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Sample records for 19a streptococcus pneumoniae

  1. Molecular epidemiology of serotype 19A Streptococcus pneumoniae isolated from children in Beijing, 1997-2006

    XUE Lian; YAO Kai-hu; YU Sang-jie; LIU Zun-jie; QIAN Jing; SHEN Xu-zhuang; YANG Yong-hong

    2011-01-01

    Background Despite the prevalence of Streptococcus pneumoniae serotype 19A, the molecular characteristics of this serotype are yet to be fully elucidated. The aim of this study was therefore to determine the homology of the serotype 19A in China.Methods Pulsed-field gel electrophoresis and multilocus sequence typing were done to these forty-nine serotype 19A isolates to investigate the relationship between the strains prevalent in Beijing and other regions. Results From 1997 to 2006, the percentage of serotype 19A isolates increased. The susceptibility rate to penicillin and amoxicillin decreased and the resistance rate to cefuroxime increased. ST320 was the most prevalent ST, followed by ST3546. There were six new STs identified in our study. The serotype 19A strains were classified into six different pulsed-field gel electrophoresis (PFGE) patterns. ST320, which was associated with two different PFGE patterns (A and D), accounted for 32 isolates, and ST3546, which was associated with two PFGE patterns (B and E), accounted for eightConclusions From 2003 onwards, ST320 was the most common ST and the rate of resistance to cefuroxime increased significantly. Further long-term surveys of Streptococcus pneumoniae serotype 19A are required to monitor ST prevalence and antimicrobial resistance in this important human pathogen.

  2. Genome-wide dissection of globally emergent multi-drug resistant serotype 19A Streptococcus pneumoniae

    Wong Andrew

    2009-12-01

    Full Text Available Abstract Background Emergence of multi-drug resistant (MDR serotype 19A Streptococcus pneumoniae (SPN is well-documented but causal factors remain unclear. Canadian SPN isolates (1993-2008, n = 11,083 were serotyped and in vitro susceptibility tested. A subset of MDR 19A were multi-locus sequence typed (MLST and representative isolates' whole genomes sequenced. Results MDR 19A increased in the post-PCV7 era while 19F, 6B, and 23F concurrently declined. MLST of MDR 19A (n = 97 revealed that sequence type (ST 320 predominated. ST320 was unique amongst MDR 19A in that its minimum inhibitory concentration (MIC values for penicillin, amoxicillin, ceftriaxone, and erythromycin were higher than for other ST present amongst post-PCV7 MDR 19A. DNA sequencing revealed that alleles at key drug resistance loci pbp2a, pbp2x, pbp2b, ermB, mefA/E, and tetM were conserved between pre-PCV7 ST 320 19F and post-PCV7 ST 320 19A most likely due to a capsule switch recombination event. A genome wide comparison of MDR 19A ST320 with MDR 19F ST320 identified 822 unique SNPs in 19A, 61 of which were present in antimicrobial resistance genes and 100 in virulence factors. Conclusions Our results suggest a complex genetic picture where high-level drug resistance, vaccine selection pressure, and SPN mutational events have created a "perfect storm" for the emergence of MDR 19A.

  3. Complete Genome Sequences of Three Multidrug-Resistant Clinical Isolates of Streptococcus pneumoniae Serotype 19A with Different Susceptibilities to the Myxobacterial Metabolite Carolacton

    Bunk, Boyke; Schober, Isabel; Spröer, Cathrin; Bergmann, Simone; Jarek, Michael; Overmann, Jörg; Wagner-Döbler, Irene

    2017-01-01

    ABSTRACT The full-genome sequences of three drug- and multidrug-resistant Streptococcus pneumoniae clinical isolates of serotype 19A were determined by PacBio single-molecule real-time sequencing, in combination with Illumina MiSeq sequencing. A comparison to the genomes of other pneumococci indicates a high nucleotide sequence identity to strains Hungary19A-6 and TCH8431/19A. PMID:28209832

  4. Draft Genome Sequences of Six Strains of Streptococcus pneumoniae from Serotypes 5, 6A, 6B, 18C, 19A, and 23F

    Jakobsson, Hedvig E.; Salvà-Serra, Francisco; Karlsson, Roger; Gonzales-Silès, Lucia; Boulund, Fredrik; Engstrand, Lars; Kristiansson, Erik

    2017-01-01

    ABSTRACT Streptococcus pneumoniae is a pathogenic bacterium found most commonly in the respiratory tract of humans and is a common cause of pneumonia and bacterial meningitis. Here, we report the draft genome sequences of six S. pneumoniae strains: CCUG 1350, CCUG 7206, CCUG 11780, CCUG 33774, CCUG 35180, and CCUG 35272. PMID:28385844

  5. Necrotizing pneumonia and acute purulent pericarditis caused by Streptococcus pneumoniae serotype 19A in a healthy 4-year-old girl after one catch-up dose of 13-valent pneumococcal conjugate vaccine.

    Lu, Shay; Tsai, Jeng-Dau; Tsao, Ten-Fu; Liao, Pei-Fen; Sheu, Ji-Nan

    2016-08-01

    Streptococcus pneumoniae is a common cause of infectious diseases in children that may lead to life-threatening complications. Acute purulent pericarditis is an uncommon complication of S. pneumoniae in the antibiotic era. A healthy 4-year-old girl was admitted with pneumonia and pleural effusion. She had received one catch-up dose of 13-valent pneumococcal conjugate vaccine at 2 years of age. She rapidly developed necrotizing pneumonia, complicated by bronchopleural fistula presenting as subcutaneous emphysema and pneumothorax and acute purulent pericarditis. S. pneumoniae serotype 19A was subsequently identified from blood, empyema and pericardial fluid cultures. After appropriate antibiotic therapy and a right lower lobectomy, her condition stabilized and she promptly recovered. This case highlights two rare potential clinical complications of pneumococcal disease in a child: necrotizing pneumonia and acute purulent pericarditis. This is the first report of a child who received just one catch-up dose of 13-valent pneumococcal conjugate vaccine at 2 years of age, as per the United States' Advisory Committee on Immunization Practice's recommendations, but who still developed severe invasive pneumococcal disease with life-threatening complications caused by S. pneumoniae serotype 19A.

  6. Whole Genome Sequencing of 39 Invasive Streptococcus pneumoniae Sequence Type 199 Isolates Revealed Switches from Serotype 19A to 15B

    Lucas, Marie; Brandt, Christian; Herrmann, Leonie; Albersmeier, Andreas; Blom, Jochen; Goesmann, Alexander

    2017-01-01

    Streptococcus pneumoniae is a major pathogen that causes different invasive pneumococcal diseases (IPD). The pneumococcal polysaccharide capsule is a main virulence factor. More than 94 capsule types have been described, but only a limited number of capsule types accounted for the majority of IPD cases before the introduction of pneumococcal vaccines. After the introduction of the conjugated pneumococcal vaccine PCV7, which covered the seven most frequent serotypes in IPD in the USA, an increase in IPD caused by non-vaccine serotypes was observed, and serotype 19A, which belongs to sequence type (ST) 199, was among the most prevalent STs. After the introduction of the extended vaccine PCV13, which includes serotype 19A, serogroup 15B/C increased in IPD. Therefore, whole genome sequences of 39 isolates of ST199 from Germany (collected between 1998 and 2011) with serotype 19A (n = 24) and serogroup 15B/C (n = 15) were obtained using an Illumina platform and were analysed to identify capsular switches within ST199. Two 19A to 15B/C serotype switch events were identified. Both events occurred before the introduction of PCV7, which indicates that a capsular switch from 19A to 15B among ST199 isolates is not unusual and is not directly linked to the vaccination. The observed serotype replacement appears to be the result of a vacant niche due to the displacement of vaccine serotypes that is now successfully occupied by ST199 clones. PMID:28046133

  7. Capsular serotypes and antimicrobial susceptibilities of Streptococcus pneumoniae causing invasive pneumococcal disease from 2009-2012 with an emphasis on serotype 19A in bacteraemic pneumonia and empyema and β-lactam resistance.

    Lee, Meng-Rui; Chen, Chung-Ming; Chuang, Tzu-Yi; Huang, Yu-Tsung; Hsueh, Po-Ren

    2013-11-01

    Capsular serotypes and antimicrobial susceptibilities of Streptococcus pneumoniae isolates that cause invasive pneumococcal disease (IPD) were studied and the role of serotype 19A in the development of bacteraemic pneumonia and empyema was investigated. Subjects comprised 98 patients (56 adults and 42 children) who were treated for IPD at a university-affiliated tertiary referral centre in Taiwan during 2009-2012. Serotypes of the isolates were identified using the latex agglutination method. In vitro susceptibilities of the isolates to 13 antimicrobial agents were determined using the broth microdilution method and were interpreted as recommended by the Clinical and Laboratory Standards Institute. During the study period, bacteraemic pneumonia was the most common type of infection (43/98; 43.9%), followed by primary bacteraemia (30/98; 30.6%). Serotype 19A was the most common serotype (23/98; 23.5%) in all patients. Fourteen (70.0%) of 20 children (47.6% of all children) with serotype 19A infection had pneumonia with empyema, whilst eight patients had concomitant bacteraemia. 7-valent pneumococcal conjugated vaccine (PCV-7), PCV-10, PCV-13 and 23-valent pneumococcal polysaccharide vaccine (PPV-23) had coverage rates of 37.8%, 38.8%, 79.6% and 77.6%, respectively. A substantial increase in the proportion of serotype 15A (6.1%) and 6A (8.2%) was found. In addition, there was a significant reduction in rates of susceptibility of serotype 19A isolates to penicillin, cefotaxime and ceftriaxone but not to azithromycin or any quinolone tested compared with those of non-19A isolates. The prevalence of serotypes 19A, 15A and 6A in patients with IPD increased markedly during the period, especially in children with bacteraemic pneumonia and empyema.

  8. Dominance of multidrug-resistant Denmark(14)-32 (ST230) clone among Streptococcus pneumoniae serotype 19A isolates causing pneumococcal disease in Bulgaria from 1992 to 2013.

    Setchanova, Lena Petrova; Alexandrova, Alexandra; Dacheva, Daniela; Mitov, Ivan; Kaneva, Radka; Mitev, Vanio

    2015-02-01

    A pneumococcal conjugate vaccine (PCV10) was introduced in Bulgarian national immunization program since April 2010. Clonal composition based on pulsed-field gel electrophoresis and multilocus sequence typing genotyping of 52 serotype 19A Streptococcus pneumoniae isolates was analyzed. These were invasive and respiratory isolates collected between 1992 and 2013 from both children (78.8% clone. The most frequent sequence type (ST) was ST230 (48.1%) and together with four other closely related STs (15.4%), belonging to ST1611, ST276, ST7466, and ST2013, which were single- and double-locus variants; they were included in the main CC230. The disappearance of highly drug-resistant ST663 clone and emergence of new clones as CC320 and CC199 was also observed among the rest 19A isolates. A comparison of clonal composition between invasive and noninvasive isolates did not show a great genetic diversity among both kinds of isolates. Continuous surveillance of serotype 19A population following the introduction of PCV10 is essential to evaluate the impact of the vaccine on the epidemiology of this serotype.

  9. Bacteremia with Streptococcus pneumoniae

    Christensen, J S; Jensen, T G; Kolmos, H J

    2012-01-01

    We conducted a hospital-based cohort study among adult patients with first-time Streptococcus pneumoniae bacteremia (SPB) from 2000 through 2008. Patients were identified in a population-based bacteremia database and followed up for mortality through the Danish Civil Registration System (CRS...... age of the patients was 65 years. The focal diagnosis of the SPB was pneumonia in 381 (79 %) patients, followed in frequency by meningitis in 33 (7 %) patients. Of the 481 patients, 390 (81 %) had community-acquired SPB. Of these, 23 (6 %) did not have sepsis, 132 (34 %) had sepsis, 224 (57 %) had...

  10. Antimicrobial Resistant Streptococcus pneumoniae

    B Khanal

    2010-09-01

    Full Text Available Introduction: Pneumococcal infections are important cause of morbidity and mortality. Knowledge of antimicrobial susceptibility patterns plays important role in the selection of appropriate therapy. Present study was undertaken to analyze the susceptibility patterns of pneumococcal isolates against commonly used antimicrobials with special reference to determination of minimum inhibitory concentration (MIC of penicillin in a tertiary care hospital in eastern Nepal. Methods: Twenty-six strains of S. pneumoniae isolated from various clinical specimens submitted to microbiology laboratory were evaluated. All isolates were tested for antimicrobial susceptibility by disk diffusion method. MIC of penicillin was tested by broth dilution method. Results: Of the total isolates 19 (73% were from invasive infections. Seven isolates were resistant to cotrimoxazole. No resistance to penicillin was seen in disk diffusion testing. Less susceptibility to penicillin (MIC 0.1-1.0 mg/L was observed in five (17% isolates. High level resistance to penicillin was not detected. One isolate was multidrug resistant. Conclusions: S. pneumoniaeisolates with intermediate resistance to penicillin prevail in Tertiary Care Hospital in eastern Nepal, causing invasive and noninvasive infections. As intermediate resistance is not detected in routine susceptibility testing, determination of MIC is important. It helps not only in the effective management of life threatening infections but is also essential in continuous monitoring and early detection of resistance. In addition, further study on pneumococcal infections, its antimicrobial resistance profile and correlation with clinical and epidemiological features including serotypes and group prevalence is recommended in future. Keywords: antimicrobial susceptibility pattern, penicillin, Streptococcus pneumoniae.

  11. Streptococcus pneumoniae serotype 19A in Latin America and the Caribbean: a systematic review and meta-analysis, 1990–2010

    Castañeda Elizabeth

    2012-05-01

    Full Text Available Abstract Background Pneumococcal conjugate vaccines (PCVs are in the process of implementation in Latin America. Experience in developed countries has shown that they reduce the incidence of invasive and non-invasive disease. However, there is evidence that the introduction of PCVs in universal mass vaccination programs, combined with inappropriate and extensive use of antibiotics, could be associated to changes in non-PCV serotypes, including serotype 19A. We conducted a systematic review to determine the distribution of serotype 19A, burden of pneumococcal disease and antibiotic resistance in the region. Methods We performed a systematic review of serotype 19A data from observational and randomized clinical studies in the region, conducted between 1990 and 2010, for children under 6 years. Pooled prevalence estimates from surveillance activities with confidence intervals were calculated. Results We included 100 studies in 22 countries and extracted data from 63. These data reported 19733 serotyped invasive pneumococcal isolates, 3.8% of which were serotype 19A. Serotype 19A isolates were responsible for 2.4% acute otitis media episodes, and accounted for 4.1% and 4.4% of 4,380 nasopharyngeal isolates from healthy children and in hospital-based/sick children, respectively. This serotype was stable over the twenty years of surveillance in the region. A total of 53.7% Spn19A isolates from meningitis cases and only 14% from non meningitis were resistant to penicillin. Conclusions Before widespread PCV implementation in this region, serotype 19A was responsible for a relatively small number of pneumococcal disease cases. With increased use of PCVs and a greater number of serotypes included, monitoring S. pneumoniae serotype distribution will be essential for understanding the epidemiology of pneumococcal disease.

  12. Gene Regulation in Streptococcus pneumoniae: interplay between nutrition and virulence

    W.T. Hendriksen (Wouter)

    2010-01-01

    textabstractStreptococcus pneumoniae (the pneumococcus) is a Gram-positive bacterium, which belongs to the species of streptococci. Other pathogenic bacteria belonging to this class include Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus suis, Streptococcus uberis, Streptococcus bovi

  13. Seeing Streptococcus pneumoniae, a Common Killer Bacteria

    Kjærgaard, Rikke Schmidt; Andersen, Ebbe Sloth

    2014-01-01

    of the bacteria Streptococcus pneumoniae by use of ink, watercolours and computer graphics. We propose a novel artistic visual rendering of Streptococcus pneumoniae and ask what the value of these kind of representations are compared to traditional scientific data. We ask if drawings and computer...

  14. Nasopharyngeal carriage of Streptococcus pneumonia in pneumonia-prone age groups in Semarang, Java Island, Indonesia

    H. Farida (Helmia); J.A. Severin (Juliëtte); M.H. Gasem; M. Keuter (Monique); H. Wahyono (Hendro); P. van den Broek (Peterhans); P.W.M. Hermans (Peter); H.A. Verbrugh (Henri)

    2014-01-01

    textabstractIntroduction: Streptococcus pneumoniae is a worldwide occurring pathogen Nasopharyngeal carriage of Streptococcus pneumoniae precedes pneumonia and other pneumococcal diseases in the community. Little is known about S. pneumoniae carriage in Indonesia, complicating strategies to control

  15. Nasopharyngeal Carriage of Streptococcus pneumonia in Pneumonia-Prone Age Groups in Semarang, Java Island, Indonesia

    Farida, H.; Severin, J.A.; Gasem, M.H.; Keuter, M.; Wahyono, H.; Broek, P van den; Hermans, P.W.M.; Verbrugh, H.A.

    2014-01-01

    INTRODUCTION: Streptococcus pneumoniae is a worldwide occurring pathogen Nasopharyngeal carriage of Streptococcus pneumoniae precedes pneumonia and other pneumococcal diseases in the community. Little is known about S. pneumoniae carriage in Indonesia, complicating strategies to control pneumococcal

  16. Emerging resistant serotypes of invasive Streptococcus pneumoniae

    Elshafie S

    2016-06-01

    Full Text Available Sittana Elshafie,1,2 Saad J Taj-Aldeen2,3 1Qatar Orthopedic and Sports Medicine Hospital, Aspetar, Doha, Qatar; 2Weill Cornell Medicine-Qatar, 3Department of Laboratory Medicine and Pathology, Microbiology Division, Hamad Medical Corporation, Doha, Qatar Background: Streptococcus pneumoniae is the leading cause of meningitis and sepsis. The aim of the study was to analyze the distribution, vaccine serotype coverage, and antibiotic resistance of S. pneumoniae serotypes isolated from patients with invasive diseases, after the introduction of pneumococcal 7-valent conjugated vaccine (PCV-7. Methods: A total of 134 isolates were collected from blood and cerebrospinal fluid specimens at Hamad Hospital during the period from 2005 to 2009. Isolate serotyping was done using the Quellung reaction. The prevaccination period was considered before 2005. Results: The most common serotypes for all age groups were 3 (12.70%, 14 (11.90%, 1 (11.90%, 19A (9.00%, 9V (5.20%, 23F (5.20%, and 19F (4.50%. Coverage rates for infant <2 years for PCV-7, the 10-valent conjugated vaccine (PCV-10, and the 13-valent conjugated vaccine (PCV-13 were 34.78%, 52.17%, and 78.26%, respectively. Coverage rates of these vaccines were 50%, 67.86%, and 75% for the 2–5 years age group; 27.12%, 40.68%, and 64.41% for the age group 6–64 years; and 25%, 33.33%, and 66.67% for the ≥65 years age group, respectively. The percentage of nonsusceptible isolates to penicillin, cefotaxime, and erythromycin were 43.86%, 16.66%, and 22.81%, respectively. Thirty-seven isolates (32.46% were multidrug resistant (MDR and belonged to serotypes 14, 19A, 19F, 23F, 1, 9V, 12F, 4, 6B, 3, and 15A. Compared to previous results before the introduction of PCV-7, there was a significant reduction in penicillin-nonsusceptable S. pneumoniae from 66.67% to 43.86%, and a slight insignificant reduction in erythromycin nonsusceptible strains from 27.60% to 22.8%, while there was a significant increase in

  17. Bacteremic pneumonia caused by extensively drug-resistant Streptococcus pneumoniae.

    Kang, Cheol-In; Baek, Jin Yang; Jeon, Kyeongman; Kim, So Hyun; Chung, Doo Ryeon; Peck, Kyong Ran; Lee, Nam Yong; Song, Jae-Hoon

    2012-12-01

    The emergence of antimicrobial resistance threatens the successful treatment of pneumococcal infections. Here we report a case of bacteremic pneumonia caused by an extremely drug-resistant strain of Streptococcus pneumoniae, nonsusceptible to at least one agent in all classes but vancomycin and linezolid, posing an important new public health threat in our region.

  18. Heteroresistance to penicillin in Streptococcus pneumoniae.

    Morand, Brigitte; Mühlemann, Kathrin

    2007-08-28

    Heteroresistance to beta-lactam antibiotics has been mainly described for staphylococci, for which it complicates diagnostic procedures and therapeutic success. This study investigated whether heteroresistance to penicillin exists in Streptococcus pneumoniae. Population analysis profile (PAP) showed the presence of subpopulations with higher penicillin resistance in four of nine clinical pneumococcal strains obtained from a local surveillance program (representing the multiresistant clones ST179, ST276, and ST344) and in seven of 16 reference strains (representing the international clones Spain(23F)-1, Spain(9V)-3, Spain(14)-5, Hungary(19A)-6, South Africa(19A)-13, Taiwan(23F)-15, and Finland(6B)-12). Heteroresistant strains had penicillin minimal inhibitory concentrations (MICs) (for the majority of cells) in the intermediate- to high-level range (0.19-2.0 mug/ml). PAP curves suggested the presence of subpopulations also for the highly penicillin-resistant strains Taiwan(19F)-14, Poland(23F)-16, CSR(19A)-11, and CSR(14)-10. PAP of bacterial subpopulations with higher penicillin resistance showed a shift toward higher penicillin-resistance levels, which reverted upon multiple passages on antibiotic-free media. Convergence to a homotypic resistance phenotype did not occur. Comparison of two strains of clone ST179 showed a correlation between the heteroresistant phenotype and a higher-penicillin MIC and a greater number of altered penicillin-binding proteins (PBP1a, -2b, and -2x), respectively. Therefore, heteroresistance to penicillin occurs in international multiresistant clones of S. pneumoniae. Pneumococci may use heteroresistance to penicillin as a tool during their evolution to high penicillin resistance, because it gives the bacteria an opportunity to explore growth in the presence of antibiotics before acquisition of resistance genes.

  19. Evolving trends in Streptococcus pneumoniae resistance: implications for therapy of community-acquired bacterial pneumonia.

    Jones, Ronald N; Jacobs, Michael R; Sader, Helio S

    2010-09-01

    Pneumonia is a major infectious disease associated with significant morbidity, mortality and utilisation of healthcare resources. Streptococcus pneumoniae is the predominant pathogen in community-acquired pneumonia (CAP), accounting for 20-60% of bacterial cases. Emergence of multidrug-resistant S. pneumoniae has become a significant problem in the management of CAP. Although pneumococcal conjugate vaccine usage in children has led to significant decreases in morbidity and mortality due to S. pneumoniae in all age groups, disease management has been further complicated by the unexpected increase in resistant serotypes, such as 19A, in some regions. Until rapid and accurate diagnostic tests become available, initial treatment of CAP will remain empirical. Thus, selection of appropriate antimicrobial therapy for CAP must be based on prediction of the most likely pathogens and their local antimicrobial susceptibility patterns. This article reviews information on antimicrobial resistance patterns amongst S. pneumoniae and implications for managing CAP.

  20. Monoclonal Idiotope Vaccine against Streptococcus pneumoniae Infection

    McNamara, Mary K.; Ward, Ronald E.; Kohler, Heinz

    1984-12-01

    A monoclonal anti-idiotope antibody coupled to a carrier protein was used to immunize BALB/c mice against a lethal Streptococcus pneumoniae infection. Vaccinated mice developed a high titer of antibody to phosphorylcholine, which is known to protect against infection with Streptococcus pneumoniae. Measurement of the median lethal dose of the bacteria indicated that anti-idiotope immunization significantly increased the resistance of BALB/c mice to the bacterial challenge. Antibody to an idiotope can thus be used as an antigen substitute for the induction of protective immunity.

  1. [Thousand faces of Streptococcus pneumonia (pneumococcus) infections].

    Szabó, Bálint Gergely; Lénárt, Katalin Szidónia; Kádár, Béla; Gombos, Andrea; Dezsényi, Balázs; Szanka, Judit; Bobek, Ilona; Prinz, Gyula

    2015-11-01

    Incidence and mortality rates of infections caused by Streptococcus pneumoniae (pneumococcus) are high worldwide and in Hungary among paediatric as well as adult populations. Pneumococci account for 35-40% of community acquired adult pneumonias requiring hospitalization, while 25-30% of Streptococcus pneumoniae pneumonias are accompanied by bacteraemia. 5-7% of all infections are fatal but this rate is exponentially higher in high risk patients and elderly people. Mortality could reach 20% among patients with severe invasive pneumococcal infections. Complications may develop despite administration of adequate antibiotics. The authors summarize the epidemiology of pneumococcal infections, pathogenesis of non-invasive and invasive disease and present basic clinical aspects through demonstration of four cases. Early risk stratification, sampling of hemocultures, administration of antibiotics and wider application of active immunization could reduce the mortality of invasive disease. Anti-pneumococcal vaccination is advisable for adults of ≥50 years and high risk patients of ≥18 years who are susceptible to pneumococcal disease.

  2. Nontypeable Streptococcus pneumoniae as an Otopathogen

    Xu, Qingfu; Kaur, Ravinder; Casey, Janet R.; Sabharwal, Vishakha; Pelton, Stephen; Pichichero, Michael E.

    2014-01-01

    Among 34 Spn sequential isolates from middle ear fluid we found a case of a nontypeable Streptococcus pneumoniae (NT-Spn) in a child with AOM. The strain was pneumolysin PCR positive and capsule gene PCR negative. Virulence of the NT-Spn was confirmed in a chinchilla model of AOM. PMID:21251566

  3. NEW VIRULENCE FACTORS OF STREPTOCOCCUS PNEUMONIAE

    Hermans, Peter Wilhelmus Maria; Bootsma, Jeanette Hester; Burghout, Pieter Jan; Kuipers, Oscar; Bijlsma, Johanna Jacoba Elisabeth; Kloosterman, Tomas Gerrit; Andersen, Christian O.

    2011-01-01

    The present invention provides proteins/genes, which are essential for survival, and consequently, for virulence of Streptococcus pneumoniae in vivo, and thus are ideal vaccine candidates for a vaccine preparation against pneumococcal infection. Further, also antibodies against said protein(s) are i

  4. How Does Streptococcus pneumoniae Invade the Brain?

    Iovino, Federico; Seinen, Jolien; Henriques-Normark, Birgitta; van Dijl, Jan Maarten

    2016-01-01

    Streptococcus pneumoniae (the pneumococcus) is the major cause of bacterial meningitis. The mechanisms by which pneumococci from the bloodstream penetrate the blood-brain barrier to reach the brain are not fully understood. Receptor-mediated adhesion of the bacteria to the brain endothelium is consi

  5. NEW VIRULENCE FACTORS OF STREPTOCOCCUS PNEUMONIAE.

    Bootsma, Jeanette Hester; Burghout, Pieter Jan; Hermans, Peter Wilhelmus Maria; Bijlsma, Johanna; Kuipers, Oscar; Kloosterman, Tomas Gerrit

    2012-01-01

    The present invention provides proteins/genes, which are essential for survival, and consequently, for virulence of Streptococcus pneumoniae in vivo, and thus are ideal vaccine candidates for a vaccine preparation against pneumococcal infection. Further, also antibodies against said protein(s) are i

  6. Dyrkningsnegativ Streptococcus pneumoniae endokarditis diagnosticeret med polymerasekaedereaktion

    Rasmussen, Rasmus Vedby; Kemp, Michael; Bangsborg, Jette Marie

    2008-01-01

    A 60-year old man was admitted with sepsis and meningitis of unknown aetiology. Underlying aortic valve endocarditis was diagnosed by echocardiography and severe insufficiency led to aortic valve replacement. Application of broad-range PCR to cusp tissue revealed a DNA product, and a diagnosis of...... of Streptococcus pneumoniae endocarditis was obtained by DNA sequencing....

  7. Streptococcus pneumoniae and the host cell

    Gradstedt, Per Henrik

    2012-01-01

    Streptococcus pneumoniae is een bacterie die in de menselijke keel-neusholte voorkomt. Vaak is zij ongevaarlijk, maar soms kan zij van leefomgeving veranderen en zich als invasieve ziekteverwekker door het lichaam verspreiden. Dan kan de bacterie longontsteking, bloedvergiftiging of hersenvliesontst

  8. Streptococcus pneumoniae: sensibilidade a penicilina e moxifloxacina

    Rossi, Flávia; Franco, Maria Renata Gomes; Rodrigues,Heleni Mota de Pina; Andreazzi,Denise

    2012-01-01

    OBJETIVO: Determinar a concentração inibitória mínima (CIM) de penicilina parenteral e moxifloxacina contra cepas de Streptococcus pneumoniae isoladas em um centro hospitalar. Métodos: Estudo in vitro prospectivo de 100 isolados de S. pneumoniae coletados de pacientes tratados entre outubro de 2008 e julho de 2010 no complexo do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, em São Paulo (SP). Os isolados foram obtidos de culturas do trato respiratório e de amost...

  9. Clinical implications and treatment of multiresistant Streptococcus pneumoniae pneumonia.

    File, T M

    2006-05-01

    Streptococcus pneumoniae is the leading bacterial cause of community-acquired respiratory tract infections. Prior to the 1970s this pathogen was uniformly susceptible to penicillin and most other antimicrobials. However, since the 1990s there has been a significant increase in drug-resistant Streptococcus pneumoniae (DRSP) due, in large part, to increased use of antimicrobials. The clinical significance of this resistance is not definitely established, but appears to be most relevant to specific MICs for specific antimicrobials. Certain beta-lactams (amoxicillin, cefotaxime, ceftriaxone), the respiratory fluoroquinolones, and telithromycin are among several agents that remain effective against DRSP. Continued surveillance studies, appropriate antimicrobial usage campaigns, stratification of patients based on known risk factors for resistance, and vaccination programmes are needed to appropriately manage DRSP and limit its spread.

  10. Granzyme A impairs host defense during Streptococcus pneumoniae pneumonia.

    van den Boogaard, Florry E; van Gisbergen, Klaas P J M; Vernooy, Juanita H; Medema, Jan P; Roelofs, Joris J T H; van Zoelen, Marieke A D; Endeman, Henrik; Biesma, Douwe H; Boon, Louis; Van't Veer, Cornelis; de Vos, Alex F; van der Poll, Tom

    2016-08-01

    Streptococcus pneumoniae is the most common causative pathogen in community-acquired pneumonia (CAP). Granzyme A (GzmA) is a serine protease produced by a variety of cell types involved in the immune response. We sought to determine the role of GzmA on the host response during pneumococcal pneumonia. GzmA was measured in bronchoalveolar lavage fluid (BALF) harvested from CAP patients from the infected and contralateral uninfected side and in lung tissue slides from CAP patients and controls. In CAP patients, GzmA levels were increased in BALF obtained from the infected lung. Human lungs showed constitutive GzmA expression by both parenchymal and nonparenchymal cells. In an experimental setting, pneumonia was induced in wild-type (WT) and GzmA-deficient (GzmA(-/-)) mice by intranasal inoculation of S. pneumoniae In separate experiments, WT and GzmA(-/-) mice were treated with natural killer (NK) cell depleting antibodies. Upon infection with S. pneumoniae, GzmA(-/-) mice showed a better survival and lower bacterial counts in BALF and distant body sites compared with WT mice. Although NK cells showed strong GzmA expression, NK cell depletion did not influence bacterial loads in either WT or GzmA(-/-) mice. These results implicate that GzmA plays an unfavorable role in host defense during pneumococcal pneumonia by a mechanism that does not depend on NK cells.

  11. How Does Streptococcus pneumoniae Invade the Brain?

    Iovino, Federico; Seinen, Jolien; Henriques-Normark, Birgitta; van Dijl, Jan Maarten

    2016-04-01

    Streptococcus pneumoniae (the pneumococcus) is the major cause of bacterial meningitis. The mechanisms by which pneumococci from the bloodstream penetrate the blood-brain barrier to reach the brain are not fully understood. Receptor-mediated adhesion of the bacteria to the brain endothelium is considered a key event leading to meningitis development. The aim of this review is to discuss recent advances and perspectives related to the interactions of S. pneumoniae with the blood-brain barrier during the events leading to meningitis. Altogether, the available data suggest that, by precisely defining the pathways and ligands by which S. pneumoniae adheres to specific receptors, it may be possible to interfere with the respective mechanisms and develop strategies to prevent or even cure pneumococcal meningitis.

  12. Penicillin resistance and serotyping of Streptococcus pneumoniae in Latin America.

    Camargos, Paulo; Fischer, Gilberto Bueno; Mocelin, Helena; Dias, Cícero; Ruvinsky, Raúl

    2006-09-01

    Streptococcus pneumoniae (Strep. pneumoniae) is the main cause of bacterial pneumonia in children less than 5 years of age, with high mortality rates in developing countries. In 1993, the Regional System for Vaccines Group (SIREVA) of the pan-American Health Organisation (PAHO) began a study involving six Latin American countries to identify serotypes and their representativity in the new conjugated vaccines, and to determine the degree of resistance to penicillin. Serotypes 14 (highest resistance level), 5, 1, 6A/B, 23F, 7F, 9V, 19F, 18C, 19A, 9N, were prevalent in the region, with some differences among countries. Although resistance to penicillin ranged from 2% (Brazil) to 21.1% (Mexico), studies have shown that pneumonia caused by Strep. pneumoniae with diminished sensitivity to penillin can be treated with this antibiotic. Only 58% of the serotypes isolated in the region studied were represented in the seven-valent vaccine. Continual surveillance is essential to determine which formulation of conjugated vaccine will be suitable for use in Latin America.

  13. Acute Mastoiditis Caused by Streptococcus pneumoniae.

    Obringer, Emily; Chen, Judy L

    2016-05-01

    Acute mastoiditis (AM) is a relatively rare complication of acute otitis media (AOM). The most common pathogens include Streptococcus pneumoniae, Streptococcus pyogenes, and Staphylococcus aureus. Pneumococcal vaccination and changes in antibiotic prescribing recommendations for AOM may change the incidence of AM in the future. Diagnosis of AM can be made based on clinical presentation, but computed tomography of the temporal bone with contrast should be considered if there is concern for complicated AM. Both extracranial and intracranial complications of AM may occur. Previously, routine cortical mastoidectomy was recommended for AM treatment, but new data suggest that a more conservative treatment approach can be considered, including intravenous (IV) antibiotics alone or IV antibiotics with myringotomy. [Pediatr Ann. 2016;45(5):e176-e179.].

  14. Streptococcus pneumoniae: sensibilidade a penicilina e moxifloxacina Streptococcus pneumoniae: susceptibility to penicillin and moxifloxacin

    Flávia Rossi; Maria Renata Gomes Franco; Heleni Mota de Pina Rodrigues; Denise Andreazzi

    2012-01-01

    OBJETIVO: Determinar a concentração inibitória mínima (CIM) de penicilina parenteral e moxifloxacina contra cepas de Streptococcus pneumoniae isoladas em um centro hospitalar. Métodos: Estudo in vitro prospectivo de 100 isolados de S. pneumoniae coletados de pacientes tratados entre outubro de 2008 e julho de 2010 no complexo do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, em São Paulo (SP). Os isolados foram obtidos de culturas do trato respiratório e de amost...

  15. Streptococcus pneumoniae necrotizing fasciitis in systemic lupus erythematosus.

    Sánchez, A; Robaina, R; Pérez, G; Cairoli, E

    2016-04-01

    Necrotizing fasciitis is a rapidly progressive destructive soft tissue infection with high mortality. Streptococcus pneumoniae as etiologic agent of necrotizing fasciitis is extremely unusual. The increased susceptibility to Streptococcus pneumoniae infection in patients with systemic lupus erythematosus is probably a multifactorial phenomenon. We report a case of a patient, a 36-year-old Caucasian female with 8-year history of systemic lupus erythematosus who presented a fatal Streptococcus pneumoniae necrotizing fasciitis. The role of computed tomography and the high performance of blood cultures for isolation of the causative microorganism are emphasized. Once diagnosis is suspected, empiric antibiotic treatment must be prescribed and prompt surgical exploration is mandatory.

  16. Purpura Fulminans Secondary to Streptococcus pneumoniae Meningitis

    Erick F. Alvarez

    2012-01-01

    Full Text Available Purpura fulminans (PF is a rare skin disorder with extensive areas of blueblack hemorrhagic necrosis. Patients manifest typical laboratory signs of disseminated intravascular coagulation (DIC. Our case describes a 37-year-old previously healthy man who presented with 3 days of generalized malaise, headache, vomiting, photophobia, and an ecchymotic skin rash. Initial laboratory workup revealed DIC without obvious infectious trigger including unremarkable cerebrospinal fluid (CSF biochemical analysis. There was further progression of the skin ecchymosis and multiorgan damage consistent with PF. Final CSF cultures revealed Streptococcus pneumoniae. Despite normal initial CSF biochemical analysis, bacterial meningitis should always be considered in patients with otherwise unexplained DIC as this may be an early manifestation of infection. PF is a clinical diagnosis that requires early recognition and prompt empirical treatment, especially, in patients with progressive altered mental status, ecchymotic skin rash, and DIC.

  17. Differential protein expression in phenotypic variants of Streptococcus pneumoniae

    K. Overweg (Karin); C.D. Pericone; G.G. Verhoef; J.N. Weiser; H.D. Meiring; A.P. de Jong; R. de Groot (Ronald); P.W.M. Hermans (Peter)

    2000-01-01

    textabstractStreptococcus pneumoniae undergoes spontaneous phase variation resulting in opaque and transparent colony forms. Differences in colony opacity correlate with differences in virulence: the transparent variants are more capable of colonizing the nasopharynx, w

  18. Interactions between Streptococcus pneumoniae and the human host

    Mens, S.P. van

    2014-01-01

    Streptococcus pneumoniae, the pneumococcus, is an important human pathogen causing considerable morbidity and mortality worldwide. This thesis addresses several interactions between pneumococcus and man. The first part of the thesis deals with the host immune response against pneumococci. We studied

  19. Case Report of Necrotizing Fasciitis Associated with Streptococcus pneumoniae

    Lei Jiao

    2016-01-01

    Full Text Available Necrotizing fasciitis, caused by Streptococcus pneumoniae, is an extremely rare and life-threatening bacterial soft tissue infection. We report a case of early necrotizing fasciitis associated with Streptococcus pneumoniae infection in a 26-year-old man who was immunocompromised with mixed connective tissue disease. The patient presented with acute, painful, erythematous, and edematous skin lesions of his right lower back, which rapidly progressed to the right knee. The patient underwent surgical exploration, and a diagnosis of necrotizing fasciitis was confirmed by pathological evidence of necrosis of the fascia and neutrophil infiltration in tissue biopsies. Cultures of fascial tissue biopsies and blood samples were positive for Streptococcus pneumoniae. To our knowledge, this is the first report of necrotizing fasciitis resulting from Streptococcus pneumoniae diagnosed at early phase; the patient recovered well without surgical debridement.

  20. STREPTOCOCCUS PNEUMONIAE KERATITIS FOLLOWING LASER IN SITU KERATOMILEUSIS

    2011-01-01

    A 22-year-old man underwent bilateral laser in situ keratomileusis and developed Streptococcus pneumoniae keratitis after surgery.This complication occurred one day after the procedure in both eyes.Topical and systemic antibiotics were promptly administered.Bacterial culture was performed following corneal flap lift and scraping of the lesions.Afterwards,the therapeutic regimen was readjusted according to the culture results.Streptococcus pneumoniae was identified from the culture.Three months after the sur...

  1. Exogenous Streptococcus pneumoniae Endophthalmitis in Diabetic Rabbits

    Benton, Angela H.; Fulton, Linda K.; Marquart, Mary E.

    2017-01-01

    Diabetics are at increased risk for eye infections including bacterial endophthalmitis. It is unclear whether the severity of endophthalmitis is greater in these patients due to confounding factors such as pre-existing ocular diseases in some but not others. Therefore, we tested the hypothesis that disease severity and/or bacterial loads would be significantly higher in a Type I diabetic rabbit model of Streptococcus pneumoniae endophthalmitis. Rabbits were treated with alloxan to destroy pancreatic islet cells, or mock-treated with vehicle, and maintained for 10 days before intravitreal infection with S. pneumoniae E353. Clinical scoring of the eyes was performed 24 and 48 hours after infection, followed by euthanasia and vitreous harvest to quantitate bacterial loads. There were no significant differences in clinical scores (P ≥ 0.440) or bacterial loads (P = 0.736), however, 4/12 (33%) of the diabetic rabbits became bacteremic. This finding not only indicates a breakdown in the blood-ocular barrier, but also prompts further investigation into the exploitation of the diabetic eye by the streptococci. PMID:28387365

  2. Influenza Alone and in Sequence with Pneumonia Due to ’Streptococcus pneumoniae’ in the Squirrel Monkey

    1975-03-28

    rights reserved. . . . . t Influenza Alone and In Sequence with Pneumonia Due to-, Streptococcus pneumoniae in the Squirrel Monkey VI / !.llendt, G.G...rhesus drome of sequential respiratory infections. monkeys with the virus alone or in sequence with Streptococcus pneumoniae I1 l. Since that report...were also BC 0 0 observed in the glomeruli of the kidney. S 0 1027 S. pneumoniae-induced pathology. The results Streptococcus pneumoniae obtained in

  3. Diagnostic detection of Streptococcus pneumoniae PpmA in urine.

    Garcia-Suarez, M.M.; Cron, L.E.; Suarez-Alvarez, B.; Villaverde, R.; Gonzalez-Rodriguez, I.; Vazquez, F.; Hermans, P.W.M.; Mendez, F.J.

    2009-01-01

    Streptococcus pneumoniae infections are often difficult to diagnose accurately, as it is not uncommon for clinical samples to be culture-negative, particularly after antibiotic administration. The rapid Binax NOW S. pneumoniae urinary antigen test lacks specificity in children, owing to pneumococcal

  4. Host-pathogen interaction during Streptococcus pneumoniae colonization and infection

    D. Bogaert (Debby)

    2004-01-01

    markdownabstract__Abstract__ Streptococcus pneumoniae was discovered by Sternberg and Pasteur in 1880. It took another six years to discover that this microorganism, called the pneumococcus, was the actual cause of bacterial pneumonia . Subsequently, this bacterium has been shown to provoke an impr

  5. Defined neoglycoproteins as candidate vaccines against Streptococcus pneumoniae type 3

    Lefeber, Dirk Jaap

    2002-01-01

    Several bacteria that are surrounded by a polysaccharide coat can cause severe diseases like meningitis, pneumonia and otitis media, especially in young children. Against the bacterium Streptococcus pneumoniae, a polysaccharide vaccine exists. However, it does not effectively protect high-risk group

  6. Evolution of Streptococcus pneumoniae and its close commensal relatives

    Kilian, Mogens; Poulsen, Knud; Blomqvist, Trinelise

    2008-01-01

    Streptococcus pneumoniae is a member of the Mitis group of streptococci which, according to 16S rRNA-sequence based phylogenetic reconstruction, includes 12 species. While other species of this group are considered prototypes of commensal bacteria, S. pneumoniae is among the most frequent microbial...... killers worldwide. Population genetic analysis of 118 strains, supported by demonstration of a distinct cell wall carbohydrate structure and competence pheromone sequence signature, shows that S. pneumoniae is one of several hundred evolutionary lineages forming a cluster separate from Streptococcus...... oralis and Streptococcus infantis. The remaining lineages of this distinct cluster are commensals previously collectively referred to as Streptococcus mitis and each represent separate species by traditional taxonomic standard. Virulence genes including the operon for capsule polysaccharide synthesis...

  7. Absence of Streptococcus pneumoniae in pharyngeal swabs of geriatric inpatients.

    Jomrich, Nina; Kellner, Silvia; Djukic, Marija; Eiffert, Helmut; Nau, Roland

    2015-07-01

    Colonization of the pharynx by Streptococcus pneumoniae was studied in 185 in-hospital geriatric patients (median age 81 years) from 29 March 2011 to 22 June 2011. Swabs were plated on blood agar plates. Colonies with a morphology suggesting S. pneumoniae were further analyzed. Surprisingly, pneumococci were not found in any of the samples. Pneumococci chronically colonizing the pharynx of elderly people may be much rarer than previously thought and probably are not the source of pneumococcal pneumonia in old age.

  8. An outbreak of Streptococcus pneumoniae in an Italian nursing home.

    Riccardo Papalia

    2015-09-01

    Full Text Available Streptococcus pneumoniae is the main cause of community-acquired pneumonia worldwide; pneumonia occurs sporadically in most cases, but rare outbreaks have been reported. We  describe an outbreak occurred in a 21-guests nursing home for elders in Aosta (Italy; outbreak occurred in april 2014 over a 2 weeks period, resulting in 12 out 20 guests affected (all with high fever and respiratory symptoms, two deaths (at home, nine patients referred  to Hospital Emergency Room, and eight admissions. Urinary streptococcus antigen was positive in seven out of eight patient tested. None of the nursing home guests were vaccinated against Streptococcus pneumoniaeThe Hospital Medical Direction and Public Health Service gave support and adopted strategies to contain the outbreak spread.We underline the need for pneumococcal vaccination in nursing homes/ Long-term care facilities; accurate check of hygiene behaviours in those setting is also mandatory.   

  9. Streptococcus pneumoniae: sensibilidade a penicilina e moxifloxacina Streptococcus pneumoniae: susceptibility to penicillin and moxifloxacin

    Flávia Rossi

    2012-02-01

    Full Text Available OBJETIVO: Determinar a concentração inibitória mínima (CIM de penicilina parenteral e moxifloxacina contra cepas de Streptococcus pneumoniae isoladas em um centro hospitalar. Métodos: Estudo in vitro prospectivo de 100 isolados de S. pneumoniae coletados de pacientes tratados entre outubro de 2008 e julho de 2010 no complexo do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, em São Paulo (SP. Os isolados foram obtidos de culturas do trato respiratório e de amostras de sangue não relacionadas a infecções meníngeas e foram testados quanto à suscetibilidade a penicilina e moxifloxacina por E test. As interpretações categóricas de CIM foram baseadas em padrões atualizados. RESULTADOS: Todos os isolados foram suscetíveis a penicilina parenteral (CIM OBJECTIVE: To determine the minimum inhibitory concentrations (MICs of parenteral penicillin and moxifloxacin against Streptococcus pneumoniae strains isolated at a hospital center. METHODS: In-vitro, prospective study involving 100 S. pneumoniae isolates collected from patients who had been treated, between October of 2008 and July of 2010, at the Hospital das Clínicas complex of the University of São Paulo School of Medicine, located in the city of São Paulo, Brazil. The isolates were obtained from respiratory tract cultures or blood samples unrelated to meningeal infections, and they were tested for penicillin and moxifloxacin susceptibility by E-test. The MIC category interpretations were based on updated standards. RESULTS: All isolates were fully susceptible to parenteral penicillin (MIC < 2 µg/mL, and, consequently, they were also susceptible to amoxicillin, ampicillin, third/fourth generation cephalosporins, and ertapenem. Of the S. pneumoniae strains, 99% were also susceptible to moxifloxacin, and only one strain showed an MIC = 1.5 µg/mL (intermediate. CONCLUSIONS: Our results showed high susceptibility rates to parenteral penicillin and

  10. MALDI-TOF mass spectrometry for differentiation between Streptococcus pneumoniae and Streptococcus pseudopneumoniae.

    van Prehn, Joffrey; van Veen, Suzanne Q; Schelfaut, Jacqueline J G; Wessels, Els

    2016-05-01

    We compared the Vitek MS and Microflex MALDI-TOF mass spectrometry platform for species differentiation within the Streptococcus mitis group with PCR assays targeted at lytA, Spn9802, and recA as reference standard. The Vitek MS correctly identified 10/11 Streptococcus pneumoniae, 13/13 Streptococcus pseudopneumoniae, and 12/13 S. mitis/oralis. The Microflex correctly identified 9/11 S. pneumoniae, 0/13 S. pseudopneumoniae, and 13/13 S. mitis/oralis. MALDI-TOF is a powerful tool for species determination within the mitis group. Diagnostic accuracy varies depending on platform and database used.

  11. 77 FR 26014 - Prospective Grant of Exclusive License: P4 Peptide From Streptococcus Pneumoniae

    2012-05-02

    ... Prospective Grant of Exclusive License: P4 Peptide From Streptococcus Pneumoniae AGENCY: Technology Transfer... ``Functional Epitopes of Streptococcus Pneumoniae PsaA Antigen and Uses Thereof,'' filed 7/ 18/2008, claiming... Streptococcus pneumoniae. This technology also includes an antibody that can bind to the epitopes of the...

  12. Relationship Between the Inoculum Dose of Streptococcus pneumoniae and Pneumonia Onset in a Rabbit Model

    2005-04-01

    White rabbits (mean + or - SD + or - 4.75 + or - 0.25 kg (n = 27)). Rabbits were endobronchially inoculated with increasing doses of Streptococcus ... pneumoniae and pneumonia onset was observed over the following 96 h. The diagnostic approach was based on the Clinical Pulmonary Infection Score

  13. First report of an outbreak of pneumonia caused by Streptococcus pneumoniae serotype 6A.

    Prebil, Karla; Beović, Bojana; Paragi, Metka; Seme, Katja; Kastrin, Tamara; Plesničar, Blanka Kores; Petek, Bojana; Martinčič, Žiga

    2016-01-01

    Five patients in a geropsychiatric unit of a psychiatric hospital became abruptly ill with pneumonia caused by Streptococcus pneumoniae serotype 6A. Four other residents were colonized with the same serotype, which has previously not been reported in association with pneumonia outbreaks. Furthermore, serotype 6A is not included in all vaccine types, which may be important for the choice of vaccine in some settings. All isolates showed identical pulsed-field gel electrophoresis restriction patterns.

  14. Nonencapsulated Streptococcus pneumoniae resists extracellular human neutrophil elastase- and cathepsin G-mediated killing

    Windt, D. van der; Bootsma, H.J.; Burghout, P.; Gaast-de Jongh, C.E. van der; Hermans, P.W.M.; Flier, M. van der

    2012-01-01

    Although the Streptococcus pneumoniae polysaccharide capsule is an important virulence factor, ~ 15% of carriage isolates are nonencapsulated. Nonencapsulated S. pneumoniae are a cause of mucosal infections. Recent studies have shown that neutrophils kill S. pneumoniae predominately through neutroph

  15. Outbreak of Streptococcus pneumoniae in a Psychiatric Unit

    2012-11-02

    Dr. Katherine Fleming-Dutra, an epidemiologist at CDC, discusses her investigation of a Streptococcus pneumoniae outbreak in a pediatric psychiatric unit.  Created: 11/2/2012 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID); National Center for Immunization and Respiratory Diseases (NCIRD).   Date Released: 11/5/2012.

  16. Sensibilidad antibiótica y recomendaciones de tratamiento para Streptococcus pneumoniae Antibiotic sensitivity and treatment recommendations for Streptococcus pneumoniae

    A. Gil-Setas

    2004-04-01

    Full Text Available El objetivo del presente trabajo fue conocer la sensibilidad antibiótica de Streptococcus pneumoniae a los antimicrobianos usados con más frecuencia en la práctica clínica y revisar las recomendaciones actuales de tratamiento de la enfermedad neumocócica. Durante el periodo octubre 2000 a septiembre 2002 se recogieron los datos demográficos, el diagnóstico clínico del paciente, el origen de la muestra y la sensibilidad antibiótica de todos los Streptococcus pneumoniae aislados en los laboratorios de microbiología del Servicio Navarro de Salud, que atienden a una población de 555.829 habitantes. Se obtuvieron 465 aislamientos de Streptococcus pneumoniae (166 de origen invasor. Los aislamientos procedentes de exudado ótico fueron los más resistentes y los de hemocultivo los más sensibles. El porcentaje de resistencia a penicilina fue del 43%, 6,1% para amoxicilina y 6,6% para cefotaxima. El 36,3% de los aislamientos fueron resistentes a eritromicina, de ellos un 85,45% exhibía un fenotipo MLS B y un 14,55% un fenotipo M. Se detectó multirresistencia en un 32,3% de los aislamientos. La resistencia de Streptococcus pneumoniae a betalactámicos, especialmente penicilina, amoxicilina y cefotaxima/ceftriaxona no impide su uso clínico en la mayoría de los aislamientos de Streptococcus pneumoniae de nuestra área, exceptuando los casos de meningitis neumocócica.The aims of present paper were to determine the susceptibility of the strains to the most usual antibiotics in clinical practice and to review the current recomendations to guide the most appropiate treatment. During the period october 2000 to september 2002, the patient’s data (age and sex, source of the sample, diagnosis and antibiotic susceptibility were collected on Streptococcus pneumoniae isolates from microbiology laboratories in the Navarra region (555.829 inhabitans. Four hundred and sixty five isolates were identified (166 from invasive infections. Generally

  17. Clinical behavior of Streptococcus pneumoniae meningoencephalitis Comportamiento clinico y terapéutico de la meningoencefalitis por Streptococcus pneumoniae

    Raisa Bu-Coifiu Fanego

    2009-12-01

    Full Text Available OBJECTIVE: There was an increased number of cases of meningoencephalitis caused by Streptococcus pneumoniae, after the successful vaccination campaigns against Neisseria meningitidis and Haemophilus influenzae. This paper aims at describing the clinical characteristics, the laboratory findings, the complications, and the therapeutic management of these patients, who have been suffering from this disease since 1993 to 2006. METHOD: Twelve children with Streptococcus pneumoniae meningoencephalitis admitted to the pediatric hospital of San Miguel del Padron, City of Havana in this period were assessed. RESULTS: Children under one year are the most frequently affected. Septic shock and brain edema were the most severe complications. Three patients died, implying that this disease has a serious course. Early treatment of brain edema is very important to reduce mortality. The elective drugs for treatment of these cases of Streptococcus pneumoniae meningoencephalitis were vancomycin combined with cephalosporin, cefotaxime or ceftriaxone type. CONCLUSION: Patients with Streptococcus pneumoniae meningoencephalitis show clinical characteristics, complications, and sequels that are different to other bacterial meningoencephalitis, meaning that they could be helpful for physicians considering the differential diagnosis of meningoencephalitis.OBJETIVO: Existe un incremento de la meningoencefalitis producida por Streptococcus pneumoniae, después de las campañas exitosas de vacunación contra Neisseria meningitidis y Haemophilus influenzae. El objetivo de este trabajo es describir las caracteristicas clinicas, los hallazgos de laboratorio, las complicaciones y el manejo terapéutico de los pacientes que sufrieron esta enfermedad desde 1993 a 2006. MÉTODO: Se estudiaron doce niños con meningoencefalitis por Streptococcus pneumoniae ingresados en el Hospital Pediátrico de San Miguel del Padrón, Ciudad de La Habana en este periodo. RESULTADOS: Los ni

  18. Draft Genome Sequences of Streptococcus pneumoniae with High-Level Resistance to Respiratory Fluoroquinolones

    Keness, Yoram; Bisharat, Naiel

    2016-01-01

    Streptococcus pneumoniae is the leading cause of community-acquired pneumonia. Levofloxacin is a fluoroquinolone used for treatment of severe community-acquired pneumonia. Here, we describe the draft genome sequences of S. pneumoniae with emerging resistance to levofloxacin, resulting in failure of treatment of pneumococcal pneumonia.

  19. Pneumonia

    ... of pneumonia. Be sure to get the following vaccines: Flu vaccine can help prevent pneumonia caused by the flu virus. Pneumococcal vaccine lowers your chances of getting pneumonia from Streptococcus ...

  20. Nasopharyngeal carriage of Streptococcus pneumonia in pneumonia-prone age groups in Semarang, Java Island, Indonesia.

    Helmia Farida

    Full Text Available INTRODUCTION: Streptococcus pneumoniae is a worldwide occurring pathogen Nasopharyngeal carriage of Streptococcus pneumoniae precedes pneumonia and other pneumococcal diseases in the community. Little is known about S. pneumoniae carriage in Indonesia, complicating strategies to control pneumococcal diseases. We investigated nasopharyngeal carriage of S. pneumoniae in Semarang, Indonesia. METHODS: A population-based survey was performed in Semarang, Indonesia. Nasopharyngeal swabs and questionnaires were taken from 496 healthy young (6-60 month-old children and 45-70 year-old adults. RESULTS: Forty-three percent of children aged 6-60 months and 11% of adults aged 45-75 years carried S. pneumoniae. Determinants of carriage were being a child (OR 7.7; 95% CI = 4.5-13.0, passive smoking (OR 2.1; 95% CI = 1.3-3.4, and contact with toddler(s at home (OR 3.0; 95% CI = 1.9-4.7. The most frequent serotypes found were 6A/B and 15B/C. The current commercially available vaccines cover <50% serotypes found in children. Twenty-four percent of S. pneumoniae strains were penicillin non-susceptible, and 45% were resistant to cotrimoxazol. CONCLUSIONS: The limited coverage of commercially available vaccines against the serotypes found in this population, and the high proportion of non-susceptibility to penicillin and cotrimoxazol suggest the need for region-specific information and strategies to control S. pneumoniae.

  1. Copper intoxication inhibits aerobic nucleotide synthesis in Streptococcus pneumoniae

    Johnson, Michael D. L.; Kehl-Fie, Thomas E.; Rosch, Jason W.

    2015-01-01

    Copper is universally toxic in excess, a feature exploited by the human immune system to facilitate bacterial clearance. The mechanism of copper intoxication remains unknown for many bacterial species. Here, we demonstrate that copper toxicity in Streptococcus pneumoniae is independent from oxidative stress but, rather, is the result of copper inhibiting the aerobic dNTP biosynthetic pathway. Furthermore, we show that copper-intoxicated S. pneumoniae is rescued by manganese, which is an essential metal in the aerobic nucleotide synthesis pathway. These data provide insight into new targets to enhance copper-mediated toxicity during bacterial clearance. PMID:25730343

  2. Disseminated Streptococcus pneumoniae infection involving a ventricular assist device.

    Reeves, J S; Rajagopalan, N; Huaman, M A

    2015-08-01

    We describe the first reported case, to our knowledge, of disseminated pneumococcal infection involving a left ventricular assist device (LVAD). The management of this infection was extremely challenging, requiring multiple surgical debridements, LVAD removal, and prolonged courses of antibiotics. The Streptococcus pneumoniae isolate was found to be serotype 19F, which is included in both the pneumococcal polysaccharide and conjugate vaccines. This report highlights the importance of routine screening for up-to-date vaccination in patients who undergo LVAD implantation.

  3. Structure of a conjugative element in Streptococcus pneumoniae

    Vijayakumar, M.N.; Priebe, S.D.; Guild, W.R.

    1986-06-01

    The authors have cloned and mapped a 69-kilobase (kb) region of the chromosome of Streptococcus pneumoniae DP1322, which carries the conjugative Omega(cat-tet) insertion from S. pneumoniae BM6001. This element proved to be 65.5 kb in size. Location of the junctions was facilitated by cloning a preferred target region from the wild-type strain Rx1 recipient genome. This target site was preferred by both the BM6001 element and the cat-erm-tet element from Streptococcus agalactiae B109. Within the BM6001 element cat and tet were separated by 30 kb, and cat was flanked by two copies of a sequence that was also present in the recipient strain Rx1 DNA. Another sequence at least 2.4 kb in size was found inside the BM6001 element and at two places in the Rx1 genome. Its role is unknown. The ends of the BM6001 element appear to be the same as those of the B109 element, both as seen after transfer to S. pneumoniae and as mapped by others in pDP5 after transposition in Streptococcus faecalis. No homology is seen between the ends of the BM6001 element and no evidence found suggesting that it ever circularizes.

  4. Activity of Vancomycin, Teicoplanin and Cephalosporins against Penicillin-Susceptible and Penicillin-Intermediate Streptococcus Pneumoniae

    Vivian G Loo

    1995-01-01

    Full Text Available Objective: To report in vitro susceptibilities of penicillin-susceptible and penicillin-intermediate Streptococcus pneumoniae isolates to cephalosporins, vancomycin and teicoplanin.

  5. Trends of penicillin and erythromycin resistance among invasive Streptococcus pneumoniae in Europe

    Bruinsma, N; Kristinsson, KG; Bronzwaer, S; Schrijnemakers, P; Degener, J; Tiemersma, E; Hryniewicz, W; Monen, J; Grundmann, H

    2004-01-01

    Objectives: To forecast trends in resistance to penicillin and erythromycin among Streptococcus pneumoniae in Europe. Methods: Since 1999, the European Antimicrobial Resistance Surveillance System (EARSS) has collected routine antimicrobial susceptibility test results of S. pneumoniae. To observe an

  6. Gatifloxacin used for therapy of outpatient community-acquired pneumonia caused by Streptococcus pneumoniae.

    Jones, Ronald N; Andes, David R; Mandell, Lionel A; Gothelf, Samantha; Ehrhardt, Anton F; Nicholson, Susan C

    2002-09-01

    Gatifloxacin is an advanced-generation fluoroquinolone with demonstrated efficacy and safety as therapy for community-acquired pneumonia (CAP). As part of a phase IV postmarketing surveillance program (TeqCES), 136 outpatients with CAP whose sputum was culture-positive for Streptococcus pneumoniae were enrolled in an open-label trial of oral gatifloxacin 400 mg daily for 7 to 14 days. An antibiogram of isolates showed 100% susceptibility to gatifloxacin (MIC(90) 0.5 micro g/mL) and respective susceptibilities of 67%, 70%, and 80% to penicillin, erythromycin, and tetracycline. Clinical cure was achieved in 95.3% of evaluable patients, including seven patients infected with penicillin-resistant S. pneumoniae (MIC > or =2 micro g/mL). The bacteriologic eradication rate for S. pneumoniae was 94.5%. Diarrhea, nausea, and dizziness, the most common adverse events in CAP patients (pneumoniae including multidrug-resistant strains, with the newer 8-methoxy-fluoroquinolone, gatifloxacin.

