnosti pertusí?

OBJECTIVE: Comparison of antigenic structures of Bordetella pertussis (B. pertussis) strains isolated from 1967 to 2010 in the Czech Republic. MATERIAL AND METHODS: Seventy strains of B. pertussis were referred to the National Reference Laboratory (NRL) for Pertussis and Diphtheria within the surveillance of pertussis from all over the Czech Republic (CR) between 1967 and 2010. To study the strains, the analysis was performed of the genome sequences encoding the surface immunogenic structures--the pertussis toxin S1 subunit gene (ptxA), pertactin gene region 1 (prnA), type 3 fimbriae gene (fim3)--and pertussis toxin promoter (ptxP) responsible for the regulation of the production of pertussis toxin. RESULTS: For the study set of B. pertussis strains, the sequencing analysis revealed changes in all genomic regions studied. The isolates from three periods differ in the allelic profile. In period I (19671978) with the use of whole cell pertussis vaccine (wP), the following two profiles were the most common: ptxP(1), ptxA(2), prnA(1), fim3(1) and ptxP(1), ptxA(1), prnA(3), fim3(1). In period 2 (19902007) with the switch to acellular pertussis vaccine (aP), the most common profile was: ptxP(3), ptxA(1), prnA(2), fim3(2). Period 3 (20082010) with the use of aP was characterized by the predominance of the following two profiles which had never been found in period 1: ptxP(3), ptxA(1), prnA(2), fim3(2) and ptxP(3) ptxA(1), prnA(2), fim3(1). CONCLUSIONS: Sequencing of the genomic regions ptxP, ptxA, prnA, and fim3 of B. pertussis strains isolated in the CR between 1967 and 2010 confirmed changes in the allelic variants of these regions. The incidence of strains carrying the new allelic variants was increasing after 1995 at the expense of those carrying the original variants. The study results can be interpreted as a partial genetic escape of pathogenic strains of B. pertussis beyond the reach of the pertussis vaccines.

[Clonal analysis of the meningococcal populations from invasive disease and healthy carriers isolated in the Czech Republic in 1971-2014 (May)]. / Klonální analýza populace meningokoku z invazivního onemocnení a od zdravých nosicu izolovaných v Ceské republice v období 1971--2014 (kveten).

OBJECTIVE: To present the results of clonal analysis of the meningococcal populations isolated from invasive disease and healthy carriers in the Czech Republic over four decades. MATERIAL AND METHODS: A total of 2179 isolates of Neisseria meningitidis from 1971-2014 (May) were studied: 1093 isolates from patients with invasive meningococcal disease (IMD) and 1086 isolates from healthy carriers. All study isolates were analysed by multilocus sequence typing (MLST), one of the major methods used in molecular epidemiology of IMD. RESULTS: More than 94 % of N. meningitidis isolates from IMD were assigned to serogroups B or C. The strains of the leading serogroup B were genetically highly heterogeneous: 1093 isolates were assigned to 25 clonal complexes. Similarly, the strains of the second leading serogroup C appeared genetically heterogeneous and were classified into 19 clonal complexes. The third leading serogroup Y of IMD isolates showed an opposite tendency and appeared highly homogeneous, with only three clonal complexes being detected. Over 75% of the predominant clonal complexes of IMD isolates of both serogroup Y (cc23) and serogroup C (cc11) were classified as hypervirulent and, as such, posed the highest risk to the host population. Over 80% of IMD isolates of serogroup B were assigned to hypervirulent clonal complexes (cc32, cc41/44, cc18, cc269, and cc11). Of 1086 N. meningitidis isolates from healthy carriers, 41.4% were non-serogroupable, i.e. designated N. meningitidis NG. Classification of these isolates into clonal complexes was highly heterogeneous. In total, 28 clonal complexes were identified of which only a minority were hypervirulent. CONCLUSIONS: The analysis of MLST data on strains collected over four decades revealed that the population of N. meningitidis strains involved in IMD differ genetically from N. meningitidis strains isolated from healthy carriers. These results are relevant to both the optimal use of preventive measures in a focus of IMD and to the development of an effective meningococcal vaccine and vaccination strategy guidelines.

