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S. Pneumoniae (s + pneumoniae)
Selected AbstractsEpidemiology of invasive and other pneumococcal disease in children in England and Wales 1996,1998ACTA PAEDIATRICA, Issue 2000E Miller The results of enhanced national surveillance of pneumococcal disease in children <15y of age in England and Wales are reported for the period 1996,1998. Of the 1985 cases of laboratory-confirmed invasive disease (annual incidence 6.6 per 100000 overall and 39.7 per 100000 in infants <1 y of age), 485 (24%) were meningitis (annual incidence of 1.6 per 100000 overall and 15.7 per 100000 in infants <1 y of age). Fifty-nine deaths in children with invasive disease were identified-3% of the total reports. Thirty-one different serogroups/types were identified, with organisms in the 7-valent conjugate vaccine responsible for 69% of the infections in children <5 y of age; this rose to 77% and 82%, respectively, for the 9-and 11-valent vaccines. Resistance to penicillin varied from 2.3% to 6.2% in different years, but erythromycin resistance remained constant at 17%. The vast majority of resistant isolates were in vaccine serotype/groups. Computerized hospital admission records for all children <15 y of age with a discharge diagnosis code indicating probable pneumococcal disease were also analysed for 1997. The annual incidence for cases with a code specifically mentioning S. pneumoniae was 9.9 per 100000 compared with 71.2 per 100000 for lobar pneumonia; the mean duration of stay for both was < 1 wk. The incidence of admission for pneumococcal meningitis (1.9 overall and 19.6 for infants < 1 y of age) was similar to that derived from laboratory reports and resulted in an average duration of stay of 2 wk. Conclusion: This surveillance has confirmed the substantial burden of morbidity attributable to pneumococcal disease in British children and the potential public health benefits that could be achieved by the use of pneumococcal conjugate vaccines. [source] Prevention of life-threatening infections due to encapsulated bacteria in children with hyposplenia or asplenia: a brief review of current recommendations for practical purposesEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 5 2003Elio Castagnola Abstract: The aim of the present work was to summarise in a single paper all the options for prevention of life-threatening infections due to encapsulated bacteria in patients with hyposplenism or asplenia. Prevention of these infections should be obtained in all patients with 1) patient and family education, 2) prophylaxis by means of vaccination against Haemophilus influenzae and Streptococcus pneumoniae, 3) antibiotic prophylaxis, based primarily on penicillin, 4) delay of elective splenectomy or use methods of tissue salvage in splenic trauma. Vaccination is not effective against all serotypes of S. pneumoniae and Neisseria meningitidis causing life-threatening infections in hypo/asplenic patients. Moreover, antibacterial prophylaxis could select antibacterial-resistant pathogens and is highly conditioned by patient's compliance. Therefore, empirical antibacterial therapy of fever and/or suspected infection should be recommended to all splenectomised patients independently from time elapsing from splenectomy, vaccinal status and assumption of antibacterial prophylaxis. [source] Specific ICAM-3 grabbing nonintegrin-related 1 (SIGNR1) expressed by marginal zone macrophages is essential for defense against pulmonary Streptococcuspneumoniae infectionEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 10 2005Estella Abstract The dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN) homolog, SIGN-related 1 (SIGNR1) is a pathogen receptor expressed by splenic marginal zone and peritoneal macrophages, and is essential for clearance of Streptococcus pneumoniae by phagocytosis after intraperitoneal infection. Here, we identified an important in vivo function for SIGNR1 in S.pneumonia infection induced via its natural entrance route. Upon intranasal infection with S. pneumoniae, SIGNR1-deficient mice did not clear bacteria from lung and blood, and displayed severely enhanced inflammatory parameters compared to the wild-type mice. However, SIGNR1 is not expressed by alveolar macrophages, suggesting that another mechanism than a decrease in phagocytosis is responsible for this difference. Natural anti-phosphorylcholine IgM produced by marginal zone B cells is essential for protection against infection with S. pneumoniae. Strikingly, during infection, SIGNR1-deficient mice failed to produce a rapid anti-phosphorylcholine IgM response. Marginal zone macrophages have been suggested to capture antigens for presentation to marginal zone B cells. We demonstrate that marginal zone macrophages from SIGNR1-deficient mice in contrast to wild-type mice are not able to capture pneumococci from blood, suggesting that SIGNR1 on marginal zone macrophages captures S. pneumoniae for antigen presentation to and activation of marginal zone B cells, resulting in an anti-phosphorylcholine IgM response. [source] Inhibition of pneumococcal choline-binding proteins and cell growth by esters of bicyclic aminesFEBS JOURNAL, Issue 2 2007Beatriz Maestro Streptococcus pneumoniae is one of the major pathogens worldwide. The use of currently available antibiotics to treat pneumococcal diseases is hampered by increasing resistance levels; also, capsular polysaccharide-based vaccination is of limited efficacy. Therefore, it is desirable to find targets for the development of new antimicrobial drugs specifically designed to fight pneumococcal infections. Choline-binding proteins are a family of polypeptides, found in all S. pneumoniae strains, that take part in important physiologic processes of this bacterium. Among them are several murein hydrolases whose enzymatic activity is usually inhibited by an excess of choline. Using a simple chromatographic procedure, we have identified several choline analogs able to strongly interact with the choline-binding module (C-LytA) of the major autolysin of S. pneumoniae. Two of these compounds (atropine and ipratropium) display a higher binding affinity to C-LytA than choline, and also increase the stability of the protein. CD and fluorescence spectroscopy analyses revealed that the conformational changes of C-LytA upon binding of these alkaloids are different to those induced by choline, suggesting a different mode of binding. In vitro inhibition assays of three pneumococcal, choline-dependent