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Pneumococcal Infections (pneumococcal + infections)
Kinds of Pneumococcal Infections Selected AbstractsEpidemiology of invasive pneumococcal infections in children aged 0,6 years in Denmark: a 19-year nationwide surveillance studyACTA PAEDIATRICA, Issue 2000MS Kaltoft The impact of the new pneumococcal conjugate vaccines on invasive disease burden in Danish children was evaluated by analysing the results from the last 19 years of a nationwide surveillance of invasive pneumococcal infections. During 1981,1999, the Streptococcus Unit at Statens Serum Institut, Copenhagen, received 1123 invasive pneumococcal isolates from children aged 0,6 years. Nearly 72% (71.8%) of the pneumococcal isolates were from children aged <2 y. The median ages of children with pneumococcal meningitis and bacteraemia were 10.2 mo and 15.9 mo, respectively. The incidence of pneumococcal meningitis remained stable during the study period. The mean annual incidence rates of pneumococcal meningitis among children aged <1, <2, and <7 years were 17.4, 12.4, and 4.3 per 100000, respectively, during 1981,1999 (overlapping age groups are used throughout this article to facilitate the comparison of incidence data from different countries or among different studies). The annual incidence of pneumococcal bacteraemia increased from 1981 to 1996, after which a slight fall was noted. During the last six years of the study period, the mean annual incidence rates of bacteraemia were 30.1, 32.5, and 14.0 per 100000 children aged <1, <2, and <7 years. In the 1990s, pneumococcal isolates with reduced sensitivity to penicillin (0,5% each year) and erythromycin (7.4% in 1999) emerged as a cause of invasive infections in children aged 0,6 years in Denmark. During 1981,1999, 10 serotypes (1, 4, 6A, 6B, 7F, 9V, 14, 18C, 19F, 23F) caused 82% of invasive infections in Danish children. Importantly, no significant temporal changes in overall serotype distribution or differences in serotype distributions between girls and boys could be documented during the study period. Conclusion: According to the Kaiser Permanente trial, the 7-, 9-, and 11-valent pneumococcal conjugate vaccines will probably cover around 60%, 70%, and 80%, respectively, of all invasive pneumococcal infections in Danish children aged 0,6 y, corresponding to 12,14 episodes of meningitis and 40,60 episodes of bacteraemia per year. [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] Novel vaccine strategies with protein antigens of Streptococcus pneumoniaeFEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 1 2003Edwin Swiatlo Abstract Infections caused by Streptococcus pneumoniae (pneumococcus) are a major cause of mortality throughout the world. This organism is primarily a commensal in the upper respiratory tract of humans, but can cause pneumonia in high-risk persons and disseminate from the lungs by invasion of the bloodstream. Currently, prevention of pneumococcal infections is by immunization with vaccines which contain capsular polysaccharides from the most common serotypes causing invasive disease. However, there are more than 90 antigenically distinct serotypes and there is concern that serotypes not included in the vaccines may become more prevalent in the face of continued use of polysaccharide vaccines. Also, certain high-risk groups have poor immunological responses to some of the polysaccharides in the vaccine formulations. Protein antigens that are conserved across all capsular serotypes would induce more effective and durable humoral immune responses and could potentially protect against all clinically relevant pneumococcal capsular types. This review provides a summary of work on pneumococcal proteins that are being investigated as components for future generations of improved pneumococcal vaccines. [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] 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] New insights into pneumococcal diseaseRESPIROLOGY, Issue 2 2009Charles FELDMAN ABSTRACT Streptococcus pneumoniae (pneumococcus) remains a common cause of disease and death throughout the world. Despite considerable research into various aspects of this infection, there still remain a number of unresolved issues, as well as considerable ongoing controversies, particularly with regard to its optimal management. Among the risk factors for pneumococcal pneumonia, cigarette smoking has been shown to play a major role, more recently among HIV-infected individuals. Considerable recent research has focused on determining the role of the various protein virulence factors in disease pathogenesis. Among the ongoing controversies has been an appreciation of the true impact of antimicrobial resistance on the outcome of pneumococcal infections, as well an understanding of the role of combination antibiotic therapy in the more severely ill hospitalized cases. An important advance in the prevention of pneumococcal infections has been the introduction of the pneumococcal protein conjugate vaccine. [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] Fighting infections due to multidrug-resistant