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https://www.readbyqxmd.com/read/29351189/the-role-of-cadaverine-synthesis-on-pneumococcal-capsule-and-protein-expression
#1
Mary F Nakamya, Moses B Ayoola, Seongbin Park, Leslie A Shack, Edwin Swiatlo, Bindu Nanduri
Invasive infections caused by Streptococcus pneumoniae, a commensal in the nasopharynx, pose significant risk to human health. Limited serotype coverage by the available polysaccharide-based conjugate vaccines coupled with increasing incidence of antibiotic resistance complicates therapeutic strategies. Bacterial physiology and metabolism that allows pathogens to adapt to the host are a promising avenue for the discovery of novel therapeutics. Intracellular polyamine concentrations are tightly regulated by biosynthesis, transport and degradation...
January 19, 2018: Medical Sciences: Open Access Journal
https://www.readbyqxmd.com/read/29350141/spread-of-meropenem-resistant-streptococcus-pneumoniae-serotype-15a-st63-clone-in-japan-2012-2014
#2
Satoshi Nakano, Takao Fujisawa, Yutaka Ito, Bin Chang, Yasufumi Matsumura, Masaki Yamamoto, Miki Nagao, Shigeru Suga, Makoto Ohnishi, Satoshi Ichiyama
After the introduction of pneumococcal conjugate vaccines, the incidence of pneumococcal infections due to meropenem-resistant serotype 15A-ST63 strains increased in Japan. By using whole-genome sequencing and comparing sequences with those of clones from the United Kingdom, the United States, and Canada, we clarified the traits of the serotype 15A-ST63 clone. Our analysis revealed that the meropenem-resistant serotype 15A-ST63 strains from Japan originated from meropenem-susceptible strains from Japan. Recombination site prediction analysis showed that the meropenem-resistant strain-specific recombination regions included the pbp1a and pbp2b regions...
February 2018: Emerging Infectious Diseases
https://www.readbyqxmd.com/read/29324986/the-impact-of-the-13-valent-pneumococcal-conjugate-vaccine-on-pneumococcal-carriage-in-the-community-acquired-pneumonia-immunization-trial-in-adults-capita-study
#3
Anna M M van Deursen, Marlies A van Houten, Chris Webber, Michael Patton, Daniel Scott, Scott Patterson, Qin Jiang, William C Gruber, Beate Schmoele-Thoma, Diederick E Grobbee, Marc J M Bonten, Elisabeth A M Sanders
Background: The impact of pneumococcal conjugate vaccination on the prevalence of nasopharyngeal carriage with pneumococci and other bacteria in adults is unknown. The direct effects of the 13-valent pneumococcal conjugate vaccine (PCV13) in community dwelling older adults was investigated as part of the randomized controlled Community Acquired Pneumonia immunization Trial in Adults (CAPiTA). Methods: We determined the carriage of S. pneumoniae, S. aureus, H. influenzae, and M...
January 6, 2018: Clinical Infectious Diseases: An Official Publication of the Infectious Diseases Society of America
https://www.readbyqxmd.com/read/29311231/capsule-prolongs-survival-of-streptococcus-pneumoniae-during-starvation
#4
Shigeto Hamaguchi, M Ammar Zafar, Michael Cammer, Jeffrey N Weiser
Person-to-person transmission of Streptococcus pneumoniae (the pneumococcus) may occur via environmental sources in close contact with carriers. Pneumococcal polysaccharide capsules, the determinant of serotype (or type), are heterogeneous in structure and amount and these differences affect rates of transmission. In this study, we examined the contribution of capsule and its variations to the maintenance of pneumococcal viability under starvation conditions. S. pneumoniae retained its ability to colonize infant mice even after incubation for 24hrs in PBS at 25°C...
January 8, 2018: Infection and Immunity
https://www.readbyqxmd.com/read/29298677/the-variome-of-pneumococcal-virulence-factors-and-regulators
#5
Gustavo Gámez, Andrés Castro, Alejandro Gómez-Mejia, Mauricio Gallego, Alejandro Bedoya, Mauricio Camargo, Sven Hammerschmidt
BACKGROUND: In recent years, the idea of a highly immunogenic protein-based vaccine to combat Streptococcus pneumoniae and its severe invasive infectious diseases has gained considerable interest. However, the target proteins to be included in a vaccine formulation have to accomplish several genetic and immunological characteristics, (such as conservation, distribution, immunogenicity and protective effect), in order to ensure its suitability and effectiveness. This study aimed to get comprehensive insights into the genomic organization, population distribution and genetic conservation of all pneumococcal surface-exposed proteins, genetic regulators and other virulence factors, whose important function and role in pathogenesis has been demonstrated or hypothesized...