cell wall lytic enzymes also demonstrated a greater inhibitory efficiency of those molecules. Moreover, atropine and ipratropium strongly inhibited in vitro pneumococcal growth, altering cell morphology and reducing cell viability, a very different response than that observed upon addition of an excess of choline. These results may open up the possibility of the development of bicyclic amines as new antimicrobials for use against pneumococcal pathologies. [source] Structures of two cell wall-associated polysaccharides of a Streptococcus mitis biovar 1 strainFEBS JOURNAL, Issue 24 2000A unique teichoic acid-like polysaccharide, the group O antigen which is a C-polysaccharide in common with pneumococci The cell wall of Streptococcus mitis biovar 1 strain SK137 contains the C-polysaccharide known as the common antigen of a closely related species Streptococcus pneumoniae, and a teichoic acid-like polysaccharide with a unique structure. The two polysaccharides are different entities and could be partially separated by gel chromatography. The structures of the two polysaccharides were determined by chemical methods and by NMR spectroscopy. The teichoic acid-like polymer has a heptasaccharide phosphate repeating unit with the following structure: The structure neither contains ribitol nor glycerol phosphate as classical teichoic acids do, thus we have used the expression teichoic acid-like for this polysaccharide. The following structure of the C-polysaccharide repeating unit was established: where AAT is 2-acetamido-4-amino-2,4,6-trideoxy- d -galactose. It has a carbohydrate backbone identical to that of one of the two structures of C-polysaccharide previously identified in S. pneumoniae. C-polysaccharide of S. mitis is characterized by the presence, in each repeating unit, of two residues of phosphocholine and both galactosamine residues in the N-acetylated form. Immunochemical analysis showed that C-polysaccharide constitutes the Lancefield group O antigen. Studies using mAbs directed against the backbone and against the phosphocholine moiety of the C-polysaccharide revealed several different patterns of these epitopes among 95 S. mitis and Streptococcus oralis strains tested and the exclusive presence of the group O antigen in the majority of S. mitis biovar 1 strains. [source] Smoke Exposure and Ethanol Ingestion Modulate Intrapulmonary Polymorphonuclear Leukocyte Killing, but Not Recruitment or PhagocytosisALCOHOLISM, Issue 9 2006Elizabeth A. Vander Top Background: People who smoke and abuse alcohol are uniquely susceptible to pulmonary infections caused by Streptococcus pneumoniae, the pneumococcus. The primary cellular defense against pneumococci within the lungs is the polymorphonuclear leukocyte (PMN). Cigarette smoke and ethanol (EtOH) are known to alter certain PMN functions, but little is known about their concurrent effects. Methods: Male Sprague,Dawley rats were exposed twice daily for 8 weeks to cigarette smoke (smoke-exposed) or room air (sham-exposed). During the final week of exposure, the rats were pair-fed a liquid diet containing either 36 or 0% EtOH calories. Polymorphonuclear leukocytes were prerecruited into the rats' lungs by transtracheal injection of lipopolysaccharide. Five hours later, the rats were infected transtracheally with S. pneumoniae, and PMN recruitment, phagocytosis, and bactericidal activity were quantified within their lungs. Chemokine levels were also measured in bronchoalveolar lavage fluids, lung homogenates, and sera. Results: Neither PMN recruitment nor phagocytic uptake of pneumococci was altered by EtOH ingestion or smoke exposure. Killing of the organisms, however, was significantly decreased in sham-exposed, but not smoke-exposed, rats ingesting EtOH. Parallel results were determined for serum cytokine-induced neutrophil chemoattractant-1 (CINC-1), with EtOH ingestion significantly decreasing the levels in sham-exposed, but not smoke-exposed, rats. Pulmonary levels of macrophage inflammatory protein-2 (MIP-2) and CINC-1 were highly elevated by the combination of EtOH and smoke. Conclusions: One week of EtOH ingestion by rats impaired the ability of their PMNs to kill S. pneumoniae within their lungs. This was not due to decreased recruitment of the PMNs to the lungs or to diminished phagocytosis of intrapulmonary pneumococci. The addition of twice-daily cigarette smoke exposure to this short-term EtOH ingestion model restored PMN bactericidal ability to levels observed in the absence of either treatment. These EtOH-induced and smoke-induced alterations in PMN killing may be related to alterations in both pulmonary and systemic inflammatory chemokine levels. [source] Smoke Exposure Exacerbates an Ethanol-Induced Defect in Mucociliary Clearance of Streptococcus pneumoniaeALCOHOLISM, Issue 5 2005Elizabeth A. Vander Top Background: Alcoholics and smokers are particularly susceptible to pulmonary infections caused by Streptococcus pneumoniae, the pneumococcus. Infection begins when pneumococci colonizing the nasopharynx are aspirated into the lower respiratory tract. The major host defense against this movement is the mucociliary clearance apparatus. Both cigarette smoke and ethanol (EtOH) exposure alter ciliary beating and protein kinase activity in the respiratory mucosa in vitro, but their effects on bacterial clearance in the intact animal have not been determined. Methods: Male Sprague Dawley rats were exposed twice daily for 12 weeks to either the smoke generated from 30 cigarettes (smoke,exposed) or room air (sham,exposed). For the last five weeks of smoke exposure, the rats were fed Lieber-DeCarli liquid diets containing 0%, 16%, 26%, or 36% EtOH calories. The rats then were infected intranasally with S. pneumoniae, and movement of the organisms into the lower respiratory tract was quantified by plate counts of the tracheas and lungs 4 hr later. Ciliary beat frequency (CBF) analysis was performed on tracheal ring explants from each animal before and after stimulation with the ,-agonist isoproterenol, and tracheal epithelial cell protein kinase C (PKC) activity was measured. Results: Ingestion of any of the EtOH-containing diets resulted in a dose-dependent increase in movement of S. pneumoniae into the rats' lungs. This EtOH-induced defect was augmented further by concurrent smoke exposure, although smoke exposure alone had little effect on S. pneumoniae movement. Smoke, but not EtOH exposure, activated tracheal epithelial cell PKC. Increased movement of