[Pertussis trend in children under one year of age in the Czech Republic in 1997-2013]. / Trend pertuse u detí do jednoho roku zivota v Ceské republice v letech 1997-2013.

STUDY OBJECTIVE: To characterize the epidemiological situation of pertussis in children under one year of age in the Czech Republic in 1997-2013. MATERIAL AND METHODS: The study cohort consisted of children under one year of age with laboratory confirmed pertussis reported to the communicable disease system from 1997 to 2013. A total of 265 pertussis cases were reported in children under one year of age over the study period. Selected demographic data, need for hospitalization, and vaccination history were evaluated in the study cohort. RESULTS: Children under one year of age have shown a steady upward trend in reported cases of pertussis since the 1990s. The reported incidence of pertussis in this age group was the lowest in 1998 (1.1/100,000 population) and the highest in 2013 (31.3/100,000). In 1997-2013, 265 pertussis cases were reported in children under one year of age, 128 females and 137 males, to the communicable disease system in the Czech Republic. Most of these children, nearly 77%, developed pertussis within the first four months of life. Of the 265 children, 79% were not vaccinated before the onset of the disease and 21% were immunized with at least one dose of pertussis vaccine before developing the disease. As many as 75% of the children with pertussis needed hospitalization. Most of them, nearly 81%, were hospitalized with pertussis in the first four months of life and 90% of them in the first six months of life. CONCLUSIONS: In 1997-2013, an upward trend was observed in pertussis cases in children under one year of age. Most children developed the disease within the first four months of life while not vaccinated against pertussis. This fact unambiguously supports the "cocoon" strategy, i.e. vaccination of the closest contacts of the child, and a booster dose at 25 years of age. At the same time, a question arises whether to provide vaccination to pregnant women.

Predicted strain coverage of a new protein-based meningococcal vaccine in the Czech Republic.

BACKGROUND: Recent data indicate that Neisseria meningitidis B strains cause about 70% of invasive meningococcal disease (IMD) cases in Europe and the availability of a vaccine effective against N. meningitidis B is desirable. A new protein-based MenB vaccine was licensed for use in Europe in January 2013. Meningococcal antigen typing system (MATS) was developed to predict strain coverage of this vaccine. Reports have recently been published for a European consortium, including aggregated data for the Czech Republic. The aim of this paper is to provide a detailed breakdown of MATS results for the Czech N. meningitidis B isolates. MATERIALS AND METHODS: One hundred and eight N. meningitidis B isolates from IMD collected in the Czech Republic during 2007-2010 were selected. MATS analysis was done according to the method previously published. RESULTS: Based on MATS analysis, the overall estimate of strain coverage of the new MenB vaccine for a panel of 108 Czech N. meningitidis B strains is 74% (95% CI: 59-87%). Thirty-nine strains (36%) are predicted to be covered by a single antigen and 41 strains (38%) by more than one antigen. For 28 strains (26%), no antigen coverage was found. CONCLUSIONS: MATS analysis showed that the new protein-based MenB vaccine could protect against a substantial proportion of IMD caused by N. meningitidis B in the Czech Republic. Continued detailed surveillance of IMD will be essential if the MenB vaccine is introduced to the country.

[Sequencing analysis of the antigens included in the four-component vaccine against serogroup B meningococcus in Czech isolates of Neisseria meningitidis from 2007-2013]. / Sekvenacní analýza antigenu zarazených v ctyrkomponentní vakcíne proti meningokoku B v ceských izolátech Neisseria meningitidis v období 2007-2013.