  7. Contribution of IL-1 to resistance to Streptococcus pneumoniae infection.

    Kafka, Daniel; Ling, Eduard; Feldman, Galia; Benharroch, Daniel; Voronov, Elena; Givon-Lavi, Noga; Iwakura, Yoichiro; Dagan, Ron; Apte, Ron N; Mizrachi-Nebenzahl, Yaffa

    2008-09-01

    The role of IL-1 in susceptibility to Streptococcus pneumoniae infection was studied in mice deficient in genes of the IL-1 family [i.e. IL-1alpha-/-, IL-1beta-/-, IL-1alpha/beta-/- and IL-1R antagonist (IL-1Ra)-/- mice] following intra-nasal inoculation. Intra-nasal inoculation of S. pneumoniae of IL-1beta-/- and IL-1alpha/beta-/- mice displayed significantly lower survival rates and higher nasopharyngeal and lung bacterial load as compared with control, IL-1alpha-/- and IL-1Ra-/- mice. Treatment of IL-1beta-/- mice with rIL-1beta significantly improved their survival. A significant increase in blood neutrophils was found in control, IL-1alpha-/- and IL-1Ra-/- but not in IL-1beta-/- and IL-1alpha/beta-/- mice. Local infiltrates of neutrophils and relatively preserved organ architecture were observed in the lungs of IL-1alpha-/- and control mice. However, S. pneumoniae-infected IL-1beta-/-, IL-1alpha/beta-/- and IL-1Ra-/- mice demonstrated diffuse pneumonia and tissue damage. Altogether, all three isoforms contribute to protection against S. pneumoniae; our results point to differential role of IL-1alpha and IL-1beta in the pathogenesis and control of S. pneumoniae infection and suggest that IL-1beta has a major role in resistance to primary pneumococcal infection while the role of IL-1alpha is less important.

  8. Differentiation of Penicillin Susceptible and Nonsusceptible Streptococcus pneumoniae

    Ali Ahmadi

    2015-11-01

    Full Text Available Introduction: Streptococcus pneumoniae cause morbidity and mortality in infants and younger children.   Because of high prevalence of penicillin  resistance, rapid  and  reliable diagnostic techniques for penicillin non-susceptible S. pneumoniae (PNSSP are important for prevention and treatment. We investigated the association of the restriction length polymorphism (RFLP patterns for pbp2b to distinguish between penicillin susceptible and resistant S. pneumoniae isolates.Methods: In this study, a total of 70 pneumococcal isolates were collected from different clinical sources. MIC of these isolates was determined and pbp2b gene was amplified by PCR and they were digested by HaeІІІ enzyme.Results: Of the 70 isolates, 86% (60 and 14% (10 pneumococcal isolates were found to be PNSSP (penicillin intermediate S. pneumoniae (PISP and penicillin resistant S. pneumoniae (PRSP and penicillin susceptible S. pneumoniae (PSSP. In addition, 10 RFLP patterns (A-J which were based on the HaeІІІ digestion of pbp2b gene were observed. All PSSP isolates showed that they belonged to pattern D, whereas, all PNSSP showed 10 different patterns.Conclusion:  In  general,  the  present  study  suggests  that  RFLP  can  be  a  powerful  tool  in differentiation between the penicillin resistant and susceptible strains.

  9. Antibiotic susceptibility in relation to genotype of Streptococcus pneumoniae, Haemophilus influenzae, and Mycoplasma pneumoniae responsible for community-acquired pneumonia in children.

    Morozumi, Miyuki; Chiba, Naoko; Okada, Takafumi; Sakata, Hiroshi; Matsubara, Keita; Iwata, Satoshi; Ubukata, Kimiko

    2013-06-01

    Streptococcus pneumoniae, Haemophilus influenzae, and Mycoplasma pneumoniae are the main pathogens causing community-acquired pneumonia (CAP). We identified S. pneumoniae (n = 241), H. influenzae (n = 123), and M. pneumoniae (n = 54) as causative pathogens from clinical findings and blood tests from pediatric CAP patients (n = 903) between April 2008 and April 2009. Identification of genes mediating antimicrobial resistance by real-time PCR was performed for all isolates of these three pathogens, as was antibiotic susceptibility testing using an agar dilution method or broth microdilution method. The genotypic (g) resistance rate was 47.7 % for penicillin-resistant S. pneumoniae (gPRSP) possessing abnormal pbp1a, pbp2x, and pbp2b genes, 62.6 % for β-lactamase-nonproducing, ampicillin-resistant (gBLNAR) H. influenzae possessing the amino acid substitutions Ser385Thr and Asn526Lys, and 44.4 % for macrolide-resistant M. pneumoniae (gMRMP) possessing a mutation of A2063G, A2064G, or C2617A. Serotype 6B (20.3 %) predominated in S. pneumoniae, followed by 19F (15.4 %), 14 (14.5 %), 23F (12.0 %), 19A (6.2 %), and 6C (5.4 %). Coverage for the isolates by heptavalent pneumococcal conjugate vaccine (PCV7) and PCV13, respectively, was calculated as 68.5 and 80.9 %. A small number of H. influenzae were identified as type b (6.5 %), type e (0.8 %), or type f (0.8 %); all others were nontypeable. Proper use of antibiotics based on information about resistance in CAP pathogens is required to control rapid increases in resistance. Epidemiological surveillance of pediatric patients also is needed to assess the effectiveness of PCV7 and Hib vaccines after their introduction in Japan.

  10. Streptococcus pneumoniae carriage in the Gaza strip.

    Gili Regev-Yochay

    Full Text Available BACKGROUND: Pneumococcal infections cause major morbidity and mortality in developing countries. We report the epidemiology of S. pneumoniae carriage in a developing region, the Gaza strip, and evaluate the theoretical coverage of carriage strains by pneumococcal conjugate vaccines (PCVs. METHODOLOGY: In 2009 we conducted a cross-sectional survey of S. pneumoniae carriage in healthy children and their parents, living throughout the Gaza strip. Data were collected and nasopharyngeal swabs were obtained. Antibiotic susceptibilities were determined by Vitek-2 and serotypes by the Quellung reaction. PRINCIPAL FINDINGS: S. pneumoniae carriage was detected in 189/379 (50% of children and 30/376 (8% of parents. Carriage prevalence was highest in children <6 months of age (63%. Significant predictors for child carriage were number of household members and DCC attendance. The proportion of pediatric and adults isolates with serotypes included in PCV7 were 32% and 20% respectively, and 46% and 33% in PCV13 respectively. The most prominent non-vaccine serotypes (NVT were 35B, 15B/C and 23B. Penicillin-nonsusceptible strains were carried by 70% of carriers, penicillin-resistant strains (PRSP by 13% and Multi-drug-resistant (MDR by 30%. Of all PRSP isolates 54% belonged to serotypes included in PCV7 and 71% in the PCV13. Similarly, 59% and 73% of MDR-SP isolates, would theoretically be covered by PCV7 and PCV13, respectively. CONCLUSIONS: This study demonstrates that, PCV13-included strains were carried by 46% and 33% of pediatric and adult subjects respectively. In the absence of definitive data regarding the virulence of the NVT strains, it is difficult to predict the effect of PCVs on IPD in this region.

  11. [Case of severe streptococcus pyogenes pneumonia with streptococcus toxic shock syndrome].

    Izumiyama, Noriko; Miki, Hiroshi; Shishikura, Yutaka; Kawaguchi, Chiharu; Saitou, Wakana; Kikuchi, Tadashi; Kumagai, Katsunori; Sasamori, Kan; Kikuchi, Yoshihiro

    2008-06-01

    A 30-year-old woman who had until recently been healthy, was transferred to our hospital by ambulance with complaints of dyspnea and pain in both lower limbs. She had 1-week history of sore throat, fever and cough. She had been to a neighboring clinic three days previously, and had been prescribed some medication for bronchitis, but her symptoms had not improved. By the time of admission, she was already in shock and had severe respiratory failure. Laboratory data showed renal dysfunction, disseminated intravascular coagulation, CPK elevation and severe metabolic acidosis. Chest x-ray and CT films revealed consolidation of the entire right lung field. The patient was quickly intubated and we began mechanical ventilation. We immediately initiated broad-spectrum antibiotics, immunogloblin, dopamine hydrochloride and gabexate mesilate, but she died 7 hours later. From cultures of blood and sputum taken from the patient, Streptococcus pyogenes was isolated. On the basis of these clinical and bacteriological findings, we confirmed a diagnosis of pneumonia and toxic shock syndrome caused by Streptococcus pyogenes (STSS). Serologically her M protein was serotyped as M1, and with regard to Streptococcal pyrogenic exotoxin genes were identified as speA and speB. These serological findings were consistent with the most frequent type that causes STSS. In spite of the uncommon cause of community-acquired pneumonia, Streptococcus pyogenes can potentially affect healthy individuals. The pneumonia can be complicated with STSS and so the clinical course may be severe and fulminant. The evidence acquired from this case suggests that in the event of severe pneumonia with shock, we should be aware that this may represent the presence of Streptococcus pyogenes and/or toxic shock syndrome.

  12. Capsule Switching and Antimicrobial Resistance Acquired during Repeated Streptococcus pneumoniae Pneumonia Episodes.

    Chang, Bin; Nariai, Akiyoshi; Sekizuka, Tsuyoshi; Akeda, Yukihiro; Kuroda, Makoto; Oishi, Kazunori; Ohnishi, Makoto

    2015-10-01

    Streptococcus pneumoniae colonizes the nasopharyngeal mucus in healthy people and causes otitis media, pneumonia, bacteremia, and meningitis. In this study, we analyzed an S. pneumoniae strain that caused 7 repeated pneumonia episodes in an 80-month-old patient with cerebral palsy during a period of 25 months. A total of 10 S. pneumoniae strains were obtained from sputum samples, and serotype 6B was isolated from samples from the first 5 episodes, whereas serotype 6A was isolated from samples from the last 2. Whole-genome sequencing showed clonality of the 10 isolates with 10 single nucleotide polymorphisms (SNPs) in the genomes. Among these SNPs, one single point mutation in the wciP gene was presumed to relate to the serotype switching from 6B to 6A, and the other mutations in parC and gyrA were related to fluoroquinolone resistance. These results suggested that an S. pneumoniae strain, which asymptomatically colonized the patient's nasopharynx or was horizontally transmitted from an asymptomatic carrier, caused the repeated pneumonia events. Phenotypic variations in the capsule type and antimicrobial susceptibility occurred during the carrier state. Hyporesponsiveness to serotypes 6B and 6A of S. pneumoniae was found even after vaccination with the 7-valent pneumococcal conjugate vaccine and the 23-valent pneumococcal polysaccharide vaccine. After an additional vaccination with the 13-valent pneumococcal conjugate vaccine, opsonic activities for both serotypes 6A and 6B significantly increased and are expected to prevent relapse by the same strain.

  13. Characterization of the inflammatory infiltrate in Streptococcus pneumoniae pneumonia in young and elderly patients.

    Menter, Thomas; Giefing-Kroell, Carmen; Grubeck-Loebenstein, Beatrix; Tzankov, Alexandar

    2014-01-01

    There is an increased susceptibility and mortality in the elderly due to pneumonia caused by Streptococcus pneumoniae. We aimed to assess the inflammatory cell composition with respect to age in pneumococcal pneumonia patients. Neutrophilic granulocytes and various lymphocyte and macrophage subpopulations were immunohistochemically quantified on lung tissue specimens of young (n = 5; mean age 8.4 years), middle-aged (n = 8; mean age 55.9 years) and elderly (n = 9; mean age 86.6 years) pneumonia patients with microbiologically proven S. pneumoniae pneumonia. We discovered a higher percentage of neutrophilic granulocytes in elderly as opposed to young patients (95 vs. 75%, p = 0.012). Conversely, young patients versus elderly patients had more alveolar macrophages (CD11c+: 20 vs. 9%, p = 0.029) and M1 macrophages (CD14+: 30 vs. 10%, p = 0.012 and HLA-DR+: 52 vs. 11%, p = 0.019). There was no significant difference concerning M2 macrophages and lymphocytes. Comparison of young patients with middle-aged patients showed similar significant results for alveolar macrophages (p = 0.019) and subsignificant results for M1 macrophages and neutrophilic granulocytes (p pneumonia in situ. Our observations improve the understanding of the innate immune mechanisms of pneumococcal lung infection and point at the potential of therapies for restoring macrophage function and decreasing neutrophilic influx in order to help prevent or cure pneumonia.

  14. Recombinant expression of Streptococcus pneumoniae capsular polysaccharides in Escherichia coli.

    Kay, Emily J; Yates, Laura E; Terra, Vanessa S; Cuccui, Jon; Wren, Brendan W

    2016-04-01

    Currently, Streptococcus pneumoniae is responsible for over 14 million cases of pneumonia worldwide annually, and over 1 million deaths, the majority of them children. The major determinant for pathogenesis is a polysaccharide capsule that is variable and is used to distinguish strains based on their serotype. The capsule forms the basis of the pneumococcal polysaccharide vaccine (PPV23) that contains purified capsular polysaccharide from 23 serotypes, and the pneumococcal conjugate vaccine (PCV13), containing 13 common serotypes conjugated to CRM197 (mutant diphtheria toxin). Purified capsule from S. pneumoniae is required for pneumococcal conjugate vaccine production, and costs can be prohibitively high, limiting accessibility of the vaccine in low-income countries. In this study, we demonstrate the recombinant expression of the capsule-encoding locus from four different serotypes of S. pneumoniae within Escherichia coli. Furthermore, we attempt to identify the minimum set of genes necessary to reliably and efficiently express these capsules heterologously. These E. coli strains could be used to produce a supply of S. pneumoniae serotype-specific capsules without the need to culture pathogenic bacteria. Additionally, these strains could be applied to synthetic glycobiological applications: recombinant vaccine production using E. coli outer membrane vesicles or coupling to proteins using protein glycan coupling technology.

  15. Molecular characteristics of serotype 3 Streptococcus pneumoniae isolates among community-acquired pneumonia patients in Japan.

    Isozumi, Rie; Ito, Yutaka; Ishida, Tadashi; Hirai, Toyohiro; Ito, Isao; Maniwa, Ko; Hayashi, Michio; Kagioka, Hitoshi; Hirabayashi, Masataka; Onaru, Koichi; Tomioka, Hiromi; Tomii, Keisuke; Gohma, Iwao; Osawa, Makoto; Imai, Seiichiro; Takakura, Shunji; Iinuma, Yoshitsugu; Chin, Kazuo; Ichiyama, Satoshi; Mishima, Michiaki

    2008-06-01

    In order to understand the spread of the erythromycin-resistant serotype 3 Streptococcus pneumoniae clone in Japan, we have assessed the molecular characteristics of this clone. Among 156 S. pneumoniae isolates recovered from adults with community-acquired pneumonia between 2003 and 2005, 42 were serotype 3 and 40 were sequence type (ST) 180/Netherlands(3)-31 by multilocus sequence typing. Thirty-eight of the 40 ST 180 isolates had acquired resistance to erythromycin via the ermB gene. Although the ermB-positive ST180 clone isolates were more susceptible to penicillin and trimethoprim-sulfamethoxazole than ermB-positive non-ST180 isolates and contained a less mutated pbp1a or pbp2b gene, without a mefA gene, the ST180 clone was highly prevalent among ermB-positive isolates. Routine surveillance for the ST180 S. pneumoniae clone may soon become necessary.

  16. National Department of Defense Surveillance for Invasive Streptococcus Pneumoniae: Antibiotic Resistance, Serotype Distribution, and Arbitrarily Primed Polymerase Chain Reaction Analyses

    2008-02-15

    penicillin -susceptible and peni- cillin-resistant Streptococcnspneuttmoniae serotypes in Canada. J Infect Dis Streptococcus pneumoniae Surveillance Group...Gray for the Streptococcus pneumonia Surveillance Group Report No. 00-44 Approved for public release; distribution unlimited. NAVAL HEALTH RESEARCH...Defense Surveillance for Invasive Streptococcus pneumoniae : Antibiotic Resistance, Serotype Distribution, and Arbitrarily Primed Polymerase Chain

  17. [Nursing-home-acquired pneumococcal pneumonia--comparison of sputum cultures with Binax NOW Streptococcus pneumoniae urinary antigen assay].

    Rikimaru, Toru; Nishiyama, Mamoru; Yonemitsu, Junko; Nagabuchi, Masako; Shimada, Akiko; Koga, Takeharu; Aizawa, Hisamichi

    2008-11-01

    To clarify the clinical significance of Pneumococcal pneumonia in nursing-home-acquired pneumonia, we examined the positive disease rate of using sputum cultures and the Binax NOW Streptococcus pneumoniae urinary antigen assay in 154 nursing-home patients with pneumonia. These included 54 males and 100 females with a mean age of 86.2 years. Bacteriological findings for sputum culture in 130 patients showed Streptococcus pneumoniae to be cultured in 11 cases (8%). In 72 in whom the Streptococcus pneumoniae-urinary antigen test (Binax NOW) was done, the urinary-antigen-positive rate (26/72 ; 36%) was higher than the culture positive rate for S. pneumoniae. Both examinations were done in 64 patients, among whom 5 in whom S. pneumoniae was cultured also had positive results for the urinary antigen test. Almost half of those undergoing percutaneous endoscopic gastroscopy (PEG) tube nutrition had positive results for the urinary antigen test, but not all such patients had positive cultures for S. pneumoniae. Although the culture-positive rate for S. pneumoniae in sputum was low, we concluded that S. pneumoniae was frequently linked to nursing-home-acquired pneumonia, especially in "total-care" patients.

  18. Peritoneal culture alters Streptococcus pneumoniae protein profiles and virulence properties

    Orihuela, C. J.; Janssen, R.; Robb, C. W.; Watson, D. A.; Niesel, D. W.

    2000-01-01

    We have examined the properties of Streptococcus pneumoniae cultured in the murine peritoneal cavity and compared its virulence-associated characteristics to those of cultures grown in vitro. Analysis of mRNA levels for specific virulence factors demonstrated a 2.8-fold increase in ply expression and a 2.2-fold increase in capA3 expression during murine peritoneal culture (MPC). Two-dimensional gels and immunoblots using convalescent-phase patient sera and murine sera revealed distinct differences in protein production in vivo (MPC). MPC-grown pneumococci adhered to A549 epithelial cell lines at levels 10-fold greater than those cultured in vitro.

  19. Fatal necrotizing fasciitis due to Streptococcus pneumoniae: a case report.

    Park, So-Youn; Park, So Young; Moon, Soo-Youn; Son, Jun Seong; Lee, Mi Suk

    2011-01-01

    Necrotizing fasciitis is known to be a highly lethal infection of deep-seated subcutaneous tissue and superficial fascia. Reports of necrotizing fasciitis due to Streptococcus pneumoniae are exceedingly rare. We report a case of necrotizing fasciitis in a 62-yr-old man with liver cirrhosis and diabetes mellitus. He presented with painful swelling of left leg and right hand. On the day of admission, compartment syndrome was aggravated and the patient underwent surgical exploration. Intra-operative findings revealed necrotizing fasciitis and cultures of two blood samples and wound aspirates showed S. pneumoniae. The patient died despite debridement and proper antimicrobial treatment. To the best of our knowledge, this is the first case of fatal necrotizing fasciitis with meningitis reported in Korea. We also review and discuss the literature on pneumococcal necrotizing fasciitis.

  20. Epidemiological Studies of Potent Environmental Pathogen: Streptococcus pneumoniae

    Nazir A. Brohi

    2016-12-01

    Full Text Available A general survey for six months was undertaken for the prevalence of environmental bacterium Streptococcus pneumoniae among the different age groups (3-65 years including both sexes from various hospitals of Hyderabad city. Laboratory examinations revealed S. pneumoniae as most potent environmental pathogen from the sputum and throat swabs of old aged patients and children respectively. During observations, 39 specimens were growth positive; the biochemistry of isolates revealed that they were coagulase, catalase and oxidase negative, TSI, gel hydrolysis positive and were able to ferment glucose, lactose, maltose, galactose, fructose, sucrose, starch and raffinose. The results of antimicrobial activity showed that pneumococci were resistant to the cefspan, septran, cravit, pipemetic acid, azomax, bacitracin, and penicillin and a clear zone of inhibition was observed on clithromycin, optochin, cefizox, genatamycin, minocyclin, levoflaxacin, and vancomycin. There were intermediate zone of inhibition found on claforan, nalidixic acid, amoxycillin, fosfomycin, fortum, and erythromycin on Mueller Hinton’s agar after 24 hours incubation

  1. Isolation and Characterization of Unsaturated Fatty Acid Auxotrophs of Streptococcus pneumoniae and Streptococcus mutans▿

    Altabe, Silvia; Lopez, Paloma; de Mendoza, Diego

    2007-01-01

    Unsaturated fatty acid (UFA) biosynthesis is essential for the maintenance of membrane structure and function in many groups of anaerobic bacteria. Like Escherichia coli, the human pathogen Streptococcus pneumoniae produces straight-chain saturated fatty acids (SFA) and monounsaturated fatty acids. In E. coli UFA synthesis requires the action of two gene products, the essential isomerase/dehydratase encoded by fabA and an elongation condensing enzyme encoded by fabB. S. pneumoniae lacks both genes and instead employs a single enzyme with only an isomerase function encoded by the fabM gene. In this paper we report the construction and characterization of an S. pneumoniae 708 fabM mutant. This mutant failed to grow in complex medium, and the defect was overcome by addition of UFAs to the growth medium. S. pneumoniae fabM mutants did not produce detectable levels of monounsaturated fatty acids as determined by gas chromatography-mass spectrometry and thin-layer chromatography analysis of the radiolabeled phospholipids. We also demonstrate that a fabM null mutant of the cariogenic organism Streptococcus mutants is a UFA auxotroph, indicating that FabM is the only enzyme involved in the control of membrane fluidity in streptococci. Finally we report that the fabN gene of Enterococcus faecalis, coding for a dehydratase/isomerase, complements the growth of S. pneumoniae fabM mutants. Taken together, these results suggest that FabM is a potential target for chemotherapeutic agents against streptococci and that S. pneumoniae UFA auxotrophs could help identify novel genes encoding enzymes involved in UFA biosynthesis. PMID:17827283

  2. Fluoroquinolone resistance in Streptococcus pneumoniae from a university hospital, Thailand.

    Srifuengfung, Somporn; Tribuddharat, Chanwit; Chokephaibulkit, Kulkanya; Comerungsee, Sopita

    2010-11-01

    The most frequent markers of fluoroquinolone resistance in S. pneumoniae are chromosomal mutations in the quinolone-resistance-determining regions of DNA gyrase and topoisomerase IV encoding for the gyrA, gyrB and parC, parE genes. In 2008, 6.5% of the Streptococcus pneumoniae isolates in a Bangkok university hospital were resistant to ofloxacin. Using PCR and DNA sequencing, we identified mutations in both the gyrA and parC genes of four ofloxacin- and ciprofloxacin-resistant S. pneumoniae isolates (minimum inhibitory concentrations > 32 microg/ml). Mutations were found in the gyrA gene at positions Ser81Phe, Glu85Gly, Glu85Lys and in the parC gene at position Ser79Tyr. Three isolates had mutations in both genes. Two of the isolates were serotype 6B and two were serotypes not contained in currently licensed pneumococcal vaccines. This is the first report of the mechanisms of fluoroquinolone resistance in S. pneumoniae in Thailand.

  3. Proteomic analysis of the copper resistance of Streptococcus pneumoniae.

    Guo, Zhong; Han, Junlong; Yang, Xiao-Yan; Cao, Kun; He, Ke; Du, Gaofei; Zeng, Guandi; Zhang, Liang; Yu, Guangchuang; Sun, Zhenghua; He, Qing-Yu; Sun, Xuesong

    2015-03-01

    Streptococcus pneumoniae is a Gram-positive bacterial pathogen causing a variety of diseases, including otitis media, bacteraemia and meningitis. Although copper is an essential trace metal for bacterial growth, high intracellular levels of free-copper are toxic. Copper resistance has emerged as an important virulence determinant of microbial pathogens. In this study, we determined the minimum inhibition concentration of copper for the growth inhibition of S. pneumoniae. Two-dimensional-electrophoresis coupled with mass spectrometry was applied to identify proteins involved in copper resistance of S. pneumoniae. In total, forty-four proteins with more than 1.5-fold alteration in expression (p < 0.05) were identified. Quantitative reverse transcription PCR was used to confirm the proteomic results. Bioinformatics analysis showed that the differentially expressed proteins were mainly involved in the cell wall biosynthesis, protein biosynthesis, purine biosynthesis, pyrimidine biosynthesis, primary metabolic process, and the nitrogen compound metabolic process. Many up-regulated proteins in response to the copper treatment directly or indirectly participated in the cell wall biosynthesis, indicating that the cell wall is a critical determinant in copper resistance of S. pneumoniae.

  4. Characterisation of Invasive Streptococcus pneumoniae Isolated from Cambodian Children between 2007 – 2012

    Giess, Adam; Soeng, Sona; Sar, Poda; Kumar, Varun; Nhoung, Pheakdey; Bousfield, Rachel; Turner, Paul; Stoesser, Nicole; Day, Nicholas P. J.; Parry, Christopher M.

    2016-01-01

    Background The 13-valent pneumococcal vaccine (PCV13) was introduced in Cambodia in January 2015. There are limited data concerning the common serotypes causing invasive pneumococcal disease (IPD). Knowledge of the circulating pneumococcal serotypes is important to monitor epidemiological changes before and after vaccine implementation. Methods All episodes of IPD defined by the isolation of Streptococcus pneumoniae from blood, cerebrospinal fluid or other sterile site in Cambodian children admitted to the Angkor Hospital for Children in Siem Reap, Northwestern Cambodia, between 1st January 2007 and 1st July 2012 were retrospectively studied. Streptococcus pneumoniae isolates that could be retrieved underwent phenotypic typing and whole genome sequencing. Results There were 90 Cambodian children hospitalized with IPD with a median (IQR) age of 2.3 years (0.9–6.2). The case fatality was 15.6% (95% CI 8–23). Of 50 Streptococcus pneumoniae isolates available for further testing, 46% were penicillin non-susceptible and 8% were ceftriaxone non-susceptible, 78% were cotrimoxazole resistant, 30% were erythromycin resistant and 30% chloramphenicol resistant. There were no significant changes in resistance levels over the five-year period. The most common serotypes were 1 (11/50; 22%), 23F (8/50; 16%), 14 (6/50; 12%), 5 (5/50; 10%) and 19A (3/50; 6%). Coverage by PCV7, PCV10 and PCV13 was 44%, 76% and 92% respectively. We identified novel multilocus sequence types and resistotypes using whole genome sequencing. Conclusions This study suggests IPD is an important disease in Cambodian children and can have a significant mortality. PCV13 coverage of the serotypes determined in studied strains was high and consistent with another recent study. The phenotypic resistance patterns observed were similar to other regional studies. The use of whole genome sequencing in the present study provides additional typing and resistance information together with the description of novel

  5. Characterisation of Invasive Streptococcus pneumoniae Isolated from Cambodian Children between 2007 - 2012.

    Catrin E Moore

    Full Text Available The 13-valent pneumococcal vaccine (PCV13 was introduced in Cambodia in January 2015. There are limited data concerning the common serotypes causing invasive pneumococcal disease (IPD. Knowledge of the circulating pneumococcal serotypes is important to monitor epidemiological changes before and after vaccine implementation.All episodes of IPD defined by the isolation of Streptococcus pneumoniae from blood, cerebrospinal fluid or other sterile site in Cambodian children admitted to the Angkor Hospital for Children in Siem Reap, Northwestern Cambodia, between 1st January 2007 and 1st July 2012 were retrospectively studied. Streptococcus pneumoniae isolates that could be retrieved underwent phenotypic typing and whole genome sequencing.There were 90 Cambodian children hospitalized with IPD with a median (IQR age of 2.3 years (0.9-6.2. The case fatality was 15.6% (95% CI 8-23. Of 50 Streptococcus pneumoniae isolates available for further testing, 46% were penicillin non-susceptible and 8% were ceftriaxone non-susceptible, 78% were cotrimoxazole resistant, 30% were erythromycin resistant and 30% chloramphenicol resistant. There were no significant changes in resistance levels over the five-year period. The most common serotypes were 1 (11/50; 22%, 23F (8/50; 16%, 14 (6/50; 12%, 5 (5/50; 10% and 19A (3/50; 6%. Coverage by PCV7, PCV10 and PCV13 was 44%, 76% and 92% respectively. We identified novel multilocus sequence types and resistotypes using whole genome sequencing.This study suggests IPD is an important disease in Cambodian children and can have a significant mortality. PCV13 coverage of the serotypes determined in studied strains was high and consistent with another recent study. The phenotypic resistance patterns observed were similar to other regional studies. The use of whole genome sequencing in the present study provides additional typing and resistance information together with the description of novel sequence types and resistotypes.

  6. Serotype and genotype distribution among invasive Streptococcus pneumoniae isolates in Colombia, 2005-2010.

    Parra, Eliana L; Ramos, Viviana; Sanabria, Olga; Moreno, Jaime

    2014-01-01

    In Colombia, a laboratory-based surveillance of invasive Streptococcus pneumoniae isolates as part of SIREVA II PAHO has been conducted since 1994. This study describes the serotype distribution, antimicrobial resistance, and genetic relationships of pneumococcal isolates recovered in Colombia from 2005 to 2010. In this study, demographic data of invasive S. pneumoniae isolates were analyzed, and antimicrobial susceptibility patterns were determined. Pulse field gel electrophoresis (n = 629) and multilocus sequence typing (n = 10) were used to determine genetic relationship of isolates with minimal inhibitory concentration to penicillin ≥0.125 µg/mL. A total of 1775 isolates of S. pneumoniae were obtained. Fifteen serotypes accounted for 80.7% of isolates. Serotype 14 (23.1%) was the most frequent in the general population. Penicillin resistance was 30.7% in meningitis and 9.0% in non-meningitis. Clones Spain(6B)ST90, Spain(9V)ST156, Spain(23F)ST81, and Colombia(23F)ST338 were associated to isolates. Additionally, serotype 6A isolates were associated with ST460 and ST473, and 19A isolates with ST276, ST320, and ST1118. In conclusion, the surveillance program provided updated information of trends in serotype distribution, antimicrobial resistance and the circulation of clones in invasive pneumococcal diseases. These results could be helpful to understand the epidemiology of S. pneumoniae in Colombia, and provide a baseline to measure the impact of vaccine introduction.

  7. Pneumonia and purulent pericarditis caused by Streptococcus pneumoniae: an uncommon association in the antibiotic era.

    Flores-González, Jose Carlos; Rubio-Quiñones, Fernando; Hernández-González, Arturo; Rodríguez-González, Moisés; Blanca-García, Jose Antonio; Lechuga-Sancho, Alfonso María; Quintero-Otero, Sebastián

    2014-08-01

    Bacterial pericarditis in children has become a rare entity in the modern antibiotic era. The most common pathogen is Staphylococcus aureus, being Streptococcus pneumoniae an exceptional cause. We present 2 children, who were diagnosed of pneumonia complicated with a pleural effusion that developed a purulent pericarditis with signs of cardiac tamponade. One of them had received 4 doses of the 7-valent conjugated pneumococcal vaccine. Systemic antibiotics and pericardial and pleural drainages were used. Pneumococcal antigens were positive in pleural and pericardial fluids in both cases, and S. pneumoniae was isolated from pleural effusion in one of them. Both children fully recovered, and none of them developed constrictive pericarditis, although 1 case presented a transient secondary left ventricular dysfunction. Routine immunization with 10- and 13-valent vaccines including a wider range of serotypes should further decrease the already low incidence.

  8. Draft Genome Sequences of Streptococcus pneumoniae with High-Level Resistance to Respiratory Fluoroquinolones.

    Keness, Yoram; Bisharat, Naiel

    2016-03-31

    Streptococcus pneumoniaeis the leading cause of community-acquired pneumonia. Levofloxacin is a fluoroquinolone used for treatment of severe community-acquired pneumonia. Here, we describe the draft genome sequences ofS. pneumoniaewith emerging resistance to levofloxacin, resulting in failure of treatment of pneumococcal pneumonia.

  9. Influence of the blood bacterial load on the meningeal inflammatory response in Streptococcus pneumoniae meningitis

    Østergaard, C; O´Reilly, T; Brandt, C

    2006-01-01

    was induced by intracisternal injection of approximately 1 x 10(6) CFU Streptococcus pneumoniae, type 3, and the 26 rabbits were either provided with approximately 1 x 10(6) CFU S. pneumoniae intravenously at 0 hour ("bacteraemic" rabbits, n = 9), immunized with paraformaldehyde-killed S. pneumoniae for 5...

  10. Structure and Inhibition of Quorum Sensing Target from Streptococcus pneumoniae

    Singh,V.; Shi, W.; Almo, S.; Evans, G.; Furneaux, R.; Tyler, P.; Painter, G.; Lenz, D.; Mee, S.; et al.

    2006-01-01

    Streptococcus pneumoniae 5'-methylthioadenosine/S-adenosylhomocysteine hydrolase (MTAN) catalyzes the hydrolytic deadenylation of its substrates to form adenine and 5-methylthioribose or S-ribosylhomocysteine (SRH). MTAN is not found in mammals but is involved in bacterial quorum sensing. MTAN gene disruption affects the growth and pathogenicity of bacteria, making it a target for antibiotic design. Kinetic isotope effects and computational studies have established a dissociative S{sub N}1 transition state for Escherichia coli MTAN, and transition state analogues resembling the transition state are powerful inhibitors of the enzyme [Singh, V., Lee, J. L., Nunez, S., Howell, P. L., and Schramm, V. L. (2005) Biochemistry 44, 11647-11659]. The sequence of MTAN from S. pneumoniae is 40% identical to that of E. coli MTAN, but S. pneumoniae MTAN exhibits remarkably distinct kinetic and inhibitory properties. 5'-Methylthio-Immucillin-A (MT-ImmA) is a transition state analogue resembling an early S{sub N}1 transition state. It is a weak inhibitor of S. pneumoniae MTAN with a K{sub i} of 1.0 {mu}M. The X-ray structure of S. pneumoniae MTAN with MT-ImmA indicates a dimer with the methylthio group in a flexible hydrophobic pocket. Replacing the methyl group with phenyl (PhT-ImmA), tolyl (p-TolT-ImmA), or ethyl (EtT-ImmA) groups increases the affinity to give K{sub i} values of 335, 60, and 40 nM, respectively. DADMe-Immucillins are geometric and electrostatic mimics of a fully dissociated transition state and bind more tightly than Immucillins. MT-DADMe-Immucillin-A inhibits with a K{sub i} value of 24 nM, and replacing the 5'-methyl group with p-Cl-phenyl (p-Cl-PhT-DADMe-ImmA) gave a K{sub i}* value of 0.36 nM. The inhibitory potential of DADMe-Immucillins relative to the Immucillins supports a fully dissociated transition state structure for S. pneumoniae MTAN. Comparison of active site contacts in the X-ray crystal structures of E. coli and S. pneumoniae

  11. Streptococcus pneumoniae DNA Load in Blood as a Marker of Infection in Patients with Community-Acquired Pneumonia

    Peters, R.P.H.; Boer, de R.F.; Schuurman, T.; Gierveld, S.; Kooistra-Smid, M.; Agtmael, van M.A.; Vandenbroucke-Grauls, C.M.J.E.; Persoons, M.C.J.; Savelkoul, P.H.M.

    2009-01-01

    Direct detection of Streptococcus pneumoniae DNA in blood adds to culture results in the etiological diagnosis of patients with community-acquired pneumonia (CAP). Quantification of the amount of DNA, the bacterial DNA load (BDL), provides a measurement of DNAemia that may increase the understanding

  12. Mechanisms of interferon-γ production by neutrophils and its function during Streptococcus pneumoniae pneumonia.

    Gomez, John C; Yamada, Mitsuhiro; Martin, Jessica R; Dang, Hong; Brickey, W June; Bergmeier, Wolfgang; Dinauer, Mary C; Doerschuk, Claire M

    2015-03-01

    Bacterial pneumonia is a common public health problem associated with significant mortality, morbidity, and cost. Neutrophils are usually the earliest leukocytes to respond to bacteria in the lungs. Neutrophils rapidly sequester in the pulmonary microvasculature and migrate into the lung parenchyma and alveolar spaces, where they perform numerous effector functions for host defense. Previous studies showed that migrated neutrophils produce IFN-γ early during pneumonia induced by Streptococcus pneumoniae and that early production of IFN-γ regulates bacterial clearance. IFN-γ production by neutrophils requires Rac2, Hck/Lyn/Fgr Src family tyrosine kinases, and NADPH oxidase. Our current studies examined the mechanisms that regulate IFN-γ production by lung neutrophils during acute S. pneumoniae pneumonia in mice and its function. We demonstrate that IFN-γ production by neutrophils is a tightly regulated process that does not require IL-12. The adaptor molecule MyD88 is critical for IFN-γ production by neutrophils. The guanine nucleotide exchange factor CalDAG-GEFI modulates IFN-γ production. The CD11/CD18 complex, CD44, Toll-like receptors 2 and 4, TRIF, and Nrf2 are not required for IFN-γ production by neutrophils. The recently described neutrophil-dendritic cell hybrid cell, identified by its expression of Ly6G and CD11c, is present at low numbers in pneumonic lungs and is not a source of IFN-γ. IFN-γ produced by neutrophils early during acute S. pneumoniae pneumonia induces transcription of target genes in the lungs, which are critical for host defense. These studies underline the complexity of the neutrophil responses during pneumonia in the acute inflammatory response and in subsequent resolution or initiation of immune responses.

  13. Susceptibility of Streptococcus pneumoniae to fluoroquinolones in Canada.

    Patel, Samir N; McGeer, Allison; Melano, Roberto; Tyrrell, Gregory J; Green, Karen; Pillai, Dylan R; Low, Donald E

    2011-08-01

    Ciprofloxacin, the first fluoroquinolone to be used to treat lower respiratory tract infections (LRTI), demonstrates poor potency against Streptococcus pneumoniae, and its use has been associated with the emergence of resistance. During the last decade, fluoroquinolones with enhanced in vitro activity against S. pneumoniae have replaced ciprofloxacin for the treatment of LRTI. Here, we analyzed the impact of more active fluoroquinolone usage on pneumococci by examining the fluoroquinolone usage, prevalence of fluoroquinolone resistance, and mutations in the genes that encode the major target sites for the fluoroquinolones (gyrA and parC) in pneumococcal isolates collected in Canada-wide surveillance. A total of 26,081 isolates were collected between 1998 and 2009. During this time period, total per capita outpatient use of fluoroquinolones increased from 64 to 96 prescriptions per 1,000 persons per year. The proportion of prescriptions for respiratory tract infection that were for fluoroquinolones increased from 5.9% to 10.7%, but the distribution changed: the proportion of prescriptions for ciprofloxacin decreased from 5.3% to 0.5%, and those for levofloxacin or moxifloxacin increased from 1.5% in 1999 to 5.9% in 2009. The prevalence of ciprofloxacin resistance (MIC ≥ 4 μg/ml), levofloxacin resistance, and moxifloxacin resistance remained unchanged at fluoroquinolones did not change during the surveillance period. If fluoroquinolone therapy is required, the preferential use of fluoroquinolones with enhanced pneumococcal activity to treat pneumococcal infections may slow the emergence of resistance in S. pneumoniae.

  14. Estado actual de la vacuna conjugada contra Streptococcus pneumoniae

    Hernán Sierra- Fernandez

    2006-06-01

    Full Text Available Las infecciones por Streptococcus pneumoniae son frecuentes en la población pediátrica especialmente en los niños menores de 2 años. El S. pneumoniae puede producir infecciones invasoras con una alta tasa de mortalidad y morbilidad como lo son las meningitis bacterianas, la neumonía y bacteremias siendo a la vez el agente que con mayor frecuencia se detecta en el oído medio de niños con otitis media. En la actualidad existe una vacuna conjugada contra esta bacteria que protege contra los siete serotipos de S. pneumoniae más frecuentes en el mundo y que a su vez son los mismos serotipos que presentan una mayor incidencia de resistencia a los antibioticos de uso frecuente. La vacuna no solo protege contra este tipo de infecciones sino que se ha demostrado que disminuye la colonización nasofaringea de los niños que han recibido la vacuna produciendo a su vez, una reducción en el numero de infecciones, por esta bacteria, en poblaciones de personas mayores de 5 años, incluyendo adultos y personas mayores a los 65 años (efecto rebaño. Con base en los serotipos aislados en niños costarricenses con otitis media, se puede calcular que la cobertura de esta vacuna en Costa Rica sería de aproximadamente un 74% e incluyendo mayoritariamente, los serotipos que presentan resistencia antimicrobriana más frecuentemente.The heptavalent S. pneumoniae conjugate vaccine has shown to be safe and effective in preventing pediatric invasive infections and otitis media caused by S. pneumoniae. The routine use of these vaccines has dramatically reduced the incidence of invasive pneumococcal diseases in children younger than 2 years old and because of a reduction in colonization of the children’s nasopharynx, the transmission from child to adult has been reduced and the number of secondary S. pneumoniae infections in adults. Another benefit of the routine use of this vaccine has been the reduction of vaccine-type antimicrobial resistant strains. Based on

  15. Aromatic Esters of Bicyclic Amines as Antimicrobials against Streptococcus pneumoniae.

    de Gracia Retamosa, María; Díez-Martínez, Roberto; Maestro, Beatriz; García-Fernández, Esther; de Waal, Bas; Meijer, E W; García, Pedro; Sanz, Jesús M

    2015-11-09

    A double approach was followed in the search of novel inhibitors of the surface choline-binding proteins (CBPs) of Streptococcus pneumoniae (pneumococcus) with antimicrobial properties. First, a library of 49 rationally-designed esters of alkyl amines was screened for their specific binding to CBPs. The best binders, being esters of bicyclic amines (EBAs), were then tested for their in vitro effect on pneumococcal growth and morphology. Second, the efficiency of EBA-induced CBP inhibition was enhanced about 45,000-fold by multivalency effects upon synthesizing a poly(propylene imine) dendrimer containing eight copies of an atropine derivative. Both approaches led to compounds that arrest bacterial growth, dramatically decrease cell viability, and exhibit a protection effect in animal disease models, demonstrating that the pneumococcal CBPs are adequate targets for the discovery of novel antimicrobials that overcome the currently increasing antimicrobial resistance issues.

  16. Streptococcus pneumoniae proteomics: determinants of pathogenesis and vaccine development.

    Bittaye, Mustapha; Cash, Phil

    2015-01-01

    Streptococcus pneumoniae is a major pathogen that is responsible for a variety of invasive diseases. The bacteria gain entry initially by establishing a carriage state in the nasopharynx from where they migrate to other sites in the body. The worldwide distribution of the bacteria and the severity of the diseases have led to a significant level of interest in the development of vaccines against the bacteria. Current vaccines, based on the bacterial polysaccharide, have a number of limitations including poor immunogenicity and limited effectiveness against all pneumococcal serotypes. There are many challenges in developing vaccines that will be effective against the diverse range of isolates and serotypes for this highly variable bacterial pathogen. This review considers how proteomic technologies have extended our understanding of the pathogenic mechanisms of nasopharyngeal colonization and disease development as well as the critical areas in developing protein-based vaccines.

  17. Novel clones of Streptococcus pneumoniae causing invasive disease in Malaysia.

    Johanna M Jefferies

    Full Text Available Although Streptococcus pneumoniae is a leading cause of childhood disease in South East Asia, little has previously been reported regarding the epidemiology of invasive pneumococcal disease in Malaysia and very few studies have explored pneumococcal epidemiology using multilocus sequence typing (MLST. Here we describe serotype, multilocus sequence type (ST, and penicillin susceptibility of thirty pneumococcal invasive disease isolates received by the University of Malaya Medical Centre between February 2000 and January 2007 and relate this to the serotypes included in current pneumococcal conjugate vaccines. A high level of diversity was observed; fourteen serotypes and 26 sequence types (ST, (11 of which were not previously described were detected from 30 isolates. Penicillin non-susceptible pneumococci accounted for 33% of isolates. The extent of molecular heterogeneity within carried and disease-causing Malaysian pneumococci remains unknown. Larger surveillance and epidemiological studies are now required in this region to provide robust evidence on which to base future vaccine policy.

  18. Fatal Streptococcus pneumoniae Sepsis in a Patient With Celiac Disease-Associated Hyposplenism

    Ouseph, Madhu M.; Simons, Malorie; Treaba, Diana O.; Yakirevich, Evgeny; Green, Peter H.; Bhagat, Govind; Moss, Steven F.

    2016-01-01

    We present a 59-year-old male with poorly controlled celiac disease (CD) and fatal Streptococcus pneumoniae sepsis, describe the morphologic findings, and stress the need for monitoring splenic function and pneumococcal vaccination in these patients. PMID:27761478

  19. Onderzoek naar de gevoeligheid van streptococcus pneumoniae, haemophilus influenzae en Moraxella catarrhalis voor antibiotica

    de Neeling AJ; Overbeek BP; Timmerman CP; de Jong J; Dessens-Kroon M; van Klingeren B

    1992-01-01

    The susceptibility to antibiotics of three respiratory pathogens, Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis, was determined. The isolates were obtainied in three regional laboratories in the Netherlands and tested using the microdilution method. After incubation th

  20. Genetic relatedness within serotypes of penicillin-susceptible Streptococcus pneumoniae isolates

    K. Overweg (Karin); D. Bogaert (Debby); M. Sluijter (Marcel); J. Yother; J. Dankert; R. de Groot (Ronald); P.W.M. Hermans (Peter)

    2000-01-01

    textabstractThe molecular epidemiological characteristics of all Streptococcus pneumoniae strains isolated in a nationwide manner from patients with meningitis in The Netherlands in 1994 were investigated. Restriction fragment end labeling analysis demonstrated 52% gene

  1. Molecular epidemiology of penicillin-nonsusceptible Streptococcus pneumoniae among children in Greece

    D. Bogaert (Debby); G.A. Syrogiannopoulos; I.N. Grivea; R. de Groot (Ronald); N.G. Beratis; P.W.M. Hermans (Peter)

    2000-01-01

    textabstractA total of 145 penicillin-nonsusceptible Streptococcus pneumoniae strains were isolated from young carriers in Greece and analyzed by antibiotic susceptibility testing, serotyping, restriction fragment end labeling (RFEL), and penicillin-binding protein (PBP

  2. Genotyping and serotyping of macrolide and multidrug resistant Streptococcus pneumoniae isolated from carrier children

    S F Swedan

    2016-01-01

    Full Text Available Aims: Streptococcus pneumoniae, an opportunistic pathogen commonly carried asymptomatically in the nasopharynx of children, is associated with increasing rates of treatment failures due to a worldwide increase in drug resistance. We investigated the carriage of S. pneumoniae in children 5 years or younger, the identity of prevalent serotypes, the rates of resistance to macrolides and other antimicrobial agents and the genotypes responsible for macrolide resistance. Materials and Methods: Nasopharyngeal swabs were collected from 157 children under 5 years for cultural isolation of S. pneumoniae. Antibiogram of isolates  was determined using the disk diffusion test, and the minimal inhibitory concentration to macrolides was determined using the E-test. Isolate serotypes and macrolide resistance genes, erm(B and mef(E, were identified using multiplex polymerase chain reactions. Results: S. pneumoniae was recovered from 33.8% of children; 41.9% among males and 21.9% among females (P = 0.009. The highest carriage rate occurred among age groups 7-12 months and 49-60 months. Most frequent serotypes were 19F, 6A/B, 11A, 19A, 14 and 15B/C.  Resistance to macrolides was 60.4%. Resistance to oxacillin, trimethoprim/sulfamethoxazole and clindamycin was present among 90.6%, 54.7% and 32.1% of isolates, respectively. All isolates were susceptible to chloramphenicol, levofloxacin and vancomycin. Isolates resistant to one or more macrolide drugs were more likely to be multidrug resistant. Resistance to clindamycin or oxacillin coexisted with macrolide resistance. Among the erythromycin-resistant isolates, erm(B, mef(E and erm(B and mef(E genes were present at rates of 43.8%, 37.5% and 6.3%, respectively. Erm(B and mef(E were associated with very high level and moderate-to-high level resistance to macrolides, respectively. Conclusion: A significant proportion of children harboured macrolide and multidrug-resistant S. pneumoniae.

  3. Antimicrobial susceptibilities and capsular types of invasive Streptococcus pneumoniae isolated in children in Mexico City.

    Echániz-Aviles, G; Velázquez-Meza, M E; Carnalla-Barajas, M N; Soto-Noguerón, A; Solórzano-Santos, F; Pérez Miravete, A; Gatica-Marquina, R; di Fabio, J L

    1997-01-01

    As part of the Sistema Regional de Vacunas (SIREVA) initiative, we conducted a surveillance study to determine the relative prevalence of capsular types of Streptococcus pneumoniae and antimicrobial susceptibility of invasive isolates in children less than 5 years old. We collected 220 isolates and found 33 of the 90 known types, with type 23F as the most common followed by types 6A+B, 14, 19F, and 19A. High penicillin resistance was found in 49 strains (22.2%), 31 belonging to type 23F. Twenty-nine (13.1%) were resistant to erythromycin, 95 (43.1%) were resistant to chloramphenicol, and 24 (10.9%) were resistant to cefotaxime. No strains were resistant to vancomycin.

  4. Genetic diversity of penicillin-resistant Streptococcus pneumoniae

    T. A. Savinova

    2009-01-01

    Full Text Available Fifty five Streptococcus pneumoniae isolates with reduced susceptibility to penicillin, obtained from patients with respiratory tract infections during 2003 –2007, were analyzed by MLST. Ten isolates were identified by MLST as Streptococcus «viridians» group. Among the remaining isolates 33,3% (n=15 belonged to global clonal complex CC81 and demonstrated reduced susceptibility to macrolides, tetracyclynes and chloramphenicol, three isolates were additionally resistant to levofloxacin. Clonal complex CC271 was represented by 5 isolated (11,1%, CC315 – by 4 (8,9%, CC315 – by 3 (6,7%, CC156, CC280 and CC1012 were represented by 2 (4,4% isolates each. Isolates of clonal complexes 271 and 315 demonstrated high level of associated resistance to macrolides. Twelve clonal complexes were represented by single isolates. More than 50% of isolates with reduced susceptibility to penicillin belonged to three global clonal complexes. Probably these clonal complexes were imported to Russia from other geographical regions.

  5. Characterization of erythromycin-resistant Streptococcus pneumoniae isolates causing invasive diseases in Chinese children

    MA Xiang; YAO Kai-hu; XIE Gui-lin; ZHENG YUE-jie; WANG Chuan-qing; SHANG Yun-xiao; WANG Hui-yun

    2013-01-01

    Background Erythromycin-resistant Streptococcus pneumoniae isolates that causing invasive pneumococcal diseases (IPD) in Chinese children remain uncharacterized.This study aims to identify the resistance genes associated with erythromycin resistance and to determine the genetic relationships of IPD isolates in Chinese children.Methods A total of 171 S.pneumoniae strains were isolated from 11 medical centers in China from 2006 to 2008.All the isolates were characterized via serotyping and antibiotic susceptibility determination.The erythromycin-resistant isolates were further characterized via ermB and mefA gene detection,multi-locus sequence typing analysis,and pulsed-field gel electrophoresis.Results A total of 164 (95.9%) isolates showed resistance to erythromycin,of which 162 strains with high high-level resistance (MIC ≥ 256 μg/ml).A total of 104 (63.4%) isolates carry the ermB gene alone,whereas 59 (36.0%) harbor both ermB and mefA genes.Of the 59 strains,54 were of serotypes 19A and 19F and were identified as highly clonal and related to the Taiwan19F-14 clone.Conclusions The erythromycin resistance rate in IPD isolates is significantly high and is predominantly mediated by the ermB gene.Isolates that carry both ermB and mefA genes are predominantly of serotypes 19A and 19F.

  6. Streptococcus pneumoniae from Palestinian nasopharyngeal carriers: serotype distribution and antimicrobial resistance.

    Abedelmajeed Nasereddin

    Full Text Available Infections of Streptococcus pneumoniae in children can be prevented by vaccination; left untreated, they cause high morbidity and fatalities. This study aimed at determining the nasopharyngeal carrier rates, serotype distribution and antimicrobial resistance patterns of S. pneumoniae in healthy Palestinian children under age two prior to the full introduction of the pneumococcal 7-valent conjugate vaccine (PCV7, which was originally introduced into Palestine in a pilot trial in September, 2010. In a cross sectional study, nasopharyngeal specimens were collected from 397 healthy children from different Palestinian districts between the beginning of November 2012 to the end of January 2013. Samples were inoculated into blood agar and suspected colonies were examined by amplifying the pneumococcal-specific autolysin gene using a real-time PCR. Serotypes were identified by a PCR that incorporated different sets of specific primers. Antimicrobial susceptibility was measured by disk diffusion and MIC methods. The resulting carrier rate of Streptococcus pneumoniae was 55.7% (221/397. The main serotypes were PCV7 serotypes 19F (12.2%, 23F (9.0%, 6B (8.6% and 14 (4% and PCV13 serotypes 6A (13.6% and 19A (4.1%. Notably, serotype 6A, not included in the pilot trial (PCV7 vaccine, was the most prevalent. Resistance to more than two drugs was observed for bacteria from 34.1% of the children (72/211 while 22.3% (47/211 carried bacteria were susceptible to all tested antibiotics. All the isolates were sensitive to cefotaxime and vancomycin. Any or all of these might impinge on the type and efficacy of the pneumococcal conjugate vaccines and antibiotics to be used for prevention and treatment of pneumococcal disease in the country.

  7. Discrimination between Streptococcus pneumoniae and Streptococcus mitis based on sorting of their MALDI mass spectra.

    Ikryannikova, L N; Filimonova, A V; Malakhova, M V; Savinova, T; Filimonova, O; Ilina, E N; Dubovickaya, V A; Sidorenko, S V; Govorun, V M

    2013-11-01

    Accurate species-level identification of alpha-hemolytic (viridans) streptococci (VGS) is very important for understanding their pathogenicity and virulence. However, an extremely high level of similarity between VGS within the mitis group (S. pneumoniae, S. mitis, S. oralis and S. pseudopneumoniae) often results in misidentification of these organisms. Earlier, matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has been suggested as a tool for the rapid identification of S. pneumoniae. However, by using Biotyper 3.0 (Bruker) or Vitek MS (bioMérieux) databases, Streptococcus mitis/oralis species can be erroneously identified as S. pneumoniae. ClinProTools 2.1 software was used for the discrimination of MALDI-TOF mass spectra of 25 S. pneumoniae isolates, 34 S. mitis and three S. oralis. Phenotypical tests and multilocus gene typing schemes for the S. pneumoniae (http://spneumoniae.mlst.net/) and viridans streptococci (http://viridans.emlsa.net/) were used for the identification of isolates included in the study. The classifying model was generated based on different algorithms (Genetic Algorithm, Supervised Neural Network and QuickClassifier). In all cases, values of sensitivity and specificity were found to be equal or close to 100%, allowing discrimination of mass spectra of different species. Three peaks (6949, 9876 and 9975 m/z) were determined conferring the maximal statistical weight onto each model built. We find this approach to be promising for viridans streptococci discrimination.

  8. Streptococcus pneumoniae-associated pneumonia complicated by purulent pericarditis: case series

    Cilloniz, Catia; Torres, Antoni [Servicio de Neumologia, Hospital Clinic de Barcelona, Ciber de Enfermedades Respiratorias (CIBERES), Instituto de Investigacion Biomedica Agusti Pi i Sunyer, Universidad de Barcelona (Spain); Rangel, Ernesto [Facultad de Medicina, Universidad Autonoma de Nayarit, Tepic (Mexico); Barlascini, Cornelius [Servizio di Igiene e Sanita Pubblica, Ospedale Generale di Sestri Levante, Sestri Levante (Italy); Piroddi, Ines Maria Grazia; Nicolini, Antonello, E-mail: antonellonicolini@gmail.com [Servizio di Pneumologia, Ospedale Generale di Sestri Levante, Sestri Levante (Italy)

    2015-07-15

    Objective: In the antibiotic era, purulent pericarditis is a rare entity. However, there are still reports of cases of the disease, which is associated with high mortality, and most such cases are attributed to delayed diagnosis. Approximately 40-50% of all cases of purulent pericarditis are caused by Gram-positive bacteria, Streptococcus pneumoniae in particular. Methods: We report four cases of pneumococcal pneumonia complicated by pericarditis, with different clinical features and levels of severity. Results: In three of the four cases, the main complication was cardiac tamponade. Microbiological screening (urinary antigen testing and pleural fluid culture) confirmed the diagnosis of severe pneumococcal pneumonia complicated by purulent pericarditis. Conclusions: In cases of pneumococcal pneumonia complicated by pericarditis, early diagnosis is of paramount importance to avoid severe hemodynamic compromise. The complications of acute pericarditis appear early in the clinical course of the infection. The most serious complications are cardiac tamponade and its consequences. Antibiotic therapy combined with pericardiocentesis drastically reduces the mortality associated with purulent pericarditis. (author)

  9. Streptococcus pneumoniae-associated pneumonia complicated by purulent pericarditis: case series *

    Cillóniz, Catia; Rangel, Ernesto; Barlascini, Cornelius; Piroddi, Ines Maria Grazia; Torres, Antoni; Nicolini, Antonello

    2015-01-01

    Abstract Objective: In the antibiotic era, purulent pericarditis is a rare entity. However, there are still reports of cases of the disease, which is associated with high mortality, and most such cases are attributed to delayed diagnosis. Approximately 40-50% of all cases of purulent pericarditis are caused by Gram-positive bacteria, Streptococcus pneumoniae in particular. Methods: We report four cases of pneumococcal pneumonia complicated by pericarditis, with different clinical features and levels of severity. Results: In three of the four cases, the main complication was cardiac tamponade. Microbiological screening (urinary antigen testing and pleural fluid culture) confirmed the diagnosis of severe pneumococcal pneumonia complicated by purulent pericarditis. Conclusions: In cases of pneumococcal pneumonia complicated by pericarditis, early diagnosis is of paramount importance to avoid severe hemodynamic compromise. The complications of acute pericarditis appear early in the clinical course of the infection. The most serious complications are cardiac tamponade and its consequences. Antibiotic therapy combined with pericardiocentesis drastically reduces the mortality associated with purulent pericarditis. PMID:26398760

  10. Pherotypes are driving genetic differentiation within Streptococcus pneumoniae

    Ramirez Mario

    2009-09-01

    Full Text Available Abstract Background The boundaries of bacterial species and the mechanisms underlying bacterial speciation are matters of intense debate. Theoretical studies have shown that recombination acts as a strong cohesive force preventing divergence in bacterial populations. Streptococcus pneumoniae populations have the telltale signs of high recombination with competence implicated as the major driving force behind gene exchange. Competence in S. pneumoniae is triggered by a quorum-sensing mechanism controlled by the competence-stimulating peptide pheromone. Results We studied the distribution of the two major pherotypes in the pneumococcal population and their association with serotype, antimicrobial resistance and genetic lineage. Using multilocus sequence data we evaluated pherotype influence on the dynamics of horizontal gene transfer. We show that pherotype is a clonal property of pneumococci. Standard population genetic analysis and multilocus infinite allele model simulations support the hypothesis that two genetically differentiated populations are defined by the major pherotypes. Conclusion Severe limitations to gene flow can therefore occur in bacterial species in the absence of geographical barriers and within highly recombinogenic populations. This departure from panmixia can have important consequences for our understanding of the response of pneumococci to human imposed selective pressures such as vaccination and antibiotic use.

  11. Effect of Streptococcus pneumoniae on human respiratory epithelium in vitro.

    Steinfort, C; Wilson, R; Mitchell, T; Feldman, C; Rutman, A; Todd, H; Sykes, D; Walker, J; Saunders, K; Andrew, P W

    1989-07-01

    A total of 11 of 15 Streptococcus pneumoniae culture filtrates and all five bacterial autolysates produced by cell death in the stationary phase caused slowed ciliary beating and disruption of the surface integrity of human respiratory epithelium in organ culture. This effect was inhibited by cholesterol and was heat labile and reduced by standing at room temperature but was stable at -40 degrees C. The activity was detected at the late stationary phase of culture and was associated with the presence of hemolytic activity. Gel filtration of a concentrated culture filtrate and autolysate both yielded a single fraction of approximately 50 kilodaltons which slowed ciliary beating and were the only fractions with hemolytic activity. Rabbit antiserum to pneumolysin, a sulfhydryl-activated hemolytic cytotoxin released by S. pneumoniae during autolysis, neutralized the effect of the culture filtrate on respiratory epithelium. Both native and recombinant pneumolysin caused ciliary slowing and epithelial disruption. Electron microscopy showed a toxic effect of pneumolysin on epithelial cells: cytoplasmic blebs, mitochondrial swelling, cellular extrusion, and cell death, but no change in ciliary ultrastructure. Recombinant pneumolysin (10 micrograms/ml) caused ciliary slowing in the absence of changes in cell ultrastructure. Release of pneumolysin in the respiratory tract during infection may perturb host defenses, allowing bacterial proliferation and spread.