organisms into lungs correlated with a decrease in CBF and loss of the ciliary response to isoproterenol. Conclusion: EtOH ingestion in our model facilitated movement of S. pneumoniae into rats' lungs, a phenomenon exacerbated by concurrent smoke exposure. Furthermore, the organism's movement into the lungs correlated with a blunting of the rats' ciliary response to an established stimulus. Defects in mucociliary clearance thus may be one cause of the increased risk of pneumococcal infections in people who abuse alcohol, particularly if they also smoke. [source] Study of human metapneumovirus-associated lower respiratory tract infections in Egyptian adultsMICROBIOLOGY AND IMMUNOLOGY, Issue 11 2009Maysaa El Sayed Zaki ABSTRACT There is a deficiency in the data concerning the role of hMPV in lower respiratory tract infections in adults, and until now there has been no data available regarding the prevalence of hMPV in adults in our region. In the present study the association of hMPV with varieties of lower respiratory tract disorders in immunocompetent adult patients, either alone or with bacterial pathogens, has been highlighted. Eighty-eight patients were included in the study. They included 46 males and 42 females with an age range of 38,65 years. Patients presented with lower respiratory tract infections associated with acute exacerbation of asthma (67%), pneumonia (17%), and acute exacerbation of chronic obstructive lung diseases. Sputum and nasopharyngeal samples were obtained from the patients and subjected to a full microbiological study. In addition, detection of hMPV was performed by nested reverse transcriptase polymerase chain reaction. The pathogens isolated were Streptococcus pneumoniae 46.6%, Staphylococci aureus 35.2%, and human metapneumovirus 13.6%. Influenza virus and rhinovirus were each isolated from 4.5% of patients. Human metapneumovirus was associated with S. pneumoniae in 4.5% in studied patients, while in 9.1% it was the only pathogen found in those patients. The commonest clinical condition with significant association with human metapneumovirus was pneumonia. The clinical and laboratory studies demonstrated an association between lower respiratory tract infections in adults and hMPV either as sole pathogen or in association with Streptococcus pneumoniae. It was a common pathogen in community-acquired pneumonia. [source] Sucrose metabolism contributes to in vivo fitness of Streptococcus pneumoniaeMOLECULAR MICROBIOLOGY, Issue 1 2007Ramkumar Iyer Summary We characterized two sucrose-metabolizing systems ,sus and scr, and describe their roles in the physiology and virulence of Streptococcus pneumoniae in murine models of carriage and pneumonia. The sus and scr systems are regulated by LacI family repressors SusR and ScrR respectively. SusR regulates an adjacent ABC transporter (susT1/susT2/susX) and sucrose-6-phosphate (S-6-P) hydrolase (susH). ScrR controls an adjacent PTS transporter (scrT), fructokinase (scrK) and second S-6-P hydrolase (scrH). sus and scr play niche-specific roles in virulence. The susH and sus locus mutants are attenuated in the lung, but dispensable in nasopharyngeal carriage. Conversely, the scrH and scr locus mutants, while dispensable in the lung, are attenuated for nasopharyngeal colonization. The scrH/susH double mutant is more attenuated than scrH in the nasopharynx, indicating SusH can substitute in this niche. Both systems are sucrose-inducible, with ScrH being the major in vitro hydrolase. The scrH/susH mutant does not grow on sucrose indicating that sus and scr are the only sucrose-metabolizing systems in S. pneumoniae. We propose a model describing hierarchical regulation of the scr and sus systems by the putative inducer, S-6-P. The transport and metabolism of sucrose or a related disaccharide thus contributes to S. pneumoniae colonization and disease. [source] MicroReview: Competence-induced fratricide in streptococciMOLECULAR MICROBIOLOGY, Issue 6 2007Jean-Pierre Claverys Summary Competence for natural genetic transformation in Streptococcus pneumoniae is controlled by the extracellular concentration of the competence-stimulating peptide (CSP), an exported peptide pheromone. Upon entering the competent state, pneumococci start transcribing a number of CSP-responsive genes, termed the early and late competence (com) genes. Some of the proteins encoded by these com genes are absolutely required for DNA uptake and transformation, but most of them are dispensable. This finding indicates that the majority of CSP-regulated proteins in S. pneumoniae is involved in processes unrelated to natural genetic transformation. Recently, however, it became clear that the biological role of a few of the dispensable proteins might be linked to the transformation process. Although these proteins are not needed for transformation per se, they constitute a killing mechanism that could be used by competent cells to acquire DNA from non-competent pneumococci. This mechanism, termed fratricide, has so far only been described for pneumococci. In this manuscript, we review evidence that suggests the conservation of fratricide as well as the independent evolution of its genetic control and of its effectors in several species of the genus Streptococcus, and discuss its possible biological significance in relation to natural transformation. [source] A proteomic analysis of penicillin resistance in Streptococcus pneumoniae reveals a novel role for PstS, a subunit of the phosphate ABC transporterMOLECULAR MICROBIOLOGY, Issue 5 2005Hafid Soualhine Summary Resistance to penicillin is widespread in the Gram-positive bacterium Streptococcus pneumoniae, and while several mutations are known to be implicated in resistance other mechanisms are likely to occur. We used a proteomic screen of two independent mutants in which resistance was selected in vitro. We found a number of differentially expressed proteins including PstS, a subunit of the phosphate ABC transporter of S. pneumoniae. This protein was increased in both mutants, a phenotype correlated to increased RNA expression of the entire phosphate ABC transporter operon. Inactivation of the pstS gene led to increased susceptibility to penicillin in the wild-type strain. To further link the expression of the ABC phosphate transporter with penicillin resistance, we looked at pstS mRNA levels in 12 independent clinical isolates sensitive and resistant to penicillin and found an excellent correlation between resistance and increased expression of