The spa gene of Staphylococcus aureus encodes protein A and is used for typing of methicillin-resistant Staphylococcus aureus (MRSA). We used sequence typing of the spa gene repeat region to study the epidemiology of MRSA at a German university hospital. One hundred seven and 84 strains were studied during two periods of 10 and 4 months, respectively. Repeats and spa types were determined by Ridom StaphType, a novel software tool allowing rapid repeat determination, data management and retrieval, and Internet-based assignment of new spa types following automatic quality control of DNA sequence chromatograms. Isolates representative of the most abundant spa types were subjected to multilocus sequence typing and pulsed-field gel electrophoresis. One of two predominant spa types was replaced by a clonally related variant in the second study period. Ten unique spa types, which were equally distributed in both study periods, were recovered. The data show a rapid dynamics of clone circulation in a university hospital setting. spa typing was valuable for tracking of epidemic isolates. The data show that disproval of epidemiologically suggested transmissions of MRSA is one of the main objectives of spa typing in departments with a high incidence of MRSA.Staphylococcus aureus is a major human pathogen causing skin and tissue infections, pneumonia, septicemia, and deviceassociated infections. The emergence of strains resistant to methicillin and other antibacterial agents has become a major concern especially in the hospital environment, because of the higher mortality due to systemic methicillin-resistant Staphylococcus aureus (MRSA) infections (2). Typing of MRSA is used to support infection control measures. While pulsed-field gel electrophoresis (PFGE) is a "gold standard" for strain typing of MRSA (20), DNA sequence-based approaches are becoming more frequently used because sequence data can easily be transferred between laboratories via the Internet. Multilocus sequence typing (MLST), which was developed by using Neisseria meningitidis as the model species (9, 18), has been successfully adapted to S. aureus (7,8). However, MLST is not suitable for routine surveillance of MRSA because of the high cost and the necessity of access to a high-throughput DNA sequencing facility.Although there is evidence for recombination in S. aureus (10), it has been shown that point mutations by far exceed recombination events, in contrast to N. meningitidis or Streptococcus pneumoniae (11). Furthermore, there is only a small number of clonal groupings of MRSA circulating worldwide (7). Therefore, single-locus DNA sequencing of repeat regions of the coa (coagulase) gene and the spa gene (protein A), respectively, could be used for reliable and accurate typing of MRSA (12,13,(26)(27)(28)(29). spa typing is especially interesting for rapid typing of MRSA in a hospital setting since it offers higher resolution than coa typing (27). The repeat region of the spa gene is subject to spontaneous mutations, as well as loss and gain of repeats. ...

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Pathogenic Neisseria meningitidis isolates contain a polysaccharide capsule that is the main virulence determinant for this bacterium. Thirteen capsular polysaccharides have been described, and nuclear magnetic resonance spectroscopy has enabled determination of the structure of capsular polysaccharides responsible for serogroup specificity. Molecular mechanisms involved in N. meningitidis capsule biosynthesis have also been identified, and genes involved in this process and in cell surface translocation are clustered at a single chromosomal locus termed cps. The use of multiple names for some of the genes involved in capsule synthesis, combined with the need for rapid diagnosis of serogroups commonly associated with invasive meningococcal disease, prompted a requirement for a consistent approach to the nomenclature of capsule genes. In this report, a comprehensive description of all N. meningitidis serogroups is provided, along with a proposed nomenclature, which was presented at the 2012 XVIIIth International Pathogenic Neisseria Conference.

Background Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis, which are typically transmitted via respiratory droplets, are leading causes of invasive diseases, including bacteraemic pneumonia and meningitis, and of secondary infections subsequent to post-viral respiratory disease. The aim of this study was to investigate the incidence of invasive disease due to these pathogens during the early months of the COVID-19 pandemic. MethodsIn this prospective analysis of surveillance data, laboratories in 26 countries and territories across six continents submitted data on cases of invasive disease due to S pneumoniae, H influenzae, and N meningitidis from Jan 1, 2018, to May, 31, 2020, as part of the Invasive Respiratory Infection Surveillance (IRIS) Initiative. Numbers of weekly cases in 2020 were compared with corresponding data for 2018 and 2019. Data for invasive disease due to Streptococcus agalactiae, a non-respiratory pathogen, were collected from nine laboratories for comparison. The stringency of COVID-19 containment measures was quantified using the Oxford COVID-19 Government Response Tracker. Changes in population movements were assessed using Google COVID-19 Community Mobility Reports. Interrupted time-series modelling quantified changes in the incidence of invasive disease due to S pneumoniae, H influenzae, and N meningitidis in 2020 relative to when containment measures were imposed. Findings 27 laboratories from 26 countries and territories submitted data to the IRIS Initiative for S pneumoniae (62 434 total cases), 24 laboratories from 24 countries submitted data for H influenzae (7796 total cases), and 21 laboratories from 21 countries submitted data for N meningitidis (5877 total cases). All countries and territories had experienced a significant and sustained reduction in invasive diseases due to S pneumoniae, H influenzae, and N meningitidis in early 2020 (Jan 1 to May 31, 2020), coinciding with the introduction of COVID-19 containment measures in each country. By contrast, no significant changes in the incidence of invasive S agalactiae infections were observed. Similar trends were observed across most countries and territories despite differing stringency in COVID-19 control policies. The incidence of reported S pneumoniae infections decreased by 68% at 4 weeks (incidence rate ratio 0•32 [95% CI 0•27-0•37]) and 82% at 8 weeks (0•18 [0•14-0•23]) following the week in which significant changes in population movements were recorded. Interpretation The introduction of COVID-19 containment policies and public information campaigns likely reduced transmission of S pneumoniae, H influenzae, and N meningitidis, leading to a significant reduction in life-threatening invasive diseases in many countries worldwide.