  12. Disentangling competence for genetic transformation and virulence in Streptococcus pneumoniae.

    Lin, Jingjun; Zhu, Luchang; Lau, Gee W

    2016-02-01

    Horizontal gene transfer mediated by the competence regulon is a major driver of genome plasticity in Streptococcus pneumoniae. When pneumococcal cells enter the competent state, about 6% of the genes in the genome are up-regulated. Among these, some genes are essential for genetic transformation while others are dispensable for the process. Exhaustive deletion analyses show that some up-regulated genes dispensable for genetic transformation contribute to pneumococcal-mediated pneumonia and bacteremia infections. Interestingly, virulence functions of such genes are either dependent or independent of the competent state. Among the competent-state-dependent genes are those mediating allolysis, a process where small fraction of non-competent cells within the pneumococcal population are lysed by their competent counterparts, releasing DNA presumably for transformation. Inadvertently, the pore-forming toxin pneumolysin is also released during allolysis, contributing to virulence. In this review, we discuss recent advances in our understanding of pneumococcal virulence processes mediated by the competence regulon. We proposed that coupling of competence induction and bacterial fitness drives the natural selection to favor an intact competence regulon, which in turn, provides the long-term benefits of genetic plasticity.

  13. Serotypes of Streptococcus pneumoniae causing major pneumococcal infections

    Yu. V. Lobzin

    2013-01-01

    Full Text Available First in Russia prospective non-interventional hospital-based study on Streptococcus pneumoniae serotypes causing meningitis and acute otitis media (AOM in children and community-acquired pneumonia (CAP in children and adults, as well as serotype coverage by pneumococcal conjugate vaccines (PCV’s of different composition has been conducted. Serotypes 19F, 14 and serogroup 6 are the leading in meningitis; serotype coverage is 70,6% for PCV7, and 76,5% – for PCV10 and PCV13. Among S. pneumoniae serotypes causing AOM 19F, 3, 23F and serogroup 6 have been the most prevalent in Saint Petersburg. PCV7 and PCV10 provide equal serotypes coverage in AOM – 63,2% among children 0–2 years old, and 32,5% among children 5–17 years old. PCV13 covers up to 79% of serotypes in infants. In CAP PCV7 and PCV10 provide 57,1% serotype coverage in children and 56,1% – in adults. Serotype coverage in CAP for PCV13 has been 14,3% and 34,5% higher for children and adults, correspondingly. Obtained data supports PCV inclusion in children immunization program in Saint Petersburg, whereas PCV13 provides the broadest serotype coverage. In the course PCV’s implementation continued pneumococcal infection surveillance is advisable.

  14. Combined effects of lactoferrin and lysozyme on Streptococcus pneumoniae killing.

    André, G O; Politano, W R; Mirza, S; Converso, T R; Ferraz, L F C; Leite, L C C; Darrieux, M

    2015-12-01

    Streptococcus pneumoniae is a common colonizer of the human nasopharynx, which can occasionally spread to sterile sites, causing diseases such as otitis media, sinusitis, pneumonia, meningitis and bacteremia. Human apolactoferrin (ALF) and lysozyme (LZ) are two important components of the mucosal innate immune system, exhibiting lytic effects against a wide range of microorganisms. Since they are found in similar niches of the host, it has been proposed that ALF and LZ could act synergistically in controlling bacterial spread throughout the mucosa. The combination of ALF and LZ has been shown to enhance killing of different pathogens in vitro, with ALF facilitating the latter action of LZ. The aim of the present work was to investigate the combined effects of ALF and LZ on S pneumoniae. Concomitant addition of ALF and LZ had a synergistic killing effect on one of the pneumococci tested. Furthermore, the combination of ALF and ALZ was more bactericidal than lysozyme alone in all pneumococcal strains. Pneumococcal surface protein A (PspA), an important vaccine candidate, partially protects pneumococci from ALF mediated killing, while antibodies against one PspA enhance killing of the homologous strain by ALF. However, the serological variability of this molecule could limit the effect of anti-PspA antibodies on different pneumococci. Therefore, we investigated the ability of anti-PspA antibodies to increase ALF-mediated killing of strains that express different PspAs, and found that antisera to the N-terminal region of PspA were able to increase pneumococcal lysis by ALF, independently of the sequence similarities between the molecule expressed on the bacterial surface and that used to produce the antibodies. LF binding to the pneumococcal surface was confirmed by flow cytometry, and found to be inhibited in presence of anti-PspA antibodies. On a whole, the results suggest a contribution of ALF and LZ to pneumococcal clearance, and confirm PspA's ability to interact

  15. Estado actual de la vacuna conjugada contra Streptococcus pneumoniae

    Hernán Sierra- Fernandez

    2006-06-01

    Full Text Available Las infecciones por Streptococcus pneumoniae son frecuentes en la población pediátrica especialmente en los niños menores de 2 años. El S. pneumoniae puede producir infecciones invasoras con una alta tasa de mortalidad y morbilidad como lo son las meningitis bacterianas, la neumonía y bacteremias siendo a la vez el agente que con mayor frecuencia se detecta en el oído medio de niños con otitis media. En la actualidad existe una vacuna conjugada contra esta bacteria que protege contra los siete serotipos de S. pneumoniae más frecuentes en el mundo y que a su vez son los mismos serotipos que presentan una mayor incidencia de resistencia a los antibioticos de uso frecuente. La vacuna no solo protege contra este tipo de infecciones sino que se ha demostrado que disminuye la colonización nasofaringea de los niños que han recibido la vacuna produciendo a su vez, una reducción en el numero de infecciones, por esta bacteria, en poblaciones de personas mayores de 5 años, incluyendo adultos y personas mayores a los 65 años (efecto rebaño. Con base en los serotipos aislados en niños costarricenses con otitis media, se puede calcular que la cobertura de esta vacuna en Costa Rica sería de aproximadamente un 74% e incluyendo mayoritariamente, los serotipos que presentan resistencia antimicrobriana más frecuentemente.

  16. Resistencia a penicilina y otros antimicrobianos en 103 aislamientos clínicos de Streptococcus pneumoniae (2000-2001) Resistance to penicillin and other antimicrobials in 103 clinical isolations of Streptococcus pneumoniae (2000-2001)

    J.J. García-Irure; A. Navascués; I. Martín; C. Gastesi

    2003-01-01

    Fundamentos. Conocer en nuestro hospital la sensibilidad a penicilina de aislamientos de Streptococcus pneumoniae, así como analizar la asociación de resistencia a penicilina y otros antimicrobianos y la actividad de cefotaxima y cefepima en cepas de Streptococcus pneumoniae resistentes a penicilina. Métodos. Se determinó la sensibilidad de 103 aislamientos de Streptococcus pneumoniae, procedentes de muestras clínicas durante los años 2000-2001, a penicilina, eritromicina, cloramfenicol, tetr...

  17. Protective Immunity to Hepatitis B and Streptococcus Pneumoniae in Active Duty Women Versus Men: Prevalence and Responses to Preventive Immunization

    1996-04-01

    Protective Immunity to Hepatitis B and Streptococcus Pneumoniae in Active Duty Women Versus Men: Prevalence and Responses to Preventive Immunization...April 1996 I Final (1 Dec 94 - 31 Dec 95) 4. TITLE AND SUBTITLE Prot~ecti•ve Inmnunity¥ to Hepat~it~is B and 6. FUNDING NUMBERS Streptococcus Pneumoniae in...pneumococcal vaccine is not included in the standard vaccinations for active duty military. The prevalence of immunity to pathogenic Streptococcus pneumoniae in

  18. Acute bacterial meningitis caused by Streptococcus pneumoniae resistant to the antimicrobian agents and their serotypes Meningite bacteriana aguda por Streptococcus pneumoniae resistente aos antimicrobianos e seus sorotipos

    Andrea Maciel de Oliveira Rossoni; Libera Maria Dalla Costa; Denize Bonato Berto; Sônia Santos Farah; Marilene Gelain; Maria Cristina de Cunto Brandileone; Vitor Hugo Mariano Ramos; Sergio Monteiro de Almeida

    2008-01-01

    The main objectives of this study are to evaluate the resistance rates of Streptococcus pneumonia to penicillin G, ceftriaxone and vancomycin in patients with meningitis; to analyze possible risk factors to the antimicrobian resistance; to describe the serotypes detected and to suggest an initial empirical treatment for meningitis. The sensitiveness and serotypes of all isolated S. pneumoniae of patients with acute bacterial meningitis received by the Paraná State Central Laboratory from Apri...

  19. N-acetylgalatosamine-Mediated Regulation of the aga Operon by AgaR in Streptococcus pneumoniae

    Afzal, Muhammad; Shafeeq, Sulman; Ahmed, Hifza; Kuipers, Oscar P

    2016-01-01

    Here, we analyze the transcriptomic response of Streptococcus pneumoniae D39 to N-acetylgalactosamine (NAGa). Transcriptome comparison of S. pneumoniae D39 grown in NAGaM17 (0.5% NAGa + M17) to that grown in GM17 (0.5% Glucose + M17) revealed the elevated expression of various carbon metabolic genes

  20. Cellular localization of choline-utilization proteins in Streptococcus pneumoniae using novel fluorescent reporter systems

    Eberhardt, Alice; Wu, Ling J.; Errington, Jeff; Vollmer, Waldemar; Veening, Jan-Willem

    2009-01-01

    P>The molecular mechanisms underlying cell growth, cell division and pathogenesis in Streptococcus pneumoniae are still not fully understood. Single-cell methodologies are potentially of great value to investigate S. pneumoniae cell biology. Here, we report the construction of novel plasmids for sin

  1. Characterization and transfer studies of macrolide resistance genes in Streptococcus pneumoniae from Denmark

    Nielsen, Karen L; Hammerum, Anette M; Lambertsen, Lotte M

    2010-01-01

    Over the last decade, erythromycin resistance has been increasing in frequency in Streptococcus pneumoniae in Denmark. In the present study, 49 non-related erythromycin-resistant S. pneumoniae isolates from invasive sites and 20 isolates from non-invasive sites were collected; antimicrobial...

  2. Multiple mycotic aneurysms due to penicillin nonsusceptible Streptococcus pneumoniae solved with endovascular repair.

    Rojas, Alvaro; Mertens, Renato; Arbulo, Douglas; Garcia, Patricia; Labarca, Jaime

    2010-08-01

    Mycotic aneurysm is a life-threatening condition. We report the case of an 83-year-old white female who had pneumonia, and 3 months later she was admitted with multiple sacular mycotic aneurysms due to penicillin nonsusceptible Streptococcus pneumoniae. Successful combination therapy with antibiotics and endovascular repair was done.

  3. Streptococcus pneumoniae and reactive oxygen species : an unusual approach to living with radicals

    Yesilkaya, Hasan; Andisi, Vahid Farshchi; Andrew, Peter W.; Bijlsma, Jetta J. E.

    2013-01-01

    Streptococcus pneumoniae, an aerotolerant anaerobe, is an important human pathogen that regularly encounters toxic oxygen radicals from the atmosphere and from the host metabolism and immune system. Additionally, S. pneumoniae produces large amounts of H2O2 as a byproduct of its metabolism, which co

  4. Carriage rate and serotypes of Streptococcus pneumoniae amongst children in Thika Hospital, Kenya

    Susan Githii

    2013-03-01

    Full Text Available Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide. Rates of carriage are highest in infants and the elderly. The objectives of this study were to determine the rate of nasopharyngeal colonization by S. pneumoniae, and to describe the antibiotic resistant patterns and the serotypes of the carried isolates. A cross-sectional study design was used. Nasopharyngeal swabs were collected from 315 children in the months of Octoberand November 2010 and processed to isolate S. pneumoniae. The isolates were serotyped by the Quellung reaction and their antibiotic susceptibilities assessed by the disc diffusion method. The overall nasopharyngeal carriage rate for S. pneumoniae was 17%. Seventeen serotypes were detected amongst 55 strains analysed: 6A, 23F, 19F, 13, 6B, 14A, 20, 7C, 1,15B, 35B, 19A, 11A, 34, 5, 3 and 23A. Susceptibility testing revealed that nearly all (98% were resistant to cotrimoxazole, 9% were resistant to penicillin and 7% to cefotaxime. Resistance to chloramphenicol and erythromycin was 2% and 4%, respectively. All isolates were fully sensitive to tetracycline. High levels of cotrimoxazole resistance and some resistance to other antimicrobial agents commonly used in Thika District Hospital shows that there is need to revise antimicrobial policy in this region in the treatment of invasive pneumococcal infections. The frequent serotypes found in this study have previously been associated with pneumococcal infectionsin children. Several of these serotypes are included in the ten-valent vaccine and therefore useof this vaccine will help reduce pneumococcal infections in Thika.

  5. Emergence of a Streptococcus pneumoniae clinical isolate highly resistant to telithromycin and fluoroquinolones.

    Faccone, Diego; Andres, Patricia; Galas, Marcelo; Tokumoto, Marta; Rosato, Adriana; Corso, Alejandra

    2005-11-01

    Streptococcus pneumoniae is a major pathogen causing community-acquired pneumonia and acute bronchitis. Macrolides, fluoroquinolones (FQs), and, recently, telithromycin (TEL) constitute primary therapeutic options, and rare cases of resistance have been reported. In this report, we describe the emergence of an S. pneumoniae clinical isolate with high-level TEL resistance (MIC, 256 microg/ml) and simultaneous resistance to FQs. Ongoing studies are oriented to elucidate the precise mechanism of resistance to TEL.

  6. Emergence of a Streptococcus pneumoniae Clinical Isolate Highly Resistant to Telithromycin and Fluoroquinolones

    Faccone, Diego; Andres, Patricia; Galas, Marcelo; Tokumoto, Marta; Rosato, Adriana; Corso, Alejandra

    2005-01-01

    Streptococcus pneumoniae is a major pathogen causing community-acquired pneumonia and acute bronchitis. Macrolides, fluoroquinolones (FQs), and, recently, telithromycin (TEL) constitute primary therapeutic options, and rare cases of resistance have been reported. In this report, we describe the emergence of an S. pneumoniae clinical isolate with high-level TEL resistance (MIC, 256 μg/ml) and simultaneous resistance to FQs. Ongoing studies are oriented to elucidate the precise mechanism of res...

  7. Characterization of a Multipeptide Lantibiotic Locus in Streptococcus pneumoniae

    Natalie Maricic

    2016-01-01

    Full Text Available Bacterial communities are established through a combination of cooperative and antagonistic interactions between the inhabitants. Competitive interactions often involve the production of antimicrobial substances, including bacteriocins, which are small antimicrobial peptides that target other community members. Despite the nearly ubiquitous presence of bacteriocin-encoding loci, inhibitory activity has been attributed to only a small fraction of gene clusters. In this study, we characterized a novel locus (the pld locus in the pathogen Streptococcus pneumoniae that drives the production of a bacteriocin called pneumolancidin, which has broad antimicrobial activity. The locus encodes an unusual tandem array of four inhibitory peptides, three of which are absolutely required for antibacterial activity. The three peptide sequences are similar but appear to play distinct roles in regulation and inhibition. A modification enzyme typically found in loci encoding a class of highly modified bacteriocins called lantibiotics was required for inhibitory activity. The production of pneumolancidin is controlled by a two-component regulatory system that is activated by the accumulation of modified peptides. The locus is located on a mobile element that has been found in many pneumococcal lineages, although not all elements carry the pld genes. Intriguingly, a minimal region containing only the genes required for pneumolancidin immunity was found in several Streptococcus mitis strains. The pneumolancidin-producing strain can inhibit nearly all pneumococci tested to date and provided a competitive advantage in vivo. These peptides not only represent a unique strategy for bacterial competition but also are an important resource to guide the development of new antimicrobials.

  8. A novel method for rapid detection of Streptococcus pneumoniae antigens in blood.

    Fukushima, Kiyoyasu; Kubo, Toru; Ehara, Naomi; Nakano, Reiji; Matsutake, Toyoshi; Ishimatu, Yuji; Tanaka, Yumi; Akamatsu, Suguru; Izumikawa, Koichi; Kohno, Shigeru

    2016-03-01

    In this study, we used "RAPIRUN(®)Streptococcus pneumoniae HS (otitis media/sinusitis) (RAPIRUN-HS)," a rapid S. pneumoniae antigen detection kit, to investigate methods for detecting S. pneumoniae antigens in blood of 32 bacterial pneumonia patients. We simultaneously performed PCR to detect S. pneumoniae in blood samples. The results of these tests were compared based on pneumonia severity, determined using the Pneumonia Severity Index (PSI) score classification. Four S. pneumoniae PCR-positive patients of the six severe pneumococcal pneumonia patients (PSI risk class IV/V) also tested positive using RAPIRUN-HS. Twenty-four mild to moderate pneumonia patients (PSI risk class I-III) were S. pneumoniae PCR-negative; of these, 21 tested negative using RAPIRUN-HS. The pneumococcal pneumonia patients testing positive using RAPIRUN-HS had low leukocyte counts and elevated C-reactive protein and procalcitonin levels, indicating that RAPIRUN-HS results were correlated with pneumonia severity. The time course evaluations of the laboratory tests for severe pneumococcal pneumonia patients showed that RAPIRUN-HS and S. pneumoniae PCR yielded positive results earlier than the changes in procalcitonin and IL-6. Thus, concomitant pneumococcal bacteremia was strongly suspected in patients testing positive using RAPIRUN-HS. In conclusion, RAPIRUN-HS may be useful for determining whether to admit patients into hospitals and selecting the appropriate antimicrobial agents.

  9. Streptococcus pneumoniae biofilm formation and dispersion during colonization and disease.

    Chao, Yashuan; Marks, Laura R; Pettigrew, Melinda M; Hakansson, Anders P

    2014-01-01

    Streptococcus pneumoniae (the pneumococcus) is a common colonizer of the human nasopharynx. Despite a low rate of invasive disease, the high prevalence of colonization results in millions of infections and over one million deaths per year, mostly in individuals under the age of 5 and the elderly. Colonizing pneumococci form well-organized biofilm communities in the nasopharyngeal environment, but the specific role of biofilms and their interaction with the host during colonization and disease is not yet clear. Pneumococci in biofilms are highly resistant to antimicrobial agents and this phenotype can be recapitulated when pneumococci are grown on respiratory epithelial cells under conditions found in the nasopharyngeal environment. Pneumococcal biofilms display lower levels of virulence in vivo and provide an optimal environment for increased genetic exchange both in vitro and in vivo, with increased natural transformation seen during co-colonization with multiple strains. Biofilms have also been detected on mucosal surfaces during pneumonia and middle ear infection, although the role of these biofilms in the disease process is debated. Recent studies have shown that changes in the nasopharyngeal environment caused by concomitant virus infection, changes in the microflora, inflammation, or other host assaults trigger active release of pneumococci from biofilms. These dispersed bacteria have distinct phenotypic properties and transcriptional profiles different from both biofilm and broth-grown, planktonic bacteria, resulting in a significantly increased virulence in vivo. In this review we discuss the properties of pneumococcal biofilms, the role of biofilm formation during pneumococcal colonization, including their propensity for increased ability to exchange genetic material, as well as mechanisms involved in transition from asymptomatic biofilm colonization to dissemination and disease of otherwise sterile sites. Greater understanding of pneumococcal biofilm

  10. Capsular Serotyping of Streptococcus pneumoniae by latex agglutination.

    Porter, Barbara D; Ortika, Belinda D; Satzke, Catherine

    2014-09-25

    Latex agglutination reagents are widely used in microbial diagnosis, identification and serotyping. Streptococcus pneumoniae (the pneumococcus) is a major cause of morbidity and mortality world-wide. Current vaccines target the pneumococcal capsule, and there are over 90 capsular serotypes. Serotyping pneumococcal isolates is therefore important for assessing the impact of vaccination programs and for epidemiological purposes. The World Health Organization has recommended latex agglutination as an alternative method to the 'gold standard' Quellung test for serotyping pneumococci. Latex agglutination is a relatively simple, quick and inexpensive method; and is therefore suitable for resource-poor settings as well as laboratories with high-volume workloads. Latex agglutination reagents can be prepared in-house utilizing commercially-sourced antibodies that are passively attached to latex particles. This manuscript describes a method of production and quality control of latex agglutination reagents, and details a sequential testing approach which is time- and cost-effective. This method of production and quality control may also be suitable for other testing purposes.

  11. Protease activated receptor 4 limits bacterial growth and lung pathology during late stage Streptococcus pneumoniae induced pneumonia in mice.

    de Stoppelaar, S F; Van't Veer, C; van den Boogaard, F E; Nieuwland, R; Hoogendijk, A J; de Boer, O J; Roelofs, J J T H; van der Poll, T

    2013-09-01

    Streptococcus pneumoniae is a common causative pathogen of pneumonia and sepsis. Pneumonia and sepsis are associated with enhanced activation of coagulation, resulting in the production of several host-derived proteases at the primary site of infection and in the circulation. Serine proteases cleave protease activated receptors (PARs), which form a molecular link between coagulation and inflammation. PAR4 is one of four subtypes of PARs and is widely expressed by multiple cell types in the respiratory tract implicated in pulmonary inflammation, by immune cells and by platelets. In mice, mouse (m)PAR4 is the only thrombin receptor expressed by platelets. We here sought to determine the contribution of mPAR4 to the host response during pneumococcal pneumonia. Pneumonia was induced by intranasal inoculation with S. pneumoniae in mPAR4-deficient (par4-/-) and wild-type mice. Mice were sacrificed after 6, 24 or 48 hours (h). Blood, lungs, liver and spleen were collected for analyses. Ex vivo stimulation assays were performed with S. pneumoniae and mPAR4 activating peptides. At 48 h after infection, higher bacterial loads were found in the lungs and blood of par4-/- mice (p pneumoniae. Thrombin inhibition resulted in decreased cytokine release after S. pneumoniae stimulation in human whole blood. Our findings suggest that mPAR4 contributes to antibacterial defence during murine pneumococcal pneumonia.

  12. Single immunoglobulin interleukin-1 receptor-related molecule impairs host defense during pneumonia and sepsis caused by Streptococcus pneumoniae.

    Blok, Dana C; van Lieshout, Miriam H P; Hoogendijk, Arie J; Florquin, Sandrine; de Boer, Onno J; Garlanda, Cecilia; Mantovani, Alberto; van't Veer, Cornelis; de Vos, Alex F; van der Poll, Tom

    2014-01-01

    Streptococcus pneumoniae is a common cause of pneumonia and sepsis. Toll-like receptors (TLRs) play a pivotal role in the host defense against infection. In this study, we sought to determine the role of single immunoglobulin interleukin-1 receptor-related molecule (SIGIRR a.k.a. TIR8), a negative regulator of TLR signaling, in pneumococcal pneumonia and sepsis. Wild-type and SIGIRR-deficient (sigirr-/-) mice were infected intranasally (to induce pneumonia) or intravenously (to induce primary sepsis) with S. pneumoniae and euthanized after 6, 24, or 48 h for analyses. Additionally, survival studies were performed. sigirr-/- mice showed delayed mortality during lethal pneumococcal pneumonia. Accordingly, sigirr-/- mice displayed lower bacterial loads in lungs and less dissemination of the infection 24 h after the induction of pneumonia. SIGIRR deficiency was associated with increased interstitial and perivascular inflammation in lung tissue early after infection, with no impact on neutrophil recruitment or cytokine production. sigirr-/- mice also demonstrated reduced bacterial burdens at multiple body sites during S. pneumoniae sepsis. sigirr-/- alveolar macrophages and neutrophils exhibited an increased capacity to phagocytose viable pneumococci. These results suggest that SIGIRR impairs the antibacterial host defense during pneumonia and sepsis caused by S. pneumoniae.

  13. Prevalence of Streptococcus pneumoniae resistance to penicillin in two hospitals of Caxias do Sul

    Spiandorello Wilson Paloschi

    2003-01-01

    Full Text Available Streptococcus pneumoniae resistance to penicillin was studied in two hospitals in Caxias do Sul, Rio Grande do Sul, Brazil, between May 1998 and November 2001. From the 176 strains of invasive Streptococcus pneumoniae that were identified, 2.28% (CI 0.62-5.74 presented intermediate resistance, and 3.42% (CI 1.26-7.31 presented high-level resistance. The conclusion was that in Caxias do Sul the use of penicillin was still justified as treatment of pneumococcal pneumonia, differently from other centers where penicillin was replaced by other antibiotics. These results confirm the statement of IDSA (Infectious Diseases Society of America guideline for the management of community-acquired pneumonia in adults, that the choice of antimicrobial drug to treat pneumococcal pneumonia should be guided by local or regional prevalence of resistance to penicillin.

  14. Septic arthritis of shoeulder caused by Streptococcus pneumoniae serotype 23F in a female infant. Report of a case

    Flores Nava Gerardo

    2014-07-01

    Full Text Available We present the case of a female infant previously vaccinated against Streptococcus pneumoniae who developed a septic arthritis in the right shoulder. An artrothomy was performed. The culture of the sy- novial fluid was positive for serotype 23F Streptococcus pneumonia.

  15. Lung abscess due to Streptococcus pneumoniae simulating pulmonary tuberculosis: presentation of two cases

    Alessandro Perazzo

    2014-03-01

    Full Text Available In the past, anaerobes were the most common cause of community-acquired lung abscess; Streptococcus species were the second most common cause. In recent years, this has changed. Klebsiella pneumoniae is now most common cause of community- acquired lung abscess, although Streptococcus species remain pathogen of major importance. We present two cases of pulmonary cavitation due to Streptococcus pneumoniae which resembled pulmonary tuberculosis with regards to their history and radiological findings. These are examples of a common diagnosis presenting in an uncommon way. Our cases had some peculiarities: they had a clinical picture strongly suggestive of pulmonary tuberculosis or lung cancer rather than necrotizing infectious pneumonia in patients with no comorbidities or underlying diseases (including oral or dental pathologies. Radiological findings did not help the clinicians: pulmonary tuberculosis was the first diagnostic hypothesis in both cases. An underlying lung cancer was excluded in the first case only after invasive pulmonary procedures.

  16. Serotype Distribution, Antimicrobial Susceptibility, and Molecular Epidemiology of Streptococcus pneumoniae Isolated from Children in Shanghai, China.

    Fen Pan

    Full Text Available Streptococcus pneumoniae is a common pathogenic cause of pediatric infections. This study investigated the serotype distribution, antimicrobial susceptibility, and molecular epidemiology of pneumococci before the introduction of conjugate vaccines in Shanghai, China.A total of 284 clinical pneumococcal isolates (270, 5, 4,3, and 2 of which were isolated from sputum, bronchoalveolar lavage fluid, blood, cerebral spinal fluid, and ear secretions, respectively from children less than 14 years of age who had not been vaccinated with a conjugate vaccine, were collected between January and December in 2013. All isolates were serotyped by multiplex polymerase chain reaction or quellung reactions and antimicrobial susceptibility testing was performed using the broth microdilution method. The molecular epidemiology of S.pneumoniae was analyzed by multilocus sequence typing (MLST.Among the 284 pneumococcal isolates, 19F (33.5%, 19A (14.1%, 23F (12.0%, and 6A (8.8% were the most common serotypes and the coverage rates of the 7-, 10-, and 13-valent pneumococcal conjugate vaccines (PCV7, PCV10, and PCV13 were 58.6%, 59.4% and 85.1%, respectively. Antimicrobial susceptibility showed that the prevalence rates of S.pneumoniae resistance to penicillin were 11.3% (32/284. Approximately 88.0% (250/284 of the isolates exhibited multi-drug resistance. MLST analysis revealed a high level of diversity, with 65 sequence types (STs among 267 isolates. Specifically, the four predominant STs were ST271 (24.3%, 65/267, ST320 (11.2%, 30/267, ST81 (9.7%, 26/267, and ST3173 (5.2%, 14/267, which were mainly associated with serotypes 19F, 19A, 23F, and 6A, respectively.The prevalent serotypes among clinical isolates from children were 19F, 19A, 23F, and 6A and these isolates showed high resistance rates to β-lactams and macrolides. The Taiwan19F-14 clone played a predominant role in the dissemination of pneumococcal isolates in Shanghai, China. Therefore, continued and

  17. The Streptococcus pneumoniae pilus-1 displays a biphasic expression pattern.

    Gabriella De Angelis

    Full Text Available The Streptococcus pneumoniae pilus-1 is encoded by pilus islet 1 (PI-1, which has three clonal variants (clade I, II and III and is present in about 30% of clinical pneumococcal isolates. In vitro and in vivo assays have demonstrated that pilus-1 is involved in attachment to epithelial cells and virulence, as well as protection in mouse models of infection. Several reports suggest that pilus-1 expression is tightly regulated and involves the interplay of numerous genetic regulators, including the PI-1 positive regulator RlrA. In this report we provide evidence that pilus expression, when analyzed at the single-cell level in PI-1 positive strains, is biphasic. In fact, the strains present two phenotypically different sub-populations of bacteria, one that expresses the pilus, while the other does not. The proportions of these two phenotypes are variable among the strains tested and are not influenced by genotype, serotype, growth conditions, colony morphology or by the presence of antibodies directed toward the pilus components. Two sub-populations, enriched in pilus expressing or not expressing bacteria were obtained by means of colony selection and immuno-detection methods for five strains. PI-1 sequencing in the two sub-populations revealed the absence of mutations, thus indicating that the biphasic expression observed is not due to a genetic modification within PI-1. Microarray expression profile and western blot analyses on whole bacterial lysates performed comparing the two enriched sub-populations, revealed that pilus expression is regulated at the transcriptional level (on/off regulation, and that there are no other genes, in addition to those encoded by PI-1, concurrently regulated across the strains tested. Finally, we provide evidence that the over-expression of the RrlA positive regulator is sufficient to induce pilus expression in pilus-1 negative bacteria. Overall, the data presented here suggest that the observed biphasic pilus

  18. Bridging Chromosomal Architecture and Pathophysiology of Streptococcus pneumoniae

    Ferrándiz, María J.; de la Campa, Adela G.

    2017-01-01

    The chromosome of Streptococcus pneumoniae is organized into topological domains based on its transcriptional response to DNA relaxation: Up-regulated (UP), down-regulated (DOWN), nonregulated (NR), and AT-rich. In the present work, NR genes found to have highly conserved chromosomal locations (17% of the genome) were categorized as members of position-conserved nonregulated (pcNR) domains, while NR genes with a variable position (36% of the genome) were classified as members of position-variable nonregulated (pvNR) domains. On average, pcNR domains showed high transcription rates, optimized codon usage, and were found to contain only a small number of RUP/BOX/SPLICE repeats. They were also poor in exogenous genes but enriched in leading strand genes that code for proteins involved in primary metabolism with central roles within the interactome. In contrast, pvNR genes coding for cell wall proteins, paralogs, virulence factors and immunogenic candidates for protein-based vaccines were found to be overrepresented. DOWN domains were enriched in genes essential for infection. Many UP and DOWN domain genes were seen to be activated during different stages of competence, whereas pcNR genes tended to be repressed until the competence was switched off. Pneumococcal genes appear to be subject to a topology-driven selection pressure that defines the chromosomal location of genes involved in metabolism, virulence and competence. The pcNR domains are interleaved between UP and DOWN domains according to a pattern that suggests the existence of macrodomain entities. The term “topogenomics” is here proposed to describe the study of the topological rules of genomes and their relationship with physiology. PMID:28158485

  19. Streptococcus pneumoniae: estudo das cepas isoladas de liquor Streptococcus pneumoniae: a study of strains isolated from cerebrospinal fluid

    Ataiza C. Vieira

    2007-02-01

    Full Text Available OBJETIVO: Determinar a freqüência dos sorotipos capsulares e a susceptibilidade antimicrobiana de cepas de Streptococcus pneumoniae, assim como dar suporte à indicação de vacinas disponíveis e ao uso de antimicrobianos. MÉTODOS: Neste estudo retrospectivo, foram adotadas metodologias padronizadas para identificar, sorotipar e determinar a susceptibilidade à penicilina, cefotaxima e vancomicina. O estudo foi realizado com cepas de pneumococo isoladas de liquor em pacientes atendidos nos hospitais públicos e em três hospitais particulares do Distrito Federal no período de janeiro de 1995 a dezembro de 2004. A identificação e a determinação de susceptibilidade a antimicrobianos foi realizada no Laboratório Central de Saúde Pública no Distrito Federal. A sorotipagem foi realizada no Instituto Adolfo Lutz. RESULTADOS: Foram isoladas 232 cepas de pneumococo, compreendendo 126 cepas (54,31% de pacientes do sexo masculino. A idade dos pacientes variou de 0 a 62 anos, sendo agrupados em faixas etárias de 0 a 5, 6 a 17, 18 a 50 e acima de 50 anos. Identificaram-se 36 sorotipos distintos. Desses destacaram-se oito: 14, 6B, 18C, 5, 19F, 23F, 9V e 6A. O teste de oxacilina caracterizou 67 cepas resistentes à penicilina; dessas, 47 foram confirmadas pelo E teste com resistência de nível intermediário. Nenhuma cepa apresentou resistência de alto nível. CONCLUSÃO: A resistência do pneumococo à penicilina apresentou um aumento gradativo nos últimos 10 anos no Distrito Federal. Os sorotipos mais isolados na faixa etária de 0 a 5 anos foram também os mais envolvidos na resistência à penicilina, e estão incluídos na vacina 7-valente.OBJECTIVE: To determine the frequency of capsular serotypes and the antimicrobial susceptibility of strains of Streptococcus pneumoniae, as well as to provide recommendations on the use of available vaccines and antimicrobial drugs. METHODS: In this retrospective study, standard procedures were followed

  20. C-type Lectin Mincle Recognizes Glucosyl-diacylglycerol of Streptococcus pneumoniae and Plays a Protective Role in Pneumococcal Pneumonia.

    Behler-Janbeck, Friederike; Takano, Tomotsugu; Maus, Regina; Stolper, Jennifer; Jonigk, Danny; Tort Tarrés, Meritxell; Fuehner, Thomas; Prasse, Antje; Welte, Tobias; Timmer, Mattie S M; Stocker, Bridget L; Nakanishi, Yoichi; Miyamoto, Tomofumi; Yamasaki, Sho; Maus, Ulrich A

    2016-12-01

    Among various innate immune receptor families, the role of C-type lectin receptors (CLRs) in lung protective immunity against Streptococcus pneumoniae (S. pneumoniae) is not fully defined. We here show that Mincle gene expression was induced in alveolar macrophages and neutrophils in bronchoalveolar lavage fluids of mice and patients with pneumococcal pneumonia. Moreover, S. pneumoniae directly triggered Mincle reporter cell activation in vitro via its glycolipid glucosyl-diacylglycerol (Glc-DAG), which was identified as the ligand recognized by Mincle. Purified Glc-DAG triggered Mincle reporter cell activation and stimulated inflammatory cytokine release by human alveolar macrophages and alveolar macrophages from WT but not Mincle KO mice. Mincle deficiency led to increased bacterial loads and decreased survival together with strongly dysregulated cytokine responses in mice challenged with focal pneumonia inducing S. pneumoniae, all of which was normalized in Mincle KO mice reconstituted with a WT hematopoietic system. In conclusion, the Mincle-Glc-DAG axis is a hitherto unrecognized element of lung protective immunity against focal pneumonia induced by S. pneumoniae.

  1. Translation quality control is maintained by the penicillin resistance factor MurM in Streptococcus pneumoniae

    Shepherd, Jennifer; Ibba, Michael

    2013-01-01

    Streptococcus pneumoniae is a causative agent of nosocomial infections such as pneumonia, meningitis and septicaemia. Penicillin resistance in S. pneumoniae depends in part upon MurM, an aminoacyl-tRNA-ligase that attaches L-serine or L-alanine to the stem peptide lysine of Lipid II in cell wall....... pneumoniae tRNAPhe has an unusual U4:C69 mismatch in its acceptor stem that prevents editing by phenylalanyl-tRNA synthetase (PheRS), leading to the accumulation of misaminoacylated tRNAs that could serve as substrates for translation or for MurM. Whilst the peptidoglycan layer of S. pneumoniae tolerates...... a combination of both branched and linear muropeptides, deletion of MurM results in a reversion to penicillin sensitivity in strains that were previously resistant. However, since MurM is not required for cell viability, the reason for its functional conservation across all strains of S. pneumoniae has remained...

  2. Determination of penicillin susceptibility of Streptococcus pneumoniae using the polymerase chain reaction.

    Jalal, H; Organji, S.; Reynolds, J.; Bennett, D; O'Mason, E.; Millar, M R

    1997-01-01

    AIM: To develop a polymerase chain reaction (PCR) based method to detect penicillin susceptibility in isolates of Streptococcus pneumoniae (SP). METHOD: PCR primers were designed to amplify differential nucleotide sequences of the penicillin-binding protein (PBP) genes 2b, 2x, and 1a in penicillin susceptible and resistant strains of SP. Primers derived from the PBP 2x and 2b genes were designed to amplify products from penicillin susceptible S pneumoniae (PSSP), whereas primers derived from ...

  3. Characteristics and Outcome of Streptococcus pneumoniae Endocarditis in the XXI Century

    de Egea, Viviana; Muñoz, Patricia; Valerio, Maricela; de Alarcón, Arístides; Lepe, José Antonio; Miró, José M.; Gálvez-Acebal, Juan; García-Pavía, Pablo; Navas, Enrique; Goenaga, Miguel Angel; Fariñas, María Carmen; Vázquez, Elisa García; Marín, Mercedes; Bouza, Emilio; ,

    2015-01-01

    Abstract Streptococcus pneumoniae is an infrequent cause of severe infectious endocarditis (IE). The aim of our study was to describe the epidemiology, clinical and microbiological characteristics, and outcome of a series of cases of S. pneumoniae IE diagnosed in Spain and in a series of cases published since 2000 in the medical literature. We prospectively collected all cases of IE diagnosed in a multicenter cohort of patients from 27 Spanish hospitals (n = 2539). We also performed a systema...

  4. Drug-resistance in Streptococcus pneumoniae isolates among Spanish middle aged and older adults with community-acquired pneumonia

    Raga-Luria Xavier

    2009-03-01

    Full Text Available Abstract Background Pneumococcal diseases remain a major cause of morbidity and mortality worldwide. Updated data on drug-resistance from different populations may be important to recognize changes in disease patterns. This study assessed current levels of penicilin resistance among Streptococcus Pneumoniae causing pneumonia in Spanish middle age and older adults. Methods Antimicrobial susceptibility was tested for 104 consecutive isolates of Streptococcus pneumoniae recovered from patients 50 years or older with radiographically confirmed pneumonia in the region of Tarragona (Spain between 2002 and 2007. According to the minimum inhibitory concentration of tested antimicrobials (penicillin, erythromycin, cefotaxime and levofloxacin strains were classified as susceptible or resistant. Antimicrobial resistance was determined for early cases (2002–2004 and contemporary cases (2005–2007. Results Twenty-seven (25.9% were penicillin-resistant strains (19 strains with intermediate resistance and 8 strains with high resistance. Penicillin-resistance was higher in 2002–2004 than in 2005–2007 (39.5% vs 18.2%, p = 0.017. Of 27 penicillin-resistant strains, 10 (37% were resistant to erythromycin, 8 (29.6% to cefotaxime, 2 (7.4% to levofloxacin, and 4 (14.8% were identified as multidrug resistant. Case-fatality rate was higher among those patients who had an infection caused by any penicillin susceptible strain (16.9% than in those with infections due to penicillin-resistant strains. Conclusion Resistance to penicillin among Streptococcus pneumoniae remains high, but such resistance does not result in increased mortality in patients with pneumococcal pneumonia.

  5. Persistence and complex evolution of fluoroquinolone-resistant Streptococcus pneumoniae clone.

    Ben-David, Debby; Schwaber, Mitchell J; Adler, Amos; Masarwa, Samira; Edgar, Rotem; Navon-Venezia, Shiri; Schwartz, David; Porat, Nurith; Kotlovsky, Tali; Polivkin, Nikolay; Weinberg, Irina; Lazary, Avraham; Ohana, Nissim; Dagan, Ron

    2014-05-01

    Prolonged outbreaks of multidrug-resistant Streptococcus pneumoniae in health care facilities are uncommon. We found persistent transmission of a fluroquinolone-resistant S. pneumoniae clone during 2006-2011 in a post-acute care facility in Israel, despite mandatory vaccination and fluoroquinolone restriction. Capsular switch and multiple antimicrobial nonsusceptibility mutations occurred within this single clone. The persistent transmission of fluoroquinolone-resistant S. pneumoniae during a 5-year period underscores the importance of long-term care facilities as potential reservoirs of multidrug-resistant streptococci.

  6. Acute suppurative parotitis caused by Streptococcus pneumoniae in an HIV-infected man.

    Guzman Vinasco, Luis; Bares, Sara; Sandkovsky, Uriel

    2015-03-02

    We report a case of a 32-year-old man who presented with progressive unilateral parotid gland enlargement and subsequently tested positive for HIV. A CT scan of the neck performed with contrast showed a phlegmon in the region of the right parotid tail measuring approximately 2.5×2.4 cm. Cultures of the aspirated fluid grew Streptococcus pneumoniae and the S. pneumoniae urinary antigen test was also positive. The patient underwent surgical debridement and received antimicrobial therapy with complete resolution of the parotitis. Parotitis caused by S. pneumoniae is rare, and HIV infection should be suspected in any case of invasive pneumococcal disease.

  7. Amoxicillin is effective against penicillin-resistant Streptococcus pneumoniae strains in a mouse pneumonia model simulating human pharmacokinetics.

    Abgueguen, Pierre; Azoulay-Dupuis, Esther; Noel, Violaine; Moine, Pierre; Rieux, Veronique; Fantin, Bruno; Bedos, Jean-Pierre

    2007-01-01

    High-dose oral amoxicillin (3 g/day) is the recommended empirical outpatient treatment of community-acquired pneumonia (CAP) in many European guidelines. To investigate the clinical efficacy of this treatment in CAP caused by Streptococcus pneumoniae strains with MICs of amoxicillin > or =2 microg/ml, we used a lethal bacteremic pneumonia model in leukopenic female Swiss mice with induced renal failure to replicate amoxicillin kinetics in humans given 1 g/8 h orally. Amoxicillin (15 mg/kg of body weight/8 h subcutaneously) was given for 3 days. We used four S. pneumoniae strains with differing amoxicillin susceptibility and tolerance profiles. Rapid bacterial killing occurred with an amoxicillin-susceptible nontolerant strain: after 4 h, blood cultures were negative and lung homogenate counts under the 2 log(10) CFU/ml detection threshold (6.5 log(10) CFU/ml in controls, P pneumonia due to S. pneumoniae for which MICs were 2 to 4 microg/ml. The killing rate depends not only on resistance but also on tolerance of the S. pneumoniae strains.

  8. Cysteine-Mediated Gene Expression and Characterization of the CmbR Regulon in Streptococcus pneumoniae

    Afzal, Muhammad; Manzoor, Irfan; Kuipers, Oscar P; Shafeeq, Sulman

    2016-01-01

    In this study, we investigated the transcriptomic response of Streptococcus pneumoniae D39 to cysteine. Transcriptome comparison of the D39 wild-type grown at a restricted concentration of cysteine (0.03 mM) to one grown at a high concentration of cysteine (50 mM) in chemically-defined medium (CDM)

  9. Carriage of streptococcus pneumoniae 3 years after start of vaccination program, the Netherlands

    Spijkerman, J.; van Gils, E.J.M.; Veenhoven, R.H.; Hak, E.; Yzerman, E.P.F.; van der Ende, A.; Wijmenga-Monsuur, A.J.; van den Dobbelsteen, G.P.J.M.; Sanders, E.A.M.

    2011-01-01

    To evaluate the effectiveness of the 7-valent pneumococcal conjugate vaccine (PCV7) program, we conducted a cross-sectional observational study on nasopharyngeal carriage of Streptococcus pneumoniae 3 years after implementation of the program in the Netherlands. We compared pneumococcal serotypes in

  10. The ParB-parS Chromosome Segregation System Modulates Competence Development in Streptococcus pneumoniae

    Attaiech, Laetitia; Minnen, Anita; Kjos, Morten; Gruber, Stephan; Veening, Jan-Willem

    2015-01-01

    UNLABELLED: ParB proteins bind centromere-like DNA sequences called parS sites and are involved in plasmid and chromosome segregation in bacteria. We previously showed that the opportunistic human pathogen Streptococcus pneumoniae contains four parS sequences located close to the origin of replicati

  11. Streptococcus pneumoniae: the evolution of antimicrobial resistance to beta-lactams, fluoroquinolones and macrolides.

    Cornick, J E; Bentley, S D

    2012-07-01

    Multi drug resistant Streptococcus pneumoniae constitute a major public health concern worldwide. In this review we discuss how the transformable nature of the pneumococcus, in parallel with antimicrobial induced stress, contributes to the evolution of antimicrobial resistance; and how the introduction of the pneumococcal conjugate vaccine has affected the situation.

  12. Extensively drug-resistant Streptococcus pneumoniae, South Korea, 2011-2012.

    Cho, Sun Young; Baek, Jin Yang; Kang, Cheol-In; Kim, So Hyun; Ha, Young Eun; Chung, Doo Ryeon; Lee, Nam Yong; Peck, Kyong Ran; Song, Jae-Hoon

    2014-05-01

    To better understand extensively drug resistant Streptococcus pneumoniae, we assessed clinical and microbiological characteristics of 5 extensively drug-resistant pneumococcal isolates. We concluded that long-term care facility residents who had undergone tracheostomy might be reservoirs of these pneumococci; 13- and 23-valent pneumococcal vaccines should be considered for high-risk persons; and antimicrobial drugs should be used judiciously.

  13. Temporary increase of invasive infection due to Streptococcus pneumoniae in the Netherlands.

    Neeling, A.J. de; Pelt, W. van; Hol, C.; Ligtvoet, E.E.J.; Sabbe, L.J.M.; Bartelds, A.; Embden, J.D.A. van

    1999-01-01

    In 1996 and 1997, the Netherlands Reference Laboratory for Bacterial Meningitis (Amsterdam) noted an increase in Streptococcus pneumoniae isolates from blood but not from CSF. To find an explanation for this increase, we determined the incidence of invasive pneumococcal disease detected in the perio

  14. Transcriptional profiling of UlaR-regulated genes in Streptococcus pneumoniae

    Shafeeq, Sulman; Afzal, Muhammad; Henriques-Normark, Birgitta; Kuipers, Oscar P

    2015-01-01

    The transcriptional regulator UlaR belongs to the family of PRD-containing transcriptional regulators, which are mostly involved in the regulation of carbohydrate metabolism. The role of the transcriptional regulator UlaR in Streptococcus pneumoniae has recently been described [1]. Here, we report d

  15. Pyruvate Oxidase Influences the Sugar Utilization Pattern and Capsule Production in Streptococcus pneumoniae

    Carvalho, Sandra M.; Farshchi Andisi, Vahid; Gradstedt, Henrik; Neef, Jolanda; Kuipers, Oscar P.; Neves, Ana R.; Bijlsma, Jetta J. E.

    2013-01-01

    Pyruvate oxidase is a key function in the metabolism and lifestyle of many lactic acid bacteria and its activity depends on the presence of environmental oxygen. In Streptococcus pneumoniae the protein has been suggested to play a major role in metabolism and has been implicated in virulence, oxidat

  16. Draft Genome Sequence of the Streptococcus pneumoniae Avery Strain A66

    Hahn, Christoph; Harrison, Ewan M.; Parkhill, Julian; Holmes, Mark A.; Paterson, Gavin K.

    2015-01-01

    We have used HiSeq 2000 technology to generate a draft genome sequence of Streptococcus pneumoniae strain A66. This is a common study strain used in investigations of pneumococcal bacterium-host interactions and was used in the seminal genetic studies of Avery et al.

  17. Bilateral Acromioclavicular Septic Arthritis as an Initial Presentation of Streptococcus pneumoniae Endocarditis

    Neda Hashemi-Sadraei

    2014-01-01

    Full Text Available Infective endocarditis (IE is infrequently associated with septic arthritis. Moreover, septic arthritis of the acromioclavicular (AC joint is rarely reported in the literature. We report a case of Streptococcus pneumoniae IE in a patient who presented with bilateral AC joint septic arthritis and we review the literature on the topic.

  18. Transcriptome analysis of Streptococcus pneumoniae D39 in the presence of cobalt

    Manzoor, Irfan; Shafeeq, Sulman; Kuipers, Oscar

    2015-01-01

    Cobalt (Co2 +) is an important transition metal ion that plays a vital role in cellular physiology of bacteria. The role of Co2 + in the regulation of several genes/operons in Streptococcus pneumoniae has recently been reported [1]. The data described in this article relate to the genome-wide transc

  19. Bartholinitis caused by Streptococcus pneumoniae : Case report and review of literature

    Parvathi S

    2009-04-01

    Full Text Available Most of the Bartholin′s gland abscesses have been thought to be caused by colonizing micro-organisms of the perineal region. We encountered an interesting case of acute Bartholins abscess caused by Streptococcus pneumoniae in a primigravida. The abscess was incised and drained. The patient was treated with Cefuroxime. This case is presented for its rarity.

  20. Multidrug-resistant Streptococcus pneumoniae in Poland: identification of emerging clones

    K. Overweg (Karin); P.W.M. Hermans (Peter); K. Trzcinski; M. Sluijter (Marcel); W. Hryniewicz

    1999-01-01

    textabstractPenicillin resistance among Streptococcus pneumoniae isolates has rapidly emerged in Poland during the last decade and has reached prevalence levels of up to 14.4% in 1997. In order to investigate the nature of this increase, a molecular epidemiological anal

  1. Antimicrobial susceptibility of Streptococcus pneumoniae isolates from vaccinated and non-vaccinated patients with a clinically confirmed diagnosis of community-acquired pneumonia in Belgium.

    Lismond, Ann; Carbonnelle, Sylviane; Verhaegen, Jan; Schatt, Patricia; De Bel, Annelies; Jordens, Paul; Jacobs, Frédérique; Dediste, Anne; Verschuren, Frank; Huang, Te-Din; Tulkens, Paul M; Glupczynski, Youri; Van Bambeke, Françoise

    2012-03-01

    We assessed the in vitro susceptibility of Streptococcus pneumoniae isolates from patients with confirmed community-acquired pneumonia (CAP) to β-lactams, macrolides and fluoroquinolones and the association of non-susceptibility and resistance with serotypes/serogroups (STs/SGs), patient's risk factors and vaccination status. Samples (blood or lower respiratory tract) were obtained in 2007-2009 from 249 patients (from seven hospitals in Belgium) with a clinical and radiological diagnosis of CAP [median age 61 years (11.6% aged 94% ST19A), 73.5% resistant to macrolides and 18-21% intermediate to β-lactams; and SG6, 33% resistant to clarithromycin. Apparent vaccine failures: 3/17 for 7-valent vaccine (children; ST6B, 23F); 16/29 for 23-valent vaccine (adults ST3, 7F, 12F, 14, 19A, 22F, 23F, 33F). Isolates from nursing home residents, hospitalised patients and patients with non-respiratory co-morbidities showed increased MICs for amoxicillin, all β-lactams, and β-lactams and macrolides, respectively. Regarding antibiotic susceptibilities: (i) amoxicillin is still useful for empirical therapy but with a high daily dose; (ii) cefuroxime axetil and macrolides (but not telithromycin) are inappropriate for empirical therapy; and (iii) moxifloxacin and levofloxacin are the next 'best empirical choice' (no resistant isolates) but levofloxacin will require 500 mg twice-daily dosing for effective coverage.

  2. Uji Daya Hambat Ekstrak Buah Belimbing Manis (Averrhoa carambola terhadap Pertumbuhan Bakteri Streptococcus pneumoniae secara In Vitro

    Rita Risandi

    2016-09-01

    Full Text Available AbstrakBuah belimbing manis (Averrhoa carambola merupakan salah satu tanaman Indonesia yang diyakini memiliki khasiat obat. Salah satu manfaat yang dapat diambil dari sari buah belimbing manis (Averrhoa carambola adalah dapat mengobati radang tenggorokan. Radang tenggorokan merupakan salah satu infeksi yang disebabkan oleh bakteri Streptococcus pneumoniae. Tujuan penelitian ini adalah menentukan daya hambat ekstrak buah belimbing manis (Averrhoa carambola terhadap pertumbuhan bakteri Streptococcus pneumoniae  secara in vitro. Metode studi ini ialah eksperimental dengan desain postest only control group design yang dilakukan di Laboratorium Biota Sumatera Universitas Andalas dan Laboratorium Mikrobiologi Fakultas Kedokteran Universitas Andalas dari Agustus sampai Oktober 2014. Hasil penelitian menunjukkan bahwa ekstrak buah belimbing manis (Averrhoa carambola dengan konsentrasi yaitu 5%, 10%, 15% dan 20% tidak memiliki daya hambat terhadap pertumbuhan bakteri Streptococcus pneumoniae.  Hal ini terbukti karena tidak terbentuk zona hambat pada agar darah dan tidak terdapat pengaruh lama kontak ekstrak buah belimbing manis (Averrhoa carambola  terhadap pertumbuhan bakteri Streptococcus pneumoniae secara in vitro. Ekstrak buah belimbing manis tidak memiliki efek antibakteri terhadap pertumbuhan bakteri Streptococcus pneumoniae.Kata kunci: ekstrak buah belimbing manis, Streptococcus pneumoniae, daya hambat Abstract             Star fruit (Averrhoa carambola is a Indonesian plant that is believed to have medicinal properties. One of the benefits that can be drawn from the juice of star fruit (Averrhoa carambola is the ability to treat strep throat. Strep throat is a bacterial infection caused by Streptococcus pneumoniae. The objective of this study was to determine the inhibitory extract of star fruit (Averrhoa carambola on the growth of the bacterium Streptococcus pneumoniae in vitro. This was an experimental  research  with design

  3. Streptococcus pneumoniae Supragenome Hybridization Arrays for Profiling of Genetic Content and Gene Expression.

    Kadam, Anagha; Janto, Benjamin; Eutsey, Rory; Earl, Joshua P; Powell, Evan; Dahlgren, Margaret E; Hu, Fen Z; Ehrlich, Garth D; Hiller, N Luisa

    2015-02-02

    There is extensive genomic diversity among Streptococcus pneumoniae isolates. Approximately half of the comprehensive set of genes in the species (the supragenome or pangenome) is present in all the isolates (core set), and the remaining is unevenly distributed among strains (distributed set). The Streptococcus pneumoniae Supragenome Hybridization (SpSGH) array provides coverage for an extensive set of genes and polymorphisms encountered within this species, capturing this genomic diversity. Further, the capture is quantitative. In this manner, the SpSGH array allows for both genomic and transcriptomic analyses of diverse S. pneumoniae isolates on a single platform. In this unit, we present the SpSGH array, and describe in detail its design and implementation for both genomic and transcriptomic analyses. The methodology can be applied to construction and modification of SpSGH array platforms, as well to other bacterial species as long as multiple whole-genome sequences are available that collectively capture the vast majority of the species supragenome.

  4. Antimicrobial resistance and serotyping of Streptococcus pneumoniae isolated from pediatric patients in Belo Horizonte, MG, Brazil Resistência antimicrobiana e sorotipagem de Streptococcus pneumoniae isolado de pacientes pediátricos em Belo Horizonte, MG

    Ana Paula Gomes de Oliveira Magalhães

    2003-07-01

    Full Text Available Thirty one Streptococcus pneumoniae invasive strains were isolated from a pediatric population in Belo Horizonte from June, 1999 to May, 2001. Penicillin, trimethoprim-sulfamethoxazole, tetracycline and chloramphenicol resistance rates for the isolates were 41.9, 58.1, 25.8 and 3.2%, respectively. Intermediate penicillin resistant (MICs between 0.1 and 1.0 µg/ml and resistant (MICs > 2.0 µg/ml isolates occured at rates of 38.7 and 3.2%, respectively. Resistance to erythromycin, ofloxacin, rifampin or vancomicyn was not detected. Ten S. pneumoniae serotypes (14, 5, 10 A, 6B, 15B, 18C, 6 A, 18 A, 19 A and 19 F were identified. Serotype 14 (12 out of 31 was predominant among the isolates. Penicillin and trimethoprim-sulfamethoxazole resistance was more common in 14 and 6B serotypes.Trinta e três linhagens invasivas do S. pneumoniae foram isoladas a partir de pacientes pediátricos em Belo Horizonte, MG, Brasil, de junho de 1999 a maio de 2001. As taxas de resistência à penicilina, ao trimetoprim-sultametoxazol, tetraciclina e cloranfenicol foram respectivamente, 41, 9; 58,1 e 3,2%. A resistência intermediária à penicilina (MICs entre 0,1 e 1,0 µg/ml e resistência total (MICs>2.0 µg/ml ocorreram, respectivamente, nas porcentagens de 38,7 e 3,2%. Não foi detectada resistência à eritromicina, ofloxacin, rifampina e vancomicina. Foram identificados 9 sorotipos do S. pneumoniae (14, 5, 10 , 6B, 15B, 18C, 6 A, 18 19 A e 19F entre os isolados. O sorotipo 14 (12 de 31 foi predominate entre os isolados. A resistência à penicilina e ao trimetoprim-sulfametoxazol estava sempre associada aos sorotipos 14 e 6B.

  5. Molecular characteristics of penicillin-binding protein 2b, 2x and 1a sequences in Streptococcus pneumoniae isolates causing invasive diseases among children in Northeast China.

    Zhou, X; Liu, J; Zhang, Z; Liu, Y; Wang, Y; Liu, Y

    2016-04-01

    Streptococcus pneumoniae is one of the common pathogens causing severe invasive infections in children. This study aimed to investigate the serotype distribution and variations of penicillin-binding proteins (PBPs) 2b, 2x and 1a in S. pneumoniae isolates causing invasive diseases in Northeast China. A total of 256 strains were isolated from children with invasive pneumococcal disease (IPD) from January 2000 to October 2014. All strains were serotyped and determined for antibiotic resistance. The amplicons of penicillin-binding domains in pbp1a, pbp2b and pbp2x genes were sequenced for variation identification. The most prevalent serotypes of isolates in IPD children were 19A, 14, 19F, 23F and 6B. 19A and 19F were the most frequent serotypes of penicillin-resistant S. pneumoniae (PRSP), which present with high resistance to amoxicillin, cefotaxime, ceftriaxone and meropenem. The numbers of amino acid substitutions of penicillin-non-susceptible S. pneumoniae (PNSP) isolates were higher than those of penicillin-sensitive S. pneumoniae isolates in all the PBP genes (p pneumoniae were closely associated with resistance to β-lactam antibiotics. This study provides new data for further monitoring of genetic changes related to the emergence and spread of resistance to β-lactam antibiotics in China.

  6. High prevalence of multi-drug resistant Streptococcus pneumoniae among healthy children in Thailand.

    Thummeepak, Rapee; Leerach, Nontapat; Kunthalert, Duangkamol; Tangchaisuriya, Udomsak; Thanwisai, Aunchalee; Sitthisak, Sutthirat

    2015-01-01

    Antibiotic resistance in Streptococcus pneumoniae is an emerging health problem worldwide. The incidence of antimicrobial-resistant S. pneumoniae is increasing, and nasal colonization of S. pneumoniae in children increases the risk of pneumococcal infection. In this study, the prevalence of S. pneumoniae nasal colonization was studied in Thai children from three different districts. S. pneumoniae nasal colonization was found in 38 of 237 subjects (16.0%). The carriage rate indicated higher rates in two rural districts (18.2% and 29.8%) than in the urban district (2.8%). The antibiotic susceptibility pattern was determined using the disk diffusion method. Prevalence of multi-drug resistance S. pneumoniae (MDR-SP) was 31.6%. Resistance to commonly prescribed antibiotics was found for ampicillin (5.3%), azithromycin (26.3%), cefepime (2.6%), chloramphenicol (18.4%), clindamycin (18.4%), erythromycin (21.1%), oxacillin (44.7%), trimethoprim/sulfamethoxazole (78.9%) and tetracycline (15.8%). All isolates were sensitive to ceftriaxone. The pulsed-field gel electrophoresis pattern was used to compare genetic diversity of the S. pneumoniae isolates. PFGE demonstrated the variation in genotypes of S. pneumoniae from different areas. High prevalence of multi-drug resistance S. pneumoniae nasal colonization in healthy Thai children was indicated. Effective strategies for appropriate use of antibiotics are therefore needed in the community.

  7. Incidence of childhood pneumonia and serotype and sequence-type distribution in Streptococcus pneumoniae isolates in Japan.