pstS. Inactivation of pstS in one of the clinical isolates significantly reduced penicillin resistance. Global approaches are ideally suited for the discovery of novel factors in the biology of resistance. [source] Sputum induction as a diagnostic tool for community-acquired pneumonia in infants and young children from a high HIV prevalence areaPEDIATRIC PULMONOLOGY, Issue 1 2003H.J. Zar MD Abstract Sputum induction is a standard diagnostic procedure to identify pathogens in lower respiratory tract secretions in adults with pneumonia, but has rarely been studied or used in infants and young children. Our aim was to determine the usefulness of induced sputum (IS) as a diagnostic method for infants and children hospitalized with community-acquired pneumonia (CAP) in a high HIV prevalence area. Children hospitalized for CAP were prospectively enrolled over a year. IS was obtained by nebulization with hypertonic (5%) saline, physiotherapy, and suctioning. Sputum was submitted for bacterial and mycobacterial culture and P. carinii detection. Gastric lavages (GLs) were done for M. tuberculosis culture; a nasopharyngeal aspirate (NPA) was obtained for bacterial culture and P. carinii detection. IS was obtained in 210 children (median age, 7 (25th to 75th percentile, 3,18) months); 138 (66%) were HIV-infected; 148 (70%) were receiving supplemental oxygen. Bacteria were isolated from 101 (50%) IS and 141 (70%) NPA paired specimens (P,<,0.001). A significantly higher rate of S. aureus, H. influenzae, M. catarrhalis, and S. pneumoniae was found in NPAs compared to IS; this pattern was particularly evident in HIV-infected children. M. tuberculosis was cultured from sputum in 19 patients (9%); GLs performed in 142 children were positive in only 9 (6%). The difference (95% confidence interval) between yields for M. tuberculosis from culture of IS compared to GL was 4.3% (95% CI, 0,5.6%; P,=,0.08). P. carinii was identified from IS in 12 (5.7%) children; all corresponding NPAs were negative. Seven (3%) children could not tolerate sputum induction. Side effects included increased coughing in 4%, epistaxis in 3%, and wheezing responsive to bronchodilators in 1%. In conclusion, induced sputum is a useful and safe diagnostic procedure in infants and children with CAP from a high HIV prevalence area. Pediatr Pulmonol. 2003; 36:58,62. © 2003 Wiley-Liss, Inc. [source] Recommendations for immunizations in stem cell transplantationPEDIATRIC TRANSPLANTATION, Issue 2003Deborah C. Molrine Abstract: Investigations over the past decade have documented that there is a decline in immunity to vaccine preventable diseases in many SCT recipients. The majority of immunization studies conducted in SCT recipients to date support the use of multi-dose regimens for most protein and polysaccharide-conjugate vaccine antigens. The consensus immunization schedule recommended by ACIP/IDSA/ASBMT provides guidance for centers to utilize available vaccines in their SCT populations. With the exception of pneumococcal disease, a schedule beginning at 12 months after SCT is reasonable given the low incidence of disease in HSCT recipients for most of the recommended vaccines and improved immune reconstitution in most recipients by one year post transplant. SCT recipients respond poorly to unconjugated pneumococcal polysaccharide vaccine and the development of polysaccharide-protein conjugate vaccines against S. pneumoniae holds promise to impact potentially on clinical disease in this population. In addition, the strategy of donor immunization may also be effective in eliciting early protective immune responses to vaccine antigens. Future challenges will be the development of safe and effective vaccines against the viral pathogens responsible for considerable morbidity and mortality after SCT. [source] Investigation of risk factors for penicillin-resistant Streptococcus pneumoniae carriage in Turkish childrenPEDIATRICS INTERNATIONAL, Issue 4 2001AbstractBackground: Nasopharyngeal colonization plays an important role for infections caused by Streptococcus pneumoniae. Emergence of penicillin resistance in this organism has made it difficult to treat pneumococcal infections. The objectives of this study were to investigate the risk factors for nasopharyngeal colonization with S. pneumonia and for nasopharyngeal colonization with penicillin-resistant S. pneumoniae. Methods: Three hundred children with or without evidence of infection were investigated for various risk factors. Streptococcus pneumoniae isolated from children's nasopharyngeal swabs were examined for penicillin susceptibility. Results: Day-care attendance (odds ratio OR=2.82, P=0.003) and upper respiratory tract infection within the last month (OR=1.83, P=0.02), have been determined to be risk factors for S. pneumoniae carriage. The use of antibiotics within the last 3 months (OR=81.07, P<0.001), the presence of more than five people living in the house of the child (OR=6.63, P=0.03), and having a sibling under 5-years-old (OR=4.60, P=0.03) have been determined to be risk factors for penicillin-resistant S. pneumoniae carriage. Conclusion: Some children are inevitably exposed to and colonized with penicillin susceptible or resistant S. pneumoniae. Changes in day-care organizations, better living conditions, and restriction of antibiotic use seems to be useful precautions to prevent the emerging and colonization with penicillin-susceptible or -resistant S. pneumoniae. [source] Population antibiotic susceptibility for Streptococcus pneumoniae and treatment outcomes in common respiratory tract infections,PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 1 2006Jon P. Furuno PhD Abstract Purpose Antibiotic-resistant Streptococcus pneumoniae potentially threatens the successful treatment of common respiratory tract infections (RTIs); however, the relationship between antibiotic resistance and treatment outcomes remains unclear. We aimed to test the hypothesis that higher in vitro penicillin and erythromycin nonsusceptibility levels among clinical isolates of S. pneumoniae are associated with higher risk of treatment failure in suppurative acute otitis media (AOM), acute sinusitis, and acute exacerbation of chronic bronchitis (AECB). Methods We conducted a population-level analysis using treatment outcomes data from a national, managed-care claims database, and antibiotic susceptibility data from a national repository of antimicrobial susceptibility results between 1997 and 2000. Treatment outcomes in patients