Gram-positive pathogensCLINICAL MICROBIOLOGY AND INFECTION, Issue 3 2009G. Cornaglia Guest Editor Growing bacterial resistance in Gram-positive pathogens means that what were once effective and inexpensive treatments for infections caused by these bacteria are now being seriously questioned, including penicillin and macrolides for use against pneumococcal infections and,in hospitals,oxacillin for use against staphylococcal infections. As a whole, multidrug-resistant (MDR) Gram-positive pathogens are rapidly becoming an urgent and sometimes unmanageable clinical problem. Nevertheless, and despite decades of research into the effects of antibiotics, the actual risk posed to human health by antibiotic resistance has been poorly defined; the lack of reliable data concerning the outcomes resulting from antimicrobial resistance stems, in part, from problems with study designs and the methods used in resistence determination. Surprisingly little is known, too, about the actual effectiveness of the many types of intervention aimed at controlling antibiotic resistance. New antibiotics active against MDR Gram-positive pathogens have been recently introduced into clinical practice, and the antibiotic pipeline contains additional compounds at an advanced stage of development, including new glycopeptides, new anti-methicillin-resistant Staphylococcus aureus (MRSA) ,-lactams, and new diaminopyrimidines. Many novel antimicrobial agents are likely to be niche products, endowed with narrow antibacterial spectra and/or targeted at specific clinical problems. Therefore, an important educational goal will be to change the current, long-lasting attitudes of both physicians and customers towards broad-spectrum and multipurpose compounds. Scientific societies, such as the European Society of Clinical Microbiology and Infectious Diseases (ESCMID), must play a leading role in this process. [source] Clinical impact of antibiotic-resistant Gram-positive pathogensCLINICAL MICROBIOLOGY AND INFECTION, Issue 3 2009H. M. Lode Abstract The European Union's attention to the problem of antibacterial resistance will soon reach a 10-year mark, but the rates of resistance in Gram-positive and Gram-negative bacteria are still increasing. This review focuses on the clinical impact of resistant Gram-positive bacteria on patients. Multiple drug resistance in pneumococcal infections will lead to more treatment failures and higher mortality, which so far have been seen with penicillins and pathogens with high-level resistance. Several studies have demonstrated higher mortality, prolonged length of hospital stay and higher costs associated with methicillin-resistant Staphylococcus aureus infections, in comparison with methicillin-susceptible Staphylococcus aureus infections. Similarly, vancomycin-resistant enterococci bloodstream infections have a negative impact with respect to mortality, length of hospital stay and costs, in comparison with infections due to vancomycin-susceptible enterococci. Several distinctive prophylactic and therapeutic approaches have to be undertaken to successfully prevent the clinical consequences of antibiotic resistance in Gram-positive bacteria. This review addresses the impact of antibiotic-resistant Gram-positive pathogens on clinical outcomes. [source] Nationwide study of recurrent invasive pneumococcal infections in a population with a low prevalence of human immunodeficiency virus infectionCLINICAL MICROBIOLOGY AND INFECTION, Issue 9 2005H. M. Einarsdóttir Abstract Recurrent invasive infections caused by Streptococcus pneumoniae are rare, and often considered to be indicative of serious underlying illness. However, the prevalence of this problem, and the relevance of specific predisposing conditions, can be hard to assess, since many of the studies are based on specific risk groups. A population-based study of recurrent invasive pneumococcal disease in Iceland during the 30-year period 1975,2004 was performed. Clinical information, including mortality and vaccine use, was analysed retrospectively. Invasive pneumococcal isolates were serotyped and susceptibility testing was performed. During this period, 36 (4.4%) of 819 patients who survived an initial infection experienced recurrence, with a median time between episodes of 9.7 months. Pneumonia with bacteraemia was the most common clinical diagnosis (48% of cases), followed by bacteraemia without a clear focus (21%) and meningitis (13%). Most (94%) of the patients had identifiable predisposing conditions, most commonly, multiple myeloma in adults, and antibody deficiencies in children. Compared with children, adults were more likely to present with pneumonia (65% vs. 18%; p 0.0001). No significant change in the 30-day mortality rate was observed during the three decades of the study. Only 26% of eligible patients received pneumococcal vaccination. Patients with recurrent invasive pneumococcal disease should be investigated thoroughly for underlying diseases. Greater use of pneumococcal vaccines should be encouraged among high-risk patients. More effective preventive and therapeutic measures are needed to improve outcomes. [source] | ||||||||||