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https://www.readbyqxmd.com/read/27914087/in-vitro-and-in-vivo-biofilm-formation-by-pathogenic-streptococci
#1
Yashuan Chao, Caroline Bergenfelz, Anders P Håkansson
This manuscript presents novel approaches to grow and evaluate Streptococcal biofilm formation using the human respiratory pathogen Streptococcus pneumoniae (the pneumococcus) as the main model organism on biological surfaces in vitro and in vivo. Most biofilm models are based on growth on abiotic surfaces, which is relevant for many pathogens whose growth on surfaces or medical devices is a major cause of disease transmission and infections, especially in hospital environments. However, most infections with commensal organisms require biofilm formation on biological surfaces in the host at the site of colonization or infection...
2017: Methods in Molecular Biology
https://www.readbyqxmd.com/read/27911391/a-murine-model-of-group-b-streptococcus-vaginal-colonization
#2
Kathryn A Patras, Kelly S Doran
Streptococcus agalactiae (group B Streptococcus, GBS), is a Gram-positive, asymptomatic colonizer of the human gastrointestinal tract and vaginal tract of 10 - 30% of adults. In immune-compromised individuals, including neonates, pregnant women, and the elderly, GBS may switch to an invasive pathogen causing sepsis, arthritis, pneumonia, and meningitis. Because GBS is a leading bacterial pathogen of neonates, current prophylaxis is comprised of late gestation screening for GBS vaginal colonization and subsequent peripartum antibiotic treatment of GBS-positive mothers...
November 16, 2016: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/27909995/solithromycin-a-novel-fluoroketolide-for-the-treatment-of-community-acquired-bacterial-pneumonia
#3
REVIEW
George G Zhanel, Erika Hartel, Heather Adam, Sheryl Zelenitsky, Michael A Zhanel, Alyssa Golden, Frank Schweizer, Bala Gorityala, Philippe R S Lagacé-Wiens, Andrew J Walkty, Alfred S Gin, Daryl J Hoban, Joseph P Lynch, James A Karlowsky
Solithromycin is a novel fluoroketolide developed in both oral and intravenous formulations to address increasing macrolide resistance in pathogens causing community-acquired bacterial pneumonia (CABP). When compared with its macrolide and ketolide predecessors, solithromycin has several structural modifications which increase its ribosomal binding and reduce its propensity to known macrolide resistance mechanisms. Solithromycin, like telithromycin, affects 50S ribosomal subunit formation and function, as well as causing frame-shift errors during translation...
December 1, 2016: Drugs
https://www.readbyqxmd.com/read/27907156/increased-nasopharyngeal-density-and-concurrent-carriage-of-streptococcus-pneumoniae-haemophilus-influenzae-and-moraxella-catarrhalis-are-associated-with-pneumonia-in-febrile-children
#4
Sopio Chochua, Valérie D'Acremont, Christiane Hanke, David Alfa, Joshua Shak, Mary Kilowoko, Esther Kyungu, Laurent Kaiser, Blaise Genton, Keith P Klugman, Jorge E Vidal
BACKGROUND: We assessed nasopharyngeal (NP) carriage of five pathogens in febrile children with and without acute respiratory infection (ARI) of the upper (URTI) or lower tract, attending health facilities in Tanzania. METHODS: NP swabs collected from children (N = 960) aged 2 months to 10 years, and with a temperature ≥38°C, were utilized to quantify bacterial density of S. pneumoniae (Sp), H. influenzae (Hi), M. catarrhalis (Mc), S. aureus (Sa), and N. meningitidis (Nm)...
2016: PloS One
https://www.readbyqxmd.com/read/27902439/evidence-that-pneumococcal-walk-is-regulated-by-stkp-through-protein-protein-interaction
#5
Gro Anita Stamsås, Daniel Straume, Zhian Salehian, Leiv Sigve Håvarstein
WalRK is the only two-component regulatory system essential for viability in Streptococcus pneumoniae. Despite its importance, the biological role of this system is not well understood. However, previous studies have shown that it has a crucial role in controlling pneumococcal cell division. Considerable efforts have been made to understand how the WalRK system is regulated, but no signal(s) sensed by the WalK histidine kinase has been identified so far. Here, we provide evidence that the serine/threonine protein kinase StkP modulates the activity of WalK through direct protein-protein interaction, suggesting that this interaction is one of the signals sensed by WalK...