with suppurative AOM, acute sinusitis, or AECB receiving selected macrolides or beta-lactams were assessed. Associations between RTI-specific treatment outcomes and antibiotic nonsusceptibility were determined using Spearman correlation coefficients with condition-specific paired outcome and susceptibility data for each region and each year. Results There were 649,552 available RTI outcomes and 7252 susceptibility tests performed on S. pneumoniae isolates. There were no statistically significant trends across time for resolution proportions following treatment by either beta-lactams or macrolides among any of the RTIs. Correlation analyses found no statistically significant association between S. pneumoniae susceptibility and RTI treatment outcomes apart from a significant positive association between of erythromycin nonsusceptibility in ear isolates and macrolide treatment resolution for suppurative AOM. Conclusion On the population level, in vitroS. pneumoniae nonsusceptibility to macrolide or beta-lactam antibiotics was not associated with treatment failure in conditions of probable S. pneumoniae etiology. Copyright © 2005 John Wiley & Sons, Ltd. [source] Proteomic analysis of growth phase-dependent proteins of Streptococcus pneumoniaePROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 4 2006Kwang-Jun Lee Abstract Streptococcus pneumoniae is an important human pathogen that causes a variety of diseases, such as pneumonia, bacteremia, meningitis, otitis media, and sinusitis, in both adults and children. The global pattern of growth phase-dependent protein expression of S. pneumoniae during in vitro culture was analyzed using 2-DE combined with MALDI-TOF MS and LC/ESI-MS/MS. Several protein production patterns were observed at four time points throughout the growth stage, although some protein levels did not change significantly. We focused on the switch in protein expression at the transition from log growth phase to stationary phase. Proteins that were significantly induced or repressed at this point are likely to be involved in central intermediary metabolism, amino acid synthesis, nucleotide, and fatty acid metabolism, cell wall synthesis, protein degradation, and stress responses. This global expression profiling approach has revealed previously unrecognized relationships between proteins in the life of this pathogen. [source] Incidence of community-acquired pneumonia in children caused by Mycoplasma pneumoniae: Serological results of a prospective, population-based study in primary health careRESPIROLOGY, Issue 1 2004Matti Korppi Objective: The objective of the present study was to assess the incidence of community-acquired pneumonia (CAP) in children caused by Mycoplasma pneumoniae. Methodology: During 12 months in 1981,1982, all CAP cases in a defined child population were registered. M. pneumoniae aetiology, initially measured by complement fixation (CF) test, was in 1999 supplemented by measurement of IgG and IgM antibodies using enzyme immunoassays (EIA). Results: M. pneumoniae was detected in 61 (30%) of 201 paediatric CAP cases, being the most common aetiological agent in those 5 years of age or over. At that age, M. pneumoniae was responsible for over 50% of cases, and over 90% of mycoplasmal cases were treated as outpatients. The EIA detected 17 new cases over and above the 44 detected by CF, while CF alone revealed 10 cases. The incidence of M. pneumoniae CAP increased with age, being over 10/1000 children at the age of 10 years or more. Co-infections with Streptococcus pneumoniae and Chlamydia pneumoniae were present in over 30% and 15%, respectively, of mycoplasmal CAP cases. Conclusion: M. pneumoniae is a common cause of paediatric CAP in primary health care, and co-infections with S. pneumoniae are common. Both S. pneumoniae and M. pneumoniae should be taken into account when starting antibiotics for children with CAP. [source] Rhinovirus enhances various bacterial adhesions to nasal epithelial cells simultaneouslyTHE LARYNGOSCOPE, Issue 7 2009Jong Hwan Wang MD Abstract Objectives/Hypothesis: Viral upper respiratory tract infections are often followed by secondary bacterial infections in the form of acute rhinosinusitis. We investigate the effect of rhinovirus infection on the expression of cell adhesion molecules and bacterial adherence to primary human nasal epithelial cells. Methods: Cells were infected with rhinovirus serotype 16 (RV-16), and then Staphylococcus aureus, Streptococcus pneumoniae, or Hemophilus influenzae were added to the culture. Rhinovirus-induced expression of fibronectin, platelet-activating factor receptor, and carcinoembryonic antigen-related cell adhesion molecule, was assayed by confocal microscopy, real-time polymerase chain reaction, and Western blot analysis. Bacterial adhesion to cells was assessed by confocal microscopy and the fluorescence intensity of adherent bacteria was analyzed using Image-Pro Plus 5.1 (Media Cybernetics, Inc., Bethesda, MD). Results: RV-16 infection significantly increased the gene and protein expression of fibronectin, platelet-activating factor receptor, and carcinoembryonic antigen-related cell adhesion molecule in nasal epithelial cells. Compared with rhinovirus-uninfected control cells, the adhesion of S. aureus, S. pneumoniae, and H. influenzae increased significantly to 2.53-fold, 1.51-fold, and 2.74-fold of control levels, respectively, in rhinovirus-infected nasal epithelial cells. Conclusions: These findings suggest that increased expression of host cell adhesion molecules may be the mechanism accounting for the increase in susceptibility to bacterial rhinosinusitis associated with rhinovirus-induced upper respiratory infections. Laryngoscope, 2009 [source] Bacteriologic Comparison of Tonsil Core in Recurrent Tonsillitis and Tonsillar Hypertrophy,THE LARYNGOSCOPE, Issue 12 2007Jin Hyeok Jeong MD Abstract Objectives: Although many bacteriology studies on tonsillar diseases have been completed, all have been confined to children and were characterized by a paucity of cases. The purpose of this study was to analyze the underlying bacterial pathogens in tonsillar disease. Methods: A retrospective study was performed on 824 patients who underwent elective tonsillectomy with or without adenoidectomy. We analyzed the differences between the bacterial pathogens in recurrent tonsillitis and tonsillar hypertrophy with regard to age, season, and antibiotic sensitivity. Results: Among 824 cases, 966 bacterial strains from the tonsil