OBJECTIVE: Study of the antigens included in the newly registered four-component vaccine against meningococcus B (MenB vaccine) produced by the reverse vaccinology method and assessment of the potential of the vaccine for use in the Czech Republic. MATERIAL AND METHODS: Czech isolates of Neisseria meningitidis were screened for four antigens: fHbp (factor H binding protein), NHBA (Neisseria heparin binding antigen), NadA (neisserial adhesin A), and PorA P1.4 outer membrane protein. A total of 304 N. meningitidis isolates from 2007-2013 were included in the study: 262 isolates from invasive meningococcal disease (IMD) (203 serogroup B isolates and 59 non-B isolates) and 42 isolates from healthy carriers. RESULTS: The gene encoding the fHbp peptide was detected in all study isolates from both IMD cases and healthy carriers. The two types of isolates differed in the distribution of fHbp variants. The fHbp1 variant prevailed in the IMD isolates (both B and non-B) while the fHbp2 variant was expressed more often in the carrier isolates. The presence of the nhba gene encoding the NHBA peptide was revealed in all study isolates from both IMD cases and healthy carriers. The serogroup B isolates from IMD cases differed from the non-B isolates from IMD cases and from the carrier isolates in the distribution of NHBA variants. The presence of the nadA gene encoding the NadA peptide was only found in 26.6% of serogroup B isolates from IMD cases in comparison to 40.7% of non-B isolates from IMD cases. As few as 4.8% of isolates from healthy carriers harboured the nadA gene. The PorA P1.4 protein included in the new MenB vaccine was only detected in two serogroup B isolates from IMD cases (of the total of 262 serogroup B and non-B isolates from IMD cases) and in none of the isolates from healthy carriers. Isolates from both B and non-B IMD cases were positive most often for the combination of the antigens NHBA + fHbp1, followed by the NHBA antigen alone and then by the combination NHBA + fHbp1 + NadA-1+2/3. Isolates from healthy carriers showed a different antigen distribution pattern: the NHBA antigen alone was the most widespread, followed by the combination NHBA + fHbp1. CONCLUSIONS: The antigens included in the four-component MenB vaccine were revealed by sequencing in a large proportion of the Czech isolates of N. menin-gitidis from both IMD cases and healthy carriers. This four-component vaccine registered in Europe since January 2013 has proven suitable for use in the Czech Republic.

Experience with pneumococcal polysaccharide conjugate vaccine (conjugated to CRM197 carrier protein) in children and adults.

Streptococcus pneumoniae-related infections are a major cause of morbidity and mortality in people of all ages worldwide. Pneumococcal vaccine development started in 1911 with a whole cell vaccine and more recently multivalent plain polysaccharide and polysaccharide conjugate vaccines have been developed. The recent vaccines rely on capsular polysaccharide antigens to induce serotype-specific immune responses. We summarize here the presentations on pneumococcal polysaccharide conjugate vaccine (conjugated to CRM197 carrier protein) given during the integrated symposium organized and funded by Pfizer International Operations during the 22nd European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) 31 March to 3 April 2012, London, UK. A dramatic reduction in the incidence of invasive pneumococcal diseases (IPD) due to vaccine serotypes (VST-IPD) has been reported since the introduction of a hepta-valent pneumococcal conjugate vaccine (PCV7). An indirect (herd) effect has been demonstrated to be associated with PCV7 infant vaccination programmes, with many studies reporting reductions in VST-IPD in populations that are not eligible for PCV7 vaccination. Since 2010, a 13-valent pneumococcal conjugate vaccine (PCV13) has been introduced into national immunization programmes and results from early surveillance suggest that this vaccine also has an impact on the serotypes unique to PCV13, as well as continuing to protect against the PCV7 serotypes. Data from a passive surveillance system in Europe in 2009, for instance, showed that the highest incidence of IPD remains in those aged >65 years and in children <5 years. PCV13 has now been licensed for vaccination of adults >50 years based on safety and immunogenicity data; an efficacy trial is being conducted. Regardless of previous pneumococcal vaccination status, if the use of 23-valent polysaccharide is considered appropriate, it is recommended to give PCV13 first. Novel immunization strategies remain the only practical means to reduce significantly the remaining global mortality and morbidity due to S. pneumoniae in adults.