    Tanaka, J; Ishiwada, N; Wada, A; Chang, B; Hishiki, H; Kurosaki, T; Kohno, Y

    2012-06-01

    The 7-valent pneumococcal conjugate vaccine (PCV7) is reported to decrease the incidence of community-acquired pneumonia (CAP) in children. To determine the annual incidence of CAP before the introduction of PCV7, we counted the number of children hospitalized with CAP between 2008 and 2009 in Chiba City, Japan. We investigated serotype and multilocus sequence typing (MLST) for Streptococcus pneumoniae isolates in CAP cases. The annual incidence of hospitalized CAP in children aged pneumoniae was dominant in 14.7% and 0.8% of sputum and blood samples, respectively. The most common serotypes were 6B, 23F and 19F. The coverage rates of PCV7 were 66.7% and 80% in sputum samples and blood samples, respectively. MLST analysis revealed 37 sequence types. Furthermore, 54.1% of the sputum isolates and 40% of the blood isolate were related to international multidrug-resistant clones.

  8. Rapid urine antigen testing for Streptococcus pneumoniae in adults with community-acquired pneumonia: clinical use and barriers.

    Harris, Aaron M; Beekmann, Susan E; Polgreen, Philip M; Moore, Matthew R

    2014-08-01

    Streptococcus pneumoniae (pneumococcus) is the most common bacterial etiology of community-acquired pneumonia (CAP) in adults, a leading cause of death. The majority of pneumococcal CAP is diagnosed by blood culture, which likely underestimates the burden of disease. The 2007 CAP guidelines recommend routine use of the rapid pneumococcal urinary antigen (UAg) test. To assess the how pneumococcal UAg testing is being used among hospitalized adult CAP patients and what barriers restrict its use, a Web-based survey was distributed in 2013 to 1287 infectious disease physician members of the Emerging Infectious disease Network of the Infectious Disease Society of America. Of 493 eligible responses, 65% use the pneumococcal UAg test. The primary barrier to UAg use was availability (46%). UAg users reported ordering fewer other diagnostic tests and tailoring antibiotic therapy. Increased access to UAg tests could improve pneumonia management and pneumococcal CAP surveillance.

  9. Garenoxacin activity against isolates form patients hospitalized with community-acquired pneumonia and multidrug-resistant Streptococcus pneumoniae.

    Jones, Ronald N; Sader, Helio S; Stilwell, Matthew G; Fritsche, Thomas R

    2007-05-01

    Community-acquired pneumonia (CAP) continues to cause significant morbidity worldwide, and the principal bacterial pathogens (Streptococcus pneumoniae and Haemophilus influenzae) have acquired numerous resistance mechanisms over the last few decades. CAP treatment guidelines have suggested the use of broader spectrum agents, such as antipneumococcal fluoroquinolones as the therapy for at-risk patient population. In this report, we studied 3087 CAP isolates from the SENTRY Antimicrobial Surveillance Program (1999-2005) worldwide and all respiratory tract infection (RTI) isolate population of pneumococci (14665 strains) grouped by antibiogram patterns against a new des-F(6)-quinolone, garenoxacin. Results indicated that garenoxacin was highly active against CAP isolates of S. pneumoniae (MIC(90), 0.06 microg/mL) and H. influenzae (MIC(90), 99.9% of strains were inhibited at pneumoniae strains to penicillin or erythromycin; however, coresistances were high among the beta-lactams (penicillins and cephalosporins), macrolides, tetracyclines, and trimethoprim/sulfamethoxazole. Analysis of S. pneumoniae isolates with various antimicrobial resistance patterns to 6 drug classes demonstrated that garenoxacin was active against >99.9% (MIC, pneumoniae that have created therapeutic dilemmas for all RTI presentations. Garenoxacin appears to be a welcome addition to the CAP treatment options, particularly for the emerging MDR pneumococci strains.

  10. The role of Streptococcus pneumoniae in community-acquired pneumonia among adults in Europe: a meta-analysis.

    Rozenbaum, M H; Pechlivanoglou, P; van der Werf, T S; Lo-Ten-Foe, J R; Postma, M J; Hak, E

    2013-03-01

    The primary objective of this meta-analysis was to estimate the prevalence of adult community-acquired pneumonia (CAP) caused by Streptococcus pneumoniae in Europe, adjusted for possible independent covariates. Two reviewers conducted a systematic literature search using PubMed on English-language articles that involved human subjects with CAP during the period from January 1990 to November 2011 across European countries. A mixed-effects meta-regression model was developed and populated with 24,410 patients obtained from 77 articles that met the inclusion criteria. The model showed that the observed prevalence of S. pneumoniae in CAP significantly varies between European regions, even after adjusting for explanatory covariates, including patient characteristics, diagnostic tests, antibiotic resistance, and health-care setting. The probability of detecting S. pneumoniae was substantially higher in studies that performed more frequently a diagnostic polymerase chain reaction assay compared to all the other diagnostic tests included. Furthermore, S. pneumoniae was more likely to be confirmed as the cause of a CAP in studies with intensive care unit patients as compared to those with hospital- or community-treated patients. This study provides estimates of the average observed prevalence of S. pneumoniae, which could be used for projecting the health and economic benefits of pneumococcal immunization.

  11. Determination of Characteristics of Erythromycin Resistant Streptococcus pneumoniae with Preferred PCV Usage in Iran

    Talebi, Malihe; Azadegan, Azadeh; Sadeghi, Javad; Ahmadi, Ali; Katouli, Mohammad

    2016-01-01

    Amongst 100 Streptococcus pneumoniae isolated from clinical cases and nasopharynx of healthy individuals, 60 erythromycin resistant strains were isolated and characterized using MLST, PFGE, transposon analysis and Quellung reaction. Most of the S. pneumoniae erythromycin resistant (80%) were found to be attributable to the ermB-edncoded ribosome methylase activity which differs from the dominant mechanism of macrolide resistance seen in North America. The most predominant transposons were; Tn1545/6003 (27%), Tn6002 (22%), Tn2009 (20%), Tn2010 (17%). Number of the clinical isolates carrying Tn2010 was more significant than the normal flora. The serotypes found were; 14 (33%), 3 (22%), 23F (15%), 19F (15%), 19A (7%), 6A (3%), 9V (3%) and 6B (2%). The most prevalent serotypes among the clinical (n = 28) and normal flora (n = 32) isolates were serotypes 14 (46%) and 3 (31%), respectively. The most prevalent vaccine serotypes amongst the clinical isolates and the healthy individuals were pneumococcal conjugate vaccines (PCV) 13 and PCV10, respectively. PFGE revealed 34 pulsotypes with 9 common and 25 single types. Significant number of the normal isolates belonged to CT5 and CT6. On the other hand, significant number of clinical isolates belonged to CT8 as compared to the normal flora isolates. MLST showed 2 dominant sequence types. ST3130 (23%) and ST180 (22%) were the most predominant sequence types in the clinical and normal isolates, respectively. There was no significant difference in other sequence types between clinical and normal flora isolates. Three polyclonal complexes including Sweden15A -25, Spain23F-1 and Spain9V-3 constituted 58% of the isolates. Our results suggest that the genetic diversity and transposon distribution were high among S. pneumoniae, particularly in the isolates containing erm(B) and double antibiotic resistant genes (erm/mef). The results presented here could influence the change in the current vaccination practices in Iran which

  12. [The prevalence of different Streptococcus pneumoniaе serotypes in the children presenting with ENT infections or carrying nasopharyngeal pathogens].

    Boronina, L G; Samatova, E V; Druĭ, A E; Panina, E Iu; Kochneva, N A; Vodovoz, N Iu; Murunova, N V; Gruzdev, A I; Lakhno, T I

    2013-01-01

    The objective of the present study was to elucidate the etiopathological significance of various Streptococcus pneumoniae serotypes in the children presenting with ENT infections and carrying nasopharyngeal pathogens. The incidence of the latter condition was 19.5% in the children free from S. pneumoniae infection in comparison with 20.9% and 30.7% in those having diagnosis of otitis media and rhinosinusitis respectively. Fifty five (88.8%) of the 62 isolated streptococcal strains were grouped into types with the use of multiplex PCR. Twelve serotypes were identified in the patients presenting with rhinosinusitis with the predominance of 6A/6B and 3 (40.5%) compared with seven isolated from the carriers of nasopharyngeal pathogens. In this group, type 3 also prevailed (26.5%) whereas other serotypes occurred less frequently: 23F (13,4%), indivisible totality of 8, 9V, 9A, 1F, 11A, 211B, 11C, 11D, 12F, 15A, and 33F (13.4%), 20 (6.7%), 19A (6.7%), 14 (6.7%), 6A,6B (6.7%). The serotypes of S. pneumoniae isolated from the patients with rhinosinusitis were found to show 55.3% identity with those present in the composition of the conjugated 7-valent pneumococcal vaccines, 63.2% identity with the 10-valent vaccine, 81.6% identity with the 11p-valnet vaccine, and 84.2% identity with the 13-valent vaccine.

  13. EARSS: European Antimicrobial Resistance Surveillance System; data from the Netherlands .Incidence and resistance rates for Streptococcus pneumoniae and Staphylococcus aureus

    Goettsch WG; de Neeling AJ; CIE; LIO

    2001-01-01

    Gevoeligheid voor antimicrobiele middelen in Streptococcus pneumoniae en Staphylococcus aureus werd bepaald in 1999 in Nederland binnen het raamwerk van het European antomicrobial Resistance Surveillance System (EARSS). Het EARSS project had in Nederland een dekkingsgraad van 40% van de Nederlandse

  14. EARSS: European Antimicrobial Resistance Surveillance System; data from the Netherlands .Incidence and resistance rates for Streptococcus pneumoniae and Staphylococcus aureus

    Goettsch WG; Neeling AJ de; CIE; LIO

    2001-01-01

    In a porspective prevalence and incidence survey in The Netherlands in 1999 antimicrobial susceptibility data on invasive Streptococcus pneumoniae and Staphylococcus aureus infections were collected sithin the framework of European Antomicrobial Resistance Surveillance System (EARSS). The EARSS proj

  15. Protective contributions against invasive Streptococcus pneumoniae pneumonia of antibody and Th17-cell responses to nasopharyngeal colonisation.

    Cohen, Jonathan M; Khandavilli, Suneeta; Camberlein, Emilie; Hyams, Catherine; Baxendale, Helen E; Brown, Jeremy S

    2011-01-01

    The nasopharyngeal commensal bacteria Streptococcus pneumoniae is also a frequent cause of serious infections. Nasopharyngeal colonisation with S. pneumoniae inhibits subsequent re-colonisation by inducing Th17-cell adaptive responses, whereas vaccination prevents invasive infections by inducing antibodies to S. pneumoniae capsular polysaccharides. In contrast, protection against invasive infection after nasopharyngeal colonisation with mutant S. pneumoniae strains was associated with antibody responses to protein antigens. The role of colonisation-induced Th17-cell responses during subsequent invasive infections is unknown. Using mouse models, we show that previous colonisation with S. pneumoniae protects against subsequent lethal pneumonia mainly by preventing bacteraemia with a more modest effect on local control of infection within the lung. Previous colonisation resulted in CD4-dependent increased levels of Th17-cell cytokines during subsequent infectious challenge. However, mice depleted of CD4 cells prior to challenge remained protected against bacteraemia, whereas no protection was seen in antibody deficient mice and similar protection could be achieved through passive transfer of serum. Serum from colonised mice but not antibody deficient mice promoted phagocytosis of S. pneumoniae, and previously colonised mice were able to rapidly clear S. pneumoniae from the blood after intravenous inoculation. Thus, despite priming for a Th17-cell response during subsequent infection, the protective effects of prior colonisation in this model was not dependent on CD4 cells but on rapid clearance of bacteria from the blood by antibody-mediated phagocytosis. These data suggest that whilst nasopharyngeal colonisation induces a range of immune responses, the effective protective responses depend upon the site of subsequent infection.

  16. DC-SIGN specifically recognizes Streptococcus pneumoniae serotypes 3 and 14.

    Koppel, Estella A; Saeland, Eirikur; de Cooker, Désirée J M; van Kooyk, Yvette; Geijtenbeek, Teunis B H

    2005-01-01

    The Gram-positive bacterium Streptococcus pneumoniae is the leading causative pathogen in community-acquired pneumonia. The ever-increasing frequency of antibiotic-resistant S. pneumoniae strains severely hampers effective treatments. Thus, a better understanding of the mechanisms involved in the pathogenesis of pneumococcal disease is needed; in particular, of the initial interactions that take place between the host and the bacterium. Recognition of pathogens by dendritic cells is one of the most crucial steps in the induction of an immune response. For efficient pathogen recognition, dendritic cells express various kinds of receptors, including the DC-specific C-type lectin DC-SIGN. Pathogens such as Mycobacterium tuberculosis and HIV target DC-SIGN to escape immunity. Here the in vitro binding of DC-SIGN with S. pneumoniae was investigated. DC-SIGN specifically interacts with S. pneumoniae serotype 3 and 14 in contrast to other serotypes such as 19F. While the data described here suggest that DC-SIGN interacts with S. pneumoniae serotype 14 through a ligand expressed by the capsular polysaccharide, the binding to S. pneumoniae serotype 3 appears to depend on an as yet unidentified ligand. Despite the binding capacity of the capsular polysaccharide of S. pneumoniae 14 to DC-SIGN, no immunomodulatory effects on the dendritic cells were observed. The immunological consequences of the serotype-specific capacity to interact with DC-SIGN should be further explored and might result in new insights in the development of new and more potent vaccines.

  17. Search for coherent gene modules that predict streptococcus pneumoniae strain invasiveness

    Catarino, Rui Ribeiro

    2012-01-01

    Tese de mestrado em Bioquímica, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2012 O Streptococcus pneumoniae, também chamado pneumococcus, é uma bactéria grampositiva do subgrupo alfa-hemolítico do género Streptococcus. É um colonizador frequente do trato respiratório superior humano e embora possa ser encontrado em qualquer pessoa, tem maior prevalência em crianças e idosos. A colonização decorre tipicamente sem causar sintomas, mas pode por vezes culminar na in...

  18. Meningitis caused by streptococci other than Streptococcus pneumoniae: a retrospective clinical study

    Møller, Kirsten; Harder, Eva; Wandall, Johan

    1999-01-01

    We reviewed the medical records of 26 patients (median age 62 years, range 5-76 years) admitted to our institution during 1978-98 with acute bacterial meningitis (ABM) caused by streptococci other than Streptococcus pneumoniae (comprising 1.9% of all patients with ABM). 19 cases were community....... Staphylococcus aureus grew together with a streptococcus in 2 cases. Blood culture was positive in 9 cases (35%). Neurologic complications occurred in 11 patients (42%) and extraneurologic complications in 18 patients (69%). Adverse outcomes occurred in 10 patients (38%), including 3 patients who died...

  19. Antibiotic treatment and the diagnosis of Streptococcus pneumoniae in lower respiratory tract infections in adults

    Korsgaard, Jens; Møller, Jens Kjølseth; Kilian, Mogens

    2005-01-01

    OBJECTIVE: To analyze the possible influence of antibiotic treatment on the results of different diagnostic tests for the diagnosis of lower respiratory tract infections with Streptococcus pneumoniae. MATERIAL AND METHODS: A prospective cohort of 159 unselected adult immunocompetent patients...... of S. pneumoniae. RESULTS: When stratified for antibiotic treatment prior to microbiological sampling, three different groups of patients with documented or probable infection with S. pneumoniae could be identified. The first group comprised 14 patients who were culture positive in one or more culture...... in the diagnosis of infection with S. pneumoniae. The third group of patients with probable pneumococcal infection were identified as 26% and 20% of the remaining 137 patients with unknown or known non-pneumococcal etiology, respectively, who received recent antibiotic treatment within 2-4 weeks of diagnostic...

  20. Accuracy of using the lytA gene to distinguish Streptococcus pneumoniae from related species

    Greve, Thomas; Møller, Jens Kjølseth

    2012-01-01

    The need for a microbial identification of Streptococcus pneumoniae independent of culture methods has resulted in the introduction of other laboratory principles. The verification of a proper and exclusive gene for the detection of the pneumococcus by the nucleic acid-based tests (NAT) is however......A-gene sequences was performed to look at gene sequence differences and the theoretical match with the primers and probes in these sequences. The lytA-gene specific PCR detected 46/46 S. pneumoniae isolates. All 49 of the non-pneumococcal isolates tested negative, including 22 isolates from the Mitis group...... streptococci. The phylogenetic analysis of 94 sequences of the lytA-gene from different strains of S. pneumoniae, S. mitis, and S. pseudopneumoniae showed that 70/87 S. pneumoniae sequences constituted one cluster and a further six sequences was outside but adjacent to this cluster, all with a complete match...

  1. Experimental otitis media in gerbils and chinchillas with Streptococcus pneumoniae, Haemophilus influenzae, and other aerobic and anaerobic bacteria.

    Fulghum, R S; Brinn, J E; Smith, A M; Daniel, H J; Loesche, P J

    1982-01-01

    To ascertain the usefulness of Mongolian gerbils as an inbred model for otitis media, 52 Mongolian gerbils (Meriones unguiculatus, strain MONT/Tum) were compared with 26 chinchillas (Chinchilla laniger) for susceptibility to Streptococcus pneumoniae type 3. Haemophilus influenzae type b, and a polymicrobic culture including anaerobes (Streptococcus intermedius, Propionibacterium acnes, Staphylococcus epidermidis, and Corynebacterium sp.). Organisms were inoculated percutaneously into the supe...

  2. Acute bacterial meningitis caused by Streptococcus pneumoniae resistant to the antimicrobian agents and their serotypes Meningite bacteriana aguda por Streptococcus pneumoniae resistente aos antimicrobianos e seus sorotipos

    Andrea Maciel de Oliveira Rossoni

    2008-09-01

    Full Text Available The main objectives of this study are to evaluate the resistance rates of Streptococcus pneumonia to penicillin G, ceftriaxone and vancomycin in patients with meningitis; to analyze possible risk factors to the antimicrobian resistance; to describe the serotypes detected and to suggest an initial empirical treatment for meningitis. The sensitiveness and serotypes of all isolated S. pneumoniae of patients with acute bacterial meningitis received by the Paraná State Central Laboratory from April 2001 to august 2002 have been evaluated. One hundred S. pneumoniae have been isolated, of which 15% were resistant to penicillin, 1% to cephalosporin and 0% to vancomycin. The serotypes most found were 14 (19%, 3 and 23F (10% each. When only the resistant serotypes were analyzed, the most prevalent was the 14 with 44%. The risk factors found in relation to the S. pneumoniae resistance were: age under one year old (p=0.01 and previous use of antibiotic (p=0.046. The resistance rates found, which were moderate to penicillin, low to cephalosporin and neutral to vancomycin, suggest the isolated use of a 3rd generation cephalosporin as an initial empirical therapy for the treatment of acute bacterial meningitis with a communitarian background.Este estudo teve como objetivo avaliar as taxas de resistência de Streptococcus pneumoniae, isolados de pacientes com meningite, à penicilina G, ceftriaxona e vancomicina; avaliar possíveis fatores de risco para resistência antimicrobiana; descrever os sorotipos encontrados e sugerir a terapêutica empírica inicial para meningite. Foram isoladas 100 amostras de S. pneumoniae, encontrando-se 15% de resistência à penicilina, 1% à cefalosporina e 0% à vancomicina. Os sorotipos mais encontrados foram 14 (19%, 3 e 23F (10% cada. Analisando-se os resistentes, o sorotipo 14 (44% também foi o mais freqüente. Os fatores de risco para resistência de S. pneumoniae encontrados foram: idade menor que um ano (p=0,01 e o uso

  3. Evaluation and selection of tandem repeat loci for Streptococcus pneumoniae MLVA strain typing

    Valjevac Samina

    2005-11-01

    Full Text Available Abstract Background Precise identification of bacterial pathogens at the strain level is essential for epidemiological purposes. In Streptococcus pneumoniae, the existence of 90 different serotypes makes the typing particularly difficult and requires the use of highly informative tools. Available methods are relatively expensive and cannot be used for large-scale or routine typing of any new isolate. We explore here the potential of MLVA (Multiple Loci VNTR Analysis; VNTR, Variable Number of Tandem Repeats, a method of growing importance in the field of molecular epidemiology, for genotyping of Streptococcus pneumoniae. Results Available genome sequences were searched for polymorphic tandem repeats. The loci identified were typed across a collection of 56 diverse isolates and including a group of serotype 1 isolates from Africa. Eventually a set of 16 VNTRs was proposed for MLVA-typing of S. pneumoniae. These robust markers were sufficient to discriminate 49 genotypes and to aggregate strains on the basis of the serotype and geographical origin, although some exceptions were found. Such exceptions may reflect serotype switching or horizontal transfer of genetic material. Conclusion We describe a simple PCR-based MLVA genotyping scheme for S. pneumoniae which may prove to be a powerful complement to existing tools for epidemiological studies. Using this technique we uncovered a clonal population of strains, responsible for infections in Burkina Faso. We believe that the proposed MLVA typing scheme can become a standard for epidemiological studies of S. pneumoniae.

  4. Consumption patterns and in vitro resistance of Streptococcus pneumoniae to fluoroquinolones.

    Simoens, Steven; Verhaegen, Jan; van Bleyenbergh, Pascal; Peetermans, Willy E; Decramer, Marc

    2011-06-01

    This article analyzes patterns of consumption of fluoroquinolones and documents the in vitro resistances of Streptococcus pneumoniae isolates to fluoroquinolones in the ambulatory care setting in Belgium over time. The volume of fluoroquinolone consumption has fallen consistently since 2003. Fluoroquinolones were used primarily for their registered indications (i.e., urinary tract infections and lower respiratory tract infections). The MIC distributions of moxifloxacin and levofloxacin in S. pneumoniae isolates remained stable during 2004 to 2009, and the level of resistance to moxifloxacin and levofloxacin was low (≤1%).

  5. Call for the international adoption of microbiological breakpoints for fluoroquinolones and Streptococcus pneumoniae.

    Schurek, Kristen N; Adam, Heather J; Hoban, Daryl J; Zhanel, George G

    2006-09-01

    The use of current Clinical and Laboratory Standards Institute levofloxacin breakpoints for assessing fluoroquinolone resistance in Streptococcus pneumoniae is inadequate for detecting isolates possessing first-step parC mutations. Consequently, the risk for development of fluoroquinolone resistance is greatly underestimated. Adopting microbiological breakpoints for fluoroquinolones and S. pneumoniae, where parC mutations are rare in susceptible isolates, more accurately describes the emergence of resistance and may help to prevent a number of future fluoroquinolone treatment failures. Additionally, we propose that the use of a second fluoroquinolone marker, such as ciprofloxacin, offers the best prediction for detecting an isolate possessing a first-step parC mutation.

  6. Multidrug-resistant Streptococcus pneumoniae isolates from healthy Ghanaian preschool children

    Dayie, Nicholas Tete Kwaku Dzifa; Arhin, Reuben E.; Newman, Mercy J.

    2015-01-01

    Streptococcus pneumoniae is the cause of high mortality among children worldwide. Antimicrobial treatment and vaccination are used to control pneumococcal infections. In Ghana, data on antimicrobial resistance and the prevalence of multidrug-resistant pneumococcal clones are scarce; hence, the aim...... of this study was to determine the antibiogram of S. pneumoniae recovered from Ghanaian children younger than six years of age and to what extent resistances were due to the spread of certain sero- and multilocus sequence typing (MLST) types. The susceptibility of 115 pneumococcal isolates, recovered...

  7. Genome-wide identification of Streptococcus pneumoniae genes essential for bacterial replication during experimental meningitis

    Molzen, T E; Burghout, P; Bootsma, H J

    2010-01-01

    Meningitis is the most serious of invasive infections caused by the Gram-positive bacterium Streptococcus pneumoniae. Vaccines protect only against a limited number of serotypes, and evolving bacterial resistance to antimicrobials impedes treatment. Further insight into the molecular pathogenesis...... of invasive pneumococcal disease is required in order to enable the development of new or adjunctive treatments and/or pneumococcal vaccines that are efficient across serotypes. We applied genomic array footprinting (GAF) in the search for S. pneumoniae genes that are essential during experimental meningitis...

  8. Antagonism between penicillin and erythromycin against Streptococcus pneumoniae in vitro and in vivo

    Johansen, H K; Jensen, T G; Dessau, R B

    2000-01-01

    the effect of the bactericidal agent. In this study, the possible interaction between penicillin and erythromycin was investigated in vitro and in vivo against four clinical isolates of Streptococcus pneumoniae with MICs of penicillin ranging from 0.016 to 0.5 mg/L and of erythromycin from 0. 25 to >128 mg......The combination of beta-lactam antibiotics and macrolides is often recommended for the initial empirical treatment of acute pneumonia in order to obtain activity against the most important pathogens. Theoretically, this combination may be inexpedient, as the bacteriostatic agent may antagonize...

  9. In Vitro Activity of Delafloxacin Tested against Isolates of Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis.

    Flamm, Robert K; Rhomberg, Paul R; Huband, Michael D; Farrell, David J

    2016-10-01

    Delafloxacin, an investigational anionic fluoroquinolone, is active against a broad range of Gram-positive and Gram-negative bacteria. In this study, 200 Streptococcus pneumoniae (plus 30 levofloxacin-resistant isolates), 200 Haemophilus influenzae, and 100 Moraxella catarrhalis isolates selected primarily from the United States (2014) were tested against delafloxacin and comparator agents. Delafloxacin was the most potent agent tested. MIC50 and MIC90 values against all S. pneumoniae isolates were 0.008 and 0.015 μg/ml. Delafloxacin susceptibility was not affected by β-lactamase status against H. influenzae and M. catarrhalis.

  10. 48株儿童侵袭性肺炎链球菌血清型分布%Study on serotype distribution in 48 isolates of invasive Streptococcus pneumoniae with which children infected

    徐飞; 迟富丽; 谈华; 刘雪梅; 曹彤; 潘伟; 钟天鹰

    2012-01-01

    目的 了解南京地区临床分离的侵袭性肺炎链球菌血清型分布情况.方法 用英膜肿胀实结果检测2007年1月-2010年12月临床分离的48株侵袭性肺炎链球菌的血清型别.结果 48株侵袭性肺炎链球菌常见的血清型别为19F(27.1%)、19A(22.8%)、14(18.7%)和9v(8.3%),有2株用丹麦抗血清无法确定血清型.结论 南京地区儿童临床分离的侵袭性肺炎链球菌的常见血清型为19F、19A、14和9v,与其它地区报道有一定差别.%Purpose To investigate serotype distribution of invasive Streptococcus pneumoniae of clinical isolates in Nanjin. Methods A total of 48 strains invasive Streptococcus pneumoniae were collected from January 2007 to December 2010. Serotyping of Streptococcus pneumoniae was performed by using quelling reaction. Results The most common serotypes 48 Streptococcus pneumoniae isolates were 19F (27.1% ) 19A(22. 8% ) ,14( 18.7% )and 9v(8. 3% ) . There were two strains(4.2% )that cannot be I-dentified with the antisera used. Conclusion The major serotypes of invasive Streptococcus pneumoniae with which children infected in Nanjing are 19F,19A,14 and 9v.

  11. Prevalência de sorotipos e resistência antimicrobiana de cepas invasivas do Streptococcus pneumoniae

    Mantese Orlando C.

    2003-01-01

    Full Text Available OBJETIVO: Avaliar o perfil de sorotipos e a susceptibilidade aos antimicrobianos de cepas de Streptococcus pneumoniae obtidas em espécimes clínicos de pacientes com doença invasiva, bem como suas implicações na formulação de vacinas pneumocócicas. MÉTODOS: Cepas de pneumococo isoladas no Laboratório de Análises Clínicas do Hospital de Clínicas da Universidade Federal de Uberlândia a partir de amostras clínicas de pacientes com doença invasiva foram identificadas e enviadas ao Instituto Adolfo Lutz em São Paulo para confirmação da identificação, sorotipagem e determinação da susceptibilidade aos antimicrobianos. RESULTADOS: De abril de 1999 a março de 2003, foram isoladas 148 cepas invasivas de pneumococo, sendo 84 (56,7% provenientes de pacientes do sexo masculino. A idade variou de um dia a 88,83 anos, com média de 21,33+25,82 anos e mediana de 4,42 anos. Os diagnósticos clínicos mais comuns foram pneumonia (91 casos; 61,4%, meningite (32 casos; 21,6% e bacteremia sem foco evidente (15 casos; 10,1%. As principais fontes de recuperação foram sangue (76 amostras; 51,3%, líquido pleural (39; 26,3% e liquor (30; 20,2%. No total, foram identificados 23 diferentes sorotipos entre 143 amostras testadas, sendo os mais comuns os seguintes: 14, 3, 1, 5, 6A, 6B e 18C. Dentre 30 (20,2% cepas oxacilina-resistentes, 23 (15,5% confirmaram a resistência à penicilina (12,8% com nível intermediário e 2,7%, com nível pleno, que esteve restrita aos sorotipos 14, 23F, 19A e 6B, predominando em indivíduos com até dois anos de idade (p = 0,0008. Foi detectada susceptibilidade diminuída ao cotrimoxazol (63,4%, à eritromicina (8,3%, à clindamicina (8,7% e à ofloxacina (0,8%. A resistência à cefotaxima foi detectada em três das 30 cepas testadas (2% das 148, todas elas com resistência confirmada à penicilina. Não foi observada resistência a cloranfenicol, rifampicina ou vancomicina. CONCLUSÕES: A resistência

  12. Incomplete Kawasaki disease associated with complicated Streptococcus pyogenes pneumonia: A case report.

    Leahy, Timothy Ronan; Cohen, Eyal; Allen, Upton D

    2012-01-01

    A three-year-old boy presented with community-acquired pneumonia complicated by empyema. Streptococcus pyogenes (group A streptococcus) was identified on culture of the pleural fluid. The patient improved with antibiotic therapy and drainage of the empyema. During his convalescence, the patient developed persistent fever, lethargy and anorexia. His inflammatory markers were elevated, and repeat cultures were negative. Although the patient had none of the classical mucocutaneous features of Kawasaki disease, an echocardiogram was performed, which revealed coronary artery dilation. The patient was diagnosed with incomplete Kawasaki disease and treated with intravenous immunoglobulin and high-dose acetylsalicylic acid. The fever subsided within 48 h. To the authors' knowledge, the present report is the first report of Kawasaki disease associated with complicated S pyogenes pneumonia. It emphasizes the importance of considering incomplete Kawasaki disease among children with persistent fever, the role of echocardiography in diagnosis, and the potential link between Kawasaki disease and superantigen-producing organisms such as S pyogenes.

  13. Consumption Patterns and In Vitro Resistance of Streptococcus pneumoniae to Fluoroquinolones▿

    Simoens, Steven; Verhaegen, Jan; van Bleyenbergh, Pascal; Willy E Peetermans; Decramer, Marc

    2011-01-01

    This article analyzes patterns of consumption of fluoroquinolones and documents the in vitro resistances of Streptococcus pneumoniae isolates to fluoroquinolones in the ambulatory care setting in Belgium over time. The volume of fluoroquinolone consumption has fallen consistently since 2003. Fluoroquinolones were used primarily for their registered indications (i.e., urinary tract infections and lower respiratory tract infections). The MIC distributions of moxifloxacin and levofloxacin in S. ...

  14. Apparent involvement of a multidrug transporter in the fluoroquinolone resistance of Streptococcus pneumoniae.

    Baranova, N N; Neyfakh, A A

    1997-01-01

    A Streptococcus pneumoniae strain selected for resistance to ethidium bromide demonstrated enhanced energy-dependent efflux of this toxic dye. Both the ethidium resistance and the ethidium efflux could be inhibited by the plant alkaloid reserpine. The ethidium-selected cells demonstrated cross-resistance to the fluoroquinolones norfloxacin and ciprofloxacin; this resistance could also be completely reversed by reserpine. Furthermore, reserpine potentiated the susceptibility of wild-type S. pn...

  15. In Vitro Activity of Telithromycin against Spanish Streptococcus pneumoniae Isolates with Characterized Macrolide Resistance Mechanisms

    Morosini, María-Isabel; Cantón, Rafael; Loza, Elena; Negri, María-Cristina; Galán, Juan-Carlos; Almaraz, Felisa; Baquero, Fernando

    2001-01-01

    The susceptibilities to telithromycin of 203 Streptococcus pneumoniae isolates prospectively collected during 1999 and 2000 from 14 different geographical areas in Spain were tested and compared with those to erythromycin A, clindamycin, quinupristin-dalfopristin, penicillin G, cefotaxime, and levofloxacin. Telithromycin was active against 98.9% of isolates (MICs, ≤0.5 μg/ml), with MICs at which 90% of isolates are inhibited being 0.06 μg/ml, irrespective of the resistance genotype. The corre...

  16. Time to positivity in blood cultures of adults with Streptococcus pneumoniae bacteremia

    Ansorena Luis

    2006-04-01

    Full Text Available Abstract Background previous studies have established that bacterial blood concentration is related with clinical outcome. Time to positivity of blood cultures (TTP has relationship with bacterial blood concentration and could be related with prognosis. As there is scarce information about the usefulness of TTP, we study the relationship of TTP with clinical parameters in patients with Streptococcus pneumoniae bacteremia. Methods TTP of all cases of Streptococcus pneumoniae bacteremia, detected between January 1995 and December 2004 using the BacT/Alert automated blood culture system in a teaching community hospital was analyzed. When multiple cultures were positive only the shortest TTP was selected for the analysis. Results in the study period 105 patients with Streptococcus pneumoniae bacteremia were detected. Median TTP was 14.1 hours (range 1.2 h to 127 h. Immunosuppressed patients (n = 5, patients with confusion (n = 19, severe sepsis or shock at the time of blood culture extraction (n = 12, those with a diagnosis of meningitis (n = 7 and those admitted to the ICU (n = 14 had lower TTP. Patients with TTP in the first quartile were more frequently hospitalized, admitted to the ICU, had meningitis, a non-pneumonic origin of the bacteremia, and a higher number of positive blood cultures than patients with TTP in the fourth quartile. None of the patients with TTP in the 90th decile had any of these factors associated with shorter TTP, and eight out of ten patients with TTP in the 10th decile had at least one of these factors. The number of positive blood cultures had an inverse correlation with TTP, suggesting a relationship of TTP with bacterial blood concentration. Conclusion Our data support the relationship of TTP with several clinical parameters in patients with Streptococcus pneumoniae bacteremia, and its potential usefulness as a surrogate marker of outcome.

  17. Activity of Vancomycin, Teicoplanin and Cephalosporins against Penicillin-Susceptible and Penicillin-Intermediate Streptococcus Pneumoniae

    Loo, Vivian G.; Jocelyne Lavallée; Diane McAlear; Robson, Hugh G.

    1995-01-01

    Objective: To report in vitro susceptibilities of penicillin-susceptible and penicillin-intermediate Streptococcus pneumoniae isolates to cephalosporins, vancomycin and teicoplanin.Design: Minimal inhibitory concentrations (mic) were determined according to National Committee for Clinical Laboratory Standards guidelines for 17 penicillin-susceptible isolates (mic 0.06 mg/L or less) and 16 isolates showing intermediate susceptibility to penicillin (mic 0.12 to 1.0 mg/L).Setting: Tertiary care ...

  18. Characterization of a mutation in the parE gene that confers fluoroquinolone resistance in Streptococcus pneumoniae.

    Perichon, B; Tankovic, J; Courvalin, P

    1997-01-01

    We report a mutation in the parE genes of two in vitro mutants of Streptococcus pneumoniae responsible for low-level resistance to fluoroquinolones. Sequential acquisition of mutations in parE and gyrA leads to higher levels of resistance. This confirms that topoisomerase IV is the primary target of fluoroquinolones in S. pneumoniae.

  19. Meningitis in a Canadian adult due to high level penicillin-resistant, cefotaxime-intermediate Streptococcus pneumoniae

    Cécile Tremblay; Anne-Marie Bourgault; Pierre St-Antoine

    1996-01-01

    Invasive penicillin-resistant pneumococcal (PRSP) infections are increasing worldwide. In Canada, the incidence of penicillin resistance among Streptococcus pneumoniae isolates is estimated at greater than 6%. In Quebec, only one case of PRSP meningitis has been reported and involved an infant. An adult patient is described who presented with meningitis caused by high level penicillin-resistant, cefotaxime-intermediate S pneumoniae.

  20. The pavA gene of Streptococcus pneumoniae encodes a fibronectin-binding protein that is essential for virulence

    Holmes, AR; McNab, R; Millsap, KW; Rohde, M; Hammerschmidt, S; Mawdsley, JL; Jenkinson, HF

    2001-01-01

    Streptococcus pneumoniae colonizes the nasopharynx in up to 40% of healthy subjects, and is a leading cause of middle ear infections (otitis media), meningitis and pneumonia. Pneumococci adhere to glycosidic receptors on epithelial cells and to immobilized fibronectin, but the bacterial adhesins med

  1. Quorum Sensing Regulation of Competence and Bacteriocins in Streptococcus pneumoniae and mutans

    Shanker, Erin; Federle, Michael J.

    2017-01-01

    The human pathogens Streptococcus pneumoniae and Streptococcus mutans have both evolved complex quorum sensing (QS) systems that regulate the production of bacteriocins and the entry into the competent state, a requirement for natural transformation. Natural transformation provides bacteria with a mechanism to repair damaged genes or as a source of new advantageous traits. In S. pneumoniae, the competence pathway is controlled by the two-component signal transduction pathway ComCDE, which directly regulates SigX, the alternative sigma factor required for the initiation into competence. Over the past two decades, effectors of cellular killing (i.e., fratricides) have been recognized as important targets of the pneumococcal competence QS pathway. Recently, direct interactions between the ComCDE and the paralogous BlpRH pathway, regulating bacteriocin production, were identified, further strengthening the interconnections between these two QS systems. Interestingly, a similar theme is being revealed in S. mutans, the primary etiological agent of dental caries. This review compares the relationship between the bacteriocin and the competence QS pathways in both S. pneumoniae and S. mutans, and hopes to provide clues to regulatory pathways across the genus Streptococcus as a potential tool to efficiently investigate putative competence pathways in nontransformable streptococci. PMID:28067778

  2. Use of the Directigen Latex Agglutination Test for Detection of Haemphilus influenzae, Streptococcus pneumoniae, and Neisseria meningitidis Antigens in Cerebrospinal Fluid from Meningitis Patients,

    Reprint: Use of the Directigen Latex Agglutination Test for Detection of Haemphilus influenzae, Streptococcus pneumoniae , and Neisseria meningitidis Antigens in Cerebrospinal Fluid from Meningitis Patients.

  3. Serotyping, Antibiotic Susceptibility and Related Risk Factors Aspects of Nasopharyngeal Carriage of Streptococcus pneumoniae in Healthy School Students.

    Hamed Mirzaei Ghazikalayeh

    2014-09-01

    Full Text Available Streptococcus pneumoniae is an important problem worldwide and nasopharyngeal colonization plays significant role in pneumococcal infections. The aims of this study were to determine the nasopharyngeal colonization rate, serotyping, antibiotics susceptibility and study the risk factors for nasopharyngeal colonization with S. pneumoniae in students in Kashan, Iran.A cross-sectional study was conducted on children aged 7 to 19 years from December 2011 to November 2012. Nasopharyngeal swabs were plated onto brain heart infusion agar plates with 5% sheep blood and 4µg/ml of gentamycin. Antimicrobial susceptibility profiles were determined on Mueller-Hinton agar in accordance with CLSI. S. pneumoniae strains were investigated for the presence of the most common pneumococcal serotypes using a multiplex polymerase chain reaction.13.9% were found to be carriers. The most prevalent serogroups were 19F (30%, 6A/B (18.9%, 15A (16.5%, 11 (11.3%, 23F (8.2%, 1 (6.2%, 19A (3.4%, and 35B (2.4%. Nine strains (3.1% were non-typeable. The carrier rate was significantly higher in 12 to15 year old age group. Upper respiratory tract infections within the last month (OR=1.5, P<0.011, previous hospitalization (OR=1.6, P<0.001, previous antibiotic usage last two weeks (OR=1.89, P<0.001, rhinorea (OR=1.9 P<0.001, male sex (OR=3.5 P< 0.001 and passive smoking (OR=1.56, P< 0.001 have been determined to be risk factors for S. pneumoniae carriage. The highest pneumococcal resistance was to tetracycline (25.4%. All strains were susceptible to linezolid and levofloxacin.Our information leads to an important source to screen the future impact of pneumococcal vaccination on bacterial colonization.

  4. Macrolide resistance determinants among Streptococcus pneumoniae isolates from carriers in Central Greece

    Grivea Ioanna N

    2012-10-01

    Full Text Available Abstract Background We sought to characterize the temporal trends in nasopharyngeal carriage of macrolide-resistant pneumococci during a period with increased heptavalent pneumococcal conjugate vaccine (PCV7 coverage in Central Greece. Methods Streptococcus pneumoniae isolates were recovered from 2649 nasopharyngeal samples obtained from day-care center attendees in Central Greece during 2005–2009. A phenotypic and genotypic analysis of the isolates was performed, including the identification of macrolide resistance genes mef(A, subclasses mef(A and mef(E, as well as erm(B. Results Of the 1105 typeable S. pneumoniae isolates, 265 (24% were macrolide-resistant; 22% in 2005, 33.3% in 2006, 23.7% in 2007, and 20.5% in 2009 (P=0.398. Among these macrolide-resistant pneumococci, 28.5% possessed erm(B, 24.3% erm(B+mef(E, 41.8% mef(E, and 5.3% mef(A. A mef gene as the sole resistance determinant was carried by 31% of macrolide-resistant isolates belonging to PCV7 serotypes and 75.8% of the non-PCV7 serotypes. Across the 4 annual surveillances, pneumococci carrying mef(A gradually disappeared, whereas serotype 19F isolates carrying both erm(B and mef(E persisted without significant yearly fluctuations. Among isolates belonging to non-PCV7 serotypes, macrolide-resistance was observed in those of serotypes 6A, 19A, 10A, 15A, 15B/C, 35F, 35A, and 24F. In 2009, ie 5 years after the introduction of PCV7 in our country, 59% of macrolide-resistant pneumococci belonged to non-PCV7 serotypes. Conclusions Across the study period, the annual frequency of macrolide-resistant isolates did not change significantly, but in 2009 a marked shift to non-PCV7 serotypes occurred. Overall, more than half of the macrolide-resistant isolates possessed erm(B either alone or in combination with mef(E. erm(B dominated among isolates belonging to PCV7 serotypes, but not among those of non-PCV7 serotypes.

  5. Bactericidal effect of bovine lactoferrin and synthetic peptide lactoferrin chimera in Streptococcus pneumoniae and the decrease in luxS gene expression by lactoferrin

    N. León-Sicairos; U.A. Angulo-Zamudio; J.E. Vidal; C.A. López-Torres; J.G.M. Bolscher; K. Nazmi; R. Reyes-Cortes; M. Reyes-López; M. de la Garza; A. Canizalez-Román

    2014-01-01

    Streptococcus pneumoniae (pneumococcus) is responsible for nearly one million child deaths annually. Pneumococcus causes infections such as pneumonia, otitis media, meningitis, and sepsis. The human immune system includes antibacterial peptides and proteins such as lactoferrin (LF), but its activity

  6. A protein-based pneumococcal vaccine protects rhesus macaques from pneumonia after experimental infection with Streptococcus pneumoniae.

    Denoël, Philippe; Philipp, Mario T; Doyle, Lara; Martin, Dale; Carletti, Georges; Poolman, Jan T

    2011-07-26

    Infections caused by Streptococcus pneumoniae are a major cause of mortality throughout the world. Protein-based pneumococcal vaccines are envisaged to replace or complement the current polysaccharide-based vaccines. In this context, detoxified pneumolysin (dPly) and pneumococcal histidine triad protein D (PhtD) are two potential candidates for incorporation into pneumococcal vaccines. In this study, the protective efficacy of a PhtD-dPly vaccine was evaluated in a rhesus macaque (Macaca mulatta) model of pneumonia. The animals were immunized twice with 10 μg of PhtD and 10 μg of dPly formulated in the Adjuvant System AS02 or with AS02 alone, before they were challenged with a 19F pneumococcal strain. The survival was significantly higher in the protein-vaccinated group and seemed to be linked to the capacity to greatly reduce bacterial load within the first week post-challenge. Vaccination elicited high concentrations of anti-PhtD and anti-Ply antibodies and a link was found between survival and antibody levels. In conclusion, AS02-adjuvanted PhtD-dPly vaccine protects against S. pneumoniae-induced pneumonia. It is probable that the protection is at least partially mediated by PhtD- and Ply-specific antibodies.

  7. A reação em cadeia da polimerase na detecção da resistência à penicilina em Streptococcus pneumoniae Polymerase chain reaction used to detect Streptococcus pneumoniae resistance to penicillin

    Eduardo Walker Zettler

    2004-12-01

    Full Text Available INTRODUÇÃO: O Streptococcus pneumoniae é o mais freqüente agente etiológico de infecções respiratórias adquiridas na comunidade e sua resistência aos antimicrobianos tem aumentado nos últimos anos. A determinação da resistência é feita rotineiramente por método lento que depende do crescimento em cultura e determinação da concentração inibitória mínima (CIM. A reação em cadeia da polimerase (PCR detecta os genes responsáveis pela resistência do Streptococcus pneumoniae a penicilina em cerca de 8 horas. OBJETIVO: Comparar a PCR com o método da CIM no diagnóstico da resistência da Streptococcus pneumoniae a penicilina. MÉTODO: Foram estudadas 153 amostras de Streptococcus pneumoniae, isoladas de diferentes sítios anatômicos, usando-se para detecção de mutações nos genes que codificam as proteínas ligadoras de penicilina 1a, 2b e 2x, responsáveis pela resistência à penicilina. A ocorrência das mutações foi correlacionada com a CIM de penicilina, determinada pelo teste de difusão em ágar. RESULTADOS: A resistência global à penicilina do Streptococcus pneumoniae foi de 22,8% (16,3% de resistência intermediária e 6,5% de resistência alta. Em proporções estatisticamente significativas, as amostras sensíveis à penicilina não tinham mutações, as intermediárias apenas uma, geralmente na proteína ligadora de penicilina 2x, e as altamente resistentes tinham mutações nas três proteínas investigadas. CONCLUSÃO: A PCR é um método rápido para a detecção da resistência à penicilina do Streptococcus pneumoniae, que poderá vir a ser utilizado na prática clínica.BACKGROUND: Streptococcus pneumoniae is the most common etiologic agent of community-acquired respiratory infections. In recent years, S. pneumoniae resistance to antimicrobial agents has increased. Minimum inhibitory concentration (MIC is routinely used to determine resistance. Polymerase chain reaction (PCR detects the genes

  8. Nebulized C1-Esterase Inhibitor does not Reduce Pulmonary Complement Activation in Rats with Severe Streptococcus Pneumoniae Pneumonia.

    de Beer, Friso; Lagrand, Wim; Glas, Gerie J; Beurskens, Charlotte J P; van Mierlo, Gerard; Wouters, Diana; Zeerleder, Sacha; Roelofs, Joris J T H; Juffermans, Nicole P; Horn, Janneke; Schultz, Marcus J

    2016-12-01

    Complement activation plays an important role in the pathogenesis of pneumonia. We hypothesized that inhibition of the complement system in the lungs by repeated treatment with nebulized plasma-derived human C1-esterase inhibitor reduces pulmonary complement activation and subsequently attenuates lung injury and lung inflammation. This was investigated in a rat model of severe Streptococcus pneumoniae pneumonia. Rats were intra-tracheally challenged with S. pneumoniae to induce pneumonia. Nebulized C1-esterase inhibitor or saline (control animals) was repeatedly administered to rats, 30 min before induction of pneumonia and every 6 h thereafter. Rats were sacrificed 20 or 40 h after inoculation with bacteria. Brochoalveolar lavage fluid and lung tissue were obtained for measuring levels of complement activation (C4b/c), lung injury and inflammation. Induction of pneumonia was associated with pulmonary complement activation (C4b/c at 20 h 1.24 % [0.56-2.59] and at 40 h 2.08 % [0.98-5.12], compared to 0.50 % [0.07-0.59] and 0.03 % [0.03-0.03] in the healthy control animals). The functional fraction of C1-INH was detectable in BALF, but no effect was found on pulmonary complement activation (C4b/c at 20 h 0.73 % [0.16-1.93] and at 40 h 2.38 % [0.54-4.19]). Twenty hours after inoculation, nebulized C1-esterase inhibitor treatment reduced total histology score, but this effect was no longer seen at 40 h. Nebulized C1-esterase inhibitor did not affect other markers of lung injury or lung inflammation. In this negative experimental animal study, severe S. pneumoniae pneumonia in rats is associated with pulmonary complement activation. Repeated treatment with nebulized C1-esterase inhibitor, although successfully delivered to the lungs, does not affect pulmonary complement activation, lung inflammation or lung injury.

  9. Recombination rates of Streptococcus pneumoniae isolates with both erm(B) and mef(A) genes.

    Lee, Ji-Young; Song, Jae-Hoon; Ko, Kwan Soo

    2010-08-01

    Erythromycin-resistant Streptococcus pneumoniae isolates containing both erm(B) and mef(A) genes have a higher rate of multidrug resistance (MDR). We investigated the relationships between the presence of erythromycin resistance determinants and the recombination rate. We determined the mutation and recombination frequencies of 46 S. pneumoniae isolates, which included 19 with both erm(B) and mef(A), nine with only erm(B), six with only mef(A), and 11 erythromycin-susceptible isolates. Mutation frequency values were estimated as the number of rifampin-resistant colonies as a proportion of total viable count. Genotypes and serotypes of isolates with the hyper-recombination phenotype were determined. Twelve S. pneumoniae isolates were hypermutable and four isolates were determined to have hyper-recombination frequency. Streptococcus pneumoniae isolates with both erm(B) and mef(A) genes did not show a high mutation frequency. In contrast, all isolates with a hyper-recombination phenotype contained both erm(B) and mef(A) genes. In addition, the recombination rate of isolates with both erm(B) and mef(A) genes was statistically higher than the rate of other isolates. The dual presence of erm(B) and mef(A) genes in some pneumococcal isolates may be associated with high recombination frequency. This may be one of the reasons for the frequent emergence of MDR in certain pneumococcal isolates.

  10. Prevalence of Streptococcus Pneumoniae, Haemophilus Influenzae and Moraxella Catarrhalis in Adenoid Tissues of Children with Adenoid Hypertrophy

    SS Khoramrooz

    2012-08-01

    Full Text Available Background & aim: Chronic infection of the adenoid tissue is one of the causes of hypertrophy. Adenoids are considered to be as reservoirs of pathogenic bacteria such as Streptococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenzae. The aim of this study was to determine the prevalence of mentioned bacteria in children with adenoid hypertrophy. Methods: A total of 113 children with adenoid hypertrophy who underwent adenoidectomy were included in this study. Subsequently, adenoidectomy was performed under general anesthesia. All of the adenoid samples were evaluated for bacterial infection by culture and PCR methods. Results: Streptococcus. pneumoniae was the most common (33.6% bacteria isolated by culture followed by H. influenzae (22.9% and M. catarrhalis (9.7%. PCR method detected S. pneumoniae, H. influenzae and M. catarrhalis in 31%, 29.2% and 9.7% of samples respectively. Conclusion: Streptococcus. Pneumonia, H. influenzae and M. catarrhalis are isolated with different frequency in patients with adenoid hypertrophy.

  11. A type IV pilus mediates DNA binding during natural transformation in Streptococcus pneumoniae.

    Raphaël Laurenceau

    Full Text Available Natural genetic transformation is widely distributed in bacteria and generally occurs during a genetically programmed differentiated state called competence. This process promotes genome plasticity and adaptability in Gram-negative and Gram-positive bacteria. Transformation requires the binding and internalization of exogenous DNA, the mechanisms of which are unclear. Here, we report the discovery of a transformation pilus at the surface of competent Streptococcus pneumoniae cells. This Type IV-like pilus, which is primarily composed of the ComGC pilin, is required for transformation. We provide evidence that it directly binds DNA and propose that the transformation pilus is the primary DNA receptor on the bacterial cell during transformation in S. pneumoniae. Being a central component of the transformation apparatus, the transformation pilus enables S. pneumoniae, a major Gram-positive human pathogen, to acquire resistance to antibiotics and to escape vaccines through the binding and incorporation of new genetic material.

  12. Total synthesis of a Streptococcus pneumoniae serotype 12F CPS repeating unit hexasaccharide

    Pereira, Claney L; Govindan, Subramanian

    2017-01-01

    The Gram-positive bacterium Streptococcus pneumoniae causes severe disease globally. Vaccines that prevent S. pneumoniae infections induce antibodies against epitopes within the bacterial capsular polysaccharide (CPS). A better immunological understanding of the epitopes that protect from bacterial infection requires defined oligosaccharides obtained by total synthesis. The key to the synthesis of the S. pneumoniae serotype 12F CPS hexasaccharide repeating unit that is not contained in currently used glycoconjugate vaccines is the assembly of the trisaccharide β-D-GalpNAc-(1→4)-[α-D-Glcp-(1→3)]-β-D-ManpNAcA, in which the branching points are equipped with orthogonal protecting groups. A linear approach relying on the sequential assembly of monosaccharide building blocks proved superior to a convergent [3 + 3] strategy that was not successful due to steric constraints. The synthetic hexasaccharide is the starting point for further immunological investigations.

  13. Ethanol-induced alcohol dehydrogenase E (AdhE) potentiates pneumolysin in Streptococcus pneumoniae.

    Luong, Truc Thanh; Kim, Eun-Hye; Bak, Jong Phil; Nguyen, Cuong Thach; Choi, Sangdun; Briles, David E; Pyo, Suhkneung; Rhee, Dong-Kwon

    2015-01-01

    Alcohol impairs the host immune system, rendering the host more vulnerable to infection. Therefore, alcoholics are at increased risk of acquiring serious bacterial infections caused by Streptococcus pneumoniae, including pneumonia. Nevertheless, how alcohol affects pneumococcal virulence remains unclear. Here, we showed that the S. pneumoniae type 2 D39 strain is ethanol tolerant and that alcohol upregulates alcohol dehydrogenase E (AdhE) and potentiates pneumolysin (Ply). Hemolytic activity, colonization, and virulence of S. pneumoniae, as well as host cell myeloperoxidase activity, proinflammatory cytokine secretion, and inflammation, were significantly attenuated in adhE mutant bacteria (ΔadhE strain) compared to D39 wild-type bacteria. Therefore, AdhE might act as a pneumococcal virulence factor. Moreover, in the presence of ethanol, S. pneumoniae AdhE produced acetaldehyde and NADH, which subsequently led Rex (redox-sensing transcriptional repressor) to dissociate from the adhE promoter. An increase in AdhE level under the ethanol condition conferred an increase in Ply and H2O2 levels. Consistently, S. pneumoniae D39 caused higher cytotoxicity to RAW 264.7 cells than the ΔadhE strain under the ethanol stress condition, and ethanol-fed mice (alcoholic mice) were more susceptible to infection with the D39 wild-type bacteria than with the ΔadhE strain. Taken together, these data indicate that AdhE increases Ply under the ethanol stress condition, thus potentiating pneumococcal virulence.

  14. Molecular epidemiology of nonencapsulated Streptococcus pneumoniae among Japanese children with acute otitis media.

    Hotomi, Muneki; Nakajima, Kouji; Hiraoka, Masanobu; Nahm, Moon H; Yamanaka, Noboru

    2016-02-01

    The introduction of pneumococcal conjugate vaccine may change the epidemiology of Streptococcus pneumoniae. The increased prevalence of non-vaccine serotypes as the cause of pneumococcal diseases has already reported in the United States and Europe. However, little attention has been focused on the S. pneumoniae. In this study, nonencapsulated S. pneumoniae were identified in 15 isolates (6.4%) out of 236 pneumococcal strains obtained from the nasopharynges of children with acute otitis media (AOM), in 3 isolates (14.3%) out of 21 strains from acute rhinosinusitis, and in 2 isolates (12.5%) out of 16 nasopharyngeal carriage strains obtained from normal healthy children. Among the 20 nonencapsulated S. pneumoniae isolates, 15 (75.0%) isolates had the pspK gene. Seven sequence types (STs) were identified: ST7502 (5 strains), ST1106 (2 strains), ST7803 (2 strains), ST7786 (1 strain), ST6741 (1 strain), ST7496 (1 strain), and ST8642 (1 strain). Because nonencapsulated S. pneumoniae strains are not targeted by the current available pneumococcal vaccines, these strains will gradually become more common in nasopharyngeal carriage. The increase in colonization and dissemination of these strains would increase the risk of AOM and other systemic pneumococcal diseases against which current vaccines cannot provide protection. Nonencapsulated S. pneumoniae may thus become more prevalent as human pathogen.

  15. Therapeutic effects of garenoxacin in murine experimental secondary pneumonia by Streptococcus pneumoniae after influenza virus infection.

    Fukuda, Yoshiko; Furuya, Yuri; Nozaki, Yusuke; Takahata, Masahiro; Nomura, Nobuhiko; Mitsuyama, Junichi

    2014-02-01

    In a pneumococcal pneumonia murine model following influenza virus infection, garenoxacin was more effective than other fluoroquinolones and demonstrated high levels of bacterial eradication in the lung, low mortality, and potent histopathological improvements. Garenoxacin could potentially be used for the treatment of secondary pneumococcal pneumonia following influenza.

  16. Multiplex PCR to determine Streptococcus pneumoniae serotypes causing otitis media in the Republic of Ireland with further characterisation of antimicrobial susceptibilities and genotypes.

    Vickers, I

    2011-03-01

    The purpose of this study was to determine the serotypes, genotypes and antimicrobial susceptibilities of Streptococcus pneumoniae causing otitis media (OM) in children in Dublin, Ireland. S. pneumoniae isolates (n = 28) from spontaneously discharging OM were studied. Serotyping was performed using a previously undescribed multiplex polymerase chain reaction (PCR) scheme in combination with serological methods. Multilocus sequence typing (MLST) was performed using standard procedures. Antimicrobial susceptibility testing was performed using the Etest method. Fourteen different S. pneumoniae serotypes were identified. The five most common serotypes were 3, 19F, 19A, 14 and 6A, which accounted for 68% of all infections. The 7-valent pneumococcal conjugate vaccine (PCV7), 10-valent pneumococcal conjugate vaccine (PHiD-CV) and 13-valent pneumococcal conjugate vaccine (PCV13) provided potential coverages of 43%, 46% and 86%, respectively. Reduced susceptibility to penicillin was evident for 25% of isolates and was associated with serotypes 14, 19A, 19F and 9V. A total of 21 different sequence types (STs) were identified. Pneumococcal Molecular Epidemiology Network (PMEN) clones or their variants represented 54% (15\\/28) of all isolates. Continued monitoring and characterisation of S. pneumoniae causing OM in Ireland is warranted in order to guide future vaccine and treatment policies.

  17. Reporting emerging resistance of Streptococcus pneumoniae from India

    Chawla Kiran

    2010-01-01

    Full Text Available Background: There are reports of emergence of resistant strains of S. pneumoniae showing resistance to penicillin from all over the world, and now, resistance to multiple drugs (multidrug-resistant strains has been added to it. However, scanty reports are available so far from India, depicting such resistance. Aims: The aim of the present study is to look for the prevalence of penicillin-resistant pneumococci and also the multidrug-resistant strains among S. pneumoniae, isolated from respiratory specimens, in the coastal part of South India. Settings and Design: A cross-sectional study was conducted from June 2008 to December 2008, in our tertiary care center. Fifty pathogenic clinical isolates were collected from patients suffering from lower respiratory tract infections. Materials and Methods: Penicillin resistance was screened by 1 µg oxacillin disk on Muller-Hinton blood agar followed by Minimum Inhibitory Concentration (MIC detection by the agar dilution method according to the Clinical Laboratory Standards Institute (CLSI guidelines. Antibiotic susceptibility for other antibiotics was carried out by the Kirby Bauer disk diffusion method followed by an E-test with HiComb test strips from Hi-media. Results: Out of 50 isolates, 4% (95% Confidence Interval - 1.4, 9.4 showed total resistance to penicillin, whereas, 10% (95% CI; 1.6, 18.3 showed intermediate resistance. These penicillin-resistant pneumococci (4% were also found to be multidrug-resistant (MDR strains. Maximum resistance was observed for cotrimoxazole and tetracycline (24% each with 95% CI; 12.2, 35.8 followed by erythromycin and ciprofloxacin (14% each with 95%CI; 4.4, 23.6. Conclusions : Increasing emergence of the resistant strains of S. pneumoniae in the community set up requires continuous monitoring and a restricted use of antibiotics to keep a check on its resistance pattern, for an effective treatment plan.

  18. Genome-wide identification of genes essential for the survival of Streptococcus pneumoniae in human saliva.

    Lilly M Verhagen

    Full Text Available Since Streptococcus pneumoniae transmits through droplet spread, this respiratory tract pathogen may be able to survive in saliva. Here, we show that saliva supports survival of clinically relevant S. pneumoniae strains for more than 24 h in a capsule-independent manner. Moreover, saliva induced growth of S. pneumoniae in growth-permissive conditions, suggesting that S. pneumoniae is well adapted for uptake of nutrients from this bodily fluid. By using Tn-seq, a method for genome-wide negative selection screening, we identified 147 genes potentially required for growth and survival of S. pneumoniae in saliva, among which genes predicted to be involved in cell envelope biosynthesis, cell transport, amino acid metabolism, and stress response predominated. The Tn-seq findings were validated by testing a panel of directed gene deletion mutants for their ability to survive in saliva under two testing conditions: at room temperature without CO2, representing transmission, and at 37 °C with CO2, representing in-host carriage. These validation experiments confirmed that the plsX gene and the amiACDEF and aroDEBC operons, involved in respectively fatty acid metabolism, oligopeptide transport, and biosynthesis of aromatic amino acids play an important role in the growth and survival of S. pneumoniae in saliva at 37 °C. In conclusion, this study shows that S. pneumoniae is well-adapted for growth and survival in human saliva and provides a genome-wide list of genes potentially involved in adaptation. This notion supports earlier evidence that S. pneumoniae can use human saliva as a vector for transmission.