January 3, 2018: BMC Genomics
https://www.readbyqxmd.com/read/29298375/single-molecule-force-spectroscopy-reveals-two-domain-binding-mode-of-pilus-1-tip-protein-rrga-of-streptococcus-pneumoniae-to-fibronectin
#6
Tanja D Becke, Stefan Ness, Raimund Gürster, Arndt F Schilling, Anne-Marie di Guilmi, Stefanie Sudhop, Markus Hilleringmann, Hauke Clausen-Schaumann
For host cell adhesion and invasion, surface piliation procures benefits for bacteria. A detailed investigation of how pili adhere to host cells is therefore a key aspect in understanding their role during infection. Streptococcus pneumoniae TIGR 4, a clinical relevant serotype 4 strain, is capable of expressing pilus-1 with terminal RrgA, an adhesin interacting with host extracellular matrix (ECM) proteins. We used single molecule force spectroscopy to investigate the binding of full length RrgA and single RrgA domains to fibronectin...
January 3, 2018: ACS Nano
https://www.readbyqxmd.com/read/29290234/bacterial-meningitis-antibiotic-treatment
#7
R Cohen, J Raymond, L Hees, D Pinquier, E Grimprel, C Levy
The implementation of pneumococal conjugate vaccines (PCVs) 7 then 13 valent (Prevenar13®) in 2010-2011 has significantly changed the profile of pneumococcal meningitis. Since 3 years, the National Pediatric Meningitis Network of the Pediatric Infectious Disease Group (GPIP) and the National Reference Centre of Pneumococci have reported no cases of meningitis due to pneumococcus resistant to third-generation cephalosporins (3GC): cefotaxime or ceftriaxone. In the light of these new data, vancomycin should no longer be prescribed at the initial phase of pneumococcal meningitis treatment (confirmed or only suspected) and this antibiotic should only be added when 3GC minimum inhibitory concentration of the strain isolated is greater than 0...
December 2017: Archives de Pédiatrie: Organe Officiel de la Sociéte Française de Pédiatrie
https://www.readbyqxmd.com/read/29289314/separation-of-pathogenic-bacteria-by-chain-length
#8
Jason P Beech, Bao Dang Ho, Geneviève Garriss, Vitor Oliveira, Birgitta Henriques-Normark, Jonas O Tegenfeldt
Using Deterministic Lateral Displacement devices optimized for sensitivity to particle length, we separate subpopulations of bacteria depending on known properties that affect their capability to cause disease (virulence). For the human bacterial pathogen Streptococcus pneumoniae, bacterial chain length and the presence of a capsule are known virulence factors contributing to its ability to cause severe disease. Separation of cultured pneumococci into subpopulations based on morphological type (single cocci, diplococci and chains) will enable more detailed studies of the role they play in virulence...
February 13, 2018: Analytica Chimica Acta
https://www.readbyqxmd.com/read/29281779/inhibition-of-autolysis-by-lipase-lipa-in-streptococcus-pneumoniae-sepsis
#9
Gyu-Lee Kim, Truc Thanh Luong, Sang-Sang Park, Seungyeop Lee, Jung Ah Ha, Cuong Thach Nguyen, Ji Hye Ahn, Ki-Tae Park, Man-Jeong Paik, Suhkneung Pyo, David E Briles, Dong-Kwon Rhee
More than 50% of sepsis cases are associated with pneumonia. Sepsis is caused by infiltration of bacteria into the blood via inflammation, which is triggered by the release of cell wall components following lysis. However, the regulatory mechanism of lysis during infection is not well defined. Mice were infected with Streptococcus pneumoniae D39 wild-type (WT) and lipase mutant (ΔlipA) intranasally (pneumonia model) or intraperitoneally (sepsis model), and survival rate and pneumococcal colonization were determined...
December 26, 2017: Molecules and Cells
https://www.readbyqxmd.com/read/29279284/re-emergence-of-pneumococcal-colonization-by-vaccine-serotype-19f-in-persons-aged-%C3%A2-5-years-after-13-valent-pneumococcal-conjugate-vaccine-introduction-alaska-2008-2013
#10
Prabhu P Gounder, Dana Bruden, Karen Rudolph, Tammy Zulz, Debby Hurlburt, Gail Thompson, Michael G Bruce, Thomas W Hennessy
BACKGROUND: The pneumococcal conjugate vaccine (PCV) was introduced in 2001. Widespread PCV use nearly eradicated pneumococcal colonization by vaccine serotypes. Since 2008, however, colonization by PCV-serotype 19F has increased in Alaska residents. We describe the epidemiology of re-emerging serotype 19F colonization. METHODS: We conducted annual cross-sectional colonization surveys from 2008 to 2013. We recruited children aged <5 years at 2 urban clinics and participants of all ages from Region-A (2 villages), Region-B (4 villages), and Region-C (2 villages)...