core were isolated. In recurrent tonsillitis, Staphylococcus aureus was the most common pathogen (30.3%), followed by Haemophilus influenzae (15.5%) and group A ,-hemolytic Streptococcus (Streptococcus pyogenes, 14.4%). In patients over 14 years of age, quite differently from other age groups, Klebsiella pneumoniae was isolated at a significantly higher percentage. In tonsillar hypertrophy, H. influenzae was isolated most commonly (31.4%) regardless of age, followed by S. pyogenes (24.2%), S. aureus (22.9%), and Streptococcus pneumoniae (12.6%). Furthermore, mixed infection was common because of its high resistance to penicillin. In both groups, S. pneumoniae was more common in younger patients, whereas K. pneumoniae was relatively common in adults. We found no differences in the detection rate by season; however, H. influenzae was frequently isolated in the tonsillar hypertrophy group regardless of seasonal variations. We also found no difference in the antibiotic sensitivity between the two groups; however, strains resistant to penicillin were relatively prevalent and showed a high sensitivity to third-generation cephalosporin. Conclusions: We observed some differences in the types of bacteria in the tonsillar core between the recurrent tonsillitis and tonsillar hypertrophy groups. Our study indicates that essential bacteria have been changing and, thus, we need to change our choice of antibiotics. [source] Microbiology of Recurrent Acute RhinosinusitisTHE LARYNGOSCOPE, Issue 1 2004Itzhak Brook MD Abstract Objective We undertook to evaluate the microbiology of recurrent acute rhinosinusitis. Methods Repeated aspirations of maxillary sinus secretions by endoscopy were performed in eight patients over a period of 98 to 185 days. Results Bacteria were recovered for all 25 aspirates. A total of 31 isolates,14 Streptococcus pneumoniae, 11 Haemophilus influenzae, 5 Moraxella catarrhalis, and 1 Staphylococcus aureus,were recovered. The organism persisted in consecutive cultures in 13 instances and were eliminated in 8, and new organisms emerged in 6 instances. An increase in antimicrobial resistance was noted in 5 instances (3 in S. pneumoniae and 2 H. influenzae). Conclusions This study illustrates the microbial dynamics of recurrent acute rhinosinusitis, with the changes in microbial findings and increased bacterial resistance that occurs over time. [source] Symptoms and signs in culture-proven acute maxillary sinusitis in a general practice populationAPMIS, Issue 10 2009JENS GEORG HANSEN The objective of this study was to assess symptoms and signs in patients with maxillary sinusitis and a bacteriological diagnosis obtained by sinus aspiration or lavage. Designed as a prospective cohort study in general practice, the study included 174 patients, aged 18,65 years, suspected of having acute maxillary sinusitis by their general practitioner. The main outcome measures were the independent association of symptoms, signs, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) concentration and confirmed infection with the predominant bacterial pathogens Streptococcus pneumoniae and Haemophilus influenzae. The predominant organisms found in patients with acute maxillary sinusitis were S. pneumoniae and H. influenzae. Body temperature >38 °C and maxillary toothache were significantly associated with the presence of S. pneumoniae and H. influenzae. Positive bacteriological culture results were significantly associated with increasing ESR and CRP values. None of the symptoms and signs, with the exception of body temperature >38 °C and maxillary toothache, were particularly sensitive indicators of the specific aetiology in patients with acute maxillary sinusitis. Elevated ESR and CRP values were significantly associated with positive bacteriological culture results. On the other hand, absence of these symptoms and signs did not exclude the presence of acute maxillary sinusitis. [source] An outbreak of pneumonia associated with S. pneumoniae at a military training facility in Finland in 2006APMIS, Issue 7 2009ANNI VAINIO Streptococcus pneumoniae is a well-known cause of community-acquired bacterial pneumonia. The purpose of this study was to assess the cause and extent of the outbreak of pneumonia which occurred among military recruits following a 1-week hard encampment in Finland. We also assessed the carriage rate and molecular characteristics of the S. pneumoniae isolates. All pneumococcal isolates were studied for antibiotic susceptibility, serotyped, genotyped by multilocus sequence typing (MLST), and the presence of pneumococcal rlrA pilus islet was detected. The genotype results defined by MLST corresponded with the serotype results. S. pneumoniae serotype 7F, ST2331, seemed to be associated with an outbreak of pneumonia and nasopharyngeal carriage among 43 military recruits. Of the 43 military recruits, five (12%) were hospitalized with pneumonia and two (40%) of them were positive for S. pneumoniae serotype 7F, ST2331 by blood culture. Eighteen (42%) of the 43 men were found to be positive for S. pneumoniae by nasopharyngeal culture, and nine (50%) of them carried pneumococcal serotype 7F, ST2331. The outbreak strain covered 55% of all the pneumococcal findings. Outbreaks of invasive pneumococcal disease seem to occur in a crowded environment such as a military training facility even among previously healthy young men. [source] Synthesis and Antibacterial Activity of Novel 4,- O -Carbamoyl Erythromycin-A DerivativesARCHIV DER PHARMAZIE, Issue 8 2010Yunkun Qi Abstract Novel 4,- O -carbamoyl erythromycin-A derivatives were designed, synthesized, and evaluated for their in-vitro antibacterial activities. All of the 4,- O -carbamoyl derivatives showed excellent activity against erythromycin-susceptible Staphylococcus aureus ATCC25923, Streptococcus pyogenes, and Streptococcus pneumoniae ATCC49619. Most of the 4,- O -arylalkylcarbamoyl derivatives displayed potent activity against erythromycin-resistant S. pneumoniae encoded by the mef gene and greatly improved activity against erythromycin-resistant S. pneumoniae encoded by the erm gene or the erm and mef genes. In particular, the 4,- O -arylalkyl derivatives 4c,4e and 4g were found to possess the most potent activity against all the tested erythromycin-susceptible strains, which were comparable to those of erythromycin, clarithromycin, or azithromycin. 4,- O -Arylalkyl derivatives 4e and 4g were the most effective against erythromycin-resistant S. pneumoniae encoded by the mef gene (0.25 and 0.25,µg/mL). 