Cluster of three cases of invasive meningococcal disease in a preschool facility in West Bohemia, the Czech Republic.

From 1993 to 2009, there was only one cluster of invasive meningococcal disease (IMD) reported in a community of children in the Czech Republic. This exceptional cluster that occurred in a preschool facility is the focus of this report. In response to the announcement of the disease, anti-epidemic precautions were put in place. Neisseria meningitidis isolates were delivered from local laboratories to the National Reference Laboratory for Meningococcal Infections in Prague. Phenotyping was performed there along with multilocus sequence typing. Related factors and microbiological results were analyzed retrospectively. In October 2009, three girls contracted IMD within a period of 1 week in a 42-member group in a preschool facility attached to the elementary school in Starý Plzenec-Sedlec. In relation to three cases of the disease, another 66 people were registered of which 58 underwent a microbiological examination. N. meningitidis was detected in a total of five (8.6 %) people. The National Reference Laboratory for Meningococcal Infections defined the type of the strain to be C: P1.18-1,34-2,38: F1-7: ST-467 (cc269) and penA27. Tests showed the precise identity of all strains obtained from the three sick children and of two strains contracted through contact with the preschool facility. Despite the complete recovery of all patients with no permanent damage, the need for rapid cooperation between clinical sites, diagnostic laboratories, and epidemiologists was confirmed.

Prevention of group B streptococcal neonatal disease revisited. The DEVANI European project.

The purpose of this paper was to present the current knowledge on the prevention of group B streptococcus (GBS) neonatal infections and the status of prevention policies in European countries and to present the DEVANI pan-European program, launched in 2008. The aim of this program was to assess the GBS neonatal infection burden in Europe, to design a new vaccine to immunize neonates against GBS infections, to improve the laboratory performance for the diagnosis of GBS colonization and infection, and to improve the methods for the typing of GBS strains. The current guidelines for GBS prevention in different countries were ascertained and a picture of the burden before and after the instauration of prevention policies has been drawn. After the issue of the Centers for Disease Control and Prevention (CDC) guidelines, many European countries have adopted universal screening for the GBS colonization of pregnant women and intrapartum prophylaxis to colonized mothers. Nevertheless, some European countries continue advocating the risk factor approach to GBS prevention. Most European countries have implemented policies to prevent GBS neonatal infections and the burden of the disease has decreased during the last several years. Nevertheless, further steps are necessary in order to develop new strategies of prevention, to improve microbiological techniques to detect GBS colonization and infection, and to coordinate the prevention policies in the EU.

[Study of hypervirulent complexes of Neisseria meningitidis by methods of molecular biology and possibility of their prevention in the Czech Republic by vaccination]. / Studium hypervirulentních komplexu Neisseria meningitidis metodami molekulární biologie a moznosti prevence jejich výskytu v Ceské republice vakcinací.

A brief report is presented of the results of the Project of the Internal Grant Agency of the Ministry of Health of the Czech Republic that received the Medical Research Award 2008 from the Minister of Health of the Czech Republic (http://www.mzcr.cz/Odbornik/Pages/816-udeleni-ceny-ministra-zdravotnictvi-pro-rok-2008.html). The Science Council of the Internal Grant Agency of the Ministry of Health of the Czech Republic selected 5 award winners of 16 candidate projects recommended by the Specialty Commissions of the Internal Grant Agency. The winning project: Study of hypervirulent complexes of Neisseria meningitidis by molecular biological methods and preventive potential of vaccination against these complexes in the Czech Republic.

The influence of intrinsic coagulation pathway on blood platelets activation by oxidized cellulose.