  19. Streptococcus pneumoniae Transmission Is Blocked by Type-Specific Immunity in an Infant Mouse Model

    Zangari, Tonia; Wang, Yang

    2017-01-01

    ABSTRACT Epidemiological studies on Streptococcus pneumoniae show that rates of carriage are highest in early childhood and that the major benefit of the pneumococcal conjugate vaccine (PCV) is a reduction in the incidence of nasopharyngeal colonization through decreased transmission within a population. In this study, we sought to understand how anti-S. pneumoniae immunity affects nasal shedding of bacteria, the limiting step in experimental pneumococcal transmission. Using an infant mouse model, we examined the role of immunity (passed from mother to pup) on shedding and within-litter transmission of S. pneumoniae by pups infected at 4 days of life. Pups from both previously colonized immune and PCV-vaccinated mothers had higher levels of anti-S. pneumoniae IgG than pups from non-immune or non-vaccinated mothers and shed significantly fewer S. pneumoniae over the first 5 days of infection. By setting up cross-foster experiments, we demonstrated that maternal passage of antibody to pups either in utero or post-natally decreases S. pneumoniae shedding. Passive immunization experiments showed that type-specific antibody to capsular polysaccharide is sufficient to decrease shedding and that the agglutinating function of immunoglobulin is required for this effect. Finally, we established that anti-pneumococcal immunity and anti-PCV vaccination block host-to-host transmission of S. pneumoniae. Moreover, immunity in either the donor or recipient pups alone was sufficient to reduce rates of transmission, indicating that decreased shedding and protection from acquisition of colonization are both contributing factors. Our findings provide a mechanistic explanation for the reduced levels of S. pneumoniae transmission between hosts immune from prior exposure and among vaccinated children. PMID:28292980

  20. R-roscovitine reduces lung inflammation induced by lipoteichoic acid and Streptococcus pneumoniae.

    Hoogendijk, Arie J; Roelofs, Joris J T H; Duitman, Janwillem; van Lieshout, Miriam H P; Blok, Dana C; van der Poll, Tom; Wieland, Catharina W

    2012-09-25

    Bacterial pneumonia remains associated with high morbidity and mortality. The gram-positive pathogen Streptococcus pneumoniae is the most common cause of community-acquired pneumonia. Lipoteichoic acid (LTA) is an important proinflammatory component of the gram-positive bacterial cell wall. R-roscovitine, a purine analog, is a potent cyclin-dependent kinase (CDK)-1, -2, -5 and -7 inhibitor that has the ability to inhibit the cell cycle and to induce polymorphonuclear cell (PMN) apoptosis. We sought to investigate the effect of R-roscovitine on LTA-induced activation of cell lines with relevance for lung inflammation in vitro and on lung inflammation elicited by either LTA or viable S. pneumoniae in vivo. In vitro R-roscovitine enhanced apoptosis in PMNs and reduced tumor necrosis factor (TNF)-α and keratinocyte chemoattractant (KC) production in MH-S (alveolar macrophage) and MLE-12/MLE-15 (respiratory epithelial) cell lines. In vivo R-roscovitine treatment reduced PMN numbers in bronchoalveolar lavage fluid during LTA-induced lung inflammation; this effect was reversed by inhibiting apoptosis. Postponed treatment with R-roscovitine (24 and 72 h) diminished PMN numbers in lung tissue during gram-positive pneumonia; this step was associated with a transient increase in pulmonary bacterial loads. R-roscovitine inhibits proinflammatory responses induced by the gram-positive stimuli LTA and S. pneumoniae. R-roscovitine reduces PMN numbers in lungs upon LTA administration by enhancing apoptosis. The reduction in PMN numbers caused by R-roscovitine during S. pneumoniae pneumonia may hamper antibacterial defense.

  1. Potential Usefulness of Streptococcus pneumoniae Extracellular Membrane Vesicles as Antibacterial Vaccines

    Choi, Chi-Won; Park, Edmond Changkyun; Yun, Sung Ho; Lee, Sang-Yeop

    2017-01-01

    The secretion of extracellular membrane vesicles (EMVs) is a common phenomenon that occurs in archaea, bacteria, and mammalian cells. The EMVs of bacteria play important roles in their virulence, biogenesis mechanisms, and host cell interactions. Bacterial EMVs have recently become the focus of attention because of their potential as highly effective vaccines that cause few side effects. Here, we isolated the EMVs of Streptococcus pneumoniae and examined their potential as new vaccine candidates. Although the S. pneumoniae bacteria were highly pathogenic in a mouse model, the EMVs purified from these bacteria showed low pathological activity both in cell culture and in mice. When mice were injected intraperitoneally with S. pneumoniae EMVs and then challenged, they were protected from both the homologous strain and another pathogenic serotype of S. pneumoniae. We also identified a number of proteins that may have immunogenic activity and may be responsible for the immune responses by the hosts. These results suggest that S. pneumoniae EMVs or their individual immunogenic antigens may be useful as new vaccine agents.

  2. Silica desiccant packets for storage and transport of Streptococcus pneumoniae and other clinically relevant species.

    Casey L Pell

    Full Text Available Bacterial isolates are often transported between laboratories for research and diagnostic purposes. Silica desiccant packets (SDPs, which are inexpensive and do not require freezing, were evaluated for storage and recovery of bacterial isolates. Conditions such as inoculum size, swab type and temperature of storage were investigated using ten Streptococcus pneumoniae isolates. The optimized protocol was then tested using 49 additional S. pneumoniae isolates representing 40 serogroups. Overall, S. pneumoniae growth was considered satisfactory (>100 colony forming units for 98/109 (89.9% and 20/20 (100% swabs after 14 days at room temperature or 28 days at 4° C, respectively. Storage in SDPs did not impact on the ability of S. pneumoniae isolates to be subsequently serotyped. When the survival of nine other clinically relevant bacterial species was tested, seven were viable after 28 days at room temperature, the exceptions being Neisseria gonorrhoeae and Haemophilus influenzae. SDPs are suitable for transport and short-term storage of bacterial species including S. pneumoniae.

  3. Streptococcus pneumoniae synergizes with nontypeable Haemophilus influenzae to induce inflammation via upregulating TLR2

    Kweon Soo-Mi

    2008-07-01

    Full Text Available Abstract Background Toll-like receptor 2 (TLR2 plays a critical role in mediating inflammatory/immune responses against bacterial pathogens in lung. Streptococcus pneumoniae (S. pneumoniae and nontypeable Haemophilus influenzae (NTHi were previously reported to synergize with each other to induce inflammatory responses. Despite the relatively known intracellular signaling pathways involved in the synergistic induction of inflammation, it is still unclear if both bacterial pathogens also synergistically induce expression of surface TLR2. Results Here we provide direct evidence that S. pneumoniae synergizes with NTHi to upregulate TLR2 expression in lung and middle ear of the mice. Pneumolysin (PLY appears to be the major virulence factor involved in this synergism. Moreover, S. pneumoniae PLY induces TLR2 expression via a TLR4-MyD88-NF-κB-dependent signaling pathway. Interestingly, tumor suppressor CYLD acts as a negative regulator of S. pneumoniae-induced TLR2 up-regulation via negative-crosstalk with NF-κB signaling. Conclusion Our study thus provides novel insights into the regulation of TLR2 expression in mixed bacterial infections.

  4. Streptococcus pneumoniae-induced pneumonia and Citrobacter rodentium-induced gut infection differentially alter vitamin A concentrations in the lung and liver of mice.

    Restori, Katherine H; McDaniel, Kaitlin L; Wray, Amanda E; Cantorna, Margherita T; Ross, A Catharine

    2014-03-01

    In the developing world, vitamin A (VA) deficiency is endemic in populations that are also at great risk of morbidity and mortality because of pneumococcal pneumonia and enteric infections. To better understand how lung and gastrointestinal pathogens affect VA status, we assessed VA concentrations in serum, lung, and liver during an invasive pneumonia infection induced by Streptococcus pneumoniae serotype 3, and a noninvasive gut infection induced by Citrobacter rodentium, in vitamin A-adequate (VAA) and vitamin A-deficient (VAD) mice. For pneumonia infection, mice were immunized with pneumococcal polysaccharide serotype 3 (PPS3), or not (infected-control), 5 d prior to intranasal inoculation with S. pneumoniae. Two days post-inoculation, immunization was protective against systemic infection regardless of VA status as PPS3 immunization decreased bacteremia compared with infected-control mice (P pneumonia had less effect on VA status than gastrointestinal infection, predominantly owing to reduced hepatic VA storage at the peak of gut infection.

  5. Streptococcus pneumoniae sepsis as the initial presentation of systemic lupus erythematosus

    Erdem I

    2016-09-01

    Full Text Available Ilknur Erdem,1 Senay Elbasan Omar,1 Ridvan Kara Ali,1 Hayati Gunes,2 Aynur Eren Topkaya2 1Department of Infectious Diseases, 2Department of Medical Microbiology, Faculty of Medicine, Namik Kemal University, Tekirdag, Turkey Objective: Infections are among the most important causes of morbidity and mortality in patients with systemic lupus erythematosus (SLE but are rare initial presentation of the disease. Therefore, in this study, we describe a case of Streptococcus pneumoniae sepsis in a young woman with previously undiagnosed SLE. Case report: A 23-year-old female patient was admitted to our outpatient clinic complaining of high fever (40°C, chills, fatigue, generalized myalgia, and cough with brown sputum for 5 days. Blood cultures grew gram-positive coccus defined as S. pneumoniae using standard procedures. Antinuclear antibody was positive at a titer of 1/1,000, and anti-double-stranded DNA was positive at 984 IU/mL. She was diagnosed with SLE. Her respiratory symptoms and pleural effusion were considered to be due to pulmonary manifestation of SLE. Conclusion: The underlying immunosuppression caused by SLE could have predisposed the patient to invasive pneumococcal disease. It may also occur as a primary presenting feature, although a rare condition. Keywords: Streptococcus pneumoniae, sepsis, systemic lupus erythematosus

  6. Serotype Prevalence and Penicillin-susceptibility of Streptococcus pneumoniae in Oman

    Mubarak M. Al-Yaqoub

    2011-01-01

    Full Text Available Objectives: to determine the prevalent serotypes of Streptococcus pneumoniae and the rate of penicillin-nonsusceptibility among pneumococci in Oman.Methods: Pneumococcal isolates encountered during the period of September 2002 to December 2007 in the Royal Hospital were serotyped. Clinical information as well as the penicillin susceptibility reports were retrieved from the hospital information system and medical records.Results: 120 strains of Streptococcus pneumoniae were isolated of which 85 strains were seroptyped. 20 different serotypes were identified; the most common seroptypes were 9A, 6B, 19F, 14 and 23F. 56�0of the strains were not susceptible to pencillin, while 99�0of these were susceptible to ceftriaxone. 74.3�0and 46.1�0of the serotypes are covered by the pneumococcal polysaccharide vaccine and the 7-valent pneumococcal conjugate vaccine respectively.Conclusion: Certain few pneumococcal serotypes such as 9A, 6B and 19F are more prevalent in the Omani community than others. More than half of S. pneumoniae are not susceptible to penicillin while the great majority of the strains are susceptible to ceftriaxone.

  7. Antimicrobial susceptibilities and serotypes of Streptococcus pneumoniae isolates from elderly patients with pneumonia and acute exacerbation of chronic obstructive pulmonary disease.

    Pérez-Trallero, Emilio; Marimón, José M; Larruskain, Julián; Alonso, Marta; Ercibengoa, María

    2011-06-01

    In the elderly, Streptococcus pneumoniae is the most common cause of pneumonia and one of the most frequently isolated pathogens in cases of acute exacerbation of chronic obstructive pulmonary disease (AECOPD). This study was conducted to compare the pneumococcal isolates obtained during episodes of AECOPD and pneumonia in patients of ≥65 years old and to analyze whether in patients with AECOPD and pneumonia within a short interval, the same isolate caused both episodes. This laboratory-based study was performed between 2005 and 2008. Pneumococcal isolates from episodes of pneumonia (n = 401) and AECOPD (n = 398), matched one-to-one by date of isolation, were characterized. The serotypes and genotypes of other pneumococcal isolates causing pneumonia and AECOPD in the same patient were compared. In patients with pneumonia, COPD as an underlying disease was not associated with more-drug-resistant pneumococci. In contrast, isolates causing AECOPD showed higher rates of resistance than those causing pneumonia. Serotypes 1, 3, and 7F were more frequent in pneumonia. The same pneumococcus was involved in 25.7% (9/35 patients) of patients with two consecutive AECOPD episodes but in only 6.3% (2/32 patients) of COPD patients with pneumonia and exacerbation (Fisher's exact test; P = 0.047). Less invasive serotypes were isolated more often in AECOPD and were more resistant to antimicrobials. The presence of a specific pneumococcal serotype in AECOPD does not predict the etiology of subsequent pneumonia.

  8. Detection of Streptococcus pneumoniae and identification of pneumococcal serotypes by real-time polymerase chain reaction using blood samples from Italian children ≤ 5 years of age with community-acquired pneumonia.

    Marchese, Anna; Esposito, Susanna; Coppo, Erika; Rossi, Giovanni A; Tozzi, Alberto; Romano, Mariateresa; Da Dalt, Liviana; Schito, Gian Carlo; Principi, Nicola

    2011-09-01

    Streptococcus pneumoniae is a leading cause of severe life-threatening infections. Laboratory identification and serotyping of this pathogens is desirable to monitor vaccine impact and coverage; however, especially in pediatric patients, the yield of traditional microbiological diagnostic procedures can be very low. The aim of this study was to develop real-time polymerase chain reaction (PCR)-based assays to be performed directly on blood samples to identify the most common capsular serotypes causing pneumonia in Italian children (≤ 5 years of ages) after the introduction of the 7-valent conjugate vaccine. Our real-time PCR-based assays showed high sensitivity (at least 35 fg of pneumococcal DNA), and they were validated with 49 well-characterized pneumococcal isolates, 8 nonpneumococcal isolates, 13 simulated blood clinical samples loaded with S. pneumoniae of known serotypes, and 46 blood clinical samples. All the strains tested and the simulated blood clinical samples were correctly typed by the technique. Real-time PCR allowed serotyping in 37/46 children ≤ 5 years of age (80.4%) in whom pneumonia was diagnosed in four Italian hospitals. Non-PCV7 serotypes accounted for at least 47.8% (22/46) of cases, serotype 19A being the most common (34.7%, 16/46). Although, it is not known at present whether the incidence of 19A serotype is attributable to the use of PCV7 only, expanding pneumococcal serotype coverage has clearly the potential to prevent a larger number of pneumonias in Italian children less than ≤ 5 years of age. Molecular methods are of increasing importance in the diagnosis of pneumococcal pneumonia and in monitoring serotype distribution and replacement.

  9. A novel quantitative PCR assay for the detection of Streptococcus pneumoniae using the competence regulator gene target comX.

    Habets, Marrit N; Cremers, Amelieke J H; Bos, Martine P; Savelkoul, Paul; Eleveld, Marc J; Meis, Jacques F; Hermans, Peter W M; Melchers, Willem J; de Jonge, Marien I; Diavatopoulos, Dimitri A

    2016-02-01

    Streptococcus pneumoniae is responsible for an estimated 1.6 million deaths worldwide every year. While rapid detection and timely treatment with appropriate antibiotics is preferred, this is often difficult due to the amount of time that detection with blood cultures takes. In this study, a novel quantitative PCR assay for the detection of Streptococcus pneumoniae was developed. To identify novel targets, we analysed the pneumococcal genome for unique, repetitive DNA sequences. This approach identified comX, which is conserved and present in duplicate copies in Streptococcus pneumoniae but not in other bacterial species. Comparison with lytA, the current 'gold standard' for detection by quantitative PCR, demonstrated an analytic specificity of 100% for both assays on a panel of 10 pneumococcal and 18 non-pneumococcal isolates, but a reduction of 3.5 quantitation cycle values (± 0.23 sem), resulting in an increased analytical detection rate of comX. We validated our assay on DNA extracted from the serum of 30 bacteraemic patients who were blood culture positive for Streptococcus pneumoniae and 51 serum samples that were culture positive for other bacteria. This resulted in a similar clinical sensitivity between the comX and lytA assays (47%) and in a diagnostic specificity of 98.2 and 100% for the lytA and comX assays, respectively. In conclusion, we have developed a novel quantitative PCR assay with increased analytical sensitivity for the detection of Streptococcus pneumoniae, which may be used to develop a rapid bedside test for the direct detection of Streptococcus pneumoniae in clinical specimens.

  10. Role of Streptococcus pneumoniae Proteins in Evasion of Complement-Mediated Immunity

    Andre, Greiciely O.; Converso, Thiago R.; Politano, Walter R.; Ferraz, Lucio F. C.; Ribeiro, Marcelo L.; Leite, Luciana C. C.; Darrieux, Michelle

    2017-01-01

    The complement system plays a central role in immune defense against Streptococcus pneumoniae. In order to evade complement attack, pneumococci have evolved a number of mechanisms that limit complement mediated opsonization and subsequent phagocytosis. This review focuses on the strategies employed by pneumococci to circumvent complement mediated immunity, both in vitro and in vivo. At last, since many of the proteins involved in interactions with complement components are vaccine candidates in different stages of validation, we explore the use of these antigens alone or in combination, as potential vaccine approaches that aim at elimination or drastic reduction in the ability of this bacterium to evade complement. PMID:28265264

  11. Streptococcus pneumoniae causing mycotic aneurysm in a pediatric patient with coarctation of the aorta.

    Haas, Brian; Wilt, Heath G; Carlson, Karina M; Lofland, Gary K

    2012-01-01

    Mycotic aneurysms are rare in patients with congenital heart disease, but may occur in those with aortic coarctation and abnormal aortic valve. Rapid diagnosis of mycotic aneurysm is of extreme importance given the significant reported incidence of morbidity and mortality across all age groups. Aortic aneurysm is uncommon before the second decade of life, and here we report a 10-year-old male patient with new diagnosis of aortic coarctation and bicuspid aortic valve, who developed a rapidly enlarging mycotic aneurysm from Streptococcus pneumoniae. Cardiac magnetic resonance imaging was crucial in making the diagnosis, as well as in follow-up.

  12. In vitro activity of six macrolides, clindamycin and tetracycline on Streptococcus pneumoniae with different penicillin susceptibilities.

    Poulsen, R L; Knudsen, J D; Petersen, M B; Fuursted, K; Espersen, F; Frimodt-Møller, N

    1996-03-01

    A collection of 99 clinical isolates of Streptococcus pneumoniae, chosen due to their different susceptibilities to penicillin, were investigated with respect to their susceptibility to the macrolides azithromycin, clarithromycin, dirithromycin, erythromycin, roxithromycin, spiramycin, and to clindamycin and tetracycline by the agar dilution method. We found complete cross resistance among the macrolides. The pneumococci were either susceptible, MIC MIC > or = 16 micrograms/ml, to the tested macrolides, giving a bimodal distribution. In addition, complete cross resistance was observed between clindamycin and macrolides. Pneumococci resistant to macrolides were also resistant to tetracycline, and 26% of the macrolide-susceptible strains were tetracycline resistant.

  13. Selective IgM deficiency in an adult presenting with Streptococcus pneumoniae septic arthritis.

    Phuphuakrat, Angsana; Ngamjanyaporn, Pintip; Nantiruj, Kanokrat; Luangwedchakarn, Voravich; Malathum, Kumthorn

    2016-02-01

    Septic arthritis caused by Streptococcus pneumoniae is uncommon. Most of the patients who have invasive pneumococcal infection have underlying diseases associated with impaired immune function. We report a case of polyarticular pneumococcal septic arthritis in a previously healthy adult as the first manifestation of selective immunoglobulin (Ig)M deficiency. The patient had no evidence of autoimmune disease or malignancy. Serum IgG, IgA, and complement levels were normal. Numbers of lymphocyte subsets were in normal range except that of CD4+ cells, which was slightly low. Invasive pneumococcal disease in a healthy adult should lead to further investigation for underlying diseases including primary immunodeficiencies.

  14. Caracterización funcional del regulador esencial YycF de "Streptococcus pneumoniae"

    Mohedano Bonillo, Mª Luz

    2011-01-01

    Este trabajo se ha centrado en la caracterización de la regulación molecular del sistema esencial de dos componentes (SDC) YycFG específico de bacterias gram positivas, utilizando como sistema modelo Streptococcus pneumoniae. Se ha establecido un sistema de sobreexpresión controlada para analizar la función de YycFG in vivo y se ha realizado un análisis global genómico y proteómico de neumococos sobreproductores de este SDC. El análisis de su transcriptoma mostró un control de YycF sobre los ...

  15. Serotipos prevalentes de Streptococcus pneumoniae colonizadores de nasofaringe, en niños del Distrito Federal

    Fortino Solórzano-Santos; Gabriela Echániz-Avilés; Araceli Soto-Noguerón; Héctor Guiscafré-Gallardo; Ma Guadalupe Miranda-Novales; Laura Alicia Ortiz-Ocampo

    2005-01-01

    Objetivo. Determinar frecuencia, serotipos y susceptibilidad a ocho antimicrobianos en Streptococcus pneumoniae aislados de la nasofaringe de una muestra representativa de niños menores de cinco años de edad residentes en el Distrito Federal. Material y métodos. Estudio transversal, hecho de febrero de 2002 a enero de 2003. Se incluyeron niños de 2 meses a 5 años. A los seleccionados se les tomó una muestra de exudado faríngeo con hisopo de alginato de calcio. Bajo técnicas ya establecidas s...

  16. Transfer of penicillin resistance from Streptococcus oralis to Streptococcus pneumoniae identifies murE as resistance determinant.

    Todorova, Katya; Maurer, Patrick; Rieger, Martin; Becker, Tina; Bui, Nhat Khai; Gray, Joe; Vollmer, Waldemar; Hakenbeck, Regine

    2015-09-01

    Beta-lactam resistant clinical isolates of Streptococcus pneumoniae contain altered penicillin-binding protein (PBP) genes and occasionally an altered murM, presumably products of interspecies gene transfer. MurM and MurN are responsible for the synthesis of branched lipid II, substrate for the PBP catalyzed transpeptidation reaction. Here we used the high-level beta-lactam resistant S. oralis Uo5 as donor in transformation experiments with the sensitive laboratory strain S. pneumoniae R6 as recipient. Surprisingly, piperacillin-resistant transformants contained no alterations in PBP genes but carried murEUo5 encoding the UDP-N-acetylmuramyl tripeptide synthetase. Codons 83-183 of murEUo5 were sufficient to confer the resistance phenotype. Moreover, the promoter of murEUo5 , which drives a twofold higher expression compared to that of S. pneumoniae R6, could also confer increased resistance. Multiple independent transformations produced S. pneumoniae R6 derivatives containing murEUo5 , pbp2xUo5 , pbp1aUo5 and pbp2bUo5 , but not murMUo5 sequences; however, the resistance level of the donor strain could not be reached. S. oralis Uo5 harbors an unusual murM, and murN is absent. Accordingly, the peptidoglycan of S. oralis Uo5 contained interpeptide bridges with one L-Ala residue only. The data suggest that resistance in S. oralis Uo5 is based on a complex interplay of distinct PBPs and other enzymes involved in peptidoglycan biosynthesis.

  17. Análise das cepas de Streptococcus pneumoniae causadores de pneumonia invasiva: sorotipos e sensibilidade aos antimicrobianos

    Cristina R. M. Yoshioka

    2011-02-01

    Full Text Available OBJETIVOS: Identificar os sorotipos de pneumococo mais frequentemente isolados de crianças internadas com pneumonia invasiva, comparar os sorotipos com os incluídos em vacinas conjugadas e analisar sua sensibilidade aos antimicrobianos mais utilizados na faixa etária pediátrica. MÉTODOS: Estudo descritivo, retrospectivo das pneumonias pneumocócicas identificadas em crianças internadas no hospital universitário da Universidade de São Paulo, no período de janeiro de 2003 a outubro de 2008. Os critérios de inclusão foram: faixa etária de 29 dias até 15 anos incompletos com diagnóstico clínico e radiológico de pneumonia e com cultura de sangue e/ou líquido pleural com crescimento de Streptococcus pneumoniae. RESULTADOS: Foram incluídas no estudo 107 crianças. Os sorotipos mais frequentes foram: 14 (36,5%, 1 (16,7%, 5 (14,6%, 6B (6,3% e 3 (4,2%. A proporção de sorotipos contidos na vacina conjugada heptavalente seria de 53,1%, na vacina 10-valente de 86,5% e na 13-valente seria de 96,9%. De acordo com os padrões do Clinical and Laboratory Standards Institute 2008, 100 cepas (93,5% de pneumococos foram sensíveis à penicilina (concentração inibitória mínima, CIM 8 µg/mL. Verificamos alta taxa de sensibilidade para as cepas testadas para vancomicina, rifampicina, ceftriaxone, clindamicina, cloranfenicol e eritromicina. CONCLUSÕES: Nossos resultados confirmam um expressivo impacto potencial das vacinas conjugadas, principalmente pela 10-valente e 13-valente, sobre os casos de pneumonias invasivas. Os resultados de sensibilidade à penicilina evidenciam que a opção terapêutica de escolha para o tratamento das pneumonias invasivas continua sendo a penicilina.

  18. Antagonism between penicillin and erythromycin against Streptococcus pneumoniae in vitro and in vivo

    Johansen, H K; Jensen, T G; Dessau, Ram

    2000-01-01

    the effect of the bactericidal agent. In this study, the possible interaction between penicillin and erythromycin was investigated in vitro and in vivo against four clinical isolates of Streptococcus pneumoniae with MICs of penicillin ranging from 0.016 to 0.5 mg/L and of erythromycin from 0. 25 to >128 mg......The combination of beta-lactam antibiotics and macrolides is often recommended for the initial empirical treatment of acute pneumonia in order to obtain activity against the most important pathogens. Theoretically, this combination may be inexpedient, as the bacteriostatic agent may antagonize....../L. In vitro time-kill curves were generated with clinically relevant concentrations of penicillin (10 mg/L) and erythromycin (1 mg/L), either individually or in combination. Antagonism between penicillin and erythromycin was observed for the four isolates. In vivo interaction was investigated in the mouse...

  19. Penicillin susceptibility of non-serotypeable Streptococcus pneumoniae from ophthalmic specimens.

    Kojima, Fumiko; Nakagami, Yoshiko; Takemori, Koichi; Iwatani, Yoshinori; Fujimoto, Shuji

    2006-01-01

    Nontypeable (NT) Streptococcus pneumoniae strains isolated from eyes were examined for both penicillin susceptibility by E-test and penicillin-binding protein (PBP) gene alterations using PCR. Of the 25 ophthalmic isolates, 15 proved to be sensitive (PSSP, MIC penicillin (PISP, MIC = 0.1-1 microg/ml). No penicillin-resistant S. pneumoniae (PRSP, MIC > or = 2 microg/ml) were found. PBP gene (pbp1a and pbp2b) alteration PCR indicated that 12 (80.0%) of the 15 ophthalmic PSSPs had unaltered pbp genes and that 3 (20.0%) had alterations in either pbp1a or pbp2b, whereas 8 (80.0%) of the 10 PISPs had unaltered pbp genes and 2 (20.0%) had alterations in both pbp1a and pbp2b. These data suggest that penicillin resistance is spread among NT pneumococci typically associated with ophthalmic infections.

  20. Prevalence and antibiotic resistance of commensal Streptococcus pneumoniae in nine European countries.

    Yahiaoui, Rachid Y; den Heijer, Casper Dj; van Bijnen, Evelien Me; Paget, W John; Pringle, Mike; Goossens, Herman; Bruggeman, Cathrien A; Schellevis, François G; Stobberingh, Ellen E

    2016-06-01

    The human microbiota represents an important reservoir of antibiotic resistance. Moreover, the majority of antibiotics are prescribed in primary care. For this reason, we assessed the prevalence and antibiotic resistance of nasal carriage strains of Streptococcus pneumoniae, the most prevalent bacterial causative agent of community-acquired respiratory tract infections, in outpatients in nine European countries. Nasal swabs were collected between October 2010 and May 2011, from 32,770 patients, recruited by general practices in nine European countries. Overall prevalence of S. pneumoniae nasal carriage in the nine countries was 2.9%. The carriage was higher in men (3.7%) than in women (2.7%). Children (4-9 years) had a higher carriage prevalence (27.2%) compared with those older than 10 years (1.9%). The highest resistance observed was to cefaclor. The highest prevalence of multidrug resistance was found in Spain and the lowest prevalence was observed in Sweden.

  1. Resistencia a penicilina y otros antimicrobianos en 103 aislamientos clínicos de Streptococcus pneumoniae (2000-2001 Resistance to penicillin and other antimicrobials in 103 clinical isolations of Streptococcus pneumoniae (2000-2001

    J.J. García-Irure

    2003-04-01

    Full Text Available Fundamentos. Conocer en nuestro hospital la sensibilidad a penicilina de aislamientos de Streptococcus pneumoniae, así como analizar la asociación de resistencia a penicilina y otros antimicrobianos y la actividad de cefotaxima y cefepima en cepas de Streptococcus pneumoniae resistentes a penicilina. Métodos. Se determinó la sensibilidad de 103 aislamientos de Streptococcus pneumoniae, procedentes de muestras clínicas durante los años 2000-2001, a penicilina, eritromicina, cloramfenicol, tetraciclina, cotrimoxazol, cefotaxima, cefepima y levofloxacino. Resultados. El 68% de los aislamientos fueron sensibles a penicilina, mientras que un 32% de las cepas de Streptococcus pneumoniae aisladas fueron resistentes a penicilina, presentando el 7,7% resistencia de alto grado a la misma. La resistencia a eritromicina, cloramfenicol, tetraciclina, cotrimoxazol y levofloxacino fue del 38,8; 9,7; 20,4; 25,2 y 2,9% respectivamente, incrementándose a valores del 66,6; 30,3; 48,5; 72,7 y 9,1% en las 33 cepas con resistencia a penicilina. La resistencia a cefotaxima y cefepima fue del 9,7 y 10,6% respectivamente. Conclusiones. Un alto porcentaje de cepas de Streptococcus pneumoniae presentaron algún grado de resistencia a penicilina, pero con cifras menores que las presentadas en otros estudios de ámbito nacional. Asimismo, se demostró que la resistencia a penicilina se asociaba significativamente (p Background. To determine in our hospital the sensitivity of isolations of Streptococcus pneumoniae to penicillin, as well as to analyse the association of resistance to penicillin and other antimicrobials and the activity of cefotaxime and cefepime in pencillin resistant strains of Streptococcus pneumoniae. Methods. The sensitivity was determined on 103 isolations of Streptococcus pneumoniae, from clinical samples from the years 2000-2001, to penicillin, eritromycine, cloramfenicol, tetracycline, cotrimoxazol, cefotaxime, cefepime and levofloxacine

  2. Absence of capsule reveals glycan-mediated binding and recognition of salivary mucin MUC7 by Streptococcus pneumoniae.

    Thamadilok, S; Roche-Håkansson, H; Håkansson, A P; Ruhl, S

    2016-04-01

    Salivary proteins modulate bacterial colonization in the oral cavity and interact with systemic pathogens that pass through the oropharynx. An interesting example is the opportunistic respiratory pathogen Streptococcus pneumoniae that normally resides in the nasopharynx, but belongs to the greater Mitis group of streptococci, most of which colonize the oral cavity. Streptococcus pneumoniae also expresses a serine-rich repeat (SRR) adhesin, PsrP, which is a homologue to oral Mitis group SRR adhesins, such as Hsa of Streptococcus gordonii and SrpA of Streptococcus sanguinis. As the latter bind to salivary glycoproteins through recognition of terminal sialic acids, we wanted to determine whether S. pneumoniae also binds to salivary proteins through possibly the same mechanism. We found that only a capsule-free mutant of S. pneumoniae TIGR4 binds to salivary proteins, most prominently to mucin MUC7, but that this binding was not mediated through PsrP or recognition of sialic acid. We also found, however, that PsrP is involved in agglutination of human red blood cells (RBCs). After removal of PsrP, an additional previously masked lectin-like adhesin activity mediating agglutination of sialidase-treated RBCs becomes revealed. Using a custom-spotted glycoprotein and neoglycoprotein dot blot array, we identify candidate glycan motifs recognized by PsrP and by the putative S. pneumoniae adhesin that could perhaps be responsible for pneumococcal binding to salivary MUC7 and glycoproteins on RBCs.

  3. Gene expression platform for synthetic biology in the human pathogen Streptococcus pneumoniae.

    Sorg, Robin A; Kuipers, Oscar P; Veening, Jan-Willem

    2015-03-20

    The human pathogen Streptococcus pneumoniae (pneumococcus) is a bacterium that owes its success to complex gene expression regulation patterns on both the cellular and the population level. Expression of virulence factors enables a mostly hazard-free presence of the commensal, in balance with the host and niche competitors. Under specific circumstances, changes in this expression can result in a more aggressive behavior and the reversion to the invasive form as pathogen. These triggering conditions are very difficult to study due to the fact that environmental cues are often unknown or barely possible to simulate outside the host (in vitro). An alternative way of investigating expression patterns is found in synthetic biology approaches of reconstructing regulatory networks that mimic an observed behavior with orthogonal components. Here, we created a genetic platform suitable for synthetic biology approaches in S. pneumoniae and characterized a set of standardized promoters and reporters. We show that our system allows for fast and easy cloning with the BglBrick system and that reliable and robust gene expression after integration into the S. pneumoniae genome is achieved. In addition, the cloning system was extended to allow for direct linker-based assembly of ribosome binding sites, peptide tags, and fusion proteins, and we called this new generally applicable standard "BglFusion". The gene expression platform and the methods described in this study pave the way for employing synthetic biology approaches in S. pneumoniae.

  4. Streptococcus intermedius Causing Necrotizing Pneumonia in an Immune Competent Female: A Case Report and Literature Review

    Faris Hannoodi

    2016-01-01

    Full Text Available 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. Radiological findings varied from an isolated pleural effusion to systemic disease with the presence of brain abscesses. Immunocompetence appears to correlate well with the overall prognosis. In addition, smoking appears to be an important risk factor for S. intermedius pneumonia. In 2 (50% of cases, pleural fluid analysis identified S. intermedius. In contrast, no organism was found in our patient, necessitating the acquisition of lung tissue sample for the diagnosis. In conclusion, both medical and surgical management are necessary for effective treatment of S. intermedius pneumonia. The outcome of treatment is good in immunocompetent individuals.

  5. Antibiotic resistance of streptococcus pneumoniae and haemophilus influenzae isolated from respiratory tract specimens

    Hikmet Eda Aliskan

    2016-06-01

    Full Text Available Purpose: Streptococcus pneumoniae and Haemophilus influenzae are two of the major pathogens in respiratory infections, treatment is usually started empirically. The aim of this study was to detect in vitro resistance rates of S. pneumoniae and H. influenzae strains isolated from different lower respiratory clinical samples to the antibotics which are used for therapy of infections due to these pathogens. Material and Methods: Seventy seven S.pneumoniae and 117 H.influenzae strains, isolated from patients were included in the study. S.pneumoniae isolates which gave an inhibition zone diameter of >20 mm for oxacillin were considered susceptible for penicilin. For the isolates which had an oxacillin zone diameter of 2 mg/l and 31.1 % were intermediately resistant to parenteral penicillin. Resistance rates to antibiotics were as follows: erythromycin 40 %, trimethoprim/sulphametoxazole (TMP/SMX 54.5 % and ofloxacin 6.4%. beta-lactamases were detected in 15.6% of the H.influenzae isolates by nitrocefin positivity. Conclusion: H.influenzae strains (8.6% were identified as beta-lactamase negative ampicillin resistant (BLNAR strains. Resistance rates for other antibiotics were as follows: ampicillin 28.6%, cefaclor 36.5% , cefuroxime 30.1%, clarithromycin 9.6%, cloramphenicol 7% and TMP-SMX 43.9%. [Cukurova Med J 2016; 41(2.000: 201-207

  6. Antimicrobial activities of Eugenia caryophyllata extract and its major chemical constituent eugenol against Streptococcus pneumoniae.

    Yadav, Mukesh Kumar; Park, Seok-Won; Chae, Sung-Won; Song, Jae-Jun; Kim, Ho Chul

    2013-12-01

    In this study, we investigate the antimicrobial activities of both Eugenia caryophyllata (Ec) extract and its major component eugenol (4-allyl-2-methoxyphenol) against Streptococcus pneumoniae. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by microdilution method. Pneumococcal biofilms were detected by crystal-violet microtiter plate assay, followed by colony-forming unit counts and visualized by scanning electron microscope (SEM). The synergistic effect of eugenol and penicillin was determined by checker-board method. Both the eugenol and the Ec extract inhibited pneumococcal growth in a concentration-dependent manner. The MIC and MBC of eugenol were 0.06% and 0.12%, respectively. Eugenol at a concentration of 0.12% completely killed S. pneumoniae within 60 min of exposure. The kill rate of planktonic cells was most rapid during the first 15 min of contact with eugenol. The addition of eugenol or Ec extract inhibited in vitro biofilm formation. In already established biofilms, the inhibitory effect of eugenol or Ec extract was more significant in terms of cell viability than in terms of disruption of the biofilm matrix. SEM analysis revealed non-viable and disruptive action of eugenol on the cell membrane of bacteria of biofilms. It was found that eugenol and penicillin produced a synergistic effect against S. pneumoniae. In conclusion, eugenol and Ec extract efficiently inhibited S. pneumoniae in planktonic growth and within biofilms.

  7. Structural and functional analysis of fucose-processing enzymes from Streptococcus pneumoniae.

    Higgins, Melanie A; Suits, Michael D; Marsters, Candace; Boraston, Alisdair B

    2014-04-03

    Fucose metabolism pathways are present in many bacterial species and typically contain the central fucose-processing enzymes fucose isomerase (FcsI), fuculose kinase (FcsK), and fuculose-1-phosphate aldolase (FcsA). Fucose initially undergoes isomerization by FcsI producing fuculose, which is then phosphorylated by FcsK. FcsA cleaves the fuculose-1-phosphate product into lactaldehyde and dihydroxyacetone phosphate, which can be incorporated into central metabolism allowing the bacterium to use fucose as an energy source. Streptococcus pneumoniae has fucose-processing operons containing homologs of FcsI, FcsK, and FcsA; however, this bacterium appears unable to utilize fucose as an energy source. To investigate this contradiction, we performed biochemical and structural studies of the S. pneumoniae fucose-processing enzymes SpFcsI, SpFcsK, and SpFcsA. These enzymes are demonstrated to act in a sequential manner to ultimately produce dihydroxyacetone phosphate and have structural features entirely consistent with their observed biochemical activities. Analogous to the regulation of the Escherichia coli fucose utilization operon, fuculose-1-phosphate appears to act as an inducing molecule for activation of the S. pneumoniae fucose operon. Despite our evidence that S. pneumoniae appears to have the appropriate regulatory and biochemical machinery for fucose metabolism, we confirmed the inability of the S. pneumoniae TIGR4 strain to grow on fucose or on the H-disaccharide, which is the probable substrate of the transporter for the pathway. On the basis of these observations, we postulate that the S. pneumoniae fucose-processing pathway has a non-metabolic role in the interaction of this bacterium with its human host.

  8. Nasopharyngeal carriage rate of Streptococcus pneumoniae in Ugandan children with sickle cell disease

    Kateete David P

    2012-01-01

    Full Text Available Abstract Background Nasopharyngeal carriage of Streptococcus pneumoniae is a determinant for invasive pneumococcal disease, which often complicates homozygous sickle cell disease. Here, we determined the nasopharyngeal carriage rate of S. pneumoniae in Ugandan children with homozygous sickle cell disease, who attended the outpatient Sickle Cell Clinic at Mulago National Referral hospital in Kampala, Uganda. Results S. pneumoniae occurred in 27 of the 81 children with homozygous sickle cell disease (giving a carriage rate of 33%, 27/81. Twenty three children were previously hospitalized of whom S. pneumoniae occurred in only two (9%, 2/23, while among the 58 who were not previously hospitalized it occurred in 25 (43%, 25/58, χ2 = 8.8, p = 0.003, meaning there is an association between high carriage rate and no hospitalization. Two children previously immunized with the pneumococcal conjugate vaccine did not carry the organism. Prior antimicrobial usage was reported in 53 children (65%, 53/81. There was high resistance of pneumococci to penicillin (100%, 27/27 and trimethoprime-sulfamethoxazole (97%, 26/27, but low resistance to other antimicrobials. Of the 70 children without sickle cell disease, S. pneumoniae occurred in 38 (54%, 38/70 of whom 43 were males and 27 females (53% males, 23/43, and 56% females, 15/27. Conclusion Nasopharyngeal carriage of penicillin resistant pneumococci in Ugandan children with homozygous sickle cell disease is high. While nasopharyngeal carriage of S. pneumoniae is a determinant for invasive pneumococcal disease, pneumococcal bacteremia is reportedly low in Ugandan children with sickle cell disease. Studies on the contribution of high carriage rates to invasive pneumococcal disease in these children will be helpful. This is the first report on pneumococcal carriage rate in Ugandan children with sickle cell disease.

  9. SMC is recruited to oriC by ParB and promotes chromosome segregation in Streptococcus pneumoniae

    Minnen, Anita; Attaiech, Laetitia; Thon, Maria; Gruber, Stephan; Veening, Jan-Willem

    2011-01-01

    Segregation of replicated chromosomes is an essential process in all organisms. How bacteria, such as the oval-shaped human pathogen Streptococcus pneumoniae, efficiently segregate their chromosomes is poorly understood. Here we show that the pneumococcal homologue of the DNA-binding protein ParB recruits S. pneumoniae condensin (SMC) to centromere-like DNA sequences (parS) that are located near the origin of replication, in a similar fashion as was shown for the rod-shaped model bacterium Ba...

  10. Meningitis in a Canadian Adult due to High Level Penicillin-Resistant, Cefotaxime-Intermediate Streptococcus pneumoniae

    Cécile Tremblay

    1996-01-01

    Full Text Available Invasive penicillin-resistant pneumococcal (PRSP infections are increasing worldwide. In Canada, the incidence of penicillin resistance among Streptococcus pneumoniae isolates is estimated at greater than 6%. In Quebec, only one case of PRSP meningitis has been reported and involved an infant. An adult patient is described who presented with meningitis caused by high level penicillin-resistant, cefotaxime-intermediate S pneumoniae.

  11. Molecular Detection of Streptococcus pneumoniae on Dried Blood Spots from Febrile Nigerian Children Compared to Culture.

    Pui-Ying Iroh Tam

    Full Text Available Nigeria has one of the highest burdens of pneumococcal disease in the world, but accurate surveillance is lacking. Molecular detection of infectious pathogens in dried blood spots (DBS is an ideal method for surveillance of infections in resource-limited settings because of its low cost, minimal blood volumes involved, and ease of storage at ambient temperature. Our study aim was to evaluate a Streptococcus pneumoniae real-time polymerase chain reaction (rt-PCR assay on DBS from febrile Nigerian children on Whatman 903 and FTA filter papers, compared to the gold standard of culture.Between September 2011 to May 2015, blood was collected from children 5 years of age or under who presented to six hospital study sites throughout northern and central Nigeria with febrile illness, and inoculated into blood culture bottles or spotted onto Whatman 903 or FTA filter paper. Culture and rt-PCR were performed on all samples.A total of 537 DBS specimens from 535 children were included in the study, of which 15 were culture-positive for S. pneumoniae. The rt-PCR assay detected S. pneumoniae in 12 DBS specimens (2.2%. One positive rt-PCR result was identified in a culture-negative specimen from a high-risk subject, and two positive rt-PCR results were negative on repeat testing. Six culture-confirmed cases of S. pneumoniae bacteremia were missed. Compared to culture, the overall sensitivities of Whatman 903 and FTA DBS for detection of S. pneumoniae were 57.1% (95% CI 18.4-90.1% and 62.5% (95% CI 24.5-91.5%, respectively. Nonspecific amplification was noted in an additional 22 DBS (4.1%. Among these, six were positive for a non-S. pneumoniae pathogen on culture.Rt-PCR was able to detect S. pneumoniae from clinical DBS specimens, including from a culture-negative specimen. Our findings show promise of this approach as a surveillance diagnostic, but also raise important cautionary questions. Several DBS specimens were detected as S. pneumoniae by rt-PCR despite

  12. Streptococcus pneumoniae coinfection is correlated with the severity of H1N1 pandemic influenza.

    Gustavo Palacios

    Full Text Available BACKGROUND: Initial reports in May 2009 of the novel influenza strain H1N1pdm estimated a case fatality rate (CFR of 0.6%, similar to that of seasonal influenza. In July 2009, however, Argentina reported 3056 cases with 137 deaths, representing a CFR of 4.5%. Potential explanations for increased CFR included virus reassortment or genetic drift, or infection of a more vulnerable population. Virus genomic sequencing of 26 Argentinian samples representing both severe and mild disease indicated no evidence of reassortment, mutations associated with resistance to antiviral drugs, or genetic drift that might contribute to virulence. Furthermore, no evidence was found for increased frequency of risk factors for H1N1pdm disease. METHODS/PRINCIPAL FINDINGS: We examined nasopharyngeal swab samples (NPS from 199 cases of H1N1pdm infection from Argentina with MassTag PCR, testing for 33 additional microbial agents. The study population consisted of 199 H1N1pdm-infected subjects sampled between 23 June and 4 July 2009. Thirty-nine had severe disease defined as death (n = 20 or hospitalization (n = 19; 160 had mild disease. At least one additional agent of potential pathogenic importance was identified in 152 samples (76%, including Streptococcus pneumoniae (n = 62; Haemophilus influenzae (n = 104; human respiratory syncytial virus A (n = 11 and B (n = 1; human rhinovirus A (n = 1 and B (n = 4; human coronaviruses 229E (n = 1 and OC43 (n = 2; Klebsiella pneumoniae (n = 2; Acinetobacter baumannii (n = 2; Serratia marcescens (n = 1; and Staphylococcus aureus (n = 35 and methicillin-resistant S. aureus (MRSA, n = 6. The presence of S. pneumoniae was strongly correlated with severe disease. S. pneumoniae was present in 56.4% of severe cases versus 25% of mild cases; more than one-third of H1N1pdm NPS with S. pneumoniae were from subjects with severe disease (22 of 62 S. pneumoniae-positive NPS, p = 0.0004. In subjects 6 to 55 years of age, the adjusted odds ratio

  13. Serological and molecular capsular typing, antibiotic susceptibility and multilocus sequence typing of Streptococcus pneumoniae isolates from invasive and non-invasive infections

    ZHANG Yi-jie; CHEN Yu-shen; WANG Zhan-wei; LI Yu-qian; WANG Da-xuan; SHANG Ying; FU Rong-rong

    2013-01-01

    Background Streptococcus pneumoniae (S.pneumoniae) is a major causative agent of severe infections,including sepsis,pneumonia,meningitis,and otitis media,and has become a major public health concern.We report the pneumococcal serotype and sequence type (ST) distribution,and antimicrobial resistance of 39 S.pneumoniae strains from seven hospitals in China.Methods Blood/cerebrospinal fluid (CSF) and sputum isolates from patients were analyzed to determine S.pneumoniae serotypes by polymerase chain reaction (PCR) and the Neufeld Quellung reaction,the multilocus sequence types (MLST) by PCR and sequencing,and susceptibility to antimicrobial agents by the VITEK Gram Positive Susceptibility Card.Results A total of 39 isolates were collected including 21 blood/CSF and 18 sputum isolates.Conventional serotyping by the Quellung reaction required 749 reactions.In contrast,PCR based typing needed only 106 PCR reactions.The most frequent serotypes from the blood/CSF isolates were 14 (38.1%),19A (14.3%),23F (9.5%),and 18C (9.5%).In the sputum isolates the most frequent serotypes were 19F (33.3%),23F (16.7%),19A (11.1%),and 3 (11.1%).The incidence of penicillin resistance in the blood/CSF and sputum isolates was 66.7% and 55.6%,respectively.Statistical analysis showed that patients ≤5 years old had a higher resistance to penicillin when they compared with the patients ≥65 years old (P=0.011).Serotypes 14,19A and 19F were significantly associated with penicillin resistance (P <0.001).ST320,ST271,and ST876 isolates showed high resistant rates to several antibiotics including penicillin (P=0.006).All of the isolates of serotype 19A were resistant to both penicillin and erythromycin,and they were all multi-drug resistant (MDR) isolates.Conclusions The specificity and sensitivity of multiplexPCR are good,and this method represents a substantial savings of time and money,and can be widely used in the laboratory and clinical practice.Data from this research

  14. Activity of gemifloxacin against quinolone-resistant Streptococcus pneumoniae strains in vitro and in a mouse pneumonia model.

    Azoulay-Dupuis, E; Bédos, J P; Mohler, J; Moine, P; Cherbuliez, C; Peytavin, G; Fantin, B; Köhler, T

    2005-03-01

    Gemifloxacin is a novel fluoronaphthyridone quinolone with enhanced in vitro activity against Streptococcus pneumoniae. We investigated the activities of gemifloxacin and trovafloxacin, their abilities to select for resistance in vitro and in vivo, and their efficacies in a mouse model of acute pneumonia. Immunocompetent Swiss mice were infected with 10(5) CFU of a virulent, encapsulated S. pneumoniae strain, P-4241, or its isogenic parC, gyrA, parC gyrA, and efflux mutant derivatives (serotype 3); and leukopenic mice were infected with 10(7) CFU of two poorly virulent clinical strains (serotype 11A) carrying either a parE mutation or a parC, gyrA, and parE triple mutation. The drugs were administered six times every 12 h, starting at either 3 or 18 h postinfection. In vitro, gemifloxacin was the most potent agent against strains with and without acquired resistance to fluoroquinolones. While control mice died within 6 days, gemifloxacin at doses of 25 and 50 mg/kg of body weight was highly effective (survival rates, 90 to 100%) against the wild-type strain and against mutants harboring a single mutation, corresponding to area under the time-versus-serum concentration curve at 24 h (AUC(24))/MIC ratios of 56.5 to 113, and provided a 40% survival rate against a mutant with a double mutation (parC and gyrA). A total AUC(24)/MIC ratio of 28.5 was associated with poor efficacy and the emergence of resistant mutants. Trovafloxacin was as effective as gemifloxacin against mutants with single mutations but did not provide any protection against the mutant with double mutations, despite treatment with a high dose of 200 mg/kg. Gemifloxacin preferentially selected for parC mutants both in vitro and in vivo.

  15. Inclusion bodies and pH lowering: as an effect of gold nanoparticles in Streptococcus pneumoniae.

    Ortiz-Benitez, Edgar Augusto; Carrillo-Morales, Mariana; Velázquez-Guadarrama, Norma; Fandiño-Armas, Jesús; Olivares-Trejo, José de Jesús

    2015-07-01

    Streptococcus pneumoniae is a human pathogen whose principal virulence factor is its capsule. This structure allows the bacterium to evade the human immune system. Treatment of infections caused by this bacterium is based on antibiotics; however, the emergence of antibiotic-resistant strains makes this task increasingly difficult. Therefore, it is necessary to investigate new therapies, such as those based on gold nanoparticles, for which unfortunately the mechanisms involved have not yet been investigated. As far as we know, this study is the first that attempts to explain how gold nanoparticles destroy the bacterium Streptococcus pneumoniae. We found that the mean particle size was an important issue, and that the effect on the bacterium was dose-dependent. Cellular growth was inhibited by the presence of the nanoparticles, as was cell viability. The pH of the bacterial growth media was acidified, but interestingly the reactive species were not affected. A transmission electron microscopy analysis revealed the presence of inclusion bodies of gold nanoparticles within the bacterium. We present the first findings that attempt to explain how gold nanoparticles lyse Gram-positive bacteria.

  16. Feasibility and Safety of Local Treatment with Recombinant Human Tissue Factor Pathway Inhibitor in a Rat Model of Streptococcus pneumoniae Pneumonia.

    Florry E van den Boogaard

    Full Text Available Pulmonary coagulopathy is intrinsic to pulmonary injury including pneumonia. Anticoagulant strategies could benefit patients with pneumonia, but systemic administration of anticoagulant agents may lead to suboptimal local levels and may cause systemic hemorrhage. We hypothesized nebulization to provide a safer and more effective route for local administration of anticoagulants. Therefore, we aimed to examine feasibility and safety of nebulization of recombinant human tissue factor pathway inhibitor (rh-TFPI in a well-established rat model of Streptococcus (S. pneumoniae pneumonia. Thirty minutes before and every 6 hours after intratracheal instillation of S. pneumonia causing pneumonia, rats were subjected to local treatment with rh-TFPI or placebo, and sacrificed after 42 hours. Pneumonia was associated with local as well as systemic activation of coagulation. Nebulization of rh-TFPI resulted in high levels of rh-TFPI in bronchoalveolar lavage fluid, which was accompanied by an attenuation of pulmonary coagulation. Systemic rh-TFPI levels remained undetectable, and systemic TFPI activity and systemic coagulation were not affected. Histopathology revealed no bleeding in the lungs. We conclude that nebulization of rh-TFPI seems feasible and safe; local anticoagulant treatment with rh-TFPI attenuates pulmonary coagulation, while not affecting systemic coagulation in a rat model of S. pneumoniae pneumonia.

  17. Feasibility and Safety of Local Treatment with Recombinant Human Tissue Factor Pathway Inhibitor in a Rat Model of Streptococcus pneumoniae Pneumonia.

    van den Boogaard, Florry E; Hofstra, Jorrit J; van 't Veer, Cornelis; Levi, Marcel M; Roelofs, Joris J T H; van der Poll, Tom; Schultz, Marcus J

    2015-01-01

    Pulmonary coagulopathy is intrinsic to pulmonary injury including pneumonia. Anticoagulant strategies could benefit patients with pneumonia, but systemic administration of anticoagulant agents may lead to suboptimal local levels and may cause systemic hemorrhage. We hypothesized nebulization to provide a safer and more effective route for local administration of anticoagulants. Therefore, we aimed to examine feasibility and safety of nebulization of recombinant human tissue factor pathway inhibitor (rh-TFPI) in a well-established rat model of Streptococcus (S.) pneumoniae pneumonia. Thirty minutes before and every 6 hours after intratracheal instillation of S. pneumonia causing pneumonia, rats were subjected to local treatment with rh-TFPI or placebo, and sacrificed after 42 hours. Pneumonia was associated with local as well as systemic activation of coagulation. Nebulization of rh-TFPI resulted in high levels of rh-TFPI in bronchoalveolar lavage fluid, which was accompanied by an attenuation of pulmonary coagulation. Systemic rh-TFPI levels remained undetectable, and systemic TFPI activity and systemic coagulation were not affected. Histopathology revealed no bleeding in the lungs. We conclude that nebulization of rh-TFPI seems feasible and safe; local anticoagulant treatment with rh-TFPI attenuates pulmonary coagulation, while not affecting systemic coagulation in a rat model of S. pneumoniae pneumonia.

  18. Urine Streptococcus Pneumoniae Antigen in the Diagnosis of Streptococcus Pneumoniae Pneumonia Children the Significance%尿肺炎链球菌抗原在诊断儿童肺炎链球菌肺炎中的意义

    夏振雄; 杨冰; 黄靖雯

    2013-01-01

      目的:探讨尿肺炎链球菌抗原用于诊断儿童肺炎链球菌感染的临床意义。方法:收集2010年9月-2011年12月笔者所在医院住院部0~3岁呼吸道感染的患儿病例,对每位患儿同时采集尿标本和痰标本,用胶体金法测定尿肺炎链球菌抗原,对痰标本进行分离培养与鉴定,并根据结果分析。结果:尿肺炎链球菌抗原和痰培养检测差别无显著性(P>0.05)。痰培养阳性组和阴性组的尿抗原阳性率差异有显著性(P0.05).Sputum positive group and negative group of urinary antigen positive rate(P<0.01).With sputum culture for pure culture as a diagnostic streptococcus pneumoniae infection standard,colloidal gold method measuring the sensitivity of the antigen was 86.00%,specific degree was 84.96%and the accuracy was 85.25%.Conclusion:Colloidal gold method and sputum culture in the diagnosis of streptococcus pneumoniae infection may have the same effect, colloidal gold method for clinical diagnosis of streptococcus pneumoniae infection children have the certain reference significance.

  19. Respiratory Syncytial Virus Increases the Virulence of Streptococcus pneumoniae by Binding to Penicillin Binding Protein 1a A New Paradigm in Respiratory Infection

    Smith, Claire M.; Sandrini, Sara; Datta, Sumit; Freestone, Primrose; Shafeeq, Sulman; Radhakrishnan, Priya; Williams, Gwyneth; Glenn, Sarah M.; Kuipers, Oscar P.; Hirst, Robert A.; Easton, Andrew J.; Andrew, Peter W.; O'Callaghan, Christopher

    2014-01-01

    Rationale: Respiratory syncytial virus (RSV) and Streptococcus pneumoniae are major respiratory pathogens. Coinfection with RSV and S. pneumoniae is associated with severe and often fatal pneumonia but the molecular basis for this remains unclear. ObjeOtives: Todetermine if interaction between RSV a

  20. Decreased Streptococcus pneumoniae susceptibility to oral antibiotics among children in rural Vietnam: a community study

    Phuc Ho D

    2010-03-01

    Full Text Available Abstract Background Streptococcus pneumoniae is the most significant bacterial cause of community-acquired pneumonia among children under five years worldwide. Updated resistance information of S. pneumoniae among children is essential to adjust the recommendations for empirical treatment of community-acquired pneumonia, which will have immense implications for local and global health. This study investigated the prevalence of antibiotic resistance in isolated strains of S. pneumoniae and relationship with antibiotic use and demographic factors of children under five in rural Vietnam in 2007. Methods In Bavi district, 847 children 6 to 60 months were selected from 847 households. The main child-caregivers in the households were interviewed weekly using structured questionnaires to collect information of daily illness symptoms and drug use for the selected child over a four-week period (from March through June 2007. In the 3rd week, the children were invited for a clinical examination and to collect nasopharyngeal samples for S. pneumoniae identification. Etest and disk diffusion were used to test antibiotic susceptibility. Results Of 818 participating children, 258 (32% had ongoing respiratory infections, 421 (52% carried S. pneumoniae, and 477 (58% had used antibiotics within the previous three weeks. Of the 421 isolates, 95% were resistant to at least one antibiotic (401/421. Resistance to co-trimoxazole, tetracycline, phenoxymethylpenicillin, erythromycin and ciprofloxacin was 78%, 75%, 75%, 70% and 28%, respectively. Low resistance was noted for amoxicillin (4%, benzylpenicillin (4%, and cefotaxime (2%. The intermediate resistance to amoxicillin was 32%. Multidrug-resistance was seen in 60%. The most common pattern was co-resistance to co-trimoxazole, tetracycline and erythromycin. The proportion of children carrying resistant bacteria was higher among the children who had used antibiotics in the previous three weeks. Conclusions Resistance

  1. Detection of Streptococcus pneumoniae from Different Types of Nasopharyngeal Swabs in Children.

    Felix S Dube

    Full Text Available A better understanding of the epidemiology of nasopharyngeal carriage of Streptococcus pneumoniae is important to assess the impact of vaccination and the pathogenesis of pneumococcal disease. We compared the recovery of S. pneumoniae from nylon flocked, Dacron and rayon swabs.The recovery of S. pneumoniae from mocked specimens using flocked, Dacron and rayon swabs were compared by culture. The yield from paired nasopharyngeal (NP samples obtained from healthy children sampled with flocked and Dacron swabs was also determined using culture and lytA-targeted real-time polymerase chain reaction (qPCR.Using mock specimen, the percentage recovery of S. pneumoniae ATCC 49619 (serotype 19F strain from the flocked swabs was 100%, while it was 41% from Dacron swabs and 7% from rayon swabs. Similar results were observed for S. pneumoniae serotypes 1 and 5. S. pneumoniae was cultured from 18 of 42 (43% paired NP samples from the healthy children (median age 8 [interquartile range (IQR 5-16] months. The median number of colony-forming units (CFU recovered from flocked swabs was two-fold higher (8.8×10(4 CFU/mL [IQR, 2.0×10(2 - 4.0×10(5 CFU/mL] than Dacron swabs (3.7×10(4 CFU/mL [IQR, 4.0×10(2-3.2×10(5 CFU/mL], p = 0.17. Using lytA-targeted qPCR from paired NP samples, the median copy number of S. pneumoniae detected from flocked swabs was significantly higher than from Dacron swabs (3.0×10(5 genome copies/mL [IQR, 1.3×10(2-1.8×10(6] vs. 9.3×10(4 genome copies/mL [IQR, 7.0×10(1-1.1×10(6]; p = 0.005.Flocked swabs released more S. pneumoniae compared to both Dacron and rayon swabs from mock specimens. Similarly, higher bacterial loads were detected by qPCR from flocked swabs compared with Dacron swabs from healthy children.