4,- O -Arylalkyl derivatives 4a and 4b exhibited significantly improved activity against erythromycin-resistant S. pneumoniae encoded by the erm gene. In contrast, the 4,- O -alkylcarbamoyl derivatives hardly showed improved activity against all the tested erythromycin-resistant strains. [source] Crystallization and preliminary X-ray analysis of the human-specific toxin intermedilysinACTA CRYSTALLOGRAPHICA SECTION D, Issue 2 2004Galina Polekhina Intermedilysin is a human-specific toxin from Streptococcus intermedius, which is part of normal human oral flora. The bacterium is an opportunistic pathogen with a tendency for deep-seated infection in the brain and liver. Intermedilysin belongs to the cholesterol-dependent cytolysin (CDCs) family of toxins, which have been identified in several different bacteria including the serious human pathogens S. pneumoniae and Clostridium perfringens. Intermedilysin, however, is the only member that shows exclusive specificity for human cells. The toxin has a couple of non-conservative amino-acid substitutions in a tryptophan-rich region of the molecule (Cys to Ala and Trp to Pro), the most conserved region amongst the CDCs. Mutations in this region are known to render other CDCs inactive. In order to investigate the structure,function relationships of the unusual features of intermedilysin, which will help us to understand the molecular mechanism of the toxin family in general, recombinant intermedilysin has been crystallized. The crystals belong to an orthorhombic space group and contain two molecules per asymmetric unit. Diffraction data were collected to 2.3,Å using synchrotron radiation. [source] Crystallization of dihydrodipicolinate synthase from a clinical isolate of Streptococcus pneumoniaeACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 1 2010Natalia E. Sibarani Dihydrodipicolinate synthase (DHDPS; EC 4.2.1.52) catalyzes the rate-limiting step in the (S)-lysine biosynthesis pathway of bacteria and plants. Here, the cloning of the DHDPS gene from a clinical isolate of Streptococcus pneumoniae (OXC141 strain) and the strategy used to express, purify and crystallize the recombinant enzyme are described. Diffracting crystals were grown in high-molecular-weight PEG precipitants using the hanging-drop vapour-diffusion method. The best crystal, from which data were collected, diffracted to beyond 2.0,Å resolution. Initially, the crystals were thought to belong to space group P42212, with unit-cell parameters a = 105.5, b = 105.5, c = 62.4,Å. However, the R factors remained high following initial processing of the data. It was subsequently shown that the data set was twinned and it was thus reprocessed in space group P2, resulting in a significant reduction in the R factors. Determination of the structure will provide insight into the design of novel antimicrobial agents targeting this important enzyme from S. pneumoniae. [source] DATE analysis: A general theory of biological change applied to microarray dataBIOTECHNOLOGY PROGRESS, Issue 5 2009David Rasnick Abstract In contrast to conventional data mining, which searches for specific subsets of genes (extensive variables) to correlate with specific phenotypes, DATE analysis correlates intensive state variables calculated from the same datasets. At the heart of DATE analysis are two biological equations of state not dependent on genetic pathways. This result distinguishes DATE analysis from other bioinformatics approaches. The dimensionless state variable F quantifies the relative overall cellular activity of test cells compared to well-chosen reference cells. The variable ,i is the fold-change in the expression of the ith gene of test cells relative to reference. It is the fraction , of the genome undergoing differential expression,not the magnitude ,,that controls biological change. The state variable , is equivalent to the control strength of metabolic control analysis. For tractability, DATE analysis assumes a linear system of enzyme-connected networks and exploits the small average contribution of each cellular component. This approach was validated by reproducible values of the state variables F, RNA index, and , calculated from random subsets of transcript microarray data. Using published microarray data, F, RNA index, and , were correlated with: (1) the blood-feeding cycle of the malaria parasite, (2) embryonic development of the fruit fly, (3) temperature adaptation of Killifish, (4) exponential growth of cultured S. pneumoniae, and (5) human cancers. DATE analysis was applied to aCGH data from the great apes. A good example of the power of DATE analysis is its application to genomically unstable cancers, which have been refractory to data mining strategies. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] Children with Bacterial Meningitis Presenting to the Emergency Department during the Pneumococcal Conjugate Vaccine EraACADEMIC EMERGENCY MEDICINE, Issue 6 2008Lise E. Nigrovic MD Abstract Background:, The epidemiology of bacterial meningitis in children in the era of widespread heptavalent conjugate pneumococcal vaccination (PCV7) is unknown. Objectives:, The objective was to describe the epidemiology of bacterial meningitis in children presenting to the emergency department (ED) during the era of widespread PCV7 vaccination. Methods:, The authors retrospectively reviewed the medical records of all children aged 1 month to 19 years with bacterial meningitis who presented to the EDs of 20 U.S. pediatric centers (2001,2004). Bacterial meningitis was defined by a positive cerebrospinal fluid (CSF) culture for a bacterial pathogen or CSF pleocytosis (CSF white blood cell [WBC] count ,10 cells/mm3) in association with either a positive blood culture or a CSF latex agglutination study. Results:, A total of 231 children with bacterial meningitis were identified. The median age was 0.6 years (interquartile range [IQR] = 0.2,4.2). Eight patients (3% of all patients) died. The following bacterial pathogens were identified: Streptococcus pneumoniae (n = 77; 33.3%), Neisseria meningitidis (67; 29.0%), Group B Streptococcus (42; 18.2%), Escherichia coli (17; 7.4%), nontypeable Haemophilus influenzae (10; 4.3%), other Gram-negative bacilli (7; 3.0%), Listeria monocytogenes (5; 2.2%), Group A Streptococcus (5; 2.2%), and Moraxella catarrhalis (1; 0.4%). S. pneumoniae serotypes were determined in 37 of 77 patients; of these, 62% were due to nonvaccine serotypes (including 19A). Conclusions:, Although