Oxidized cellulose is an effective hemostat that works naturally to aid in blood coagulation. The mechanism of its action is not very well understood. Little effect on blood coagulation, but a pronounce decrease in platelet count has been reported upon the addition of the oxidized cellulose to the whole blood. As a marker of platelet activation and aggregation we used serotonin release reaction and turbidity changes in time. We found that oxidized cellulose did not activate washed platelets reconstituted in plasma-free medium or plasma-free medium with fibrinogen; no reduction of platelet count was observed. Serotonin release in platelet-rich plasma incubated with oxidized cellulose started in the range from 5 to 10 min. Serotonin release from platelets reconstituted in plasma deficient in either coagulation factor V, VIII, IX, or XII was delayed. Blood platelets activation by oxidized cellulose requires calcium ions present in dispersion of oxidized cellulose. Factor XIII deficiency had no influence on blood platelets activation by oxidized cellulose. Our results clearly indicate the significance of intrinsic coagulation pathway activation on blood platelets activation by oxidized cellulose and so indirectly on the hemostyptic effect of oxidized cellulose.

Neisseria meningitidis strains from patients with invasive meningococcal disease differ in stimulation of cytokine production.

Cytokine production was determined in vitro after stimulation with three different Neisseria meningitidis (NM) strains. Virulent NM B strain isolated from a patient with mild course of invasive meningococcal disease (IMD) elicited higher cytokine production than NM B and NM C hypervirulent strains isolated from patients with moderate and fatal course of IMD, respectively. Endotoxin concentration after in vitro stimulation correlated with cytokine production: the highest endotoxin levels were observed with virulent NM B strain. Serum cytokines and endotoxin levels showed an opposite trend. These results suggest that inflammatory response during IMD is predominantly influenced by host factors.

[Molecular epidemiology of invasive meningococcal disease in the Czech Republic]. / Molekulární epidemiologie invazivního meningokokového onemocneni v Ceské republice.

The study objective is to present results of clonal analysis of Neisseria meningitidis isolates from invasive meningococcal disease in the Czech Republic in 1993-2005. The method of multilocus sequence typing (MLST) revealed genetic heterogeneity of serogroup B isolates and homogeneity of serogroup C isolates. Three clonal sequence type complexes (STC-18, STC-32 and STC-41/44) prevailed among serogroup B isolates and almost a quarter of isolates have ST unclassifiable into clonal complexes. STC-11 showed clear predominance among serogroup C isolates. Hypervirulent clonal complex STC-11 prevailed in 1993-2004 while another clonal complex, STC-41/44, became more widespread for the first time in 2005. MLST analysis showed differences between the meningococcal population in the Czech Republic and those in western European countries and elsewhere. The results of clonal analysis of Neisseria meningitidis isolates from invasive meningococcal disease provide background information for evaluation of the adequacy of recommended measures in the focus of the disease and for updating the recommended vaccination strategy in the Czech Republic.

Invasive meningococcal disease and latex agglutination test--is it still beneficial for diagnosis?

We showed current clinical usefulness of the latex agglutination (LA) test for confirmation of meningococcal etiology on 32 cerebrospinal fluid, 77 serum and 93 urine samples collected during the first week of hospitalization from 19 patients with laboratory confirmed invasive meningococcal disease. The positivity of the LA test in cerebrospinal fluid was 47%, in serum 42% and in urine 24%, while the PCR of cerebrospinal fluid and serum was positive in 95 and 47% cases, respectively. The latest positivity of the LA test was detected on day 2 in cerebrospinal fluid, on day 3 in serum and on day 4 in urine. In the group of patients who had received antibiotic therapy we found nonsignificant reduction of LA positivity and also statistically significant reduction of culture positivity in CSF (p = 0.04); the PCR positivity changed minimally. In blood samples, nonsignificant reduction of culture positivity and no difference in LA and PCR positivity was found. We did not find any statistically significant relationship between test results and clinical forms. The LA test can be therefore considered to be an auxiliary diagnostic method, rapid and easily practicable but less sensitive than PCR. It can be recommended especially for local laboratories where PCR is not available and the patient already received antibiotics before admission to the hospital.