November 29, 2016: Microbiology
https://www.readbyqxmd.com/read/27902435/overexpression-of-the-fratricide-immunity-protein-comm-leads-to-growth-inhibition-and-morphological-abnormalities-in-streptococcus-pneumoniae
#6
Daniel Straume, Gro Anita Stamsås, Zhian Salehian, Leiv Sigve Håvarstein
The important human pathogen Streptococcus pneumoniae is a naturally transformable species. When developing the competent state, it expresses proteins involved in DNA-uptake, DNA-processing and homologous recombination. In addition to the proteins required for the transformation process, competent pneumococci express proteins involved in a predatory DNA-acquisition-mechanism termed fratricide. This is a mechanism by which the competent pneumococci secrete a muralytic fratricin termed CbpD, which lyse susceptible sister cells or closely related streptococcal species...
November 28, 2016: Microbiology
https://www.readbyqxmd.com/read/27900287/n-acetylglucosamine-mediated-expression-of-naga-and-nagb-in-streptococcus-pneumoniae
#7
Muhammad Afzal, Sulman Shafeeq, Irfan Manzoor, Birgitta Henriques-Normark, Oscar P Kuipers
In this study, we have explored the transcriptomic response of Streptococcus pneumoniae D39 to N-acetylglucosamine (NAG). Transcriptome comparison of S. pneumoniae D39 wild-type grown in chemically defined medium (CDM) in the presence of 0.5% NAG to that grown in the presence of 0.5% glucose revealed elevated expression of many genes/operons, including nagA, nagB, manLMN, and nanP. We have further confirmed the NAG-dependent expression of nagA, nagB, manLMN, and nanP by β-galactosidase assays. nagA, nagB and glmS are putatively regulated by a transcriptional regulator NagR...
2016: Frontiers in Cellular and Infection Microbiology
https://www.readbyqxmd.com/read/27899093/microbiological-profile-of-corneal-ulcer-cases-diagnosed-in-a-tertiary-care-ophthalmological-institute-in-nepal
#8
Sharmila Suwal, Dinesh Bhandari, Pratigya Thapa, Mohan Krishna Shrestha, Jyoti Amatya
BACKGROUND: Corneal ulcer, a major cause of monocular blindness in developing countries has consistently been listed as the major cause of blindness and visual disability in many of the developing nations in Asia, Africa and the Middle East, ranking second only to cataract. This study was carried out to determine the microbiological profile of corneal ulcer cases diagnosed among patients visiting Tilganga Institute of Ophthalmology (TIO), Nepal. METHODS: A total of 101 corneal scrapping samples were tested for routine culture and antibiotic susceptibility at the pathology department of TIO Nepal from April to October 2014...
November 29, 2016: BMC Ophthalmology
https://www.readbyqxmd.com/read/27897220/impact-of-the-microbial-derived-short-chain-fatty-acid-propionate-on-host-susceptibility-to-bacterial-and-fungal-infections-in-vivo
#9
Eleonora Ciarlo, Tytti Heinonen, Jacobus Herderschee, Craig Fenwick, Matteo Mombelli, Didier Le Roy, Thierry Roger
Short chain fatty acids (SCFAs) produced by intestinal microbes mediate anti-inflammatory effects, but whether they impact on antimicrobial host defenses remains largely unknown. This is of particular concern in light of the attractiveness of developing SCFA-mediated therapies and considering that SCFAs work as inhibitors of histone deacetylases which are known to interfere with host defenses. Here we show that propionate, one of the main SCFAs, dampens the response of innate immune cells to microbial stimulation, inhibiting cytokine and NO production by mouse or human monocytes/macrophages, splenocytes, whole blood and, less efficiently, dendritic cells...
November 29, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27895845/a-trial-of-a-7-valent-pneumococcal-conjugate-vaccine-in-hiv-infected-adults
#10
Neil French, Stephen B Gordon, Thandie Mwalukomo, Sarah A White, Gershom Mwafulirwa, Herbert Longwe, Martin Mwaiponya, Eduard E Zijlstra, Malcolm E Molyneux, Charles F Gilks
BACKGROUND: Streptococcus pneumoniae is a leading and serious coinfection in adults with human immunodeficiency virus (HIV) infection, particularly in Africa. Prevention of this disease by vaccination with the current 23-valent polysaccharide vaccine is suboptimal. Protein conjugate vaccines offer a further option for protection, but data on their clinical efficacy in adults are needed. METHODS: In this double-blind, randomized, placebo-controlled clinical efficacy trial, we studied the efficacy of a 7-valent conjugate pneumococcal vaccine in predominantly HIV-infected Malawian adolescents and adults who had recovered from documented invasive pneumococcal disease...