December 23, 2017: Vaccine
https://www.readbyqxmd.com/read/29248266/serotype-specific-immune-responses-to-pneumococcal-conjugate-vaccine-among-children-are-significantly-correlated-by-individual-analysis-of-randomized-controlled-trial-data
#11
Marc Lipsitch, Lucy M Li, Scott Patterson, James Trammel, Christine Juergens, William C Gruber, Daniel A Scott, Ron Dagan
BACKGROUND: The magnitude of an individual's serotype-specific immunoglobulin G (IgG) response to a pneumococcal conjugate vaccine (PCV) has been associated with the vaccine's protective efficacy against carriage of pneumococci of that serotype, though the relationship with other serotypes needs to be understood. METHODS: Using immunogenicity data collected during a trial comparing the 7-valent (PCV7) and 13-valent (PCV13) vaccines, we measured associations between serotype-specific IgG levels, and used multiple regressions to identify demographic predictors of response...
December 13, 2017: Vaccine
https://www.readbyqxmd.com/read/29229733/expression-of-tlr2-by-dendritic-cells-is-essential-for-dnaj-%C3%AE-a146ply-mediated-th1-immune-response-against-streptococcus-pneumoniae
#12
Xiaofang Wang, Taixian Yuan, Jun Yuan, Yufeng Su, Xiaoyu Sun, Jingwen Wu, Hong Zhang, Xun Min, Xuemei Zhang, Yibing Yin
The fusion protein, DnaJ-ΔA146Ply, could induce cross-protective immunity against pneumococcal infection via mucosal and subcutaneous immunization in mice in the absence of additional adjuvants. DnaJ and Ply are both TLR4 but not TLR2 ligands. However, we found that TLR2-/- mice immunized subcutaneously with DnaJ-ΔA146Ply showed significantly lower survival rates and higher bacterial loads in nasal washes than those of WT mice after being challenged with pneumococcal strains D39 or 19F. The IFN-γ level in splenocytes decreased in TLR2-/- mice, indicating that Th1 immunity elicited by DnaJ-ΔA146Ply was impaired in TLR2-/- mice...
December 11, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/29221986/streptococcus-pneumoniae-two-component-regulatory-systems-the-interplay-of-the-pneumococcus-with-its-environment
#13
REVIEW
Alejandro Gómez-Mejia, Gustavo Gámez, Sven Hammerschmidt
Streptococcus pneumoniae is a human pathobiont possessing a diverse array of multifunctional proteins essential for bacterial fitness and virulence. Gene expression is tightly controlled by regulatory components and among the pneumococcal sensorial tools, two‑component regulatory systems (TCS) are the most widespread and conserved. This review aims to provide a comprehensive analysis of original studies on pneumococcal TCS on a functional level. Despite a rather chaotic nomenclature, the current available information on pneumococcal regulation by these systems can be conveniently addressed, according to the regulation of pathophysiological cell processes and the responses to detectable environmental signals...
November 26, 2017: International Journal of Medical Microbiology: IJMM
https://www.readbyqxmd.com/read/29211859/transformation-asymmetry-and-the-evolution-of-the-bacterial-accessory-genome
#14
Katinka J Apagyi, Christophe Fraser, Nicholas J Croucher
Bacterial transformation can insert or delete genomic islands (GIs), depending on the donor and recipient genotypes, if an homologous recombination spans the GI's integration site and includes sufficiently long flanking homologous arms. Combining mathematical models of recombination with experiments using pneumococci found GI insertion rates declined geometrically with the GI's size. The decrease in acquisition frequency with length (1.08x10-3 bp-1) was higher than a previous estimate of the analogous rate at which core genome recombinations terminated...
December 1, 2017: Molecular Biology and Evolution
https://www.readbyqxmd.com/read/29209675/serotype-prevalence-and-antibiotic-susceptibility-patterns-of-pneumococcal-isolates-in-zunyi-city-china
#15
Meijing Shen, Run Yao, Huan Yue, Jingzhi Zhang, Min Chen, Weiwei Zhang, Daishun Liu, Kaifeng Wu
OBJECTIVES: To assess the serotype distribution and antimicrobial susceptibility of pneumococci isolated from inpatients of all ages suspected of having bacterial infections. METHODS: In this retrospective study, pneumococcal isolates were consecutively collected  from the Third Affiliated Hospital of Zunyi Medical University, in Zunyi city, China, between January 2014 and December 2016. Pneumococci were identified using routine microbiological assays. We performed antimicrobial susceptibility analyses using the bacteria identification/susceptibility system VITEK2 and E-tests...