Neisseria meningitidis is a leading cause of infectious childhood mortality worldwide. Most research efforts have hitherto focused on disease isolates belonging to only a few hypervirulent clonal lineages. However, up to 10% of the healthy human population is temporarily colonized by genetically diverse strains mostly with little or no pathogenic potential. Currently, little is known about the biology of carriage strains and their evolutionary relationship with disease isolates. The expression of a polysaccharide capsule is the only trait that has been convincingly linked to the pathogenic potential of N. meningitidis. To gain insight into the evolution of virulence traits in this species, whole-genome sequences of three meningococcal carriage isolates were obtained. Gene content comparisons with the available genome sequences from three disease isolates indicate that there is no core pathogenome in N. meningitidis. A comparison of the chromosome structure suggests that a filamentous prophage has mediated large chromosomal rearrangements and the translocation of some candidate virulence genes. Interspecific comparison of the available Neisseria genome sequences and dot blot hybridizations further indicate that the insertion sequence IS1655 is restricted only to N. meningitidis; its low sequence diversity is an indicator of an evolutionarily recent population bottleneck. A genome-based phylogenetic reconstruction provides evidence that N. meningitidis has emerged as an unencapsulated human commensal from a common ancestor with Neisseria gonorrhoeae and Neisseria lactamica and consecutively acquired the genes responsible for capsule synthesis via horizontal gene transfer.comparative genomics ͉ genome evolution ͉ bacterial capsule ͉ neisserial prophage ͉ IS1655

Serogroup C capsule expression during carriage may contribute to the invasive character of ST-11 complex meningococci and to the high efficacy of meningococcal serogroup C conjugate polysaccharide vaccine.

Acute bacterial meningitis is a life-threatening disease in humans. Discussed as entry sites for pathogens into the brain are the blood-brain and the blood-cerebrospinal fluid barrier (BCSFB). Although human brain microvascular endothelial cells (HBMEC) constitute a well established human in vitro model for the blood-brain barrier, until now no reliable human system presenting the BCSFB has been developed. Here, we describe for the first time a functional human BCSFB model based on human choroid plexus papilloma cells (HIBCPP), which display typical hallmarks of a BCSFB as the expression of junctional proteins and formation of tight junctions, a high electrical resistance and minimal levels of macromolecular flux when grown on transwell filters. Importantly, when challenged with the zoonotic pathogen Streptococcus suis or the human pathogenic bacterium Neisseria meningitidis the HIBCPP show polar bacterial invasion only from the physiologically relevant basolateral side. Meningococcal invasion is attenuated by the presence of a capsule and translocated N. meningitidis form microcolonies on the apical side of HIBCPP opposite of sites of entry. As a functionally relevant human model of the BCSFB the HIBCPP offer a wide range of options for analysis of disease-related mechanisms at the choroid plexus epithelium, especially involving human pathogens.

Subgingival plaque samples were obtained from 26 subjects with advanced periodontal lesions. Bacterial diversity was analysed by amplification of the 16S rRNA genes with two different primer sets, and subsequent cloning and sequencing. A total of 578 sequences was analysed after the exclusion of chimeras. The authors found 148 phylotypes with the clone library 27f/519r (number of clones n5322; coverage, C566 %) and 75 phylotypes with the clone library 515f/1525r (n5256; C584 %). Comparative sequence analysis revealed that 70 % of all of the analysed sequences showed a similarity of at least 99 % to sequences deposited in public databases. The classes Actinobacteria, Bacilli, Bacteroidetes, Clostridia, Deferribacteres, Flavobacteria, Fusobacteria, Mollicutes, Spirochaetes and all classes of the Proteobacteria were represented. Sequences that were at least 99 % identical to Porphyromonas gingivalis, Filifactor alocis and Treponema socranskii were present in at least one-third of the patients. Libraries generated with the two PCR primer pairs differed significantly in their representation of the families Porphyromonadaceae, Prevotellaceae, Fusobacteriaceae, Eubacteriaceae, Streptococcaceae and Acidaminococcaceae. A total of 14 sequences exhibited less than 97 % identity to sequences published previously and were assigned to six different families within the phyla Bacteroidetes and Firmicutes. Twelve of 20 putative pathogens were recovered, which were recently proposed to be associated with periodontitis.