September 2016: Malawi Medical Journal: the Journal of Medical Association of Malawi
https://www.readbyqxmd.com/read/27895132/protection-against-streptococcus-pneumoniae-invasive-pathogenesis-by-a-protein-based-vaccine-is-achieved-by-suppression-of-nasopharyngeal-bacterial-density-during-influenza-a-virus-co-infection
#11
M Nadeem Khan, Qingfu Xu, Michael E Pichichero
An increase in Streptococcus pneumoniae (Spn) nasopharyngeal (NP) colonization density during a viral co-infection initiates pathogenesis. To mimic natural Spn pathogenesis, we commensally colonized the NP of adult C57BL/6 mice with Spn serotypes (STs) 6A or 8, and then co-infected with mouse-adapted H1N1 influenza A virus (PR/8/34). Spn established effective commensal colonization and Influenza co-infection caused Spn NP density to increase, resulting in bacteremia and mortality. We then studied histidine triad protein D (PhtD), a Spn adhesin vaccine candidate, for its ability to prevent invasive Spn disease in adult and infant mice...
November 28, 2016: Infection and Immunity
https://www.readbyqxmd.com/read/27894963/longitudinal-surveillance-on-antibiogram-of-important-gram-positive-pathogens-in-southern-china-2001-to-2015
#12
Zhenbo Xu, Jinhong Xie, Brian M Peters, Bing Li, Lin Li, Guangchao Yu, Mark E Shirtliff
OBJECTIVES: A longitudinal surveillance aimed to investigate the antibiogram of three genus of important Gram-positive pathogens in Southern China during 2001-2015. METHODS: A total of 3849 Staphylococcus, Enterococcus and Streptococcus strains were isolated from Southern China during 2001-2015. Bacteria identification was performed by colony morphology, Gram staining, the API commercial kit and the Vitek 2 automated system. Antimicrobial susceptibility testing was determined by disk diffusion method and MIC method...
November 25, 2016: Microbial Pathogenesis
https://www.readbyqxmd.com/read/27893998/influenza-and-rhinovirus-viral-load-and-disease-severity-in-upper-respiratory-tract-infections
#13
Andrea Granados, Adriana Peci, Allison McGeer, Jonathan B Gubbay
BACKGROUND: The role of viral load in respiratory viral infection is unclear. It is proposed that the viral load of some, but not all respiratory viruses correlate with disease severity. OBJECTIVES: We aimed to determine if an association exists between viral loads among patients in ambulatory settings, compared to those requiring hospitalization/intensive care unit (ICU) admission with influenza A/H3N2, influenza B, or human rhinovirus (HRV); we also explored the impact of age, gender and co-detection of Streptococcus pneumoniae on patient setting...
November 22, 2016: Journal of Clinical Virology: the Official Publication of the Pan American Society for Clinical Virology
https://www.readbyqxmd.com/read/27892961/host-derived-extracellular-rna-promotes-adhesion-of-streptococcus-pneumoniae-to-endothelial-and-epithelial-cells
#14
Dariusz Zakrzewicz, Simone Bergmann, Miroslava Didiasova, Benedetto Daniele Giaimo, Tilman Borggrefe, Maren Mieth, Andreas C Hocke, Guenter Lochnit, Liliana Schaefer, Sven Hammerschmidt, Klaus T Preissner, Malgorzata Wygrecka
Streptococcus pneumoniae is the most frequent cause of community-acquired pneumonia. The infection process involves bacterial cell surface receptors, which interact with host extracellular matrix components to facilitate colonization and dissemination of bacteria. Here, we investigated the role of host-derived extracellular RNA (eRNA) in the process of pneumococcal alveolar epithelial cell infection. Our study demonstrates that eRNA dose-dependently increased S. pneumoniae invasion of alveolar epithelial cells...
November 28, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27892542/streptococcus-pneumoniae-disrupts-pulmonary-immune-defence-via-elastase-release-following-pneumolysin-dependent-neutrophil-lysis
#15
Hisanori Domon, Masataka Oda, Tomoki Maekawa, Kosuke Nagai, Wataru Takeda, Yutaka Terao
Streptococcus pneumoniae is a leading cause of bacterial pneumonia and is the principal cause of morbidity and mortality worldwide. Previous studies suggested that excessive activation of neutrophils results in the release of neutrophil elastase, which contributes to lung injury in severe pneumonia. Although both pneumococcal virulence factors and neutrophil elastase contribute to the development and progression of pneumonia, there are no studies analysing relationships between these factors. Here, we showed that pneumolysin, a pneumococcal pore-forming toxin, induced cell lysis in primary isolated human neutrophils, leading to the release of neutrophil elastase...