  2. PCR-based ordered genomic libraries: a new approach to drug target identification for Streptococcus pneumoniae.

    Belanger, Aimee E; Lai, Angel; Brackman, Marcia A; LeBlanc, Donald J

    2002-08-01

    Described here are the development and validation of a novel approach to identify genes encoding drug targets in Streptococcus pneumoniae. The method relies on the use of an ordered genomic library composed of PCR amplicons that were generated under error-prone conditions so as to introduce random mutations into the DNA. Since some of the mutations occur in drug target-encoding genes and subsequently affect the binding of the drug to its respective cellular target, amplicons containing drug targets can be identified as those producing drug-resistant colonies when transformed into S. pneumoniae. Examination of the genetic content of the amplicon giving resistance coupled with bioinformatics and additional genetic approaches could be used to rapidly identify candidate drug target genes. The utility of this approach was verified by using a number of known antibiotics. For drugs with single protein targets, amplicons were identified that rendered S. pneumoniae drug resistant. Assessment of amplicon composition revealed that each of the relevant amplicons contained the gene encoding the known target for the particular drug tested. Fusidic acid-resistant mutants that resulted from the transformation of S. pneumoniae with amplicons containing fusA were further characterized by sequence analysis. A single mutation was found to occur in a region of the S. pneumoniae elongation factor G protein that is analogous to that already implicated in other bacteria as being associated with fusidic acid resistance. Thus, in addition to facilitating the identification of genes encoding drug targets, this method could provide strains that aid future mechanistic studies.

  3. Detection and prediction of Streptococcus pneumoniae serotypes directly from nasopharyngeal swabs using PCR.

    Lang, Amanda L S; McNeil, Shelly A; Hatchette, Todd F; Elsherif, May; Martin, Irene; LeBlanc, Jason J

    2015-08-01

    Monitoring Streptococcus pneumoniae serotype distribution is important to assess the impact and effectiveness of pneumococcal vaccine programs. With the challenges of Quellung serotyping, PCR-based serotype prediction is increasingly being used for large-scale epidemiological studies. This study used real-time (RT)-PCR targeting the genes encoding autolysin (lytA) and capsular biosynthesis gene A (cpsA) of S. pneumoniae in nucleic acids extracted directly from nasopharyngeal (NP) swabs submitted for viral studies. If the specimen was lytA or cpsA PCR-positive, then serotype prediction was performed on the same nucleic acid using eight conventional multiplex PCRs (cmPCRs) and seven real-time multiplex PCRs (rmPCRs). Of 1770 NP swabs, 132 (7.5  %) were lytA-positive and 122 (6.9  %) were positive for both targets (lytA and cpsA). Of the 122 lytA(+)cpsA(+) specimens, a serotype could be assigned in 52 (41.8  %) using cmPCR alone and the yield was increased to 70 (57.4  %) with the addition of rmPCR. Based on sensitivity, incremental yield and more efficient workflow, an algorithm was proposed where lytA and cpsA RT-PCR screening was followed by serotype deduction using rmPCR and a modified set of four instead of eight cmPCRs. This algorithm was validated for use on NP swabs, and the distribution of S. pneumoniae serotypes deduced from this approach showed good concordance with those obtained with cultured isolates serotyped by Quellung and PCR. Overall, molecular detection and serotyping of S. pneumoniae from NP swabs was found to be a valuable tool to assess S. pneumoniae colonization and monitor trends in serotype distribution.

  4. Oxacillin disk diffusion testing for the prediction of penicillin resistance in Streptococcus pneumoniae.

    Horna, Gertrudis; Molero, María L; Benites, Liliana; Roman, Sigri; Carbajal, Luz; Mercado, Erik; Castillo, María E; Zerpa, Rito; Chaparro, Eduardo; Hernandez, Roger; Silva, Wilda; Campos, Francisco; Saenz, Andy; Reyes, Isabel; Villalobos, Alex; Ochoa, Theresa J

    2016-08-01

    Objective To 1) describe the correlation between the zones of inhibition in 1-µg oxacillin disk diffusion (ODD) tests and penicillin and ceftriaxone minimum inhibitory concentrations (MICs) of meningeal and non-meningeal strains of Streptococcus pneumoniae and 2) evaluate the usefulness of the ODD test as a predictor of susceptibility to penicillin in S. pneumoniae and as a quick and cost-effective method easily implemented in a routine clinical laboratory setting. Methods S. pneumoniae isolates from healthy nasopharyngeal carriers less than 2 years old, obtained in a multicentric cross-sectional study conducted in various Peruvian hospitals and health centers from 2007 to 2009, were analyzed. Using Clinical and Laboratory Standards Institute (CLSI) breakpoints, the correlation between the zones of inhibition of the ODD test and the MICs of penicillin and ceftriaxone was determined. Results Of the 571 S. pneumoniae isolates, 314 (55%) showed resistance to penicillin (MIC ≥ 0.12 µg/mL) and 124 (21.7%) showed resistance to ceftriaxone (MIC ≥ 1 µg/mL). Comparison of the ODD test zones of inhibition and the penicillin MICs, using the CLSI meningeal breakpoints, showed good correlation (Cohen's kappa coefficient = 0.8239). Conclusions There was good correlation between ODD zones of inhibition and penicillin meningeal breakpoints but weak correlation between the ODD results and non-meningeal breakpoints for both penicillin and ceftriaxone. Therefore, the ODD test appears to be a useful tool for predicting penicillin resistance in cases of meningeal strains of S. pneumoniae, particularly in low- and middle- income countries, where MIC determination is not routinely available.

  5. Effects of new penicillin susceptibility breakpoints for Streptococcus pneumoniae--United States, 2006-2007.

    2008-12-19

    Streptococcus pneumoniae (pneumococcus) is a common cause of pneumonia and meningitis in the United States. Antimicrobial resistance, which can result in pneumococcal infection treatment failure, is identified by measuring the minimum inhibitory concentration (MIC) of an antimicrobial that will inhibit pneumococcal growth. Breakpoints are MICs that define infections as susceptible (treatable), intermediate (possibly treatable with higher doses), and resistant (not treatable) to certain antimicrobials. In January 2008, after a reevaluation that included more recent clinical studies, the Clinical and Laboratory Standards Institute (CLSI) published new S. pneumoniae breakpoints for penicillin (the preferred antimicrobial for susceptible S. pneumoniae infections). To assess the potential effects of the new breakpoints on susceptibility categorization, CDC applied them to MICs of invasive pneumococcal disease (IPD) isolates collected by the Active Bacterial Core surveillance (ABCs) system at sites in 10 states during 2006-2007. This report summarizes the results of that analysis, which found that the percentage of IPD nonmeningitis S. pneumoniae isolates categorized as susceptible, intermediate, and resistant to penicillin changed from 74.7%, 15.0%, and 10.3% under the former breakpoints to 93.2%, 5.6%, and 1.2%, respectively, under the new breakpoints. Microbiology laboratories should be aware of the new breakpoints to interpret pneumococcal susceptibility accurately, and clinicians should be aware of the breakpoints to prescribe antimicrobials appropriately for pneumococcal infections. State and local health departments also should be aware of the new breakpoints because they might result in a decrease in the number of reported cases of penicillin-resistant pneumococcus.

  6. Mechanisms of dexamethasone-mediated inhibition of Toll-like receptor signaling induced by Neisseria meningitidis and Streptococcus pneumoniae

    Mogensen, Trine; Berg, Randi S; Paludan, Søren R

    2008-01-01

    significantly reduces mortality and morbidity from bacterial meningitis. Here we investigate the molecular mechanisms behind the inhibitory effect of dexamethasone upon the inflammatory responses evoked by Neisseria meningitidis and Streptococcus pneumoniae, two of the major causes of bacterial meningitis......B alpha synthesis. Our data also revealed that the timing of steroid treatment relative to infection was important for achieving strong inhibition, particularly in response to S. pneumoniae. Altogether, we describe important targets of dexamethasone in the inflammatory responses evoked by N. meningitidis...... and S. pneumoniae, which may contribute to our understanding of the clinical effect and the importance of timing with respect to corticosteroid treatment during bacterial meningitis. Udgivelsesdato: 2008-Jan...

  7. UlaR activates expression of the ula operon in Streptococcus pneumoniae in the presence of ascorbic acid

    Afzal, Muhammad; Shafeeq, Sulman; Henriques-Normark, Birgitta; Kuipers, Oscar P

    2015-01-01

    In this study, the regulatory mechanism of the ula (utilization of l-ascorbic acid) operon, putatively responsible for transport and utilization of ascorbic acid in Streptococcus pneumoniae strain D39, is studied. β-Galactosidase assay data demonstrate that expression of the ula operon is increased

  8. SMC is recruited to oriC by ParB and promotes chromosome segregation in Streptococcus pneumoniae

    Minnen, Anita; Attaiech, Laetitia; Thon, Maria; Gruber, Stephan; Veening, Jan-Willem

    2011-01-01

    Segregation of replicated chromosomes is an essential process in all organisms. How bacteria, such as the oval-shaped human pathogen Streptococcus pneumoniae, efficiently segregate their chromosomes is poorly understood. Here we show that the pneumococcal homologue of the DNA-binding protein ParB re

  9. In vitro activities of five fluoroquinolone compounds against strains of Streptococcus pneumoniae with resistance to other antimicrobial agents.

    Barry, A. L.; Fuchs, P C; Brown, S. D.

    1996-01-01

    Ciprofloxacin, clinafloxacin, PD 131628, sparfloxacin, and trovafloxacin were tested against 236 strains of Streptococcus pneumoniae, most of which were resistant to other agents. Resistance to multiple antibiotics did not affect the organism's susceptibility to the fluoroquinolones. The fluoroquinolones with in vitro antipneumococcal activity might be particularly useful against strains that are resistant to the more traditional therapeutic agents.

  10. Surface-associated lipoprotein PpmA of Streptococcus pneumoniae is involved in colonization in a strain-specific manner.

    Cron, L.E.; Bootsma, H.J.; Noske, N.; Burghout, P.J.; Hammerschmidt, S.; Hermans, P.W.M.

    2009-01-01

    Streptococcus pneumoniae produces two surface-associated lipoproteins that share homology with two distinct families of peptidyl-prolyl isomerases (PPIases), the streptococcal lipoprotein rotamase A (SlrA) and the putative proteinase maturation protein A (PpmA). Previously, we have demonstrated that

  11. Penicillin resistance and serotype distribution of Streptococcus pneumoniae in Ghanaian children less than six years of age

    Dayie, Nicholas T. K. D.; Arhin, Reuben E.; Newman, Mercy J.

    2013-01-01

    Background: The objective of this study was to determine the prevalence of nasopharyngeal carriage, serotype distribution, and penicillin resistance of Streptococcus pneumoniae in children 2 mu g/ml and were classified as fully penicillin resistant with 45% of the isolates having intermediate...

  12. Molecular epidemiology of penicillin-susceptible non-beta-lactam-resistant Streptococcus pneumoniae isolates from Greek children

    D. Bogaert (Debby); P.W.M. Hermans (Peter); I.N. Grivea; G.S. Katopodis; T.J. Mitchell; M. Sluijter (Marcel); R. de Groot (Ronald); N.G. Beratis; G.A. Syrogiannopoulos

    2003-01-01

    textabstractA total of 128 Streptococcus pneumoniae isolates that were susceptible to penicillin but resistant to non-beta-lactam agents were isolated from young carriers in Greece and analyzed by antibiotic susceptibility testing, serotyping, restriction fragment end labeling (RFE

  13. [Serotype distribution and antibiotic susceptibilities of Streptococcus pneumoniae causing acute exacerbations and pneumonia in children with chronic respiratory diseases].

    Altınkanat Gelmez, Gülşen; Soysal, Ahmet; Kuzdan, Canan; Karadağ, Bülent; Hasdemir, Ufuk; Bakır, Mustafa; Söyletir, Güner

    2013-10-01

    This study aimed to investigate serotype distribution and antimicrobial resistance of Streptococcus pneumoniae isolates obtained from children with chronic respiratory diseases admitted to hospital with a diagnosis of acute exacerbations between 2008-2010 at Marmara University Hospital, Istanbul, Turkey. Sixty one S.pneumoniae strains isolated from the respiratory samples of patients were studied for erythromycin, clindamycin, tetracyline, trimethoprim-sulphametoxazole (TMP-SMX), vancomycin, levofloxacin susceptibilities by disk diffusion method; MIC values of penicillin and ceftriaxone were determined by E-test (AB Biodisk, Sweden). Results were evaluated according to the CLSI standards. The erythromycin-clindamycin double disc method was applied for the detection of macrolide resistance phenotypes. The presence of macrolide resistance genes, ermB, mef(A)/(E), ermTR were determined by PCR using specific primers for each gene. The serotypes were determined by multiplex PCR using specific primers for 40 different serotypes. According to CLSI criteria, penicillin resistance in S.pneumoniae isolates were found to be 8.2% (5/61) and intermediate resistance rate was 54% (33/61) for oral penicillin. Penicillin resistance were found to be only 1.6% (1/61) for parenteral penicillin. Resistance rates of erythromycin, clindamycin, tetracyline, TMP-SMX were detected as 55.8%, 46%, 47.5% and 67.2%; respectively. No resistance was detected to vancomycin and levofloxacin. Constitutive macrolide-lincosamide-streptogramin B (cMLSB) phenotype and M phenotype were observed in 82.4% (n= 28) and 17.6% (n= 6) of the macrolide resistant isolates, respectively. Inducible macrolide-lincosamide-streptogramin B (iMLSB) phenotype was not detected. The macrolid resistance genotypes, ermB, mef(A)/(E), were positive 50% and 14.7%; respectively. Both ermB and mef(A)/(E) genes were detected 35.3% of the macrolid resistant isolates. None of the isolates were positive for ermTR gene. The most

  14. Multilocus sequence typing of Streptococcus pneumoniae by use of mass spectrometry.

    Dunne, Eileen M; Ong, Eng Kok; Moser, Ralf J; Siba, Peter M; Phuanukoonnon, Suparat; Greenhill, Andrew R; Robins-Browne, Roy M; Mulholland, E Kim; Satzke, Catherine

    2011-11-01

    Multilocus sequence typing (MLST) is an important tool for the global surveillance of bacterial pathogens that is performed by comparing the sequences of designated housekeeping genes. We developed and tested a novel mass spectrometry-based method for MLST of Streptococcus pneumoniae. PCR amplicons were subjected to in vitro transcription and base-specific cleavage, followed by analysis of the resultant fragments by using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Comparison of the cleavage fragment peak patterns to a reference sequence set permitted automated identification of alleles. Validation experiments using 29 isolates of S. pneumoniae revealed that the results of MALDI-TOF MS MLST matched those obtained by traditional sequence-based MLST for 99% of alleles and that the MALDI-TOF MS method accurately identified two single-nucleotide variations. The MADLI-TOF MS method was then used for MLST analysis of 43 S. pneumoniae isolates from Papua New Guinean children. The majority of the isolates present in this population were not clonal and contained seven new alleles and 30 previously unreported sequence types.

  15. Streptococcus pneumoniae TIGR4 Flavodoxin: Structural and Biophysical Characterization of a Novel Drug Target

    Rodríguez-Cárdenas, Ángela; Rojas, Adriana L.; Conde-Giménez, María; Velázquez-Campoy, Adrián; Hurtado-Guerrero, Ramón; Sancho, Javier

    2016-01-01

    Streptococcus pneumoniae (Sp) strain TIGR4 is a virulent, encapsulated serotype that causes bacteremia, otitis media, meningitis and pneumonia. Increased bacterial resistance and limited efficacy of the available vaccine to some serotypes complicate the treatment of diseases associated to this microorganism. Flavodoxins are bacterial proteins involved in several important metabolic pathways. The Sp flavodoxin (Spfld) gene was recently reported to be essential for the establishment of meningitis in a rat model, which makes SpFld a potential drug target. To facilitate future pharmacological studies, we have cloned and expressed SpFld in E. coli and we have performed an extensive structural and biochemical characterization of both the apo form and its active complex with the FMN cofactor. SpFld is a short-chain flavodoxin containing 146 residues. Unlike the well-characterized long-chain apoflavodoxins, the Sp apoprotein displays a simple two-state thermal unfolding equilibrium and binds FMN with moderate affinity. The X-ray structures of the apo and holo forms of SpFld differ at the FMN binding site, where substantial rearrangement of residues at the 91–100 loop occurs to permit cofactor binding. This work will set up the basis for future studies aiming at discovering new potential drugs to treat S. pneumoniae diseases through the inhibition of SpFld. PMID:27649488

  16. New Alkaloid Antibiotics That Target the DNA Topoisomerase I of Streptococcus pneumoniae*

    García, María Teresa; Blázquez, María Amparo; Ferrándiz, María José; Sanz, María Jesús; Silva-Martín, Noella; Hermoso, Juan A.; de la Campa, Adela G.

    2011-01-01

    Streptococcus pneumoniae has two type II DNA-topoisomerases (DNA-gyrase and DNA topoisomerase IV) and a single type I enzyme (DNA-topoisomerase I, TopA), as demonstrated here. Although fluoroquinolones target type II enzymes, antibiotics efficiently targeting TopA have not yet been reported. Eighteen alkaloids (seven aporphine and 11 phenanthrenes) were semisynthesized from boldine and used to test inhibition both of TopA activity and of cell growth. Two phenanthrenes (seconeolitsine and N-methyl-seconeolitsine) effectively inhibited both TopA activity and cell growth at equivalent concentrations (∼17 μm). Evidence for in vivo TopA targeting by seconeolitsine was provided by the protection of growth inhibition in a S. pneumoniae culture in which the enzyme was overproduced. Additionally, hypernegative supercoiling was observed in an internal plasmid after drug treatment. Furthermore, a model of pneumococcal TopA was made based on the crystal structure of Escherichia coli TopA. Docking calculations indicated strong interactions of the alkaloids with the nucleotide-binding site in the closed protein conformation, which correlated with their inhibitory effect. Finally, although seconeolitsine and N-methyl-seconeolitsine inhibited TopA and bacterial growth, they did not affect human cell viability. Therefore, these new alkaloids can be envisaged as new therapeutic candidates for the treatment of S. pneumoniae infections resistant to other antibiotics. PMID:21169356

  17. Dried Saliva Spots: A Robust Method for Detecting Streptococcus pneumoniae Carriage by PCR.

    Krone, Cassandra L; Oja, Anna E; van de Groep, Kirsten; Sanders, Elisabeth A M; Bogaert, Debby; Trzciński, Krzysztof

    2016-03-05

    The earliest studies in the late 19th century on Streptococcus pneumoniae (S. pneumoniae) carriage used saliva as the primary specimen. However, interest in saliva declined after the sensitive mouse inoculation method was replaced by conventional culture, which made isolation of pneumococci from the highly polymicrobial oral cavity virtually impossible. Here, we tested the feasibility of using dried saliva spots (DSS) for studies on pneumococcal carriage. Saliva samples from children and pneumococcus-spiked saliva samples from healthy adults were applied to paper, dried, and stored, with and without desiccant, at temperatures ranging from -20 to 37 °C for up to 35 days. DNA extracted from DSS was tested with quantitative-PCR (qPCR) specifically for S. pneumoniae. When processed immediately after drying, the quantity of pneumococcal DNA detected in spiked DSS from adults matched the levels in freshly spiked raw saliva. Furthermore, pneumococcal DNA was stable in DSS stored with desiccant for up to one month over a broad range of temperatures. There were no differences in the results when spiking saliva with varied pneumococcal strains. The collection of saliva can be a particularly useful in surveillance studies conducted in remote settings, as it does not require trained personnel, and DSS are resilient to various transportation conditions.

  18. Tracking of chromosome dynamics in live Streptococcus pneumoniae reveals that transcription promotes chromosome segregation.

    Kjos, Morten; Veening, Jan-Willem

    2014-03-01

    Chromosome segregation is an essential part of the bacterial cell cycle but is poorly characterized in oval-shaped streptococci. Using time-lapse fluorescence microscopy and total internal reflection fluorescence microscopy, we have tracked the dynamics of chromosome segregation in live cells of the human pathogen Streptococcus pneumoniae. Our observations show that the chromosome segregation process last for two-thirds of the total cell cycle; the origin region segregates rapidly in the early stages of the cell cycle while nucleoid segregation finishes just before cell division. Previously we have demonstrated that the DNA-binding protein ParB and the condensin SMC promote efficient chromosome segregation, likely by an active mechanism. We now show that in the absence of SMC, cell division can occur over the unsegregated chromosomes. However, neither smc nor parB are essential in S. pneumoniae, suggesting the importance of additional mechanisms. Here we have identified the process of transcription as one of these mechanisms important for chromosome segregation in S. pneumoniae. Transcription inhibitors rifampicin and streptolydigin as well as mutants affected in transcription elongation cause chromosome segregation defects. Together, our results highlight the importance of passive (or indirect) processes such as transcription for chromosome segregation in oval-shaped bacteria.

  19. Molecular characterization of genes encoding the quinolone resistance determining regions of Malaysian Streptococcus pneumoniae strains

    Kumari N

    2008-01-01

    Full Text Available Genes encoding the quinolones resistance determining regions (QRDRs in Streptococcus pneumoniae were detected by PCR and the sequence analysis was carried out to identify point mutations within these regions. The study was carried out to observe mutation patterns among S. pneumoniae strains in Malaysia. Antimicrobial susceptibility testing of 100 isolates was determined against various antibiotics, out of which 56 strains were categorised to have reduced susceptibility to ciprofloxacin (≥2 μg/mL. These strains were subjected to PCR amplification for presence of the gyrA, parC , gyrB and parE genes. Eight representative strains with various susceptibilities to fluoroquinolones were sequenced. Two out of the eight isolates that were sequenced were shown to have a point mutation in the gyrA gene at position Ser81. The detection of mutation at codon Ser81 of the gyrA gene suggested the potential of developing fluoroquinolone resistance among S. pneumoniae isolates in Malaysia. However, further experimental work is required to confirm the involvement of this mutation in the development of fluoroquinolone resistance in Malaysia.

  20. IL-22 Defect During Streptococcus pneumoniae Infection Triggers Exacerbation of Chronic Obstructive Pulmonary Disease

    Muriel Pichavant

    2015-11-01

    Full Text Available Progression of chronic obstructive pulmonary disease (COPD is linked to episodes of exacerbations caused by bacterial infections due to Streptococcus pneumoniae. Our objective was to identify during COPD, factors of susceptibility to bacterial infections among cytokine network and their role in COPD exacerbations. S. pneumoniae was used to sub-lethally challenge mice chronically exposed to air or cigarette smoke (CS and to stimulate peripheral blood mononuclear cells (PBMC from non-smokers, smokers and COPD patients. The immune response and the cytokine production were evaluated. Delayed clearance of the bacteria and stronger lung inflammation observed in infected CS-exposed mice were associated with an altered production of IL-17 and IL-22 by innate immune cells. This defect was related to a reduced production of IL-1β and IL-23 by antigen presenting cells. Importantly, supplementation with recombinant IL-22 restored bacterial clearance in CS-exposed mice and limited lung alteration. In contrast with non-smokers, blood NK and NKT cells from COPD patients failed to increase IL-17 and IL-22 levels in response to S. pneumoniae, in association with a defect in IL-1β and IL-23 secretion. This study identified IL-17 and IL-22 as susceptibility factors in COPD exacerbation. Therefore targeting such cytokines could represent a potent strategy to control COPD exacerbation.

  1. Identification of pneumococcal surface protein A as a lactoferrin-binding protein of Streptococcus pneumoniae.

    Hammerschmidt, S; Bethe, G; Remane, P H; Chhatwal, G S

    1999-04-01

    Lactoferrin (Lf), an iron-sequestering glycoprotein, predominates in mucosal secretions, where the level of free extracellular iron (10(-18) M) is not sufficient for bacterial growth. This represents a mechanism of resistance to bacterial infections by prevention of colonization of the host by pathogens. In this study we were able to show that Streptococcus pneumoniae specifically recognizes and binds the iron carrier protein human Lf (hLf). Pretreatment of pneumococci with proteases reduced hLf binding significantly, indicating that the hLf receptor is proteinaceous. Binding assays performed with 63 clinical isolates belonging to different serotypes showed that 88% of the tested isolates interacted with hLf. Scatchard analysis showed the existence of two hLf-binding proteins with dissociation constants of 5.7 x 10(-8) and 2.74 x 10(-7) M. The receptors were purified by affinity chromatography, and internal sequence analysis revealed that one of the S. pneumoniae proteins was homologous to pneumococcal surface protein A (PspA). The function of PspA as an hLf-binding protein was confirmed by the ability of purified PspA to bind hLf and to competitively inhibit hLf binding to pneumococci. S. pneumoniae may use the hLf-PspA interaction to overcome the iron limitation at mucosal surfaces, and this might represent a potential virulence mechanism.

  2. Characterization of Spbhp-37, a Hemoglobin-Binding Protein of Streptococcus pneumoniae.

    Romero-Espejel, María E; Rodríguez, Mario A; Chávez-Munguía, Bibiana; Ríos-Castro, Emmanuel; Olivares-Trejo, José de Jesús

    2016-01-01

    Streptococcus pneumoniae is a Gram-positive microorganism that is the cause of bacterial pneumonia, sinusitis and otitis media. This human pathogen also can cause invasive diseases such as meningitis, bacteremia and septicemia. Hemoglobin (Hb) and haem can support the growth and viability of S. pneumoniae as sole iron sources. Unfortunately, the acquisition mechanism of Hb and haem in this bacterium has been poorly studied. Previously we identified two proteins of 37 and 22 kDa as putative Hb- and haem-binding proteins (Spbhp-37 and Spbhp-22, respectively). The sequence of Spbhp-37 protein was database annotated as lipoprotein without any function or localization. Here it was immunolocalized in the surface cell by transmission electron microscopy using specific antibodies produced against the recombinant protein. The expression of Spbhp-37 was increased when bacteria were grown in media culture supplied with Hb. In addition, the affinity of Sphbp-37 for Hb was determined. Thus, in this work we are presenting new findings that attempt to explain the mechanism involved in iron acquisition of this pathogen. In the future these results could help to develop new therapy targets in order to avoid the secondary effects caused by the traditional therapies.

  3. Characterization of Spbhp-37, a Hemoglobin-Binding Protein of Streptococcus pneumoniae

    Romero-Espejel, María E.; Rodríguez, Mario A.; Chávez-Munguía, Bibiana; Ríos-Castro, Emmanuel; Olivares-Trejo, José de Jesús

    2016-01-01

    Streptococcus pneumoniae is a Gram-positive microorganism that is the cause of bacterial pneumonia, sinusitis and otitis media. This human pathogen also can cause invasive diseases such as meningitis, bacteremia and septicemia. Hemoglobin (Hb) and haem can support the growth and viability of S. pneumoniae as sole iron sources. Unfortunately, the acquisition mechanism of Hb and haem in this bacterium has been poorly studied. Previously we identified two proteins of 37 and 22 kDa as putative Hb- and haem-binding proteins (Spbhp-37 and Spbhp-22, respectively). The sequence of Spbhp-37 protein was database annotated as lipoprotein without any function or localization. Here it was immunolocalized in the surface cell by transmission electron microscopy using specific antibodies produced against the recombinant protein. The expression of Spbhp-37 was increased when bacteria were grown in media culture supplied with Hb. In addition, the affinity of Sphbp-37 for Hb was determined. Thus, in this work we are presenting new findings that attempt to explain the mechanism involved in iron acquisition of this pathogen. In the future these results could help to develop new therapy targets in order to avoid the secondary effects caused by the traditional therapies. PMID:27200302

  4. Dominance of multidrug resistant CC271 clones in macrolide-resistant streptococcus pneumoniae in Arizona

    Bowers Jolene R

    2012-01-01

    Full Text Available Abstract Background Rates of resistance to macrolide antibiotics in Streptococcus pneumoniae are rising around the world due to the spread of mobile genetic elements harboring mef(E and erm(B genes and post-vaccine clonal expansion of strains that carry them. Results Characterization of 592 clinical isolates collected in Arizona over a 10 year period shows 23.6% are macrolide resistant. The largest portion of the macrolide-resistant population, 52%, is dual mef(E/erm(B-positive. All dual-positive isolates are multidrug-resistant clonal lineages of Taiwan19F-14, mostly multilocus sequence type 320, carrying the recently described transposon Tn2010. The remainder of the macrolide resistant S. pneumoniae collection includes 31% mef(E-positive, and 9% erm(B-positive strains. Conclusions The dual-positive, multidrug-resistant S. pneumoniae clones have likely expanded by switching to non-vaccine serotypes after the heptavalent pneumococcal conjugate vaccine release, and their success limits therapy options. This upsurge could have a considerable clinical impact in Arizona.

  5. Differential Recognition and Hydrolysis of Host Carbohydrate Antigens by Streptococcus pneumoniae Family 98 Glycoside Hydrolases

    Higgins, M.; Whitworth, G; El Warry, N; Randriantsoa, M; Samain, E; Burke, R; Vocadlo, D; Boraston, A

    2009-01-01

    The presence of a fucose utilization operon in the Streptococcus pneumoniae genome and its established importance in virulence indicates a reliance of this bacterium on the harvesting of host fucose-containing glycans. The identities of these glycans, however, and how they are harvested is presently unknown. The biochemical and high resolution x-ray crystallographic analysis of two family 98 glycoside hydrolases (GH98s) from distinctive forms of the fucose utilization operon that originate from different S. pneumoniae strains reveal that one enzyme, the predominant type among pneumococcal isolates, has a unique endo-{beta}-galactosidase activity on the LewisY antigen. Altered active site topography in the other species of GH98 enzyme tune its endo-{beta}-galactosidase activity to the blood group A and B antigens. Despite their different specificities, these enzymes, and by extension all family 98 glycoside hydrolases, use an inverting catalytic mechanism. Many bacterial and viral pathogens exploit host carbohydrate antigens for adherence as a precursor to colonization or infection. However, this is the first evidence of bacterial endoglycosidase enzymes that are known to play a role in virulence and are specific for distinct host carbohydrate antigens. The strain-specific distribution of two distinct types of GH98 enzymes further suggests that S. pneumoniae strains may specialize to exploit host-specific antigens that vary from host to host, a factor that may feature in whether a strain is capable of colonizing a host or establishing an invasive infection.

  6. Ethanol impairs mucosal immunity against Streptococcus pneumoniae infection by disrupting interleukin 17 gene expression.

    Trevejo-Nunez, Giraldina; Chen, Kong; Dufour, Jason P; Bagby, Gregory J; Horne, William T; Nelson, Steve; Kolls, Jay K

    2015-05-01

    Acute ethanol intoxication suppresses the host immune responses against Streptococcus pneumoniae. As interleukin 17 (IL-17) is a critical cytokine in host defense against extracellular pathogens, including S. pneumoniae, we hypothesized that ethanol impairs mucosal immunity against this pathogen by disrupting IL-17 production or IL-17 receptor (IL-17R) signaling. A chronic ethanol feeding model in simian immunodeficiency virus (SIV)-infected rhesus macaques and acute ethanol intoxication in a murine model were used. Transcriptome analysis of bronchial brushes in the nonhuman primate model showed downregulation of the expression of IL-17-regulated chemokines in ethanol-fed animals, a finding also replicated in the murine model. Surprisingly, recombinant CXCL1 and CXCL5 but not IL-17 or IL-23 plus IL-1β rescued bacterial burden in the ethanol group to control levels. Taken together, the results of this study suggest that ethanol impairs IL-17-mediated chemokine production in the lung. Thus, exogenous luminal restoration of IL-17-related chemokines, CXCL1 and CXCL5, improves host defenses against S. pneumoniae.

  7. Characterization of Spbhp-37, a haemoglobin-binding protein of Streptococcus pneumoniae

    María Elena eRomero-Espejel

    2016-05-01

    Full Text Available Streptococcus pneumoniae is a Gram-positive microorganism that is the cause of bacterial pneumonia, sinusitis and otitis media. This human pathogen also can cause invasive diseases such as meningitis, bacteremia and septicemia. Haemoglobin (Hb and haem can support the growth and viability of S. pneumoniae as sole iron sources. Unfortunately, the acquisition mechanism of Hb and haem in this bacterium has been poorly studied. Previously we identified two proteins of 37 and 22 kDa as putative Hb- and haem-binding proteins (Spbhp-37 and Spbhp-22, respectively. The sequence of Spbhp-37 protein was database annotated as lipoprotein without any function or localization. Here it was immunolocalized in the surface cell by transmission electron microscopy using specific antibodies produced against the recombinant protein. The expression of Spbhp-37 was increased when bacteria were grown in media culture supplied with Hb. In addition, the affinity of Sphbp-37 for Hb was determined. Thus, in this work we are presenting new findings that attempt to explain the mechanism involved in iron acquisition of this pathogen. In the future these results could help to develop new therapy targets in order to avoid the secondary effects caused by the traditional therapies.

  8. Evaluation of a new lateral flow test for detection of Streptococcus pneumoniae and Legionella pneumophila urinary antigen.

    Jørgensen, Charlotte S; Uldum, Søren A; Sørensen, Jesper F; Skovsted, Ian C; Otte, Sanne; Elverdal, Pernille L

    2015-09-01

    Pneumonia is a major cause of morbidity and mortality worldwide. Early diagnosis of the etiologic agent is important in order to choose the correct antibiotic treatment. In this study we evaluated the first commercial combined test for the agents of pneumococcal pneumonia and Legionnaires' disease based on urinary antigen detection, the ImmuView® Streptococcus pneumoniae and Legionella pneumophila Urinary Antigen Test. In this evaluation, the new test had a significantly higher sensitivity than the BinaxNOW® lateral flow tests and the Binax® EIA test. This identifies the ImmuView® S. pneumoniae and L. pneumophila Urinary Antigen Test as a fast and sensitive point of care test for identification of the infectious agent in a major group of patients with pneumonia.

  9. The enhanced pneumococcal LAMP assay: a clinical tool for the diagnosis of meningitis due to Streptococcus pneumoniae.

    Dong Wook Kim

    Full Text Available BACKGROUND: Streptococcus pneumoniae is a leading cause of invasive bacterial disease in developed and developing countries. We studied the loop-mediated isothermal amplification (LAMP technique to assess its suitability for detecting S. pneumoniae nucleic acid in cerebrospinal fluid (CSF. METHODOLOGY/PRINCIPAL FINDINGS: We established an improved LAMP assay targeting the lytA gene (Streptococcus pneumoniae [Sp] LAMP. The analytical specificity of the primers was validated by using 32 reference strains (10 Streptococcus and seven non-Streptococcus species plus 25 clinical alpha-hemolytic streptococcal strains, including four S. pneumoniae strains and 21 other strains (3 S. oralis, 17 S. mitis, and one Streptococcus species harboring virulence factor-encoding genes (lytA or ply. Within 30 minutes, the assay could detect as few as 10 copies of both purified DNA and spiked CSF specimens with greater sensitivity than conventional polymerase chain reaction (PCR. The linear determination range for this assay is 10 to 1,000,000 microorganisms per reaction mixture using real-time turbidimetry. We evaluated the clinical sensitivity and specificity of the Sp LAMP assay using 106 randomly selected CSF specimens from children with suspected meningitis in Korea, China and Vietnam. For comparison, CSF specimens were also tested against conventional PCR and culture tests. The detection rate of the LAMP method was substantially higher than the rates of PCR and culture tests. In this small sample, relative to the LAMP assay, the clinical sensitivity of PCR and culture tests was 54.5% and 33.3%, respectively, while clinical specificity of the two tests was 100%. CONCLUSIONS/SIGNIFICANCE: Compared to PCR, Sp LAMP detected S. pneumoniae with higher analytical and clinical sensitivity. This specific and sensitive LAMP method offers significant advantages for screening patients on a population basis and for diagnosis in clinical settings.

  10. Novel molecular method for identification of Streptococcus pneumoniae applicable to clinical microbiology and 16S rRNA sequence-based microbiome studies

    Scholz, Christian F. P.; Poulsen, Knud; Kilian, Mogens

    2012-01-01

    The close phylogenetic relationship of the important pathogen Streptococcus pneumoniae and several species of commensal streptococci, particularly Streptococcus mitis and Streptococcus pseudopneumoniae, and the recently demonstrated sharing of genes and phenotypic traits previously considered...... specific for S. pneumoniae hamper the exact identification of S. pneumoniae. Based on sequence analysis of 16S rRNA genes of a collection of 634 streptococcal strains, identified by multilocus sequence analysis, we detected a cytosine at position 203 present in all 440 strains of S. pneumoniae but replaced...... by an adenosine residue in all strains representing other species of mitis group streptococci. The S. pneumoniae-specific sequence signature could be demonstrated by sequence analysis or indirectly by restriction endonuclease digestion of a PCR amplicon covering the site. The S. pneumoniae-specific signature...

  11. Aspectos Clínicos y neuroinmunológicos de la meningoencefalitis por Streptococcus pneumoniae

    Raisa Bu-Coifiu

    2007-12-01

    Full Text Available Después de exitosas campañas de vacunación contra Neisseria meningitidis y Haemophilus influenzae hubo un aumento de casos de meningoencefalitis por Streptococcus pneumoniae. Con el objetivo de describir las características clínicas, los hallazgos de laboratorio y las complicaciones encontradas a un grupo de pacientes que sufrieron de esta enfermedad entre 1993 y 2006, evaluar el estado de la barrera sangre-líquido cefalorraquídeo (LCR y el patrón de respuesta de síntesis intratecal de inmunoglobulinas a través del reibergrama, se estudiaron 12 niños con meningoencefalitis por Streptococcus pneumoniae que ingresaron en el Hospital Pediátrico de San Miguel del Padrón, Ciudad de La Habana, en ese periodo. Se dosificaron albúmina IgA, IgM e IgG y sus subclases por inmunodifusión radial en suero y líquido cefalorraquídeo. La edad más frecuente resultó la menor de un año. Las mayores complicaciones fueron: shock séptico y edema cerebral. Hubo tres pacientes fallecidos. Los patrones de las tres clases mayores de inmunoglobulinas aparecieron en el 33% del total. Los dos patrones de subclases de IgG más IgM tuvieron en común la disfunción de la barrera sangre-líquido cefalorraquídeo. La respuesta inmune intratecal en los pacientes con meningoencefalitis por Streptococcus pneumoniae tiene características distintivas que lo diferencian de otras meningoencefalitis de origen bacteriano por lo que en su conjunto podrían ser elementos a ser tomados en cuenta para auxiliar al médico en su diagnóstico diferencial y en la táctica para una vacuna cubana.

  12. Streptococcus pneumoniae serine protease HtrA, but not SFP or PrtA, is a major virulence factor in pneumonia.

    de Stoppelaar, Sacha F; Bootsma, Hester J; Zomer, Aldert; Roelofs, Joris J T H; Hermans, Peter W M; van 't Veer, Cornelis; van der Poll, Tom

    2013-01-01

    Streptococcus (S.) pneumoniae is a common causative pathogen in pneumonia. Serine protease orthologs expressed by a variety of bacteria have been found of importance for virulence. Previous studies have identified two serine proteases in S. pneumoniae, HtrA (high-temperature requirement A) and PrtA (cell wall-associated serine protease A), that contributed to virulence in models of pneumonia and intraperitoneal infection respectively. We here sought to identify additional S. pneumoniae serine proteases and determine their role in virulence. The S. pneumoniae D39 genome contains five putative serine proteases, of which HtrA, Subtilase Family Protein (SFP) and PrtA were selected for insertional mutagenesis because they are predicted to be secreted and surface exposed. Mutant D39 strains lacking serine proteases were constructed by in-frame insertion deletion mutagenesis. Pneumonia was induced by intranasal infection of mice with wild-type or mutant D39. After high dose infection, only D39ΔhtrA showed reduced virulence, as reflected by strongly reduced bacterial loads, diminished dissemination and decreased lung inflammation. D39ΔprtA induced significantly less lung inflammation together with smaller infiltrated lung surface, but without influencing bacterial loads. After low dose infection, D39ΔhtrA again showed strongly reduced bacterial loads; notably, pneumococcal burdens were also modestly lower in lungs after infection with D39Δsfp. These data confirm the important role for HtrA in S. pneumoniae virulence. PrtA contributes to lung damage in high dose pneumonia; it does not however contribute to bacterial outgrowth in pneumococcal pneumonia. SFP may facilitate S. pneumoniae growth after low dose infection.

  13. [Bactericidal activity of sitafloxacin and other new quinolones against antimicrobial resistant Streptococcus pneumoniae].

    Kobayashi, Intetsu; Kanayama, Akiko; Hasegawa, Miyuki; Kaneko, Akihiro

    2013-02-01

    We conducted a study assess the bactericidal activity of sitafloxacin (STFX) against Streptococcus pneumoniae isolates recovered from respiratory infections including penicillin-resistant (PRSP) isolates, macrolide resistant isolates possessing mefA and ermB resistance genes and quinolone resistance isolates with mutations in gyrA or gyrA and parC. Each isolate tested was grown in hemosupplemented Mueller-Hinton broth and adjusted to approximately 10(5) CFU/ mL. Isolates were than exposed to a Cmax antimicrobial blood level that would be attained with routine antimicrobial administration and an antimicrobial level that would be expected 4 hours post-Cmax (Cmax 4hr). Bactericidal activity was measured for up to 8 hours. Excluding a subset of S. pneumoniae isolates with mutations in the quinolone resistance determining region (QRDR), all quinolones showed bactericidal activity at Cmax and Cmax 4 hr antimicrobial concentrations for up to 8 hours. Against S. pneumoniae isolates with either gyrA or gyrA and parC mutations, bactericidal activity of STFX was shown for up to 4 to 8 hours following Cmax based on a limit of detection of quinolones tested where adjusted to concentrations corresponding to their MICs, STFX showed the most rapid bactericidal activity against PRSP. This rapid bactericidal activity in PRSP is a key to the effectiveness of STFX. Our findings show that beyond inhibition of bacterial replication by blocking their DNA replication pathway and synthesis of proteins, STFX demonstrated characteristics contributing to greater bactericidal activity compared to GRNX. In conclusion, of the newer quinolones, STFX showed the strongest bactericidal activity against S. pneumoniae isolates with mutations in the QRDR which indicates that it may show the most effective clinical utility among the quinolones in respiratory infections.

  14. Application of two methods to determine killing of Streptococcus pneumoniae by various fluoroquinolones.

    Blondeau, J M; Blondeau, L D; Hesje, C; Borsos, S

    2006-08-01

    Minimum inhibitory concentration (MIC) testing measures the lowest drug concentration that prevents microbial growth using an inoculum of 10(5) colony forming units/ml (cfu/ml) whereas the mutant prevention concentration (MPC) (inoculum approximately 10(10) cells) defines the antimicrobial drug concentration threshold that would require an organism to possess two simultaneous mutations for continued growth in the presence of the drug. The rates at which multidrug-resistant Streptococcus pneumoniae [MDRSP] were killed by the respiratory fluoroquinolones, gatifloxacin, gemfloxacin, levofloxacin and moxifloxacin, were compared based on the MIC and MPC drug concentrations and at inocula ranging from 10(6)-10(9) cfu/ml. The MIC drug concentration failed to eradicate all viable cells whereas the MPC drug concentration resulted in 99.9% to 100% cellular reduction following 12-24 hours of drug exposure. MPC values against S. pneumoniae were different for each fluoroquinolone. The MPC drug concentration prevents the selection of multidrug-resistant or fluoroquinolone-resistant S. pneumoniae. The value of dosing of antimicrobial agents based on MPC thresholds results in a rapid reduction in viable cells--even at higher inocula which are more reflective of organism burden in pneumonia. The rapid reduction in viable cells observed at MPC drug concentrations may not only have an impact on preventing the selection of resistant mutants but may also help explain the rapid symptom resolution seen with new fluoroquinolones since these agents lead to little or low release of cell contents which are known to drive the inflammatory response.

  15. Streptococcus pneumoniae pharyngeal colonization in school-age children and adolescents with cancer.

    Principi, Nicola; Preti, Valentina; Gaspari, Stefania; Colombini, Antonella; Zecca, Marco; Terranova, Leonardo; Cefalo, Maria Giuseppina; Ierardi, Valentina; Pelucchi, Claudio; Esposito, Susanna

    2016-01-01

    Patients with cancer, particularly those with hematologic malignancies, are at an increased risk of invasive pneumococcal disease (IPD) and they are included in the list of subjects for whom pneumococcal vaccination is recommended. The main aim of this study was to evaluate Streptococcus pneumoniae colonization in school-aged children and adolescents with cancer to determine the potential protective efficacy of 13-valent pneumococcal conjugate vaccine (PCV13). An oropharyngeal swab was obtained from 277 patients (age range 6-17 years) with cancer during routine clinical visits and analyzed for S. pneumoniae using real-time polymerase chain reaction. S. pneumoniae was identified in 52 patients (18.8%), including 47/235 (20.0%) with hematologic malignancies and 5/42 (11.9%) with solid tumors. Colonization declined significantly with an increase in age (odds ratio [OR] 0.34, 95% confidence interval [CI] 0.16-0.71, and OR 0.30, 95% CI 0.11-0.82 in children aged 10-14 and ≥15 years, respectively, as compared to those <10 years). Carriage was more common among patients with leukemia or lymphoma than in children with solid tumors. Co-trimoxazole prophylaxis was significantly associated with reduced pneumococcal carriage (OR 0.41, 95% CI 0.19-0.89). A total of 15/58 (25.9%) and 26/216 (12.0%) children were colonized by PCV13 serotypes among cancer patients previously vaccinated and not vaccinated with 7-valent pneumococcal conjugate vaccine (PCV7), respectively. In conclusion, this study indicates that children and adolescents with cancer are frequently colonized by S. pneumoniae. Because most of the carried serotypes are included in PCV13, this vaccine is presently the best solution to reduce the risk of IPD in these patients.

  16. Functionally cloned pdrM from Streptococcus pneumoniae encodes a Na(+ coupled multidrug efflux pump.

    Kohei Hashimoto

    Full Text Available Multidrug efflux pumps play an important role as a self-defense system in bacteria. Bacterial multidrug efflux pumps are classified into five families based on structure and coupling energy: resistance-nodulation-cell division (RND, small multidrug resistance (SMR, major facilitator (MF, ATP binding cassette (ABC, and multidrug and toxic compounds extrusion (MATE. We cloned a gene encoding a MATE-type multidrug efflux pump from Streptococcus pneumoniae R6, and designated it pdrM. PdrM showed sequence similarity with NorM from Vibrio parahaemolyticus, YdhE from Escherichia coli, and other bacterial MATE-type multidrug efflux pumps. Heterologous expression of PdrM let to elevated resistance to several antibacterial agents, norfloxacin, acriflavine, and 4',6-diamidino-2-phenylindole (DAPI in E. coli KAM32 cells. PdrM effluxes acriflavine and DAPI in a Na(+- or Li(+-dependent manner. Moreover, Na(+ efflux via PdrM was observed when acriflavine was added to Na(+-loaded cells expressing pdrM. Therefore, we conclude that PdrM is a Na(+/drug antiporter in S. pneumoniae. In addition to pdrM, we found another two genes, spr1756 and spr1877,that met the criteria of MATE-type by searching the S. pneumoniae genome database. However, cloned spr1756 and spr1877 did not elevate the MIC of any of the investigated drugs. mRNA expression of spr1756, spr1877, and pdrM was detected in S. pneumoniae R6 under laboratory growth conditions. Therefore, spr1756 and spr1877 are supposed to play physiological roles in this growth condition, but they may be unrelated to drug resistance.

  17. Antimicrobial activity and a comparison of published pharmacodynamics of gemifloxacin and eight fluoroquinolones against Streptococcus pneumoniae.

    Saravolatz, Louis; Manzor, Odette; Pawlak, Joan; Belian, Bradley

    2005-07-01

    Gemifloxacin was evaluated for its in vitro activity and was compared with eight fluoroquinolones. Pharmacodynamic comparisons were made based on published pharmacokinetic information. Gemifloxacin demonstrated excellent in vitro activity (minimum inhibitory concentration necessary to inhibit 90% of the strains tested, MIC90 = 0.03 mg/L (range 0.0019-0.03 mg/L)) against 199 strains of Streptococcus pneumoniae. Its activity was not influenced by penicillin or ciprofloxacin non-susceptibility. Gemifloxacin demonstrated excellent pharmacodynamic parameters, with a Cmax/MIC90 of 67 (where Cmax is the peak serum level) and an AUC/MIC90 of 297 (where AUC is the area under the curve). Compared with the other eight fluoroquinolones tested, gemifloxacin demonstrated the best in vitro activity and Cmax/MIC90.

  18. Prevalence and molecular characterisation of Streptococcus pneumoniae serotype 6C in Queensland, Australia.

    Staples, Megan; Jennison, Amy V; Ariotti, Lawrence; Hicks, Vicki; Graham, Rikki M A; Smith, Helen V

    2014-03-01

    Streptococcus pneumoniae serotype 6C was first identified in 2007, although retrospective studies have since identified serotype 6C among stored isolates dating back to 1962. We investigated the incidence and genetic diversity of serotype 6C strains isolated from Queensland patients between 2001 and 2011. Isolates were identified by Quellung reaction and antimicrobial susceptibility testing was performed. The incidence of serotype 6C among serogroup 6 Queensland invasive pneumococcal disease increased from 6.8% (2001-2004) to 39% (2005-2010) of serogroup 6 isolates (P = 0). Genetic diversity of Queensland 6C isolates was high, with molecular analysis identifying 19 sequence types by multi-locus sequence typing, and 35 types by multi-locus variable-number tandem repeat analysis.

  19. Capsules of Streptococcus pneumoniae and other bacteria: paradigms for polysaccharide biosynthesis and regulation.

    Yother, Janet

    2011-01-01

    Capsular polysaccharides and exopolysaccharides play critical roles in bacterial survival strategies, and they can have important medical and industrial applications. An immense variety of sugars and glycosidic linkages leads to an almost unlimited diversity of potential polysaccharide structures. This diversity is reflected in the large number of serologically and chemically distinct polysaccharides that have been identified among both gram-positive and gram-negative bacteria. Despite this diversity, however, the genetic loci and mechanisms responsible for polysaccharide biosynthesis exhibit conserved features and can be classified into a small number of groups. In Streptococcus pneumoniae, capsule synthesis occurs by one of two distinct mechanisms that involve the polymerization of either individual sugars in a processive reaction (synthase dependent) or discrete repeat units in a nonprocessive reaction (Wzy dependent). Characterization of these systems has provided novel insights that are applicable to polymers synthesized by many gram-positive and gram-negative bacteria, as well as eukaryotes.

  20. Transcription profiles of Streptococcus pneumoniae grown under different conditions of normal gravitation

    Allen, C. A.; Galindo, C. L.; Pandya, U.; Watson, D. A.; Chopra, A. K.; Niesel, D. W.

    2007-02-01

    High-aspect rotating vessels (HARVs) are used to study the effects low-shear modeled microgravity (LSMMG) on bacterial gene expression. LSMMG is generated by orienting HARVs with the axis of rotation perpendicular to the gravity vector while gravitational controls are oriented with the axis of rotation parallel to the gravity vector. Microarray analysis was performed on Streptococcus pneumoniae TIGR4 grown in HARVs under three conditions (LSMMG, 1×g, and static) to determine if global transcriptional activity is altered between different gravitational controls and LSMMG. Results revealed 101 differentially expressed genes under static conditions compared to 1×g, 46 genes between 1×g and LSMMG, and nine genes between static and LSMMG. Hierarchical cluster analysis revealed 15 genes exhibiting similar expression patterns under static conditions compared to 1×g. These results indicate that rotation, in addition to low-shear forces, might contribute to bacterial adaptation to the LSMMG.

  1. Regulation of naturally acquired mucosal immunity to Streptococcus pneumoniae in healthy Malawian adults and children.

    Sarah J Glennie

    Full Text Available Worldwide, invasive pneumococcal disease caused by Streptococcus pneumoniae is most common in young children. In adults, disease rates decline following intermittent colonization and the acquisition of naturally acquired immunity. We characterized mucosal and systemic pneumococcal-specific T-cell responses in African children and adults who contend with intense rates of colonization, up to 100% and 60% respectively. We find most Malawian children have high pneumococcal-specific T-cell responses in tonsil tissue and peripheral blood. In addition, frequent commensalism generates CD25(hi (Tregs which modulate mucosal pneumococcal-specific T-cell responses in some children and ≥50% of adults. We propose that immune regulation may prolong pneumococcal colonization and predispose vulnerable individuals to disease.

  2. Identification of proteins in Streptococcus pneumoniae by reverse vaccinology and genetic diversity of these proteins in clinical isolates.

    Argondizzo, Ana Paula Corrêa; da Mota, Fabio Faria; Pestana, Cristiane Pinheiro; Reis, Joice Neves; de Miranda, Antonio Basílio; Galler, Ricardo; Medeiros, Marco Alberto

    2015-02-01

    Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide. Virulence-associated proteins common and conserved among all capsular types now represent the best strategy to combat pneumococcal infections. Our aim was to identify conserved targets in pneumococci that showed positive prediction for lipoprotein and extracellular subcellular location using bioinformatics programs and verify the distribution and the degree of conservation of these targets in pneumococci. These targets can be considered potential vaccine candidate to be evaluated in the future. A set of 13 targets were analyzed and confirmed the presence in all pneumococci tested. These 13 genes were highly conserved showing around >96 % of amino acid and nucleotide identity, but they were also present and show high identity in the closely related species Streptococcus mitis, Streptococcus oralis, and Streptococcus pseudopneumoniae. S. oralis clusters away from S. pneumoniae, while S. pseudopneumoniae and S. mitis cluster closer. The divergence between the selected targets was too small to be observed consistently in phylogenetic groups between the analyzed genomes of S. pneumoniae. The proteins analyzed fulfill two of the initial criteria of a vaccine candidate: targets are present in a variety of different pneumococci strains including different serotypes and are conserved among the samples evaluated.

  3. Antimicrobial susceptibility patterns of Streptococcus pneumoniae over 6 years at Gondar University Hospital, Northwest Ethiopia

    Belay Anagaw; Chandrashekhar Unakal; Mucheye Gezachew; Fantahun Biadgelgene; Berhanu Anagaw; Tariku Geleshe; Birke Taddese; Birhanu Getie; Mengistu Endris; Andargachew Mulu

    2013-01-01

    Objective:To assess the magnitude and antimicrobial susceptibility patterns of Streptococcus pneumoniae isolates from various clinical specimens. Methods:A record based on retrospective study was conducted at Gondar University Teaching Hospital from September 2007 to January 2012. All patients who visited Gondar University Hospital and provided clinical specimens (body fluids, discharge, swab and blood) for routine bacteriological culturing and antimicrobial susceptibility testing were taken for analysis. Clinical specimens were processed for bacterial culture according to the standard procedures. Antimicrobial susceptibility test for isolated organisms was done using agar disk diffusion method. The data were entered and analyzed using SPSS software version 16 package. Results: One hundred and fifty three Streptococcus pneumoniae were isolated from patients who visited Gondar University Teaching Hospital bacteriology laboratory for culture. Majority of the pneumococcal isolates were from inpatients [111(72.5%)], and 74(48.4%) were from body fluids. Out of the total isolates, 93(61%) were found to be resistant to at least one antibiotic used for susceptibility testing. Forty eight (43.2%) of the isolates were multi-drug resistant (resistant to two or more drugs). The resistance rate noted for both ciprofloxacin 17(11.1%) and ceftriaxone 15(9.8%) were alarming. Conclusions: High proportions of the isolates tend to be increasingly resistant to the commonly prescribed drugs. The recommended drug of choice like ciprofloxacin and ceftriaxone were found to be less susceptible in the study area. Based on the findings, we therefore recommend that antimicrobial agents should be inspected for acceptable activity before they are prescribed and administered empirically. Further study with a better design and survey of antimicrobial susceptibility at large scale shoule be performed to draw advanced information.

  4. Children from 0 to 4 Years Old Carrying Streptococcus Pneumoniae. A Community Study

    Olga Olivia Tejeda Hernández

    2011-08-01

    Full Text Available Fundamento: el Streptococcus pneumoniae es la primera causa de neumonías comunitarias; a la infección la precede la colonización de la nasofaringe, de ahí la importancia de determinar el estado de portador y los patrones de susceptibilidad y resistencia. Objetivo: determinar la prevalencia del estado de portador de Streptococcus pneumoniae entre una población infantil menor de cuatro años. Métodos: estudio de corte transversal que incluyó 179 niños, de áreas urbanas y rurales del municipio San Antonio de los Baños, provincia Artemisa. Se estratificó el municipio por el número de nacidos en cada año, se determinó el por ciento que representaban en la muestra, asignando un número de niños a cada grupo, proporcional al tamaño del grupo poblacional estratificado. Los niños se seleccionaron de forma aleatoria en los consultorios. Se tomaron muestras de exudados nasales y faríngeos. La identificación de las cepas se realizó por las características morfológicas y culturales, prueba de la opto quina y solubilidad en bilis; la confirmación del cultivo por aglutinación al látex. Se determinó la susceptibilidad antimicrobiana por el método de Kirby-Bauer. Resultados: el 20, 6 % era portador nasal y el 33, 6 % en la faringe, estos últimos mayormente en el área urbana. No hubo diferencias por sexo; el 60 % de las cepas mostraron susceptibilidad disminuida a la penicilina, 52 % de resistencia al trimetropin- sulfametoxasol y un 25 % a la eritromicina. El total de los aislamientos fue susceptible a ofloxacina, cefotaxima, azitromicina y vancomicina. Conclusiones: el estado de portador fue alto.