December 2017: Saudi Medical Journal
https://www.readbyqxmd.com/read/29152579/streptococcus-pneumoniae-tigr4-phase-locked-opacity-variants-differ-in-virulence-phenotypes
#16
Melissa B Oliver, Ankita Basu Roy, Ranjit Kumar, Elliot J Lefkowitz, W Edward Swords
Streptococcus pneumoniae (pneumococcus) is a leading human pathogen that can cause serious localized and invasive diseases. Pneumococci can undergo a spontaneous and reversible phase variation that is reflected in colony opacity and which allows the population to adapt to different host environments. Generally, transparent variants are adapted for nasopharyngeal colonization, whereas opaque variants are associated with invasive disease. In recent work, colony phase variation was shown to occur by means of recombination events to generate multiple alleles of the hsdS targeting domain of a DNA methylase complex, which mediates epigenetic changes in gene expression...
November 2017: MSphere
https://www.readbyqxmd.com/read/29147057/lessons-learnt-during-20-years-of-the-swedish-strategic-programme-against-antibiotic-resistance
#17
Sigvard Mölstad, Sonja Löfmark, Karin Carlin, Mats Erntell, Olov Aspevall, Lars Blad, Håkan Hanberger, Katarina Hedin, Jenny Hellman, Christer Norman, Gunilla Skoog, Cecilia Stålsby-Lundborg, Karin Tegmark Wisell, Christina Åhrén, Otto Cars
Increasing use of antibiotics and rising levels of bacterial resistance to antibiotics are a challenge to global health and development. Successful initiatives for containing the problem need to be communicated and disseminated. In Sweden, a rapid spread of resistant pneumococci in the southern part of the country triggered the formation of the Swedish strategic programme against antibiotic resistance, also known as Strama, in 1995. The creation of the programme was an important starting point for long-term coordinated efforts to tackle antibiotic resistance in the country...
November 1, 2017: Bulletin of the World Health Organization
https://www.readbyqxmd.com/read/29131872/genetic-diversity-of-pneumococcal-surface-protein-a-in-invasive-pneumococcal-isolates-from-korean-children-1991-2016
#18
Ki Wook Yun, Eun Hwa Choi, Hoan Jong Lee
Pneumococcal surface protein A (PspA) is an important virulence factor of pneumococci and has been investigated as a primary component of a capsular serotype-independent pneumococcal vaccine. Thus, we sought to determine the genetic diversity of PspA to explore its potential as a vaccine candidate. Among the 190 invasive pneumococcal isolates collected from Korean children between 1991 and 2016, two (1.1%) isolates were found to have no pspA by multiple polymerase chain reactions. The full length pspA genes from 185 pneumococcal isolates were sequenced...
2017: PloS One
https://www.readbyqxmd.com/read/29130395/pneumococcal-whole-cell-and-protein-based-vaccines-changing-the-paradigm
#19
Michael E Pichichero
Epidemiologic evaluations of Streptococcus pneumoniae nasopharyngeal (NP) colonization and pneumococcal disease suggest that newer serotypes in future formulations of pneumococcal conjugate vaccines (PCVs) are needed and there may need to be continued reformulations because there are many new emerging serotypes expressed by pneumococci. Areas covered: Mechanisms of protection by next-generation whole-cell vaccine (WCV) and/or multi-component pneumococcal purified protein vaccines (PPVs) in development for prevention of pneumococcal infections...
December 2017: Expert Review of Vaccines
https://www.readbyqxmd.com/read/29111412/serotype-distribution-and-antibiotic-susceptibility-of-streptococcus-pneumoniae-strains-in-the-south-of-tunisia-a-five-year-study-2012-2016-of-pediatric-and-adult-populations
#20
Sonia Ktari, Ikram Jmal, Manel Mroua, Sonda Maalej, Nour ElHouda Ben Ayed, Basma Mnif, Faouzia Rhimi, Adnene Hammami
OBJECTIVES: To analyze the serotype distribution of Streptococcus pneumoniae clinical isolates collected in the south of Tunisia over a 5-year period in different age groups and to assess their antimicrobial susceptibility patterns. METHODS: A total of 305 non-duplicate S. pneumoniae isolates were collected between January 2012 and December 2016 at the university hospital in Sfax, Tunisia. All isolates were serotyped by multiplex PCR. The antibiotic susceptibility of all isolates was determined using the disk diffusion test or Etest assay...
October 27, 2017: International Journal of Infectious Diseases: IJID
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