November 28, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27891283/streptococcus-intermedius-causing-necrotizing-pneumonia-in-an-immune-competent-female-a-case-report-and-literature-review
#16
Faris Hannoodi, Israa Ali, Hussam Sabbagh, Sarwan Kumar
We report a case of a 52-year-old immunocompetent Caucasian female treated for necrotizing Streptococcus intermedius pneumonia and review available literature of similar cases. Our patient presented with respiratory failure and required hospitalization and treatment in the intensive care unit. Moreover, she required surgical drainage of right lung empyema as well as decortication and resection. The review of literature revealed three cases of S. intermedius pneumonia, one of which was a mortality. Comparison of the published cases showed a highly varied prehospital course and radiological presentations, with a symptomatic phase ranging from 10 days to five months...
2016: Case Reports in Pulmonology
https://www.readbyqxmd.com/read/27889801/production-and-purification-of-an-untagged-recombinant-pneumococcal-surface-protein-a-pspa4pro-with-high-purity-and-low-endotoxin-content
#17
Douglas B Figueiredo, Eneas Carvalho, Mauricio P Santos, Stefanie Kraschowetz, Rafaela T Zanardo, Gilson Campani, Gabriel G Silva, Cíntia R Sargo, Antonio Carlos L Horta, Roberto de C Giordano, Eliane N Miyaji, Teresa C Zangirolami, Joaquin Cabrera-Crespo, Viviane Maimoni Gonçalves
Streptococcus pneumoniae is the main cause of pneumonia, meningitis, and other conditions that kill thousands of children every year worldwide. The replacement of pneumococcal serotypes among the vaccinated population has evidenced the need for new vaccines with broader coverage and driven the research for protein-based vaccines. Pneumococcal surface protein A (PspA) protects S. pneumoniae from the bactericidal effect of human apolactoferrin and prevents complement deposition. Several studies indicate that PspA is a very promising target for novel vaccine formulations...
November 26, 2016: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/27889249/analysis-of-streptococcus-pneumoniae-and-haemophilus-influenzae-isolated-from-middle-ear-fluid-before-and-after-the-introduction-of-government-subsidies-for-pneumococcal-and-h-%C3%A2-influenzae-type-b-vaccines-in-japan
#18
Tadashi Hoshino, Noriko Takeuchi, Chie Fukasawa, Shoko Hirose, Hideyuki Okui, Hiroko Sato, Mari Sato, Yukiko Arimoto, Atsuko Nakano, Naruhiko Ishiwada
This study aimed to identify trends in frequency, serotype, and antimicrobial susceptibility of Streptococcus pneumoniae and Haemophilus influenzae isolated from middle ear fluid specimens of children aged≤15 years (mean, 2 years), before and after the introduction of the 7-valent pneumococcal conjugate vaccine (PCV7) and the H. influenzae type b vaccine, at a pediatric facility in Japan. Sixty-six S. pneumoniae and 88 H. influenzae strains were isolated from 820 middle ear fluid samples. Serotyping and antimicrobial susceptibility testing were performed...
November 23, 2016: Journal of Infection and Chemotherapy: Official Journal of the Japan Society of Chemotherapy
https://www.readbyqxmd.com/read/27888365/development-of-a-novel-engineered-antibody-targeting-neisseria-species
#19
Chih-Yueh Liu, Chang-Ching Weng, Chih-Hsiang Lin, Chiou-Ying Yang, Kwok-Kong Tony Mong, Yaw-Kuen Li
OBJECTIVES: A Neissaria bacterial pilus sugar, bacillosamine, was synthesized and, for the first time, used as a probe to screen a single-chain variable fragment (scFv). RESULTS: Four Neisseria, Neisseria gonorrhoeae, Neisseria meningitidis, Neisseria sicca and Neisseria subflava, and two negative controls, Streptococcus pneumoniae and Escherichia coli, were tested through ELISA, immunostaining and gold nanoparticle immunological assay. All results indicated that the selected scFv is feasible for the specific detection of Neisseria species via the recognition of bacillosamine...
November 25, 2016: Biotechnology Letters
https://www.readbyqxmd.com/read/27885052/enhanced-protective-responses-to-a-serotype-independent-pneumococcal-vaccine-when-combined-with-an-inactivated-influenza-vaccine
#20
Rachelle Babb, Austen Chen, Abiodun D Ogunniyi, Timothy R Hirst, Ervin E Kara, Shaun R McColl, Mohammed Alsharifi, James C Paton
Streptococcus pneumoniae and influenza are the world's foremost bacterial and viral respiratory pathogens. We have previously described a gamma-irradiated influenza (γ-FLU) vaccine that provides cross-protective immunity against heterosubtypic infections. More recently, we reported a novel non-adjuvanted gamma-irradiated S. pneumoniae (γ-PN) vaccine that elicits serotype-independent protection. Considering the clinical synergism of both pathogens, combination of a serotype-independent pneumococcal vaccine with a broad-spectrum influenza vaccine to protect against both infections would have considerable clinical impact...
November 24, 2016: Clinical Science (1979-)
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