  5. The Small Molecule DAM Inhibitor, Pyrimidinedione, Disrupts Streptococcus pneumoniae Biofilm Growth In Vitro.

    Yadav, Mukesh Kumar; Go, Yoon Young; Chae, Sung-Won; Song, Jae-Jun

    2015-01-01

    Streptococcus pneumoniae persist in the human nasopharynx within organized biofilms. However, expansion to other tissues may cause severe infections such as pneumonia, otitis media, bacteremia, and meningitis, especially in children and the elderly. Bacteria within biofilms possess increased tolerance to antibiotics and are able to resist host defense systems. Bacteria within biofilms exhibit different physiology, metabolism, and gene expression profiles than planktonic cells. These differences underscore the need to identify alternative therapeutic targets and novel antimicrobial compounds that are effective against pneumococcal biofilms. In bacteria, DNA adenine methyltransferase (Dam) alters pathogenic gene expression and catalyzes the methylation of adenine in the DNA duplex and of macromolecules during the activated methyl cycle (AMC). In pneumococci, AMC is involved in the biosynthesis of quorum sensing molecules that regulate competence and biofilm formation. In this study, we examine the effect of a small molecule Dam inhibitor, pyrimidinedione, on Streptococcus pneumoniae biofilm formation and evaluate the changes in global gene expression within biofilms via microarray analysis. The effects of pyrimidinedione on in vitro biofilms were studied using a static microtiter plate assay, and the architecture of the biofilms was viewed using confocal and scanning electron microscopy. The cytotoxicity of pyrimidinedione was tested on a human middle ear epithelium cell line by CCK-8. In situ oligonucleotide microarray was used to compare the global gene expression of Streptococcus pneumoniae D39 within biofilms grown in the presence and absence of pyrimidinedione. Real-time RT-PCR was used to study gene expression. Pyrimidinedione inhibits pneumococcal biofilm growth in vitro in a concentration-dependent manner, but it does not inhibit planktonic cell growth. Confocal microscopy analysis revealed the absence of organized biofilms, where cell-clumps were scattered

  6. The Small Molecule DAM Inhibitor, Pyrimidinedione, Disrupts Streptococcus pneumoniae Biofilm Growth In Vitro.

    Mukesh Kumar Yadav

    Full Text Available Streptococcus pneumoniae persist in the human nasopharynx within organized biofilms. However, expansion to other tissues may cause severe infections such as pneumonia, otitis media, bacteremia, and meningitis, especially in children and the elderly. Bacteria within biofilms possess increased tolerance to antibiotics and are able to resist host defense systems. Bacteria within biofilms exhibit different physiology, metabolism, and gene expression profiles than planktonic cells. These differences underscore the need to identify alternative therapeutic targets and novel antimicrobial compounds that are effective against pneumococcal biofilms. In bacteria, DNA adenine methyltransferase (Dam alters pathogenic gene expression and catalyzes the methylation of adenine in the DNA duplex and of macromolecules during the activated methyl cycle (AMC. In pneumococci, AMC is involved in the biosynthesis of quorum sensing molecules that regulate competence and biofilm formation. In this study, we examine the effect of a small molecule Dam inhibitor, pyrimidinedione, on Streptococcus pneumoniae biofilm formation and evaluate the changes in global gene expression within biofilms via microarray analysis. The effects of pyrimidinedione on in vitro biofilms were studied using a static microtiter plate assay, and the architecture of the biofilms was viewed using confocal and scanning electron microscopy. The cytotoxicity of pyrimidinedione was tested on a human middle ear epithelium cell line by CCK-8. In situ oligonucleotide microarray was used to compare the global gene expression of Streptococcus pneumoniae D39 within biofilms grown in the presence and absence of pyrimidinedione. Real-time RT-PCR was used to study gene expression. Pyrimidinedione inhibits pneumococcal biofilm growth in vitro in a concentration-dependent manner, but it does not inhibit planktonic cell growth. Confocal microscopy analysis revealed the absence of organized biofilms, where cell

  7. Multicentre in-vitro evaluation of the susceptibility of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis to ciprofloxacin, clarithromycin, co-amoxiclav and sparfloxacin

    HoogkampKorstanje, JAA; DirksGo, SIS; Kabel, P; Manson, WL; Stobberingh, EE; Vreede, RW; Davies, BI

    1997-01-01

    Seven laboratories, including a reference laboratory, tested the susceptibility of Moraxella catarrhalis, Streptococcus pneumoniae and Haemophilus influenzae strains to ciprofloxacin, clarithromycin, co-amoxiclav and sparfloxacin with the Etest. A total of 976 strains were collected. The results wit

  8. Etiology of acute otitis media and serotype distribution of Streptococcus pneumoniae and Haemophilus influenzae in Chilean children <5 years of age

    Rosenblut, Andres; Napolitano, Carla; Pereira, Angelica; Moreno, Camilo; Kolhe, Devayani; Lepetic, Alejandro; Ortega-Barria, Eduardo

    2017-01-01

    Abstract The impact of bacterial conjugate vaccines on acute otitis media (AOM) is affected by several factors including population characteristics, bacterial etiology and vaccine conjugation method, carrier, and coverage. This study estimated the baseline etiology, distribution, and antibiotic susceptibility of bacterial serotypes that causes AOM in children aged Streptococcus pneumoniae (41.7% [58/139]) and Haemophilus influenzae (40.3% [56/139]) were predominant among the cultures that showed bacterial growth (85% [139/164]). All Streptococcus pneumoniae positive episodes were serotyped, 19F (21%) and 14 (17%) were the predominant serotypes; all Haemophilus influenzae strains were nontypeable. Streptococcus pneumoniae were resistant to penicillin (5%) and erythromycin (33%); Haemophilus influenzae were resistant to ampicillin (14%) and cefuroxime and cefotaxime (2% each). AOM in Chilean children is predominantly caused by Streptococcus pneumoniae and nontypeable Haemophilus influenzae. Use of a broad spectrum vaccine against these pathogens might aid the reduction of AOM in Chile. PMID:28178138

  9. Streptococcus pneumoniae infection in children: vaccine implications%儿童肺炎链球菌感染与疫苗

    陆敏

    2010-01-01

    肺炎链球菌是儿童呼吸道感染中最常见的病原之一,也是导致儿童重症肺炎、肺炎并发症和死亡的主要致病菌.近年来,由于世界各地肺炎链球菌对抗生素的耐药不断增加和广泛传播,造成疾病的负担日益增加,也使临床诊治面临严峻挑战.疫苗的出现和推广在肺炎链球菌病的防治方面有着光明的前景.%Streptococcus pneumoniae is one of the most common causes of respiratory tract infections in children, and also the major pathogen leading to severe pneumonia, complications and even death. In recent years, antimicrobial resistance of streptococcus pneumoniae is growing and widespread, resulting in the increasing burden of disease,and also bring serious challenges to clinical diagnosis and treatment. The emergence and dissemination of vaccines against Streptococcus pneumoniae in disease prevention and control has a bright future.

  10. Evolution of antimicrobial resistance and serotype distribution of Streptococcus pneumoniae isolated from children with invasive and noninvasive pneumococcal diseases in Algeria from 2005 to 2012

    N. Ramdani-Bouguessa

    2015-07-01

    Full Text Available Pneumococcal infections are a major cause of morbidity and mortality in developing countries. The introduction of pneumococcal conjugate vaccines (PCVs has dramatically reduced the incidence of pneumococcal diseases. PCVs are not currently being used in Algeria. We conducted a prospective study from 2005 to 2012 in Algeria to determine antimicrobial drug resistance and serotype distribution of Streptococcus pneumoniae from children with pneumococcal disease. Among 270 isolated strains from children, 97 (36% were invasive disease; of these, 48% were not susceptible to penicillin and 53% not susceptible to erythromycin. A high rate of antimicrobial nonsusceptibility was observed in strains isolated from children with meningitis. The serotype distribution from pneumococci isolated from children with invasive infections was (by order of prevalence: 14, 1, 19F, 19A, 6B, 5, 3, 6A and 23F. Multidrug resistance was observed in serotypes 14, 19F, 19A and 6B. The vaccine coverage of serotypes isolated from children aged <5 years was 55.3% for PCV7, 71.1% for PCV10 and 86.8% for PCV13. Our results highlight the burden of pneumococcal disease in Algeria and the increasing S. pneumoniae antibiotic resistance. The current pneumococcal vaccines cover a high percentage of the circulating strains. Therefore, vaccination would reduce the incidence of pneumococcal disease in Algeria.

  11. A Novel Metallo-β-Lactamase Involved in the Ampicillin Resistance of Streptococcus pneumoniae ATCC 49136 Strain.

    Chia-Yu Chang

    Full Text Available Streptococcus pneumoniae, a penicillin-sensitive bacterium, is recognized as a major cause of pneumonia and is treated clinically with penicillin-based antibiotics. The rapid increase in resistance to penicillin and other antibiotics affects 450 million people globally and results in 4 million deaths every year. To unveil the mechanism of resistance of S. pneumoniae is thus an important issue to treat streptococcal disease that might consequently save millions of lives around the world. In this work, we isolated a streptococci-conserved L-ascorbate 6-phosphate lactonase, from S. pneumoniae ATCC 49136. This protein reveals a metallo-β-lactamase activity in vitro, which is able to deactivate an ampicillin-based antibiotic by hydrolyzing the amide bond of the β-lactam ring. The Michaelis parameter (Km = 25 μM and turnover number (kcat = 2 s-1 were obtained when nitrocefin was utilized as an optically measurable substrate. Through confocal images and western blot analyses with a specific antibody, the indigenous protein was recognized in S. pneumoniae ATCC 49136. The protein-overexpressed S. pneumonia exhibits a high ampicillin-tolerance ability in vivo. In contrast, the protein-knockout S. pneumonia reveals the ampicillin-sensitive feature relative to the wild type strain. Based on these results, we propose that this protein is a membrane-associated metallo-β-lactamase (MBL involved in the antibiotic-resistant property of S. pneumoniae.

  12. [Evaluation of penicillin-binding protein genotypes in penicillin susceptible and resistant Streptococcus pneumoniae isolates].

    Aslan, Gönül; Tezcan, Seda; Delialioğlu, Nuran; Aydın, Fatma Esin; Kuyucu, Necdet; Emekdaş, Gürol

    2012-04-01

    Penicillin-binding proteins (PBPs) are the natural targets of beta-lactam antibiotics and mutations in pbp1a, pbp2b, and pbp2x genes, which encode PBPs, are responsible for resistance to beta-lactams in Streptococcus pneumoniae. In the present study, we intended to determine how often the common mutation patterns occurred within the pbp1a, pbp2b, and pbp2x PBP gene regions and evaluate the PBP genotype mutations which were associated with penicillin resistance in several penicillin-susceptible and - resistant S.pneumoniae isolates in Mersin, Turkey. A total of 62 S.pneumoniae strains isolated from different clinical specimens (32 nasopharyngeal swab, 16 sputum, 3 blood, 3 wound, 2 cerebrospinal fluids and one of each urine, abscess, bronchoalveolar lavage, conjunctival swab, tracheal aspirate, middle ear effusion) were included in the study. Penicillin susceptibilities of the isolates were searched by disc diffusion and E-test methods, and 23 of them were identified as susceptible, 31 were intermediate susceptible, and eight were resistant to penicillin. A rapid DNA extraction procedure was performed for the isolation of nucleic acids from the strains. Distribution of PBP gene mutations in pbp1a, pbp2b, and pbp2x gene regions related to penicillin resistance was determined by using a wild-type specific polymerase chain reaction (PCR) based technique. PBP gene alterations of those isolates were also evaluated in relation to penicillin susceptibility and resistance patterns. Twenty two (95.7%) of 23 penicillin-susceptible S.pneumoniae isolates exhibited no mutation in the three PBP genes (pbp1a, pbp2x, and pbp 2b), while 1 (4.3%) of these harbored mutations in all of the three PBP genes. The penicillin-intermediate susceptible S.pneumoniae isolates exhibited various combinations of mutations. One (3.2%) of 31 penicillin-intermediate susceptible isolates exhibited no mutation in the three PBP genes, while 22 (71%) of them yielded mutations in all of the three PBP

  13. M-ficolin binds selectively to the capsular polysaccharides of Streptococcus pneumoniae serotypes 19B and 19C and of a S. mitis strain

    Kjær, Troels Rønn; Hansen, Annette G; Sørensen, Uffe B S

    2012-01-01

    of infections. We investigated the binding selectivity by examining the binding of M-ficolin to a panel of more than 100 different streptococcal strains (Streptococcus pneumoniae and Streptococcus mitis) each expressing distinct polysaccharide structures. M-ficolin binding was observed for three strains only...... able to demonstrate specific binding of M-ficolin to some capsular polysaccharides of the opportunistic pathogen S. pneumoniae and of the commensal bacterium S. mitis....

  14. Antibody and splenocyte proliferation response to whole inactivated Streptococcus pneumoniae serotype 1, 3 and 6B in mice.

    Pană, Marina; Orhan, Rasid; Bănică, Leontina; Iancu, Adina Daniela; Stăvaru, Crina

    2011-01-01

    Animal models of infection and protection on the topic of the Streptococcus pneumoniae (S. pneumoniae) have encountered many difficulties generated by low immunogenicity, a characteristic of polysaccharide capsular bacteria and difference of virulence between serotypes and strains. We have explored the immune response after immunization with heat inactivated S. pneumoniae serotype 1, 3 and 6B in C57BL/6 mice by IgM and IgG detection, and by splenocyte in vitro 5-ethynyl-2'-deoxyuridine (EdU) incorporation after antigen specific stimulation, as a proposed method of cellular immune response evaluation. Antibody titer persistence after immunization was not lengthy while antigen specific proliferation response detected by EdU assay was remnant. Intraperitoneal (i.p.) challenge with serotype 6B S. pneumoniae proved that antibody titers and the detected specific cellular immune response do not cover seroprotective necessity and do not confer improved immunologic memory in comparison to non-immunized mice, which show natural resistance.

  15. Prophage spontaneous activation promotes DNA release enhancing biofilm formation in Streptococcus pneumoniae.

    Margarida Carrolo

    Full Text Available Streptococcus pneumoniae (pneumococcus is able to form biofilms in vivo and previous studies propose that pneumococcal biofilms play a relevant role both in colonization and infection. Additionally, pneumococci recovered from human infections are characterized by a high prevalence of lysogenic bacteriophages (phages residing quiescently in their host chromosome. We investigated a possible link between lysogeny and biofilm formation. Considering that extracellular DNA (eDNA is a key factor in the biofilm matrix, we reasoned that prophage spontaneous activation with the consequent bacterial host lysis could provide a source of eDNA, enhancing pneumococcal biofilm development. Monitoring biofilm growth of lysogenic and non-lysogenic pneumococcal strains indicated that phage-infected bacteria are more proficient at forming biofilms, that is their biofilms are characterized by a higher biomass and cell viability. The presence of phage particles throughout the lysogenic strains biofilm development implicated prophage spontaneous induction in this effect. Analysis of lysogens deficient for phage lysin and the bacterial major autolysin revealed that the absence of either lytic activity impaired biofilm development and the addition of DNA restored the ability of mutant strains to form robust biofilms. These findings establish that limited phage-mediated host lysis of a fraction of the bacterial population, due to spontaneous phage induction, constitutes an important source of eDNA for the S. pneumoniae biofilm matrix and that this localized release of eDNA favors biofilm formation by the remaining bacterial population.

  16. The Streptococcus pneumoniae cia regulon: CiaR target sites and transcription profile analysis.

    Mascher, Thorsten; Zähner, Dorothea; Merai, Michelle; Balmelle, Nadège; de Saizieu, Antoine B; Hakenbeck, Regine

    2003-01-01

    The ciaR-ciaH system is one of 13 two-component signal-transducing systems of the human pathogen Streptococcus pneumoniae. Mutations in the histidine protein kinase CiaH confer increased resistance to beta-lactam antibiotics and interfere with the development of genetic competence. In order to identify the genes controlled by the cia system, the cia regulon, DNA fragments targeted by the response regulator CiaR were isolated from restricted chromosomal DNA using the solid-phase DNA binding assay and analyzed by hybridization to an oligonucleotide microarray representing the S. pneumoniae genome. A set of 18 chromosomal regions containing 26 CiaR target sites were detected and proposed to represent the minimal cia regulon. The putative CiaR target loci included genes important for the synthesis and modification of cell wall polymers, peptide pheromone and bacteriocin production, and the htrA-spo0J region. In addition, the transcription profile of cia loss-of-function mutants and those with an apparent activated cia system representing the off and on states of the regulatory system were analyzed. The transcript analysis confirmed the cia-dependent expression of seven putative target loci and revealed three additional cia-regulated loci. Five putative target regions were silent under all conditions, and for the remaining three regions, no cia-dependent expression could be detected. Furthermore, the competence regulon, including the comCDE operon required for induction of competence, was completely repressed by the cia system.

  17. Protective effect of Plantago major L. Pectin polysaccharide against systemic Streptococcus pneumoniae infection in mice.

    Hetland, G; Samuelsen, A B; Løvik, M; Paulsen, B S; Aaberge, I S; Groeng, E C; Michaelsen, T E

    2000-10-01

    The antibacterial effect of a soluble pectin polysaccharide, PMII, isolated from the leaves of Plantago major, was examined in inbred NIH/OlaHsd and Fox Chase SCID mice experimentally infected with Streptococcus pneumoniae serotype 6B. Serotype 6B is known to give a more protracted infection when injected intraperitoneally into susceptible mice than more virulent serotypes like type 4. PMII was administered i.p. either once 3 days before challenge or once to thrice from 3 to 48 h after challenge. The number of bacteria in blood and the mouse survival rate were recorded. Pre-challenge administration of PMII and also lipopolysaccharide (LPS), included as a control, gave a dose-dependent protective effect against S. pneumoniae type 6B infection. However, injection of PMII after establishment of the infection in NIH/OlaHsd mice had no effect. The data demonstrate that, firstly, the polysaccharide fraction PMII from P. major protects against pneumococcal infection in mice when administered systemically prechallenge, and secondly that the protective effect is owing to stimulation of the innate and not the adaptive immune system.

  18. Discovery of prenylated flavonoids with dual activity against influenza virus and Streptococcus pneumoniae.

    Grienke, Ulrike; Richter, Martina; Walther, Elisabeth; Hoffmann, Anja; Kirchmair, Johannes; Makarov, Vadim; Nietzsche, Sandor; Schmidtke, Michaela; Rollinger, Judith M

    2016-06-03

    Influenza virus neuraminidase (NA) is the primary target for influenza therapeutics. Severe complications are often related to secondary pneumonia caused by Streptococcus pneumoniae (pneumococci), which also express NAs. Recently, a NA-mediated lethal synergism between influenza A viruses and pneumococci was described. Therefore, dual inhibitors of both viral and bacterial NAs are expected to be advantageous for the treatment of influenza. We investigated the traditional Chinese herbal drug sāng bái pí (mulberry root bark) as source for anti-infectives. Two prenylated flavonoid derivatives, sanggenon G (4) and sanggenol A (5) inhibited influenza A viral and pneumococcal NAs and, in contrast to the approved NA inhibitor oseltamivir, also planktonic growth and biofilm formation of pneumococci. Evaluation of 27 congeners of 5 revealed a correlation between the degree of prenylation and bioactivity. Abyssinone-V 4'-methyl ether (27) inhibited pneumococcal NA with IC50 = 2.18 μM, pneumococcal growth with MIC = 5.63 μM, and biofilm formation with MBIC = 4.21 μM, without harming lung epithelial cells. Compounds 5 and 27 also disrupt the synergism between influenza A virus and pneumococcal NA in vitro, hence functioning as dual-acting anti-infectives. The results warrant further studies on whether the observed disruption of this synergism is transferable to in vivo systems.

  19. Prevalence and characteristics of Streptococcus pneumoniae "putative serotype 6E" isolates from Asian countries.

    Baek, Jin Yang; Park, In Ho; So, Thomas Man-kit; Lalitha, M K; Shimono, Nobuyuki; Yasin, Rohani Md; Carlos, Celia C; Perera, Jennifer; Thamlikitkul, Visanu; Hsueh, Po-Ren; Van, Pham Hung; Shibl, Atef M; Song, Jae-Hoon; Ko, Kwan Soo

    2014-12-01

    The prevalence, antimicrobial susceptibility, and genotypes of Streptococcus pneumoniae “putative serotype 6E” isolates from Asian countries were investigated. A total of 244 S. pneumoniae serogroup 6 isolates obtained from 11 Asian countries were included in this study. Of the 244 serogroup 6 isolates, 101 (41.4%) were typed as "putative serotype 6E," followed by serotypes 6A, 6B, 6C, and 6D (27.0, 20.1, 5.7, and 5.7%, respectively). Multilocus sequence typing revealed that clonal complex (CC) 90, including ST90 and its variants, was the most prevalent clonal group of "putative serotype 6E" isolates (n = 63; 62.4%). CC146 and CC315 were also found frequently in some of the countries. Most of the "putative serotype 6E" isolates showed very high resistance rates against cefuroxime, erythromycin, azithromycin, clarithromycin, clindamycin, and trimethoprim/sulfamethoxazole, probably due to their highly resistant to antimicrobials clone, CC90. Our results indicate that “putative serotype 6E” is prevalent in Asian countries. The clonal dissemination of "putative serotype 6E" isolates was also identified.

  20. Adenylate kinase from Streptococcus pneumoniae is essential for growth through its catalytic activity

    Trung Thanh Thach

    2014-01-01

    Full Text Available Streptococcus pneumoniae (pneumococcus infection causes more than 1.6 million deaths worldwide. Pneumococcal growth is a prerequisite for its virulence and requires an appropriate supply of cellular energy. Adenylate kinases constitute a major family of enzymes that regulate cellular ATP levels. Some bacterial adenylate kinases (AdKs are known to be critical for growth, but the physiological effects of AdKs in pneumococci have been poorly understood at the molecular level. Here, by crystallographic and functional studies, we report that the catalytic activity of adenylate kinase from S. pneumoniae (SpAdK serotype 2 D39 is essential for growth. We determined the crystal structure of SpAdK in two conformations: ligand-free open form and closed in complex with a two-substrate mimic inhibitor adenosine pentaphosphate (Ap5A. Crystallographic analysis of SpAdK reveals Arg-89 as a key active site residue. We generated a conditional expression mutant of pneumococcus in which the expression of the adk gene is tightly regulated by fucose. The expression level of adk correlates with growth rate. Expression of the wild-type adk gene in fucose-inducible strains rescued a growth defect, but expression of the Arg-89 mutation did not. SpAdK increased total cellular ATP levels. Furthermore, lack of functional SpAdK caused a growth defect in vivo. Taken together, our results demonstrate that SpAdK is essential for pneumococcal growth in vitro and in vivo.

  1. Structure of the fucose mutarotase from Streptococcus pneumoniae in complex with L-fucose.

    Higgins, Melanie A; Boraston, Alisdair B

    2011-12-01

    Streptococcus pneumoniae relies on a variety of carbohydrate-utilization pathways for both colonization of its human host and full virulence during the development of invasive disease. One such pathway is the fucose-utilization pathway, a component of which is fucose mutarotase (SpFcsU), an enzyme that performs the interconversion between α-L-fucose and β-L-fucose. This protein was crystallized and its three-dimensional structure was solved in complex with L-fucose. The structure shows a complex decameric quaternary structure with a high overall degree of structural identity to Escherichia coli FcsU (EcFcsU). Furthermore, the active-site architecture of SpFcsU is highly similar to that of EcFcsU. When considered in the context of the fucose-utilization pathway found in S. pneumoniae, SpFcsU appears to link the two halves of the pathway by enhancing the rate of conversion of the product of the final glycoside hydrolysis step, β-fucose, into the substrate for the fucose isomerase, α-fucose.

  2. Expression,Purification,Characteristics and Homology Modeling of the HMGS from Streptococcus pneumoniae

    YA-LI BEN; GU-ZHEN CUI; CHEN LI; RUI HAN; JIE ZHANG; QING-YE ZHANG; JIAN WAN; DE-LI LIU

    2009-01-01

    Objective To understand the molecular basis for a potential reaction mechanism and develop novel antibiotics with homology modeling for 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase (HMGS). Methods The genetic engineering technology and the composer module of SYBYL7.0 program were used,while the HMGS three-dimensional structure was analyzed by homology modeling. Results The mvaS gene was cloned from Streptococcus pneumoniae and overexpressed in Escherichia coli from a pET28 vector.The expressed enzyme (about 46 kDa) was purified by affinity chromatography with a specific activity of 3.24 μmol/min/mg.Optimal conditions were pH 9.75 and 10 mmol/L MgCl2 at 37℃.The Vmax and Km were 4.69 μmol/mirdmg and 213 μmol/L respectively.The 3D model of S.pneumoniae HMGS was established based on structure template of HMGS of Enterococcus faecalis. Conclusion The structure of HMGS will facilitate the structure-based design of alternative drugs to cholesterol-lowering therapies or to novel antibiotics to the Gram-positive cocci,whereas the recombinant HMGS will prove useful for drug development against a different enzyme in the mevalonate pathway.

  3. Overexpression, purification and crystallization of a choline-binding protein CbpI from Streptococcus pneumoniae

    Paterson, Neil G., E-mail: neison@chem.gla.ac.uk; Riboldi-Tunicliffe, Alan [Department of Chemistry and WestCHEM, Glasgow Biomedical Research Centre (GBRC), University of Glasgow, 120 University Place, Glasgow G12 8TA,Scotland (United Kingdom); Mitchell, Timothy J. [Division of Infection and Immunity (IBLS), Glasgow Biomedical Research Centre (GBRC), University of Glasgow, 120 University Place, Glasgow G12 8TA,Scotland (United Kingdom); Isaacs, Neil W. [Department of Chemistry and WestCHEM, Glasgow Biomedical Research Centre (GBRC), University of Glasgow, 120 University Place, Glasgow G12 8TA,Scotland (United Kingdom)

    2006-07-01

    The choline-binding protein CbpI from S. pneumoniae has been purified and crystallized and diffraction data have been collected to 3.5 Å resolution. The choline-binding protein CbpI from Streptococcus pneumoniae is a 23.4 kDa protein with no known function. The protein has been successfully purified initially using Ni–NTA chromatography and to homogeneity using Q-Sepharose ion-exchange resin as an affinity column. CbpI was crystallized using PEG 3350 as a precipitant and X-ray crystallographic analysis showed that the crystals belonged to the tetragonal space group P4, with unit-cell parameters a = b = 83.31, c = 80.29 Å, α = β = γ = 90°. The crystal contains two molecules in the asymmetric unit with a solvent content of 55.7% (V{sub M} = 2.77 Å{sup 3} Da{sup −1}) and shows a diffraction limit of 3.5 Å.

  4. Genomic analyses of DNA transformation and penicillin resistance in Streptococcus pneumoniae clinical isolates.

    Fani, Fereshteh; Leprohon, Philippe; Zhanel, George G; Bergeron, Michel G; Ouellette, Marc

    2014-01-01

    Alterations in penicillin-binding proteins, the target enzymes for β-lactam antibiotics, are recognized as primary penicillin resistance mechanisms in Streptococcus pneumoniae. Few studies have analyzed penicillin resistance at the genome scale, however, and we report the sequencing of S. pneumoniae R6 transformants generated while reconstructing the penicillin resistance phenotypes from three penicillin-resistant clinical isolates by serial genome transformation. The genome sequences of the three last-level transformants T2-18209, T5-1983, and T3-55938 revealed that 16.2 kb, 82.7 kb, and 137.2 kb of their genomes had been replaced with 5, 20, and 37 recombinant sequence segments derived from their respective parental clinical isolates, documenting the extent of DNA transformation between strains. A role in penicillin resistance was confirmed for some of the mutations identified in the transformants. Several multiple recombination events were also found to have happened at single loci coding for penicillin-binding proteins (PBPs) that increase resistance. Sequencing of the transformants with MICs for penicillin similar to those of the parent clinical strains confirmed the importance of mosaic PBP2x, -2b, and -1a as a driving force in penicillin resistance. A role in resistance for mosaic PBP2a was also observed for two of the resistant clinical isolates.

  5. Pathophysiology of acute meningitis caused by Streptococcus pneumoniae and adjunctive therapy approaches

    Tatiana Barichello

    2012-05-01

    Full Text Available Pneumococcal meningitis is a life-threatening disease characterized by an acute purulent infection affecting piamater, arachnoid and the subarachnoid space. The intense inflammatory host's response is potentially fatal and contributes to the neurological sequelae. Streptococcus pneumoniae colonizes the nasopharynx, followed by bacteremia, microbial invasion and blood-brain barrier traversal. S. pneumoniae is recognized by antigen-presenting cells through the binding of Toll-like receptors inducing the activation of factor nuclear kappa B or mitogen-activated protein kinase pathways and subsequent up-regulation of lymphocyte populations and expression of numerous proteins involved in inflammation and immune response. Many brain cells can produce cytokines, chemokines and others pro-inflammatory molecules in response to bacteria stimuli, as consequence, polymorphonuclear are attracted, activated and released in large amounts of superoxide anion and nitric oxide, leading to the peroxynitrite formation, generating oxidative stress. This cascade leads to lipid peroxidation, mitochondrial damage, blood-brain barrier breakdown contributing to cell injury during pneumococcal meningitis.

  6. Cirrhosis-induced defects in innate pulmonary defenses against Streptococcus pneumoniae

    Vander Top Elizabeth A

    2007-10-01

    Full Text Available Abstract Background The risk of mortality from pneumonia caused by Streptococcus pneumoniae is increased in patients with cirrhosis. However, the specific pneumococcal virulence factors and host immune defects responsible for this finding have not been clearly established. This study used a cirrhotic rat model of pneumococcal pneumonia to identify defect(s in innate pulmonary defenses in the cirrhotic host and to determine the impact of the pneumococcal toxin pneumolysin on these defenses in the setting of severe cirrhosis. Results No cirrhosis-associated defects in mucociliary clearance of pneumococci were found in these studies, but early intrapulmonary killing of the organisms before the arrival of neutrophils was significantly impaired. This defect was exacerbated by pneumolysin production in cirrhotic but not in control rats. Neutrophil-mediated killing of a particularly virulent type 3 pneumococcal strain also was significantly diminished within the lungs of cirrhotic rats with ascites. Levels of lysozyme and complement component C3 were both significantly reduced in bronchoalveolar lavage fluid from cirrhotic rats. Finally, complement deposition was reduced on the surface of pneumococci recovered from the lungs of cirrhotic rats in comparison to organisms recovered from the lungs of control animals. Conclusion Increased mortality from pneumococcal pneumonia in this cirrhotic host is related to defects in both early pre-neutrophil- and later neutrophil-mediated pulmonary killing of the organisms. The fact that pneumolysin production impaired pre-neutrophil-mediated pneumococcal killing in cirrhotic but not control rats suggests that pneumolysin may be particularly detrimental to this defense mechanism in the severely cirrhotic host. The decrease in neutrophil-mediated killing of pneumococci within the lungs of the cirrhotic host is related to insufficient deposition of host proteins such as complement C3 on their surfaces. Pneumolysin

  7. A reação em cadeia da polimerase na detecção da resistência à penicilina em Streptococcus pneumoniae Polymerase chain reaction used to detect Streptococcus pneumoniae resistance to penicillin

    Eduardo Walker Zettler; Rosane M. Scheibe; Dias,Cícero A. G.; Patrícia Santafé; José da Silva Moreira; Santos, Diógenes S.; Carlos Cezar Fritscher

    2004-01-01

    INTRODUÇÃO: O Streptococcus pneumoniae é o mais freqüente agente etiológico de infecções respiratórias adquiridas na comunidade e sua resistência aos antimicrobianos tem aumentado nos últimos anos. A determinação da resistência é feita rotineiramente por método lento que depende do crescimento em cultura e determinação da concentração inibitória mínima (CIM). A reação em cadeia da polimerase (PCR) detecta os genes responsáveis pela resistência do Streptococcus pneumoniae a penicilina em cerca...

  8. Alterations in penicillin binding protein gene of Streptococcus pneumoniae and their correlation with susceptibility patterns.

    Ohsaki, Yoshinobu; Tachibana, Mineji; Nakanishi, Kyoko; Nakao, Shoko; Saito, Kumiko; Toyoshima, Eri; Sato, Maki; Takahashi, Toru; Osanai, Shinobu; Itoh, Yoshihisa; Kikuchi, Kenjiro

    2003-08-01

    Penicillin binding protein (pbp) gene alterations of 328 clinical isolates of Streptococcus pneumoniae were examined for a correlation with their antibiotic-resistance. The frequency of penicillin G (PEN-G) resistance was determined to clarify susceptibility to several antibiotics, namely PEN-G, ampicillin, sulbactam/ampicillin, cefozopram, panipenem (PAPM), clarithromycin (CLR), azithromycin (AZM) and levofloxacin (LVX). Oligonucleotide primers for three pbp genes (pbp1a, pbp2x and pbp2b) were used to detect mutations in pbp. Of the strains, 25.9% were classified as Pen-Gs, 68.0% as Pen-Gir and 6.1% as Pen-Gr. The polymerase chain reaction product for wild-type pbp1a was found in 185 isolates, that for wild-type pbp2x was found in 66 isolates and that for wild-type pbp2b was found in 213 isolates. None of these three genes was detectable in 100 isolates while all of them were detected in 64 isolates (1aw/2xw/2bw). Of those 64 isolates with 1aw/2xw/2bw, the minimum inhibitory concentration (MIC) of PEN-G was or =4.0 mg/l included one Pen-Gs and two Pen-Gir isolates. The MICs of CLR correlated significantly with those of AZM. The MIC of CLR was > or =1 mg/l for 216 isolates, and the MIC of AZM was > or =1 mg/l for 244 of them. These data suggested that PAPM may be effective against S. pneumoniae infection, although acquisition of resistance should be considered. LVX also seemed to be effective against S. pneumoniae.

  9. Molecular characterization of clinical Streptococcus pneumoniae isolates with reduced susceptibility to fluoroquinolones emerging in Italy.

    Montanari, Maria Pia; Tili, Emily; Cochetti, Ileana; Mingoia, Marina; Manzin, Aldo; Varaldo, Pietro Emanuele

    2004-01-01

    Fifteen Streptococcus pneumoniae clinical isolates with reduced fluoroquinolone susceptibility (defined as a ciprofloxacin MIC of > or = 4 microg/ml), all collected in Italy in 2000-2003, were typed and subjected to extensive molecular characterization to define the contribution of drug target alterations and efflux mechanisms to their resistance. Serotyping and pulsed-field gel electrophoresis analysis indicated substantial genetic unrelatedness among the 15 isolates, suggesting that the new resistance traits arise in multiple indigenous strains rather than through clonal dissemination. Sequencing of the quinolone resistance-determining regions of gyrA, gyrB, parC, and parE demonstrated that point mutations producing single amino acid changes were more frequent in topoisomerase IV (parC mutations in 14 isolates and parE mutations in 13) than in DNA gyrase subunits (gyrA mutations in 7 isolates and no gyrB mutations observed). No isolate displayed a quinolone efflux system susceptible to carbonyl cyanide m-chlorophenylhydrazone; conversely, four-fold or greater MIC reductions in the presence of reserpine were observed in all 15 isolates with ethidium bromide, in 13 with ulifloxacin, in 9 with ciprofloxacin, in 5 with norfloxacin, and in none with five other fluoroquinolones. The effect of efflux pump activity on the level and profile of fluoroquinolone resistance in our strains was minor compared with that of target site modifications. DNA mutations and/or efflux systems other than those established so far might contribute to the fluoroquinolone resistance expressed by our strains. Susceptibility profiles to nonquinolone class antibiotics and resistance-associated phenotypic and genotypic characteristics were also determined and correlated with fluoroquinolone resistance. A unique penicillin-binding protein profile was observed in all five penicillin-resistant isolates, whereas the same PBP profile as S. pneumoniae R6 was exhibited by all six penicillin

  10. In vitro activity of telithromycin against Spanish Streptococcus pneumoniae isolates with characterized macrolide resistance mechanisms.

    Morosini, M I; Cantón, R; Loza, E; Negri, M C; Galán, J C; Almaraz, F; Baquero, F

    2001-09-01

    The susceptibilities to telithromycin of 203 Streptococcus pneumoniae isolates prospectively collected during 1999 and 2000 from 14 different geographical areas in Spain were tested and compared with those to erythromycin A, clindamycin, quinupristin-dalfopristin, penicillin G, cefotaxime, and levofloxacin. Telithromycin was active against 98.9% of isolates (MICs, MICs at which 90% of isolates are inhibited being 0.06 microg/ml, irrespective of the resistance genotype. The corresponding values for erythromycin were 61.0% (MICs, 64 microg/ml. The erm(B) gene (macrolide-lincosamide-streptogramin B resistance phenotype) was detected in 36.4% (n = 74) of the isolates, which corresponded to 93.6% of erythromycin-intermediate and -resistant isolates, whereas the mef(A) gene (M phenotype [resistance to erythromycin and susceptibility to clindamycin and spiramycin without blunting]) was present in only 2.4% (n = 5) of the isolates. One of the latter isolates also carried erm(B). Interestingly, in one isolate for which the erythromycin MIC was 2 microg/ml, none of these resistance genes could be detected. Erythromycin MICs for S. pneumoniae erm(B)-positive isolates were higher (range, 0.5 to >64 microg/ml) than those for erm(B)- and mef(A)-negative isolates (range, 0.008 to 2 microg/ml). The corresponding values for telithromycin were lower for both groups, with ranges of 0.004 to 1 and 0.002 to 0.06 microg/ml, respectively. The erythromycin MIC was high for a large number of erm(B)-positive isolates, but the telithromycin MIC was low for these isolates. These results indicate the potential usefulness of telithromycin for the treatment of infections caused by erythromycin-susceptible and -resistant S. pneumoniae isolates when macrolides are indicated.

  11. Reduction of Streptococcus pneumoniae Colonization and Dissemination by a Nonopsonic Capsular Polysaccharide Antibody

    Christopher R. Doyle

    2016-02-01

    Full Text Available Streptococcus pneumoniae colonization of the nasopharynx (NP is a prerequisite for invasive pneumococcal disease (IPD. The marked reduction in IPD that followed the routine use of pneumococcal polysaccharide conjugate vaccines (PCVs has been linked to reduced NP colonization with vaccine-included serotypes (STs, with the caveat that PCVs are less effective against pneumonia than against IPD. Although PCV-elicited opsonic antibodies that enhance phagocytic killing of the homologous ST are considered a key correlate of PCV-mediated protection, recent studies question this relationship for some STs, including ST3. Studies with monoclonal antibodies (MAbs to the pneumococcal capsular polysaccharide (PPS of ST3 (PPS3 have shown that nonopsonic, as well as opsonic, antibodies can each protect mice against pneumonia and sepsis, but the effect of these types of MAbs on NP colonization is unknown. In this study, we determined the effects of protective opsonic and nonopsonic PPS3 MAbs on ST3 NP colonization in mice. Our results show that a nonopsonic MAb reduced early NP colonization and prevented ST3 dissemination to the lungs and blood, but an opsonic MAb did not. Moreover, the opsonic MAb induced a proinflammatory NP cytokine response, but the nonopsonic MAb had an antiinflammatory effect. The effect of the nonopsonic MAb on colonization did not require its Fc region, but its antiinflammatory effect did. Our findings challenge the paradigm that opsonic MAbs are required to prevent NP colonization and suggest that further studies of the activity of nonopsonic antibodies could advance our understanding of mechanisms of PCV efficacy and provide novel correlates of protection.

  12. Insertional mutation of orfD of the DCW cluster of Streptococcus pneumoniae attenuates virulence.

    Palmen, R; Ogunniyi, A D; Berroy, P; Larpin, S; Paton, J C; Trombe, M C

    1999-12-01

    Mutational analysis of a 5.5 kb fragment of the genome Streptococcus pneumoniae led to the identification of a putative new virulence gene, designated orfD. Insertion mutagenesis of flanking genes on the fragment suggested that the corresponding gene products were required for in vitro growth. In contrast, insertion mutation of orfD did not alter in vitro growth or the transformability pattern of the mutated strain. However, it did reduce bacterial growth in mice and attenuated virulence in an intraperitoneal model of infection. orfD is flanked by orfC (63 codons) and ftsL (105 codons) and all three genes are upstream of pbpx. orfC showed no similarity with other known proteins. ftsL of S. pneumoniae exhibits minimal sequence similarity with ftsL of E. coli, but shares 16% identical residues with the ftsL homologue encoded by ylld of B. subtilis. Also, ftsL of S. pneumoniae has a predicted topology similar to that described for ftsL of E. coli. Putative promoters with an extended -10 box could be identified upstream of both orfC or orfD. The four open reading frames (including pbpx) are orientated in the same direction, and polycistronic transcription could theoretically start at either promoter. Interestingly, this region shows organizational and sequence homologies with genes controlling division and cell wall biosynthesis (DCW) in other bacteria. The attenuation of virulence in the orfD insertion mutant might be due to the loss of function of the orfD gene product or to an altered level of expression of downstream genes.

  13. Profiling of β-lactam selectivity for penicillin-binding proteins in Streptococcus pneumoniae D39.

    Kocaoglu, Ozden; Tsui, Ho-Ching T; Winkler, Malcolm E; Carlson, Erin E

    2015-01-01

    Selective fluorescent β-lactam chemical probes enable the visualization of the transpeptidase activity of penicillin-binding proteins (PBPs) at different stages of bacterial cell division. To facilitate the development of new fluorescent probes for PBP imaging, we evaluated 20 commercially available β-lactams for selective PBP inhibition in an unencapsulated derivative of the D39 strain of Streptococcus pneumoniae. Live cells were treated with β-lactam antibiotics at different concentrations and subsequently incubated with Bocillin FL (Boc-FL; fluorescent penicillin) to saturate uninhibited PBPs. Fluorophore-labeled PBPs were visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and fluorescence scanning. Among 20 compounds tested, carbapenems (doripenem and meropenem) were coselective for PBP1a, PBP2x, and PBP3, while six of the nine penicillin compounds were coselective for PBP2x and PBP3. In contrast, the seven cephalosporin compounds tested display variability in their PBP-binding profiles. Three cephalosporin compounds (cefoxitin, cephalexin, and cefsulodin) and the monobactam aztreonam exhibited selectivity for PBP3, while only cefuroxime (a cephalosporin) was selective for PBP2x. Treatment of S. pneumoniae cultures with a sublethal concentration of cefuroxime that inhibited 60% of PBP2x activity and less than 20% of the activity of other PBPs resulted in formation of elongated cells. In contrast, treatment of S. pneumoniae cultures with concentrations of aztreonam and cefoxitin that inhibited up to 70% of PBP3 activity and less than 30% of other PBPs resulted in no discernible morphological changes. Additionally, correlation of the MIC and IC50s for each PBP, with the exception of faropenem, amdinocillin (mecillinam), and 6-APA, suggests that pneumococcal growth inhibition is primarily due to the inhibition of PBP2x.

  14. Plasma-derived human C1-esterase inhibitor does not prevent mechanical ventilation-induced pulmonary complement activation in a rat model of Streptococcus pneumoniae pneumonia.

    de Beer, F M; Aslami, H; Hoeksma, J; van Mierlo, G; Wouters, D; Zeerleder, S; Roelofs, J J T H; Juffermans, N P; Schultz, M J; Lagrand, W K

    2014-11-01

    Mechanical ventilation has the potential to cause lung injury, and the role of complement activation herein is uncertain. We hypothesized that inhibition of the complement cascade by administration of plasma-derived human C1-esterase inhibitor (C1-INH) prevents ventilation-induced pulmonary complement activation, and as such attenuates lung inflammation and lung injury in a rat model of Streptococcus pneumoniae pneumonia. Forty hours after intratracheal challenge with S. pneumoniae causing pneumonia rats were subjected to ventilation with lower tidal volumes and positive end-expiratory pressure (PEEP) or high tidal volumes without PEEP, after an intravenous bolus of C1-INH (200 U/kg) or placebo (saline). After 4 h of ventilation blood, broncho-alveolar lavage fluid and lung tissue were collected. Non-ventilated rats with S. pneumoniae pneumonia served as controls. While ventilation with lower tidal volumes and PEEP slightly amplified pneumonia-induced complement activation in the lungs, ventilation with higher tidal volumes without PEEP augmented local complement activation more strongly. Systemic pre-treatment with C1-INH, however, failed to alter ventilation-induced complement activation with both ventilation strategies. In accordance, lung inflammation and lung injury were not affected by pre-treatment with C1-INH, neither in rats ventilated with lower tidal volumes and PEEP, nor rats ventilated with high tidal volumes without PEEP. Ventilation augments pulmonary complement activation in a rat model of S. pneumoniae pneumonia. Systemic administration of C1-INH, however, does not attenuate ventilation-induced complement activation, lung inflammation, and lung injury.

  15. Toll-like receptor 4 agonistic antibody promotes innate immunity against severe pneumonia induced by coinfection with influenza virus and Streptococcus pneumoniae.

    Tanaka, Akitaka; Nakamura, Shigeki; Seki, Masafumi; Fukudome, Kenji; Iwanaga, Naoki; Imamura, Yoshifumi; Miyazaki, Taiga; Izumikawa, Koichi; Kakeya, Hiroshi; Yanagihara, Katsunori; Kohno, Shigeru

    2013-07-01

    Coinfection with bacteria is a major cause of mortality during influenza epidemics. Recently, Toll-like receptor (TLR) agonists were shown to have immunomodulatory functions. In the present study, we investigated the effectiveness and mechanisms of the new TLR4 agonistic monoclonal antibody UT12 against secondary pneumococcal pneumonia induced by coinfection with influenza virus in a mouse model. Mice were intranasally inoculated with Streptococcus pneumoniae 2 days after influenza virus inoculation. UT12 was intraperitoneally administered 2 h before each inoculation. Survival rates were significantly increased and body weight loss was significantly decreased by UT12 administration. Additionally, the production of inflammatory mediators was significantly suppressed by the administration of UT12. In a histopathological study, pneumonia in UT12-treated mice was very mild compared to that in control mice. UT12 increased antimicrobial defense through the acceleration of macrophage recruitment into the lower respiratory tract induced by c-Jun N-terminal kinase (JNK) and nuclear factor kappaB (NF-κB) pathway-dependent monocyte chemoattractant protein 1 (MCP-1) production. Collectively, these findings indicate that UT12 promoted pulmonary innate immunity and may reduce the severity of severe pneumonia induced by coinfection with influenza virus and S. pneumoniae. This immunomodulatory effect of UT12 improves the prognosis of secondary pneumococcal pneumonia and makes UT12 an attractive candidate for treating severe infectious diseases.

  16. Sensitivity and specificity of the Streptococcus pneumoniae urinary antigen test for unconcentrated urine from adult patients with pneumonia: a meta-analysis.

    Horita, Nobuyuki; Miyazawa, Naoki; Kojima, Ryota; Kimura, Naoko; Inoue, Miyo; Ishigatsubo, Yoshiaki; Kaneko, Takeshi

    2013-11-01

    Studies on the sensitivity and specificity of the Binax Now Streptococcus pneumonia urinary antigen test (index test) show considerable variance of results. Those written in English provided sufficient original data to evaluate the sensitivity and specificity of the index test using unconcentrated urine to identify S. pneumoniae infection in adults with pneumonia. Reference tests were conducted with at least one culture and/or smear. We estimated sensitivity and two specificities. One was the specificity evaluated using only patients with pneumonia of identified other aetiologies ('specificity (other)'). The other was the specificity evaluated based on both patients with pneumonia of unknown aetiology and those with pneumonia of other aetiologies ('specificity (unknown and other)') using a fixed model for meta-analysis. We found 10 articles involving 2315 patients. The analysis of 10 studies involving 399 patients yielded a pooled sensitivity of 0.75 (95% confidence interval: 0.71-0.79) without heterogeneity or publication bias. The analysis of six studies involving 258 patients yielded a pooled specificity (other) of 0.95 (95% confidence interval: 0.92-0.98) without no heterogeneity or publication bias. We attempted to conduct a meta-analysis with the 10 studies involving 1916 patients to estimate specificity (unknown and other), but it remained unclear due to moderate heterogeneity and possible publication bias. In our meta-analysis, sensitivity of the index test was moderate and specificity (other) was high; however, the specificity (unknown and other) remained unclear.

  17. Heteroduplex DNA mismatch repair system of Streptococcus pneumoniae: cloning and expression of the hexA gene.

    Balganesh, T S; Lacks, S A

    1985-01-01

    Mutations affecting heteroduplex DNA mismatch repair in Streptococcus pneumoniae were localized in two genes, hexA and hexB, by fractionation of restriction fragments carrying mutant alleles. A fragment containing the hexA4 allele was cloned in the S. pneumoniae cloning system, and the hexA+ allele was introduced into the recombinant plasmid by chromosomal facilitation of plasmid transfer. Subcloning localized the functional hexA gene to a 3.5-kilobase segment of the cloned pneumococcal DNA. ...

  18. Using the synergism strategy for highly sensitive and specific electrochemical sensing of Streptococcus pneumoniae Lyt-1 gene sequence.

    Li, Fengqin; Yu, Zhigang; Xu, Yanmei; Ma, Huiyuan; Zhang, Guiling; Song, Yongbin; Yan, Hong; He, Xunjun

    2015-07-30

    With the help of the interaction mode of capture probe-target-signal probe (CP-T-SP), an electrochemical sensing method based on the synergism strategy of dual-hybridized signaling probes modified with 6 MB (methylene blue), background suppression and large surface area Au electrode is developed for the detection of Streptococcus pneumoniae (S. pneumoniae) Lyt-1 gene sequence. The proposed sensor features a very low detection limit (LOD) of ∼0.5 fM for the target. This method also exhibits highly versatility and can apply to the construction of other sensors for the analysis of similar designated pathogenic bacteria gene sequence (PBGS).

  19. Contribución al estudio de los mecanismos moleculares de la resistencia a ciprofloxacina en "Streptococcus pneumoniae"

    Martínez Garriga, Blanca

    2005-01-01

    "Streptococcus pneumoniae", también llamado neumococo, es una bacteria Gram positiva caracterizada por la severidad de las infecciones que produce en la especie humana, siendo responsable de una elevada morbilidad y letalidad, especialmente en niños y ancianos, colectivos particularmente sensibles a sus consecuencias. La emergencia de cepas de S. pneumoniae resistentes a antibióticos como la penicilina y otros beta-lactámicos, comúnmente utilizados en el tratamiento de las infecciones neumocó...

  20. Caracterización molecular de aislamientos invasores de Streptococcus pneumoniae resistentes a la penicilina recuperados de pacientes adultos

    Jaime Moreno; Elizabeth Castañeda

    2003-01-01

    La resistencia de Streptococcus pneumoniae a la penicilina está asociada con la dispersión deciertos clones internacionales. En Colombia, se ha establecido en la población infantil la presenciay circulación de los clones 1-España23F, 2-España6B, 3-España9V y 25-Colombia23F. El objetivode este trabajo fue evaluar las relaciones clonales entre 80 aislamientos invasores de S.pneumoniae con susceptibilidad disminuida a la penicilina recuperados de pacientes adultos.El análisis genotípico incluyó ...

  1. Efficacy of ceftaroline fosamil against penicillin-sensitive and -resistant streptococcus pneumoniae in an experimental rabbit meningitis model.

    Cottagnoud, P; Cottagnoud, M; Acosta, F; Stucki, A

    2013-10-01

    Ceftaroline is a new cephalosporin with bactericidal activity against resistant Gram-positive organisms, including methicillin-resistant Staphylococcus aureus (MRSA) and penicillin-resistant Streptococcus pneumoniae, as well as common Gram-negative organisms. This study tested the prodrug, ceftaroline fosamil, against a penicillin-sensitive and a penicillin-resistant strain of S. pneumoniae in an experimental rabbit meningitis model. The penetration of ceftaroline into inflamed meninges was approximately 14%. Ceftaroline fosamil was slightly superior to ceftriaxone against the penicillin-sensitive strain and significantly superior to the combination of ceftriaxone and vancomycin against the penicillin-resistant strain.

  2. Surveillance of bacterial resistance in Streptococcus pneumoniae%肺炎链球菌的耐药性监测

    张泓

    2011-01-01

    As the prevalence of resistant Streptococcus pneumoniae has been increased significantly, understanding the characteristic of resistant strains and applying surveillance for them are helpful to guide clinical therapy and control the prevalence of resistant strains. This review describes Streptococcus pneumoniae resistance, resistance mechanism and their clinical surveillance.%肺炎链球菌耐药率不断上升,监测其耐药性并掌握耐药特征,有助于指导临床合理选药及控制肺炎链球菌耐药株流行.本文综述肺炎链球菌的耐药现状、相关机制及监测方法.

  3. Comparative in vitro activities of several new fluoroquinolones and beta-lactam antimicrobial agents against community isolates of Streptococcus pneumoniae.

    Mazzulli, T.; Simor, A E; Jaeger, R.; Fuller, S; Low, D E

    1990-01-01

    The in vitro susceptibilities of 551 community isolates of Streptococcus pneumoniae from the Canadian province of Ontario to several new fluoroquinolones and beta-lactam antimicrobial agents were determined by a broth microdilution technique. Eight (1.5%) of these isolates were moderately susceptible (MICs, greater than or equal to 0.12 and less than or equal to 1.0 microgram/ml) to penicillin; none was resistant. Temafloxacin, ciprofloxacin, and ofloxacin (MICs for 90% of strains tested, bet...

  4. Induction of prophages by fluoroquinolones in streptococcus pneumoniae: implications for emergence of resistance in genetically-related clones

    Elena López; Arnau Domenech; María-José Ferrándiz; Maria João Frias; Carmen Ardanuy; Mario Ramirez; Ernesto García; Josefina Liñares; de la Campa, Adela G.

    2014-01-01

    Antibiotic resistance in Streptococcus pneumoniae has increased worldwide by the spread of a few clones. Fluoroquinolone resistance occurs mainly by alteration of their intracellular targets, the type II DNA topoisomerases, which is acquired either by point mutation or by recombination. Increase in fluoroquinolone-resistance may depend on the balance between antibiotic consumption and the cost that resistance imposes to bacterial fitness. In addition, pneumococcal prophages could play an impo...

  5. Mismatch repair genes of Streptococcus pneumoniae: HexA confers a mutator phenotype in Escherichia coli by negative complementation.

    Prudhomme, M; Méjean, V; Martin, B; Claverys, J P

    1991-01-01

    DNA repair systems able to correct base pair mismatches within newly replicated DNA or within heteroduplex molecules produced during recombination are widespread among living organisms. Evidence that such generalized mismatch repair systems evolved from a common ancestor is particularly strong for two of them, the Hex system of the gram-positive Streptococcus pneumoniae and the Mut system of the gram-negative Escherichia coli and Salmonella typhimurium. The homology existing between HexA and ...

  6. Inhibition of Streptococcus pneumoniae penicillin-binding protein 2x and Actinomadura R39 DD-peptidase activities by ceftaroline.

    Zervosen, Astrid; Zapun, André; Frère, Jean-Marie

    2013-01-01

    Although the rate of acylation of a penicillin-resistant form of Streptococcus pneumoniae penicillin-binding protein 2x (PBP2x) by ceftaroline is 80-fold lower than that of its penicillin-sensitive counterpart, it remains sufficiently high (k(2)/K = 12,600 M(-1) s(-1)) to explain the sensitivity of the penicillin-resistant strain to this new cephalosporin. Surprisingly, the Actinomadura R39 DD-peptidase is not very sensitive to ceftaroline.

  7. Differential Regulation of Protein- and Polysaccharide-Specific Ig Isotype Production In Vivo in Response to Intact Streptococcus pneumoniae

    2006-01-01

    whether DCs played a role in either or both of these responses. We first demonstrated that immature bone marrow-derived myeloid dendritic cells ( BmDC ...1640 E-mail: csnapper@usuhs.mil Keywords: Streptococcus pneumoniae, immunoglobulin isotypes, murine, T cells , dendritic cells , cytokines, Toll...polysaccharide; PC, phosphorylcholine; PspA, pneumococcal surface protein A; DC, dendritic cell ; TLR, Toll-like receptor; TI, T cell -independent

  8. Prevalence of Streptococcus Pneumoniae, Haemophilus Influenzae and Moraxella Catarrhalis in Adenoid Tissues of Children with Adenoid Hypertrophy

    SS Khoramrooz; A. Mirsalehian; Emaneini, M.; A Sharifi; S A Khosravani; Jabalameli, F.; M.Aligholi; D Darban-Sarokhalil; M Mirzaii; A Bazargani

    2012-01-01

    Background & aim: Chronic infection of the adenoid tissue is one of the causes of hypertrophy. Adenoids are considered to be as reservoirs of pathogenic bacteria such as Streptococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenzae. The aim of this study was to determine the prevalence of mentioned bacteria in children with adenoid hypertrophy. Methods: A total of 113 children with adenoid hypertrophy who underwent adenoidectomy were included in this study. Subsequently, ad...

  9. Serotype/serogroup-specific antibiotic non-susceptibility of invasive and non-invasive Streptococcus pneumoniae, Switzerland, 2004 to 2014.

    Hauser, Christoph; Kronenberg, Andreas; Allemann, Aurélie; Mühlemann, Kathrin; Hilty, Markus

    2016-05-26

    Concurrent analysis of antibiotic resistance of colonising and invasive Streptococcus pneumoniae gives a more accurate picture than looking at either of them separately. Therefore, we analysed 2,129 non-invasive and 10,996 invasive pneumococcal isolates from Switzerland from 2004 to 2014, which spans the time before and after the introduction of the heptavalent (PCV7) and 13-valent (PCV13) conjugated pneumococcal polysaccharide vaccines. Serotype/serogroup information was linked with all antibiotic resistance profiles. During the study period, the proportion of non-susceptible non-invasive and invasive isolates significantly decreased for penicillin, ceftriaxone, erythromycin and trimethoprim/sulfamethoxazole (TMP-SMX). This was most apparent in non-invasive isolates from study subjects younger than five years (penicillin (p = 0.006), erythromycin (p = 0.01) and TMP-SMX (p = 0.002)). Resistant serotypes/serogroups included in PCV7 and/or PCV13 decreased and were replaced by non-PCV13 serotypes (6C and 15B/C). Serotype/serogroup-specific antibiotic resistance rates were comparable between invasive and non-invasive isolates. Adjusted odds ratios of serotype/serogroup-specific penicillin resistance were significantly higher in the west of Switzerland for serotype 6B (1.8; 95% confidence interval (CI): 1.4-4.8), 9V (3.4; 95% CI: 2.0-5.7), 14 (5.3; 95% CI: 3.8-7.5), 19A (2.2; 95% CI: 1.6-3.1) and 19F (3.1; 95% CI: 2.1-4.6), probably due to variations in the antibiotic consumption.

  10. Telithromycin resistance in Streptococcus pneumoniae is conferred by a deletion in the leader sequence of erm(B) that increases rRNA methylation

    Wolter, Nicole; Smith, Anthony M; Farrell, David J

    2008-01-01

    A telithromycin-resistant clinical isolate of Streptococcus pneumoniae (strain P1501016) has been found to contain a version of erm(B) that is altered by a 136-bp deletion in the leader sequence. By allele replacement mutagenesis, a second strain of S. pneumoniae (PC13) with a wild-type erm(B) gene...

  11. Antimicrobial activity of innate immune molecules against Streptococcus pneumoniae, Moraxella catarrhalis and nontypeable Haemophilus influenzae

    Teufert Karen

    2004-05-01

    Full Text Available Abstract Background Despite its direct connection to the nasopharynx which harbors otitis media pathogens as part of its normal flora, the middle ear cavity is kept free of these bacteria by as yet unknown mechanisms. Respiratory mucosal epithelia, including those of the middle ear and eustachian tube, secrete antimicrobial effectors including lysozyme, lactoferrin and β defensins-1 and -2. To elucidate the role of these innate immune molecules in the normal defense and maintenance of sterility of respiratory mucosa such as that of the middle ear, we assessed their effect on the respiratory pathogens nontypeable Haemophilus influenzae (NTHi 12, Moraxella catarrhalis 035E, and Streptococcus pneumoniae 3, and 6B. Methods Two assay methods, the radial assay and the liquid broth assay, were employed for testing the antimicrobial activity of the molecules. This was done in order to minimize the possibility that the observed effects were artifacts of any single assay system employed. Also, transmission electron microscopy (TEM was employed to evaluate the effect of antimicrobial innate immune molecules on OM pathogens. For the statistical analysis of the data, Student's t-test was performed. Results Results of the radial diffusion assay showed that β defensin-2 was active against all four OM pathogens tested, while treatment with β defensin-1 appeared to only affect M. catarrhalis. The radial assay results also showed that lysozyme was quite effective against S. pneumoniae 3 and 6B and was partially bacteriostatic/bactericidal against M. catarrhalis. Lysozyme however, appeared not to affect the growth of NTHi. Thus, lysozyme seems to have a more pronounced impact on the growth of the Gram-positive S. pneumoniae as compared to that of Gram-negative pathogens. Lactoferrin on the other hand, enhanced the growth of the bacteria tested. The results of the radial assays were confirmed using liquid broth assays for antimicrobial activity, and showed that

  12. Serotype Distribution, Antibiotic Resistance and Clonality of Streptococcus pneumoniae Isolated from Immunocompromised Patients in Tunisia.

    Anis Raddaoui

    Full Text Available Pneumococcal disease, a major cause of morbidity and mortality globally, has higher incidence among young children, the elderly and the immunocompromised of all ages. In Tunisia, pneumococcal conjugate vaccines (PCVs are not included in the national immunization program. Also, few studies have described the epidemiology of S. pneumoniae in this country and, in particular, no molecular typing studies have been performed. The aim of this study was to evaluate serotype distribution, antimicrobial resistance and clonality of Streptococcus pneumoniae isolated from neutropenic patients in Tunisia.Fifty-nine S. pneumoniae were isolated from infection (n = 31 and colonization (n = 28 sites of patients (children and adults attending the National Centre of Bone Marrow Transplantation in Tunis between 2005-2011. All isolates were characterized by serotype, antimicrobial resistance pattern and multilocus sequence typing (MLST.The majority (66.1% of the isolates belonged to five serotypes all included in PCVs: 6B, 9V, 14, 19F and 23F. The potential coverage of the 10-valent and 13-valent PCV was of 71.2% and 76.3% respectively. Resistance rates were very high and 69.5% of the isolates were multidrug resistant: non-susceptibility rates to penicillin, amoxicillin and cefotaxime were 66.1%, 40.7% and 27.1%, respectively; resistance rates to erythromycin, clindamycin, tetracycline, chloramphenicol and trimethoprim-sulfamethoxazole, were 69.5%, 61.0%, 37.3%, 22.0% and 67.8%, respectively. The most frequent serotypes had STs characteristic of multidrug resistant international clones known to be highly successful and important causes of pneumococcal infection: Spain 23F-ST81, France 9V/14-ST156, Spain 6B-ST90, 19F-ST320, and Portugal 19F-ST177.The majority of S. pneumoniae strains recovered from immunocompromised patients in Tunisia are representatives of multidrug resistant pandemic clones that express serotypes targeted by PCVs. To contain the burden of

  13. Nasopharyngeal carriage, antibiogram & serotype distribution of Streptococcus pneumoniae among healthy under five children

    K.L. Ravi Kumar

    2014-01-01

    Full Text Available Background & objectives: Information related to nasopharyngeal carriage of Streptococcus pneumoniae among healthy children is scanty in India. This prospective study was undertaken to determine the presence of asymptomatic nasopharyngeal colonization, assess serogroups/types (SGT and drug resistance of S. pneumoniae in children below five years of age. Methods: A total of 109 male and 81 female children in the age group of three months to five years belonging to different socio-economic classes were enrolled. They were recruited across all age groups from those attending paediatric OPD of a tertiary care and research centre for immunization program. Fifty three isolates identified as pneumococci were tested for their antimicrobial susceptibility pattern by Kirby-Bauer′s disc diffusion and E-Test methods. Serotyping was performed by detection of the quelling reaction with specific antiserum. Result: The pneumococcal carriage rate in the study population was 27.9 per cent. The isolation rate was associated with age being higher (49.2% in smaller children (3-12 months and among male (62.2%. The most prevalent SGTs were 19 followed by 10, 14 and 7; 21 per cent of isolates belonging to serotype 10 (n=7 were 11 (n=4 were not covered in any of the conjugate vaccines currently available in Indian market. Resistance to co-trimoxazole, tetracycline, penicillin and erythromycin was observed in 91 per cent (n=48, 36 per cent (n=19, 17 per cent (n=9 and 9 per cent (n=5 isolates, respectively. All the penicillin resistant isolates were found to be intermediately resistant by E-Test. Multidrug resistance was observed in 19 per cent (n=10 isolates. Interpretation & conclusions: High level of antibiotic resistance was present in S. pneumoniae isolated from healthy children below age five. A pneumococcal conjugate vaccine with the prevailing SGTs would help to reduce the pool of antibiotic resistant pneumococci. Continued surveillance of serotypes and tracking

  14. Post-infective transverse myelitis following Streptococcus pneumoniae meningitis with radiological features of acute disseminated encephalomyelitis: a case report

    Williams Thomas

    2012-09-01

    Full Text Available Abstract Introduction Post-infectious autoimmune demyelination of the central nervous system is a rare neurological disorder typically associated with exanthematous viral infections. We report an unusual presentation of the condition and a previously undocumented association with Streptococcus pneumonia meningitis. Case presentation A 50-year-old Caucasian woman presented to our facility with an acute myelopathy three days after discharge following acute Streptococcus pneumoniae meningitis. Imaging studies of the spine ruled out an infective focus and no other lesions were seen within the cord. Diffuse, bilateral white matter lesions were seen within the cerebral hemispheres, and our patient was diagnosed as having a post-infective demyelination syndrome that met the diagnostic criteria for an acute transverse myelitis. Our patient clinically and radiologically improved following treatment with steroids. Conclusions The novel association of a Streptococcus pneumoniae infection with post-infectious autoimmune central nervous system demyelination should alert the reader to the potentially causative role of this common organism, and gives insights into the pathogenesis. The unusual dissociation between the clinical presentation and the location of the radiological lesions should also highlight the potential for the condition to mimic the presentation of others, and stimulates debate on the definitions of acute transverse myelitis and acute disseminated encephalomyelitis, and their potential overlap.