now a rare infectious disease in United States, bacterial meningitis still causes substantial morbidity in affected children. Despite the introduction of PCV7, S. pneumoniae remains the most common cause of bacterial meningitis in U.S. children, with approximately half of cases due to nonvaccine serotypes. [source] Characterization of the Biomechanical Properties of T4 Pili Expressed by Streptococcus pneumoniae,A Comparison between Helix-like and Open Coil-like PiliCHEMPHYSCHEM, Issue 9-10 2009Mickaël Castelain Dr. Abstract Adhesion strategies: Open coil-like T4 pili use different adhesion strategies in the presence of external forces (see figure) compared to the helix-like P pili. When exposed to significant forces, bacteria expressing helix-like pili remain attached by distributing the external force among a multitude of pili, whereas bacteria expressing open coil-like pili sustain large forces primarily by their multitude of binding adhesins. Bacterial adhesion organelles, known as fimbria or pili, are expressed by Gram-positive as well as Gram-negative bacteria families. These appendages play a key role in the first steps of the invasion and infection processes, and they therefore provide bacteria with pathogenic abilities. To improve the knowledge of pili-mediated bacterial adhesion to host cells and how these pili behave under the presence of an external force, we first characterize, using force measuring optical tweezers, open coil-like T4 pili expressed by Gram-positive Streptococcus pneumoniae with respect to their biomechanical properties. It is shown that their elongation behavior can be well described by the worm-like chain model and that they possess a large degree of flexibility. Their properties are then compared with those of helix-like pili expressed by Gram-negative uropathogenic Escherichia coli (UPEC), which have different pili architecture. The differences suggest that these two types of pili have distinctly dissimilar mechanisms to adhere and sustain external forces. Helix-like pili expressed by UPEC bacteria adhere to host cells by single adhesins located at the distal end of the pili while their helix-like structures act as shock absorbers to dampen the irregularly shear forces induced by urine flow and to increase the cooperativity of the pili ensemble, whereas open coil-like pili expressed by S. pneumoniae adhere to cells by a multitude of adhesins distributed along the pili. It is hypothesized that these two types of pili represent different strategies of adhering to host cells in the presence of external forces. When exposed to significant forces, bacteria expressing helix-like pili remain attached by distributing the external force among a multitude of pili, whereas bacteria expressing open coil-like pili sustain large forces primarily by their multitude of binding adhesins which presumably detach sequentially. [source] Changes in antimicrobial resistance, serotypes and genotypes in Streptococcus pneumoniae over a 30-year periodCLINICAL MICROBIOLOGY AND INFECTION, Issue 5 2010J. Liñares Clin Microbiol Infect 2010; 16: 402,410 Abstract Over the past three decades, antimicrobial resistance in Streptococcus pneumoniae has dramatically increased worldwide. Non-susceptibility to penicillin in S. pneumoniae was first described in Australia in 1967, and later in New Guinea (1974), South Africa (1977), and Spain (1979). Most of these strains showed resistance to multiple antibiotics and belonged to serotypes 6A, 6B, 19A, 19F, and 23F. By the late 1980s and 1990s, the emergence and rapid dissemination of antibiotic-resistant pneumococci was observed in southern and eastern Europe, North America, South America, Africa, and Asia. Great geographical variability, both in serotype distribution and in the prevalence of resistant pneumococci, has been reported. However, the highest rates of resistance to penicillin and erythromycin worldwide were found in serotypes 6B, 6A, 9V, 14, 15A, 19F, 19A, and 23F. The introduction of the seven-valent pneumococcal conjugate vaccine (PCV7) in the 2000s and a reduction in antimicrobial use were associated with a significant decline in the incidence of invasive pneumococcal infections and in rates of antibiotic resistance in the USA. However, an increase in the incidence of infections caused by non-PCV7 serotypes, especially multiresistant serotype 19A pneumococci, has been observed in many countries over the last 5 years. The dynamic character of serotypes and antibiotic resistance in S. pneumoniae should be controlled by a policy of prudent antibiotic use and by implementation of the new generation of conjugate vaccines. [source] Is quantitative PCR for the pneumolysin (ply) gene useful for detection of pneumococcal lower respiratory tract infection?CLINICAL MICROBIOLOGY AND INFECTION, Issue 6 2009G. Abdeldaim Abstract The pneumolysin (ply) gene is widely used as a target in PCR assays for Streptococcus pneumoniae in respiratory secretions. However, false-positive results with conventional ply -based PCR have been reported. The aim here was to study the performance of a quantitative ply -based PCR for the identification of pneumococcal lower respiratory tract infection (LRTI). In a prospective study, fibreoptic bronchoscopy was performed in 156 hospitalized adult patients with LRTI and 31 controls who underwent bronchoscopy because of suspicion of malignancy. Among the LRTI patients and controls, the quantitative ply -based PCR applied to bronchoalveolar lavage (BAL) fluid was positive at ,103 genome copies/mL in 61% and 71% of the subjects, at ,105 genome copies/mL in 40% and 58% of the subjects, and at ,107 genome copies/mL in 15% and 3.2% of the subjects, respectively. Using BAL fluid culture, blood culture, and/or a urinary antigen test, S. pneumoniae was identified in 19 LRTI patients. As compared with these diagnostic methods used in combination, quantitative ply -based PCR showed sensitivities and specificities of 89% and 43% at a cut-off of 103 genome copies/mL, of 84% and 66% at a cut-off of 105 genome copies/mL, and of 53% and 90% at a cut-off of 107 genome copies/mL, respectively. In conclusion, a high cut-off with the quantitative ply -based PCR was required to reach acceptable specificity. However, as a high cut-off resulted in low sensitivity, quantitative ply -based PCR does not appear to be clinically useful. Quantitative PCR methods for S. pneumoniae using alternative gene targets should be evaluated. [source] | ||||||||||||||||||||||||||||