  15. Carriage of Streptococcus pneumoniae and other respiratory bacterial pathogens in low and lower-middle income countries: a systematic review and meta-analysis.

    Richard A Adegbola

    Full Text Available BACKGROUND: Infection with Streptococcus pneumoniae is a major cause of childhood morbidity and mortality worldwide, especially in low income countries where pneumococcal conjugate vaccines (PCVs are still underused. In countries where PCVs have been introduced, much of their efficacy has resulted from their impact on nasopharyngeal carriage in vaccinated children. Understanding the epidemiology of carriage for S. pneumoniae and other common respiratory bacteria in developing countries is crucial for implementing appropriate vaccination strategies and evaluating their impact. METHODS AND FINDINGS: We have systematically reviewed published studies reporting nasopharyngeal or oropharyngeal carriage of S. pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, and Neisseria meningitidis in children and adults in low and lower-middle income countries. Studies reporting pneumococcal carriage for healthy children <5 years of age were selected for a meta-analysis. The prevalences of carriage for S. pneumoniae, H. influenzae, and M. catarrhalis were generally higher in low income than in lower-middle income countries and were higher in young children than in adults. The prevalence of S. aureus was high in neonates. Meta-analysis of data from young children before the introduction of PCVs showed a pooled prevalence estimate of 64.8% (95% confidence interval, 49.8%-76.1% in low income countries and 47.8% (95% confidence interval, 44.7%-50.8% in lower-middle income countries. The most frequent serotypes were 6A, 6B, 19A, 19F, and 23F. CONCLUSIONS: In low and lower-middle income countries, pneumococcal carriage is frequent, especially in children, and the spectrum of serotypes is wide. However, because data are limited, additional studies are needed to adequately assess the impact of PCV introduction on carriage of respiratory bacteria in these countries.

  16. Immunization with LytB protein of Streptococcus pneumoniae activates complement-mediated phagocytosis and induces protection against pneumonia and sepsis.

    Corsini, Bruno; Aguinagalde, Leire; Ruiz, Susana; Domenech, Mirian; Antequera, María Luisa; Fenoll, Asunción; García, Pedro; García, Ernesto; Yuste, Jose

    2016-12-07

    The cell wall glucosaminidase LytB of Streptococcus pneumoniae is a surface exposed protein involved in daughter cell separation, biofilm formation and contributes to different aspects of the pathogenesis process. In this study we have characterized the antibody responses after immunization of mice with LytB in the presence of alhydrogel as an adjuvant. Enzyme-linked immunosorbent assays measuring different subclasses of immunoglobulin G, demonstrated that the antibody responses to LytB were predominantly IgG1 and IgG2b, followed by IgG3 and IgG2a subclasses. Complement-mediated immunity against two different pneumococcal serotypes was investigated using sera from immunized mice. Immunization with LytB increased the recognition of S. pneumoniae by complement components C1q and C3b demonstrating that anti-LytB antibodies trigger activation of the classical pathway. Phagocytosis assays showed that serum containing antibodies to LytB stimulates neutrophil-mediated phagocytosis against S. pneumoniae. Animal models of infection including invasive pneumonia and sepsis were performed with two different clinical isolates. Vaccination with LytB increased bacterial clearance and induced protection demonstrating that LytB might be a good candidate to be considered in a future protein-based vaccine against S. pneumoniae.

  17. Validation of an immunodiagnostic assay for detection of 13 Streptococcus pneumoniae serotype-specific polysaccharides in human urine.

    Pride, Michael W; Huijts, Susanne M; Wu, Kangjian; Souza, Victor; Passador, Sherry; Tinder, Chunyan; Song, Esther; Elfassy, Arik; McNeil, Lisa; Menton, Ronald; French, Roger; Callahan, Janice; Webber, Chris; Gruber, William C; Bonten, Marc J M; Jansen, Kathrin U

    2012-08-01

    To improve the clinical diagnosis of pneumococcal infection in bacteremic and nonbacteremic community-acquired pneumonia (CAP), a Luminex technology-based multiplex urinary antigen detection (UAD) diagnostic assay was developed and validated. The UAD assay can simultaneously detect 13 different serotypes of Streptococcus pneumoniae by capturing serotype-specific S. pneumoniae polysaccharides (PnPSs) secreted in human urine. Assay specificity is achieved by capturing the polysaccharides with serotype-specific monoclonal antibodies (MAbs) on spectrally unique microspheres. Positivity for each serotype was based on positivity cutoff values calculated from a standard curve run on each assay plate together with positive- and negative-control urine samples. The assay is highly specific, since significant signals are detected only when each PnPS was paired with its homologous MAb-coated microspheres. Validation experiments demonstrated excellent accuracy and precision. The UAD assay and corresponding positivity cutoff values were clinically validated by assessing 776 urine specimens obtained from patients with X-ray-confirmed CAP. The UAD assay demonstrated 97% sensitivity and 100% specificity using samples obtained from patients with bacteremic, blood culture-positive CAP. Importantly, the UAD assay identified Streptococcus pneumoniae (13 serotypes) in a proportion of individuals with nonbacteremic CAP, a patient population for which the pneumococcal etiology of CAP was previously difficult to assess. Therefore, the UAD assay provides a specific, noninvasive, sensitive, and reproducible tool to support vaccine efficacy as well as epidemiological evaluation of pneumococcal disease, including CAP, in adults.

  18. A complex of equine lysozyme and oleic acid with bactericidal activity against Streptococcus pneumoniae.

    Clementi, Emily A; Wilhelm, Kristina R; Schleucher, Jürgen; Morozova-Roche, Ludmilla A; Hakansson, Anders P

    2013-01-01

    HAMLET and ELOA are complexes consisting of oleic acid and two homologous, yet functionally different, proteins with cytotoxic activities against mammalian cells, with HAMLET showing higher tumor cells specificity, possibly due to the difference in propensity for oleic acid binding, as HAMLET binds 5-8 oleic acid molecules per protein molecule and ELOA binds 11-48 oleic acids. HAMLET has been shown to possess bactericidal activity against a number of bacterial species, particularly those with a respiratory tropism, with Streptococcus pneumoniae displaying the greatest degree of sensitivity. We show here that ELOA also displays bactericidal activity against pneumococci, which at lower concentrations shows mechanistic similarities to HAMLET's bactericidal activity. ELOA binds to S. pneumoniae and causes perturbations of the plasma membrane, including depolarization and subsequent rupture, and activates an influx of calcium into the cells. Selective inhibition of calcium channels and sodium/calcium exchange activity significantly diminished ELOA's bactericidal activity, similar to what we have observed with HAMLET. Finally, ELOA-induced death was also accompanied by DNA fragmentation into high molecular weight fragments - an apoptosis-like morphological phenotype that is seen during HAMLET-induced death. Thus, in contrast to different mechanisms of eukaryote cell death induced by ELOA and HAMLET, these complexes are characterized by rather similar activities towards bacteria. Although the majority of these events could be mimicked using oleic acid alone, the concentrations of oleic acid required were significantly higher than those present in the ELOA complex, and for some assays, the results were not identical between oleic acid alone and the ELOA complex. This indicates that the lipid, as a common denominator in both complexes, is an important component for the complexes' bactericidal activities, while the proteins are required both to solubilize and/or present the

  19. Serotype distribution of Streptococcus pneumoniae in children with invasive diseases in Turkey: 2008–2014

    Ceyhan, Mehmet; Ozsurekci, Yasemin; Gürler, Nezahat; Öksüz, Lütfiye; Aydemir, Sohret; Ozkan, Sengul; Yuksekkaya, Serife; Keser Emiroglu, Melike; Gültekin, Meral; Yaman, Akgün; Kiremitci, Abdurrahman; Yanık, Keramettin; Karli, Arzu; Ozcinar, Hatice; Aydin, Faruk; Bayramoglu, Gulcin; Zer, Yasemin; Gulay, Zeynep; Gayyurhan, Efgan Dogan; Gül, Mustafa; Özakın, Cüneyt; Güdücüoğlu, Hüseyin; Perçin, Duygu; Akpolat, Nezahat; Ozturk, Candan; Camcıoğlu, Yıldız; Karadağ Öncel, Eda; Çelik, Melda; Şanal, Laser; Uslu, Hakan

    2016-01-01

    Successful vaccination policies for protection from invasive pneumococcal diseases (IPD) dependent on determination of the exact serotype distribution in each country. We aimed to identify serotypes of pneumococcal strains causing IPD in children in Turkey and emphasize the change in the serotypes before and after vaccination with 7-valent pneumococcal conjugate vaccine (PCV-7) was included and PCV-13 was newly changed in Turkish National Immunization Program. Streptococcus pneumoniae strains were isolated at 22 different hospitals of Turkey, which provide healthcare services to approximately 65% of the Turkish population. Of the 335 diagnosed cases with S. pneumoniae over the whole period of 2008–2014, the most common vaccine serotypes were 19F (15.8%), 6B (5.9%), 14 (5.9%), and 3 (5.9%). During the first 5 y of age, which is the target population for vaccination, the potential serotype coverage ranged from 57.5 % to 36.8%, from 65.0% to 44.7%, and from 77.4% to 60.5% for PCV-7, PCV-10, and PCV-13 in 2008–2014, respectively. The ratio of non-vaccine serotypes was 27.2% in 2008–2010 whereas was 37.6% in 2011–2014 (p=0.045). S. penumoniae serotypes was less non-susceptible to penicillin as compared to our previous results (33.7 vs 16.5 %, p=0.001). The reduction of those serotype coverage in years may be attributed to increasing vaccinated children in Turkey and the increasing non-vaccine serotype may be explained by serotype replacement. Our ongoing IPD surveillance is a significant source of information for the decision-making processes on pneumococcal vaccination. PMID:26325175

  20. Characterization of the CDP-D-mannitol biosynthetic pathway in Streptococcus pneumoniae 35A.

    Wang, Quan; Xu, Yanli; Perepelov, Andrei V; Knirel, Yuriy A; Reeves, Peter R; Shashkov, Alexander S; Ding, Peng; Guo, Xi; Feng, Lu

    2012-12-01

    Streptococcus pneumoniae is a major human pathogen associated with diseases worldwide. The capsular polysaccharides (CPSs) are considered a major virulence factor and are targets for a vaccine. d-Mannitol was found to be present in the CPS of several S. pneumoniae serotypes. Two genes, mnp1 and mnp2, which are located in the CPS gene cluster, were proposed to be responsible for the synthesis of NDP-d-mannitol (the nucleotide activated form of d-mannitol). However, the pathway has never been identified by experimental methods and we aimed to characterize it in the present study. To achieve this, the two genes, mnp1 and mnp2, were cloned and the gene products were overexpressed, purified, and analyzed in vitro for their respective enzymatic activities. Products of reactions catalyzed by Mnp1 and Mnp2 were detected by capillary electrophoresis and validated using electrospray ionization mass spectrometry and nuclear magnetic resonance spectroscopy. We show that Mnp1 is responsible for the transfer of CMP from CTP to d-fructose-6-phosphate (Fru-6-P) to form CDP-d-fructose, whereas Mnp2 catalyzed the conversion of CDP-d-fructose to CDP-d-mannitol. Therefore, Mnp1 (renamed as mnpA) was identified as Fru-6-P cytidylyltransferase-encoding gene, and mnp2 (renamed as mnpB) as a CDP-d-fructose reductase-encoding gene. The kinetics of Mnp1 for the substrate (Fru-6-P and CTP) and of Mnp2 for the substrate (CDP-d-fructose) and the cofactor NADH or NADPH fitted the Michaelis-Menten model. The effects of temperature, pH and cations on the two enzymes were analyzed. This is the first time that the biosynthetic pathway of CDP-d-mannitol has been identified biochemically.

  1. A complex of equine lysozyme and oleic acid with bactericidal activity against Streptococcus pneumoniae.

    Emily A Clementi

    Full Text Available HAMLET and ELOA are complexes consisting of oleic acid and two homologous, yet functionally different, proteins with cytotoxic activities against mammalian cells, with HAMLET showing higher tumor cells specificity, possibly due to the difference in propensity for oleic acid binding, as HAMLET binds 5-8 oleic acid molecules per protein molecule and ELOA binds 11-48 oleic acids. HAMLET has been shown to possess bactericidal activity against a number of bacterial species, particularly those with a respiratory tropism, with Streptococcus pneumoniae displaying the greatest degree of sensitivity. We show here that ELOA also displays bactericidal activity against pneumococci, which at lower concentrations shows mechanistic similarities to HAMLET's bactericidal activity. ELOA binds to S. pneumoniae and causes perturbations of the plasma membrane, including depolarization and subsequent rupture, and activates an influx of calcium into the cells. Selective inhibition of calcium channels and sodium/calcium exchange activity significantly diminished ELOA's bactericidal activity, similar to what we have observed with HAMLET. Finally, ELOA-induced death was also accompanied by DNA fragmentation into high molecular weight fragments - an apoptosis-like morphological phenotype that is seen during HAMLET-induced death. Thus, in contrast to different mechanisms of eukaryote cell death induced by ELOA and HAMLET, these complexes are characterized by rather similar activities towards bacteria. Although the majority of these events could be mimicked using oleic acid alone, the concentrations of oleic acid required were significantly higher than those present in the ELOA complex, and for some assays, the results were not identical between oleic acid alone and the ELOA complex. This indicates that the lipid, as a common denominator in both complexes, is an important component for the complexes' bactericidal activities, while the proteins are required both to solubilize

  2. Invasive isolates of Streptococcus pneumoniae in Serbia: Antimicrobial susceptibility and serotypes

    Gajić Ina

    2013-01-01

    Full Text Available Introduction. Streptococcus pneumoniae is one of the leading causes of bacterial meningitis and sepsis. Invasive pneumococcal disease is a significant medical problem worldwide, particularly in children, due to a huge increase of pneumococcal resistance to antibiotics. Objective. The aim of the study was to investigate the antimicrobial susceptibility pattern of invasive pneumococcal isolates, as well as to determine whether decreased S. pneumoniae susceptibility to antibiotics was related to a particular serotype. Methods. Antimicrobial susceptibility to 19 antibiotics was determined in 58 invasive pneumococcal strains that were collected from seven regional centers during the period July 2009 to February 2011 in the National Reference Laboratory for streptococci and pneumococci. Results. The overall nonsusceptibility rate to penicillin was detected in 34% of pneumococcal isolates and to erythromycin in 36%. Higher resistance rates were observed among children than among adults. Penicillin resistance rate was 65% in children versus 22% in adults, while erythromycin nonsusceptibility rate was 47% in children versus 32% in adults. Co-resistance to penicillin and erythromycin was detected in 21% strains, mostly isolated from children. Multiresistance was found in one third of isolates. All strains were susceptible to vancomycin, linezolid, fluoroquinolones, telithromycin and rifampicin, while 23 (40% isolates were susceptible to all tested antibiotics. The most common resistant serotypes were 19F and 14. Conclusion. The study has revealed that penicillin and macrolide resistance among invasive pneumococcal isolates is very high in Serbia. This emphasizes the need for continuous monitoring for invasive pneumococcal disease to document the serotype distribution and antimicrobial susceptibility pattern. [Projekat Ministarstva nauke Republike Srbije, br. 175039: Bakterije rezistentne na antibiotike u Srbiji - fenotipska i genotipska karakterizacija

  3. Reactive Oxygen Species Contribute to the Bactericidal Effects of the Fluoroquinolone Moxifloxacin in Streptococcus pneumoniae.

    Ferrándiz, M J; Martín-Galiano, A J; Arnanz, C; Zimmerman, T; de la Campa, A G

    2015-11-02

    We studied the transcriptomic response of Streptococcus pneumoniae to the fluoroquinolone moxifloxacin at a concentration that inhibits DNA gyrase. Treatment of the wild-type strain R6, at a concentration of 10× the MIC, triggered a response involving 132 genes after 30 min of treatment. Genes from several metabolic pathways involved in the production of pyruvate were upregulated. These included 3 glycolytic enzymes, which ultimately convert fructose 6-phosphate to pyruvate, and 2 enzymes that funnel phosphate sugars into the glycolytic pathway. In addition, acetyl coenzyme A (acetyl-CoA) carboxylase was downregulated, likely leading to an increase in acetyl-CoA. When coupled with an upregulation in formate acetyltransferase, an increase in acetyl-CoA would raise the production of pyruvate. Since pyruvate is converted by pyruvate oxidase (SpxB) into hydrogen peroxide (H2O2), an increase in pyruvate would augment intracellular H2O2. Here, we confirm a 21-fold increase in the production of H2O2 and a 55-fold increase in the amount of hydroxyl radical in cultures treated during 4 h with moxifloxacin. This increase in hydroxyl radical through the Fenton reaction would damage DNA, lipids, and proteins. These reactive oxygen species contributed to the lethality of the drug, a conclusion supported by the observed protective effects of an SpxB deletion. These results support the model whereby fluoroquinolones cause redox alterations. The transcriptional response of S. pneumoniae to moxifloxacin is compared with the response to levofloxacin, an inhibitor of topoisomerase IV. Levofloxacin triggers the transcriptional activation of iron transport genes and also enhances the Fenton reaction.

  4. Antibiotic innovation may contribute to slowing the dissemination of multiresistant Streptococcus pneumoniae: the example of ketolides.

    Lulla Opatowski

    Full Text Available BACKGROUND: Despite increasingly frequent bacterial resistance to antibiotics, antibacterial innovation is rare. Ketolides constitute one of the very few new antibiotic classes active against Streptococcus pneumoniae developed during the last 25 years. Their mechanism of action resembles that of macrolides, but they are unaffected by common resistance mechanisms. However, cross-resistance to ketolides has been observed in some macrolide-resistant strains. We examined how new antibiotic exposure may affect overall pneumococcal resistance patterns in the population. The aims of this study were to assess the potential dissemination of newly emerged resistances and to control the selection of strains already multiresistant to existing antimicrobials. METHODOLOGY/PRINCIPAL FINDINGS: We developed an age-structured population model for S. pneumoniae transmission in a human community exposed to heptavalent vaccine, and beta-lactams, macrolides and ketolides. The dynamics of intra-individual selection of resistant strains under antibiotic exposure and interindividual transmission were simulated, with antibiotic-specific resistance mechanisms defining the path to co-resistances and cross-resistances, and parameters concerning the French situation. Results of this simulation study suggest that new antibiotic consumption could markedly slow the diffusion of multiresistant strains. Wider use was associated with slower progression of multiresistance. When ketolides were prescribed to all ages, resistance to them reached 10% after >15 years, while it took >40 years when they were prescribed only to adults. In the scenario according to which new antibiotics totally replaced former antimicrobials, the beta-lactam resistance rate was limited at 70%. CONCLUSIONS: In a context of widespread vaccination and rational use of antibiotics, innovative antibiotic, prescribed to all age groups, may have an added impact on multiresistant-strain dissemination in the

  5. Characterization of Streptococcus pneumoniae clones from paediatric patients with cystic fibrosis.

    Pimentel de Araujo, Fernanda; D'Ambrosio, Fabio; Camilli, Romina; Fiscarelli, Ersilia; Di Bonaventura, Giovanni; Baldassarri, Lucilla; Visca, Paolo; Pantosti, Annalisa; Gherardi, Giovanni

    2014-12-01

    The role of Streptococcus pneumoniae in cystic fibrosis (CF) is poorly understood. The pneumococcal population has changed over time after the introduction of the heptavalent conjugate vaccine (PCV7) and, more recently, the 13-valent conjugate vaccine (PCV13). Although serotypes and clones causing invasive pneumococcal disease or colonizing healthy children have been extensively analysed, little is known so far on the serotypes and clones of pneumococci in CF patients. The aim of this work was to investigate serotypes, antibiotic susceptibilities, genotypes and biofilm production of CF pneumococcal isolates. Overall, 44 S. pneumoniae strains collected from 32 paediatric CF patients from January 2010 to May 2012 in a large Italian CF Centre were tested for antimicrobial susceptibility testing by Etest, serotyped by the Quellung reaction and genotyped by a combination of different molecular typing methods, including pbp gene restriction profiling, pspA restriction profiling and sequencing, PFGE and multilocus sequence typing. Biofilm production by pneumococcal strains was also assessed. Penicillin non-susceptibility was 16 %. High resistance rates (>56 %) were observed for erythromycin, clindamycin and tetracycline. The most frequent serotype recovered was serotype 3 (31.8 %). The coverage of PCV7 and PCV13 was 6.8 and 47.7 %, respectively. More than 80 % of CF strains belonged to Pneumococcal Molecular Epidemiology Network (PMEN) reference clones, the most common being Netherlands(3)-ST180 (28.2 %), and Greece(21)-30/ST193 (15.4 %). All strains produced biofilm in vitro, although with large variability in biofilm formation efficiency. No correlation was found between biofilm levels and serotype, clone or antibiotic resistance. The high isolation rate of antibiotic-resistant serotype 3 pneumococci from CF patients suggests that PCV13 could increase protection from pneumococcal colonization and infection.

  6. Clinical presentation and prognostic factors of Streptococcus pneumoniae meningitis according to the focus of infection

    Samuelsson Susanne

    2005-10-01

    Full Text Available Abstract Background We conducted a nationwide study in Denmark to identify clinical features and prognostic factors in patients with Streptococcus pneumoniae according to the focus of infection. Methods Based on a nationwide registration, clinical information's was prospectively collected from all reported cases of pneumococcal meningitis during a 2-year period (1999–2000. Clinical and laboratory findings at admission, clinical course and outcome of the disease including follow-up audiological examinations were collected retrospectively. The focus of infection was determined according to the clinical diagnosis made by the physicians and after review of the medical records. Results 187 consecutive cases with S. pneumoniae meningitis were included in the study. The most common focus was ear (30%, followed by lung (18%, sinus (8%, and other (2%. In 42% of cases a primary infection focus could not be determined. On admission, fever and an altered mental status were the most frequent findings (in 93% and 94% of cases, respectively, whereas back rigidity, headache and convulsion were found in 57%, 41% and 11% of cases, respectively. 21% of patients died during hospitalisation (adults: 27% vs. children: 2%, Fisher Exact Test, P P = 0.0005. Prognostic factors associated with fatal outcome in univariate logistic regression analysis were advanced age, presence of an underlying disease, history of headache, presence of a lung focus, absence of an otogenic focus, having a CT-scan prior to lumbar puncture, convulsions, requirement of assisted ventilation, and alterations in various CSF parameters (WBC P P = 0.005. Conclusion These results emphasize the prognostic importance of an early recognition of a predisposing focus to pneumococcal meningitis.

  7. The impact of pneumolysin on the macrophage response to Streptococcus pneumoniae is strain-dependent.

    Richard M Harvey

    Full Text Available Streptococcus pneumoniae is the world's leading cause of pneumonia, bacteremia, meningitis and otitis media. A major pneumococcal virulence factor is the cholesterol-dependent cytolysin, which has the defining property of forming pores in cholesterol-containing membranes. In recent times a clinically significant and internationally successful serotype 1 ST306 clone has been found to express a non-cytolytic variant of Ply (Ply306. However, while the pneumococcus is a naturally transformable organism, strains of the ST306 clonal group have to date been virtually impossible to transform, severely restricting efforts to understand the role of non-cytolytic Ply in the success of this clone. In this study isogenic Ply mutants were constructed in the D39 background and for the first time in the ST306 background (A0229467 to enable direct comparisons between Ply variants for their impact on the immune response in a macrophage-like cell line. Strains that expressed cytolytic Ply were found to induce a significant increase in IL-1β release from macrophage-like cells compared to the non-cytolytic and Ply-deficient strains in a background-independent manner, confirming the requirement for pore formation in the Ply-dependent activation of the NLRP3 inflammasome. However, cytolytic activity in the D39 background was found to induce increased expression of the genes encoding GM-CSF (CSF2, p19 subunit of IL-23 (IL23A and IFNβ (IFNB1 compared to non-cytolytic and Ply-deficient D39 mutants, but had no effect in the A0229467 background. The impact of Ply on the immune response to the pneumococcus is highly dependent on the strain background, thus emphasising the importance of the interaction between specific virulence factors and other components of the genetic background of this organism.

  8. Natural genetic transformation generates a population of merodiploids in Streptococcus pneumoniae.

    Calum Johnston

    Full Text Available Partial duplication of genetic material is prevalent in eukaryotes and provides potential for evolution of new traits. Prokaryotes, which are generally haploid in nature, can evolve new genes by partial chromosome duplication, known as merodiploidy. Little is known about merodiploid formation during genetic exchange processes, although merodiploids have been serendipitously observed in early studies of bacterial transformation. Natural bacterial transformation involves internalization of exogenous donor DNA and its subsequent integration into the recipient genome by homology. It contributes to the remarkable plasticity of the human pathogen Streptococcus pneumoniae through intra and interspecies genetic exchange. We report that lethal cassette transformation produced merodiploids possessing both intact and cassette-inactivated copies of the essential target gene, bordered by repeats (R corresponding to incomplete copies of IS861. We show that merodiploidy is transiently stimulated by transformation, and only requires uptake of a ~3-kb DNA fragment partly repeated in the chromosome. We propose and validate a model for merodiploid formation, providing evidence that tandem-duplication (TD formation involves unequal crossing-over resulting from alternative pairing and interchromatid integration of R. This unequal crossing-over produces a chromosome dimer, resolution of which generates a chromosome with the TD and an abortive chromosome lacking the duplicated region. We document occurrence of TDs ranging from ~100 to ~900 kb in size at various chromosomal locations, including by self-transformation (transformation with recipient chromosomal DNA. We show that self-transformation produces a population containing many different merodiploid cells. Merodiploidy provides opportunities for evolution of new genetic traits via alteration of duplicated genes, unrestricted by functional selective pressure. Transient stimulation of a varied population of

  9. Decrease in penicillin susceptibility due to heat shock protein ClpL in Streptococcus pneumoniae.

    Tran, Thao Dang-Hien; Kwon, Hyog-Young; Kim, Eun-Hye; Kim, Ki-Woo; Briles, David E; Pyo, Suhkneung; Rhee, Dong-Kwon

    2011-06-01

    Antibiotic resistance and tolerance are increasing threats to global health as antibiotic-resistant bacteria can cause severe morbidity and mortality and can increase treatment cost 10-fold. Although several genes contributing to antibiotic tolerance among pneumococci have been identified, we report here that ClpL, a major heat shock protein, could modulate cell wall biosynthetic enzymes and lead to decreased penicillin susceptibility. On capsular type 1, 2, and 19 genetic backgrounds, mutants lacking ClpL were more susceptible to penicillin and had thinner cell walls than the parental strains, whereas a ClpL-overexpressing strain showed a higher resistance to penicillin and a thicker cell wall. Although exposure of Streptococcus pneumoniae D39 to penicillin inhibited expression of the major cell wall synthesis gene pbp2x, heat shock induced a ClpL-dependent increase in the mRNA levels and protein synthesized by pbp2x. Inducible ClpL expression correlated with PBP2x expression and penicillin susceptibility. Fractionation and electron micrograph data revealed that ClpL induced by heat shock is localized at the cell wall, and the ΔclpL showed significantly reduced net translocation of PBP2x into the cell wall. Moreover, coimmunoprecipitation with either ClpL or PBP2x antibody followed by reprobing with ClpL or PBP2x antibody showed an interaction between ClpL and PBP2x after heat stress. This interaction was confirmed by His tag pulldown assay with either ClpLHis₆ or PBP2xHis₆. Thus, ClpL stabilized pbp2x expression, interacted with PBP2x, and facilitated translocation of PBP2x, a key protein of cell wall synthesis process, contributing to the decrease of antibiotic susceptibility in S. pneumoniae.

  10. Peptidoglycan Branched Stem Peptides Contribute to Streptococcus pneumoniae Virulence by Inhibiting Pneumolysin Release.

    Neil G Greene

    2015-06-01

    Full Text Available Streptococcus pneumoniae (the pneumococcus colonizes the human nasopharynx and is a significant pathogen worldwide. Pneumolysin (Ply is a multi-functional, extracellular virulence factor produced by this organism that is critical for pathogenesis. Despite the absence of any apparent secretion or cell surface attachment motifs, Ply localizes to the cell envelope of actively growing cells. We sought to characterize the consequences of this surface localization. Through functional assays with whole cells and subcellular fractions, we determined that Ply activity and its release into the extracellular environment are inhibited by peptidoglycan (PG structure. The ability of PG to inhibit Ply release was dependent on the stem peptide composition of this macromolecule, which was manipulated by mutation of the murMN operon that encodes proteins responsible for branched stem peptide synthesis. Additionally, removal of choline-binding proteins from the cell surface significantly reduced Ply release to levels observed in a mutant with a high proportion of branched stem peptides suggesting a link between this structural feature and surface-associated choline-binding proteins involved in PG metabolism. Of clinical relevance, we also demonstrate that a hyperactive, mosaic murMN allele associated with penicillin resistance causes decreased Ply release with concomitant increases in the amount of branched stem peptides. Finally, using a murMN deletion mutant, we observed that increased Ply release is detrimental to virulence during a murine model of pneumonia. Taken together, our results reveal a novel role for branched stem peptides in pneumococcal pathogenesis and demonstrate the importance of controlled Ply release during infection. These results highlight the importance of PG composition in pathogenesis and may have broad implications for the diverse PG structures observed in other bacterial pathogens.

  11. In vitro susceptibility of six fluoroquinolones against invasive Streptococcus pneumoniae isolated from 1996 to 2001 in Taiwan.

    Chen, J Y; Fung, C P; Wang, C C; Chu, M L; Siu, L K

    2003-01-01

    A total of 331 invasive nonduplicated Streptococcus pneumoniae isolates from three sampling periods during 1996 to 2001 were tested for susceptibility to recently developed fluoroquinolones. Five major serotypes, 23F, 6B, 14, 19F, and 3, were frequently encountered in this collection. Penicillin nonsusceptible isolates constituted 52.9% from 1996 to 1997, 61.6% from 1998 to 1999, and 60.0% from 2000 to 2001. Fifty-seven percent of the isolates were susceptible to cefotaxime, 56.5% to ceftriaxone, 54.1% to cefepime, and 52.6% to cefuroxime. Macrolide-susceptible isolates constituted less than 14% of the total sample, and no vancomycin-resistant isolates were detected. For fluoroquinolones, MIC90 was lowest for gemifloxacin (MIC90 = fluoroquinolones are very effective against invasive S. pneumoniae isolates in Taiwan. Nevertheless, emerging fluoroquinolone resistance should be acknowledged and clinicians alerted. Surveillance should be carried out to monitor any changes in antibiotic resistance of S. pneumoniae.

  12. Infections invasives à "Streptococcus pneumoniae" dans la population pédiatrique genevoise de 1989 à 2000

    Pinösch, Selina

    2005-01-01

    "Streptococcus pneumoniae" est responsable d'infections invasives sévères telles que des méningites, pneumonies ou bactériémies. Nous avons effectué une étude rétrospective des enfants ayant présenté une infection invasive à "S. pneumoniae"à l'Hôpital des enfants de Genève de 1989 à 2000. 105 cas d'infections invasives à "S. pneumoniae" ont été recensés, dont 53 bactériémies, 28 pneumonies et 17 méningites. L'incidence était de 12.9/10⁵/an pour la population pédiatrique et de 48.3/10⁵/an pour...

  13. Infections invasives à "Streptococcus pneumoniae" dans la population pédiatrique genevoise de 1989 à 2000

    Pinösch, Selina; Gervaix, Alain

    2005-01-01

    "Streptococcus pneumoniae" est responsable d'infections invasives sévères telles que des méningites, pneumonies ou bactériémies. Nous avons effectué une étude rétrospective des enfants ayant présenté une infection invasive à "S. pneumoniae"à l'Hôpital des enfants de Genève de 1989 à 2000. 105 cas d'infections invasives à "S. pneumoniae" ont été recensés, dont 53 bactériémies, 28 pneumonies et 17 méningites. L'incidence était de 12.9/105/an pour la population pédiatrique et de 48.3/105/an pour...

  14. Clinical and bacteriological efficacies of sitafloxacin against community-acquired pneumonia caused by Streptococcus pneumoniae: nested cohort within a multicenter clinical trial.

    Fujita, Jiro; Niki, Yoshihito; Kadota, Jun-Ichi; Yanagihara, Katsunori; Kaku, Mitsuo; Watanabe, Akira; Aoki, Nobuki; Hori, Seiji; Tanigawara, Yusuke; Cash, Haley L; Kohno, Shigeru

    2013-06-01

    We evaluated the clinical and bacteriological efficacy of oral sitafloxacin (STFX) in clinically diagnosed community-acquired pneumonia (CAP) caused by Streptococcus pneumoniae. Additionally, we cultured these patient samples to test the minimal inhibitory concentrations (MICs) of levofloxacin (LVFX), moxifloxacin (MFLX), STFX, and penicillin G (PCG), as well as identified mutations in the quinolone resistance determinant regions (QRDRs) in LVFX-resistant strains. This study is a nested cohort from a prospective, multicenter clinical trial consisting of 139 patients with community-acquired pneumonia (CAP), from which 72 were included in this study. After diagnosis of CAP caused by S. pneumoniae, STFX (50 mg twice daily, or 100 mg once daily) was orally administered for 7 days. Sixty-five patient sputum samples were then cultured for MIC analysis. In a LVFX-resistant strain that was identified, mutations in the QRDRs of the gyrA, gyrB, parC, and parE genes were examined. Of 72 patients eligible for this study, S. pneumoniae was successfully cultured from the sputum of 65 patients, and only 7 patients were diagnosed by urinary antigen only. Clinical improvement of CAP was obtained in 65 of the 69 clinically evaluable patients (65/69, 94.2 %). Eradication of S. pneumoniae was observed in 62 patients of the 65 bacteriologically evaluable patients (62/65, 95.4 %). Additionally, STFX showed the lowest MIC distribution compared with LVFX, MFLX, and PCG, and no major adverse reactions were observed. STFX treatment in patients with CAP caused by S. pneumoniae was found to be highly effective both clinically (94.2 %) and bacteriologically (95.4 %).

  15. Longitudinal analysis of pneumococcal antibodies during community-acquired pneumonia reveals a much higher involvement of Streptococcus pneumoniae than estimated by conventional methods alone.

    van Mens, Suzan P; Meijvis, Sabine C A; Endeman, Henrik; van Velzen-Blad, Heleen; Biesma, Douwe H; Grutters, Jan C; Vlaminckx, Bart J M; Rijkers, Ger T

    2011-05-01

    In up to half of all cases of community-acquired pneumonia (CAP), no pathogen can be identified with conventional diagnostic methods. The most common identified causative agent is Streptococcus pneumoniae. In this study, pneumococcal antibody responses during CAP were analyzed to estimate the contribution of the pneumococcus to all cases of CAP for epidemiological purposes. Pneumococcal antibodies against 14 different serotypes were measured in serum of hospitalized CAP patients. Patients participated in one of two consecutive clinical trials in a general 600-bed teaching hospital in the Netherlands (between October 2004 and June 2009). A significant pneumococcal immune response was defined as at least a 2-fold increase in antibody concentrations against a single serotype between an early (day 1) and a late (day 30) serum sample of each patient with an end concentration above 0.35 μg/ml. A total of 349 adult CAP patients participated in two consecutive clinical trials. For 200 patients, sufficient serum samples were available to determine antibody responses: 62 pneumococcal pneumonia patients, 57 nonpneumococcal pneumonia patients, and 81 patients with an unidentified causative agent. A significant immune response was detected in 45% (28/62 patients) of pneumococcal pneumonia patients, in 5% (3/57) of nonpneumococcal pneumonia patients, and in 28% (23/81) of patients with an unidentified causative agent. The estimated contribution of pneumococci in patients with an unidentified causative agent was calculated to be 57% (95% confidence interval, 36 to 86%). A substantial fraction of pneumococcal pneumonia patients do not elicit a serotype-specific immune response.

  16. Development of new synthetic oligosaccharide vaccines : the immunogenicity of oligosaccharide-CRM197 neoconjugates and oligosaccharide/peptide hybrid gold nanoparticles based on the capsular polysaccharide structure of Streptococcus pneumoniae type 14

    Safari, D.

    2010-01-01

    Streptococcus pneumoniae is a leading cause of bacterial pneumonia, meningitis, and sepsis in children worldwide. Nowadays, the antibiotic resistance of S. pneumoniae bacteria has increased worldwide. This makes treatment of S. pneumoniae infections more difficult and stresses the importance of the

  17. Whole genome analysis of linezolid resistance in Streptococcus pneumoniae reveals resistance and compensatory mutations

    Légaré Danielle

    2011-10-01

    Full Text Available Abstract Background Several mutations were present in the genome of Streptococcus pneumoniae linezolid-resistant strains but the role of several of these mutations had not been experimentally tested. To analyze the role of these mutations, we reconstituted resistance by serial whole genome transformation of a novel resistant isolate into two strains with sensitive background. We sequenced the parent mutant and two independent transformants exhibiting similar minimum inhibitory concentration to linezolid. Results Comparative genomic analyses revealed that transformants acquired G2576T transversions in every gene copy of 23S rRNA and that the number of altered copies correlated with the level of linezolid resistance and cross-resistance to florfenicol and chloramphenicol. One of the transformants also acquired a mutation present in the parent mutant leading to the overexpression of an ABC transporter (spr1021. The acquisition of these mutations conferred a fitness cost however, which was further enhanced by the acquisition of a mutation in a RNA methyltransferase implicated in resistance. Interestingly, the fitness of the transformants could be restored in part by the acquisition of altered copies of the L3 and L16 ribosomal proteins and by mutations leading to the overexpression of the spr1887 ABC transporter that were present in the original linezolid-resistant mutant. Conclusions Our results demonstrate the usefulness of whole genome approaches at detecting major determinants of resistance as well as compensatory mutations that alleviate the fitness cost associated with resistance.

  18. A UDP-X diphosphatase from Streptococcus pneumoniae hydrolyzes precursors of peptidoglycan biosynthesis.

    Krisna C Duong-Ly

    Full Text Available The gene for a Nudix enzyme (SP_1669 was found to code for a UDP-X diphosphatase. The SP_1669 gene is localized among genes encoding proteins that participate in cell division in Streptococcus pneumoniae. One of these genes, MurF, encodes an enzyme that catalyzes the last step of the Mur pathway of peptidoglycan biosynthesis. Mur pathway substrates are all derived from UDP-glucosamine and all are potential Nudix substrates. We showed that UDP-X diphosphatase can hydrolyze the Mur pathway substrates UDP-N-acetylmuramic acid and UDP-N-acetylmuramoyl-L-alanine. The 1.39 Å resolution crystal structure of this enzyme shows that it folds as an asymmetric homodimer with two distinct active sites, each containing elements of the conserved Nudix box sequence. In addition to its Nudix catalytic activity, the enzyme has a 3'5' RNA exonuclease activity. We propose that the structural asymmetry in UDP-X diphosphatase facilitates the recognition of these two distinct classes of substrates, Nudix substrates and RNA. UDP-X diphosphatase is a prototype of a new family of Nudix enzymes with unique structural characteristics: two monomers, each consisting of an N-terminal helix bundle domain and a C-terminal Nudix domain, form an asymmetric dimer with two distinct active sites. These enzymes function to hydrolyze bacterial cell wall precursors and degrade RNA.

  19. Optimization of culture conditions to obtain maximal growth of penicillin-resistant Streptococcus pneumoniae

    Rodriguez Carlos A

    2005-06-01

    Full Text Available Abstract Background Streptococcus pneumoniae, particularly penicillin-resistant strains (PRSP, constitute one of the most important causes of serious infections worldwide. It is a fastidious microorganism with exquisite nutritional and environmental requirements to grow, a characteristic that prevents the development of useful animal models to study the biology of the microorganism. This study was designed to determine optimal conditions for culture and growth of PRSP. Results We developed a simple and reproducible method for culture of diverse strains of PRSP representing several invasive serotypes of clinical and epidemiological importance in Colombia. Application of this 3-step culture protocol consistently produced more than 9 log10 CFU/ml of viable cells in the middle part of the logarithmic phase of their growth curve. Conclusion A controlled inoculum size grown in 3 successive steps in supplemented agar and broth under 5% CO2 atmosphere, with pH adjustment and specific incubation times, allowed production of great numbers of PRSP without untimely activation of autolysis mechanisms.

  20. FHL2 Regulates Natural Killer Cell Development and Activation during Streptococcus pneumoniae Infection

    Baranek, Thomas; Morello, Eric; Valayer, Alexandre; Aimar, Rose-France; Bréa, Déborah; Henry, Clemence; Besnard, Anne-Gaelle; Dalloneau, Emilie; Guillon, Antoine; Dequin, Pierre-François; Narni-Mancinelli, Emilie; Vivier, Eric; Laurent, Fabrice; Wei, Yu; Paget, Christophe; Si-Tahar, Mustapha

    2017-01-01

    Recent in silico studies suggested that the transcription cofactor LIM-only protein FHL2 is a major transcriptional regulator of mouse natural killer (NK) cells. However, the expression and role of FHL2 in NK cell biology are unknown. Here, we confirm that FHL2 is expressed in both mouse and human NK cells. Using FHL2−/− mice, we found that FHL2 controls NK cell development in the bone marrow and maturation in peripheral organs. To evaluate the importance of FHL2 in NK cell activation, FHL2−/− mice were infected with Streptococcus pneumoniae. FHL2−/− mice are highly susceptible to this infection. The activation of lung NK cells is altered in FHL2−/− mice, leading to decreased IFNγ production and a loss of control of bacterial burden. Collectively, our data reveal that FHL2 is a new transcription cofactor implicated in NK cell development and activation during pulmonary bacterial infection.

  1. Identification of PblB mediating galactose-specific adhesion in a successful Streptococcus pneumoniae clone.

    Hsieh, Yu-Chia; Lin, Tzu-Lung; Lin, Che-Ming; Wang, Jin-Town

    2015-07-21

    The pneumococcal genome is variable and there are minimal data on the influence of the accessory genome on phenotype. Pneumococcal serotype 14 sequence type (ST) 46 had been the most prevalent clone causing pneumonia in children in Taiwan. A microarray was constructed using the genomic DNA of a clinical strain (NTUH-P15) of serotype 14 ST46. Using DNA hybridization, genomic variations in NTUH-P15 were compared to those of 3 control strains. Microarray analysis identified 7 genomic regions that had significant increases in hybridization signals in the NTUH-P15 strain compared to control strains. One of these regions encoded PblB, a phage-encoded virulence factor implicated (in Streptococcus mitis) in infective endocarditis. The isogenic pblB mutant decreased adherence to A549 human lung epithelial cell compared to wild-type NTUH-P15 strain (P = 0.01). Complementation with pblB restored the adherence. PblB is predicted to contain a galactose-binding domain-like region. Preincubation of NTUH-P15 with D-galactose resulted in decreases of adherence to A549 cell in a dose-dependent manner. Challenge of mice with NTUH-P15, isogenic pblB mutant and pblB complementation strains determined that PblB was required for bacterial persistence in the nasopharynx and lung. PblB, as an adhesin mediating the galactose-specific adhesion activity of pneumococci, promote pneumococcal clonal success.

  2. Changes in fluoroquinolone-resistant Streptococcus pneumoniae after 7-valent conjugate vaccination, Spain.

    de la Campa, Adela G; Ardanuy, Carmen; Balsalobre, Luz; Pérez-Trallero, Emilio; Marimón, Jose M; Fenoll, Asunción; Liñares, Josefina

    2009-06-01

    Among 4,215 Streptococcus pneumoniae isolates obtained in Spain during 2006, 98 (2.3%) were ciprofloxacin resistant (3.6% from adults and 0.14% from children). In comparison with findings from a 2002 study, global resistance remained stable. Low-level resistance (30 isolates with MIC 4-8 microg/mL) was caused by a reserpine-sensitive efflux phenotype (n = 4) or single topoisomerase IV (parC [n = 24] or parE [n = 1]) changes. One isolate did not show reserpine-sensitive efflux or mutations. High-level resistance (68 isolates with MIC >or=16 microg/mL) was caused by changes in gyrase (gyrA) and parC or parE. New changes in parC (S80P) and gyrA (S81V, E85G) were shown to be involved in resistance by genetic transformation. Although 49 genotypes were observed, clones Spain9V-ST156 and Sweden15A-ST63 accounted for 34.7% of drug-resistant isolates. In comparison with findings from the 2002 study, clones Spain14-ST17, Spain23F-ST81, and ST8819F decreased and 4 new genotypes (ST9710A, ST57016, ST43322, and ST71733) appeared in 2006.

  3. Structural determinants of host specificity of complement Factor H recruitment by Streptococcus pneumoniae.

    Achila, David; Liu, Aizhuo; Banerjee, Rahul; Li, Yue; Martinez-Hackert, Erik; Zhang, Jing-Ren; Yan, Honggao

    2015-01-15

    Many human pathogens have strict host specificity, which affects not only their epidemiology but also the development of animal models and vaccines. Complement Factor H (FH) is recruited to pneumococcal cell surface in a human-specific manner via the N-terminal domain of the pneumococcal protein virulence factor choline-binding protein A (CbpAN). FH recruitment enables Streptococcus pneumoniae to evade surveillance by human complement system and contributes to pneumococcal host specificity. The molecular determinants of host specificity of complement evasion are unknown. In the present study, we show that a single human FH (hFH) domain is sufficient for tight binding of CbpAN, present the crystal structure of the complex and identify the critical structural determinants for host-specific FH recruitment. The results offer new approaches to the development of better animal models for pneumococcal infection and redesign of the virulence factor for pneumococcal vaccine development and reveal how FH recruitment can serve as a mechanism for both pneumococcal complement evasion and adherence.

  4. Streptococcus pneumoniae GAPDH Is Released by Cell Lysis and Interacts with Peptidoglycan.

    Terrasse, Rémi; Amoroso, Ana; Vernet, Thierry; Di Guilmi, Anne Marie

    2015-01-01

    Release of conserved cytoplasmic proteins is widely spread among Gram-positive and Gram-negative bacteria. Because these proteins display additional functions when located at the bacterial surface, they have been qualified as moonlighting proteins. The GAPDH is a glycolytic enzyme which plays an important role in the virulence processes of pathogenic microorganisms like bacterial invasion and host immune system modulation. However, GAPDH, like other moonlighting proteins, cannot be secreted through active secretion systems since they do not contain an N-terminal predicted signal peptide. In this work, we investigated the mechanism of GAPDH export and surface retention in Streptococcus pneumoniae, a major human pathogen. We addressed the role of the major autolysin LytA in the delivery process of GAPDH to the cell surface. Pneumococcal lysis is abolished in the ΔlytA mutant strain or when 1% choline chloride is added in the culture media. We showed that these conditions induce a marked reduction in the amount of surface-associated GAPDH. These data suggest that the presence of GAPDH at the surface of pneumococcal cells depends on the LytA-mediated lysis of a fraction of the cell population. Moreover, we demonstrated that pneumococcal GAPDH binds to the bacterial cell wall independently of the presence of the teichoic acids component, supporting peptidoglycan as a ligand to surface GAPDH. Finally, we showed that peptidoglycan-associated GAPDH recruits C1q from human serum but does not activate the complement pathway.

  5. Streptococcus pneumoniae translocates into the myocardium and forms unique microlesions that disrupt cardiac function.

    Armand O Brown

    2014-09-01

    Full Text Available Hospitalization of the elderly for invasive pneumococcal disease is frequently accompanied by the occurrence of an adverse cardiac event; these are primarily new or worsened heart failure and cardiac arrhythmia. Herein, we describe previously unrecognized microscopic lesions (microlesions formed within the myocardium of mice, rhesus macaques, and humans during bacteremic Streptococcus pneumoniae infection. In mice, invasive pneumococcal disease (IPD severity correlated with levels of serum troponin, a marker for cardiac damage, the development of aberrant cardiac electrophysiology, and the number and size of cardiac microlesions. Microlesions were prominent in the ventricles, vacuolar in appearance with extracellular pneumococci, and remarkable due to the absence of infiltrating immune cells. The pore-forming toxin pneumolysin was required for microlesion formation but Interleukin-1β was not detected at the microlesion site ruling out pneumolysin-mediated pyroptosis as a cause of cell death. Antibiotic treatment resulted in maturing of the lesions over one week with robust immune cell infiltration and collagen deposition suggestive of long-term cardiac scarring. Bacterial translocation into the heart tissue required the pneumococcal adhesin CbpA and the host ligands Laminin receptor (LR and Platelet-activating factor receptor. Immunization of mice with a fusion construct of CbpA or the LR binding domain of CbpA with the pneumolysin toxoid L460D protected against microlesion formation. We conclude that microlesion formation may contribute to the acute and long-term adverse cardiac events seen in humans with IPD.

  6. Streptococcus pneumonia YlxR at 1.35 Å shows a putative new fold

    Osipiuk, Jerzy; Górnicki, Piotr; Maj, Luke; Dementieva, Irina; Laskowski, Roman; Joachimiak, Andrzej

    2009-01-01

    The structure of the YlxR protein of unknown function from Streptococcus pneumonia was determined to 1.35 Å. YlxR is expressed from the nusA/infB operon in bacteria and belongs to a small protein family (COG2740) that shares a conserved sequence motif GRGA(Y/W). The family shows no significant amino-acid sequence similarity with other proteins. Three-wavelength diffraction MAD data were collected to 1.7 Å from orthorhombic crystals using synchrotron radiation and the structure was determined using a semi-automated approach. The YlxR structure resembles a two-layer α/β sandwich with the overall shape of a cylinder and shows no structural homology to proteins of known structure. Structural analysis revealed that the YlxR structure represents a new protein fold that belongs to the α–β plait superfamily. The distribution of the electrostatic surface potential shows a large positively charged patch on one side of the protein, a feature often found in nucleic acid-binding proteins. Three sulfate ions bind to this positively charged surface. Analysis of potential binding sites uncovered several substantial clefts, with the largest spanning 3/4 of the protein. A similar distribution of binding sites and a large sharply bent cleft are observed in RNA-binding proteins that are unrelated in sequence and structure. It is proposed that YlxR is an RNA-binding protein. PMID:11679764

  7. A functional genomics approach to establish the complement of carbohydrate transporters in Streptococcus pneumoniae.

    Alessandro Bidossi

    Full Text Available The aerotolerant anaerobe Streptococcus pneumoniae is part of the normal nasopharyngeal microbiota of humans and one of the most important invasive pathogens. A genomic survey allowed establishing the occurrence of twenty-one phosphotransferase systems, seven carbohydrate uptake ABC transporters, one sodium:solute symporter and a permease, underlining an exceptionally high capacity for uptake of carbohydrate substrates. Despite high genomic variability, combined phenotypic and genomic analysis of twenty sequenced strains did assign the substrate specificity only to two uptake systems. Systematic analysis of mutants for most carbohydrate transporters enabled us to assign a phenotype and substrate specificity to twenty-three transport systems. For five putative transporters for galactose, pentoses, ribonucleosides and sulphated glycans activity was inferred, but not experimentally confirmed and only one transport system remains with an unknown substrate and lack of any functional annotation. Using a metabolic approach, 80% of the thirty-two fermentable carbon substrates were assigned to the corresponding transporter. The complexity and robustness of sugar uptake is underlined by the finding that many transporters have multiple substrates, and many sugars are transported by more than one system. The present work permits to draw a functional map of the complete arsenal of carbohydrate utilisation proteins of pneumococci, allows re-annotation of genomic data and might serve as a reference for related species. These data provide tools for specific investigation of the roles of the different carbon substrates on pneumococcal physiology in the host during carriage and invasive infection.

  8. Streptococcus pneumoniae GAPDH Is Released by Cell Lysis and Interacts with Peptidoglycan.

    Rémi Terrasse

    Full Text Available Release of conserved cytoplasmic proteins is widely spread among Gram-positive and Gram-negative bacteria. Because these proteins display additional functions when located at the bacterial surface, they have been qualified as moonlighting proteins. The GAPDH is a glycolytic enzyme which plays an important role in the virulence processes of pathogenic microorganisms like bacterial invasion and host immune system modulation. However, GAPDH, like other moonlighting proteins, cannot be secreted through active secretion systems since they do not contain an N-terminal predicted signal peptide. In this work, we investigated the mechanism of GAPDH export and surface retention in Streptococcus pneumoniae, a major human pathogen. We addressed the role of the major autolysin LytA in the delivery process of GAPDH to the cell surface. Pneumococcal lysis is abolished in the ΔlytA mutant strain or when 1% choline chloride is added in the culture media. We showed that these conditions induce a marked reduction in the amount of surface-associated GAPDH. These data suggest that the presence of GAPDH at the surface of pneumococcal cells depends on the LytA-mediated lysis of a fraction of the cell population. Moreover, we demonstrated that pneumococcal GAPDH binds to the bacterial cell wall independently of the presence of the teichoic acids component, supporting peptidoglycan as a ligand to surface GAPDH. Finally, we showed that peptidoglycan-associated GAPDH recruits C1q from human serum but does not activate the complement pathway.

  9. Coordinated Bacteriocin Expression and Competence in Streptococcus pneumoniae Contributes to Genetic Adaptation through Neighbor Predation.

    Wholey, Wei-Yun; Kochan, Travis J; Storck, David N; Dawid, Suzanne

    2016-02-01

    Streptococcus pneumoniae (pneumococcus) has remained a persistent cause of invasive and mucosal disease in humans despite the widespread use of antibiotics and vaccines. The resilience of this organism is due to its capacity for adaptation through the uptake and incorporation of new genetic material from the surrounding microbial community. DNA uptake and recombination is controlled by a tightly regulated quorum sensing system that is triggered by the extracellular accumulation of competence stimulating peptide (CSP). In this study, we demonstrate that CSP can stimulate the production of a diverse array of blp bacteriocins. This cross stimulation occurs through increased production and secretion of the bacteriocin pheromone, BlpC, and requires a functional competence regulatory system. We show that a highly conserved motif in the promoter of the operon encoding BlpC and its transporter mediates the upregulation by CSP. The accumulation of BlpC following CSP stimulation results in augmented activation of the entire blp locus. Using biofilm-grown organisms as a model for competition and genetic exchange on the mucosal surface, we demonstrate that DNA exchange is enhanced by bacteriocin secretion suggesting that co-stimulation of bacteriocins with competence provides an adaptive advantage. The blp and com regulatory pathways are believed to have diverged and specialized in a remote ancestor of pneumococcus. Despite this, the two systems have maintained a regulatory connection that promotes competition and adaptation by targeting for lysis a wide array of potential competitors while simultaneously providing the means for incorporation of their DNA.

  10. DEVELOPMENT OF A NEW PROCESS FOR PURIFICATION OF CAPSULAR POLYSACCHARIDE FROM Streptococcus pneumoniae SEROTYPE 14

    R. T. Zanardo

    Full Text Available Abstract The main virulence factor of Streptococcus pneumoniae is the capsular polysaccharide (PS, which is the antigen of all current vaccines that are prepared with PS purified from serotypes prevalent in the population. In this work, three purification strategies were evaluated and a new process was developed for purification of serotype 14 PS (PS14, responsible for 39.8% of diseases in children of 0-6 years old in Brazil. The developed method consists of cell separation by tangential microfiltration, concentration of the microfiltrate by tangential ultrafiltration (50 kDa, diafiltration in the presence of sodium dodecyl sulfate using a 30 kDa ultrafiltration membrane, precipitation with 5% trichloroacetic acid, precipitation with 20% and 60% ethanol, and anion exchange chromatography. The required purity regarding nucleic acids (≤ 2% and proteins (≤ 3% was achieved, resulting in a relative purity of 439 mg PS14/mg nucleic acids and 146 mg PS14/mg proteins. The final polysaccharide recovery was 65%, which is higher than the recovery of the majority of processes described in the literature.

  11. Potential of MALDI-TOF MS as an alternative approach for capsular typing Streptococcus pneumoniae isolates

    Pinto, Tatiana C. A.; Costa, Natalia S.; Castro, Luciana F. S.; Ribeiro, Rachel L.; Botelho, Ana Caroline N.; Neves, Felipe P. G.; Peralta, Jose Mauro; Teixeira, Lucia M.

    2017-01-01

    Streptococcus pneumoniae can be classified in more than 90 capsular types, as traditionally determined by serological methods and more recently by PCR-based techniques. Such methods, however, can be expensive, laborious or unable to accurately discriminate among certain serotypes. Therefore, determination of capsular types, although extremely important for epidemiological purposes and for estimating the impact of pneumococcal conjugate vaccines, is mainly restricted to research laboratories, being rarely performed in the clinical setting. In the present study, MALDI-TOF MS was evaluated as an alternative tool to characterize 416 pneumococcal isolates belonging to serotypes 6A, 6B, 6C, 9N, 9V or 14. For MALDI-TOF MS analysis, each isolate was submitted to an extraction protocol using formic acid and acetonitrile. Measurements were performed with a Bruker Microflex LT mass spectrometer using default parameters and generating spectra in the range of 2,000–20,000 m/z. Spectra were analyzed with the BioNumerics software v7.6. Isolates were mainly distributed according to the capsular type in a Neighbor Joining tree and serotypes investigated were successfully discriminated by the presence/absence of 14 selected biomarkers. The results suggest that MALDI-TOF MS is a promising alternative for typing pneumococcal strains, highlighting its usefulness for rapid and cost-effective routine application in clinical laboratories. PMID:28349999

  12. Mutational and Biochemical Analysis of the DNA-entry Nuclease EndA from Streptococcus pneumoniae

    M Midon; P Schafer; A Pingoud; M Ghosh; A Moon; M Cuneo; R London; G Meiss

    2011-12-31

    EndA is a membrane-attached surface-exposed DNA-entry nuclease previously known to be required for genetic transformation of Streptococcus pneumoniae. More recent studies have shown that the enzyme also plays an important role during the establishment of invasive infections by degrading extracellular chromatin in the form of neutrophil extracellular traps (NETs), enabling streptococci to overcome the innate immune system in mammals. As a virulence factor, EndA has become an interesting target for future drug design. Here we present the first mutational and biochemical analysis of recombinant forms of EndA produced either in a cell-free expression system or in Escherichia coli. We identify His160 and Asn191 to be essential for catalysis and Asn182 to be required for stability of EndA. The role of His160 as the putative general base in the catalytic mechanism is supported by chemical rescue of the H160A variant of EndA with imidazole added in excess. Our study paves the way for the identification and development of protein or low-molecular-weight inhibitors for EndA in future high-throughput screening assays.

  13. Cysteine-mediated gene expression and characterization of the CmbR regulon in Streptococcus pneumoniae

    Muhammad Afzal

    2016-12-01

    Full Text Available In this study, we investigated the transcriptomic response of Streptococcus pneumoniae D39 to cysteine. Transcriptome comparison of the D39 wild-type strain grown at a restricted concentration of cysteine (0.03 mM to one grown at a high concentration of cysteine (50 mM in chemically-define medium (CDM revealed elevated expression of various genes/operons, i.e. spd-0150, metQ, spd-0431, metEF, gshT, spd-0618, fhs, tcyB, metB-csd, metA, spd-1898, yvdE, and cysK, likely to be involved in the transport and utilization of cysteine and/or methionine. Microarray-based data were further confirmed by quantitative RT-PCR. Promoter lacZ-fusion studies and quantitative RT-PCR data showed that the transcriptional regulator CmbR acts as a transcriptional repressor of spd-0150, metEF, gshT, spd-0618, tcyB, metA, and yvdE, putatively involved in cysteine uptake and utilization. The operator site of CmbR in the promoter regions of CmbR-regulated genes is predicted and confirmed by mutating or deleting CmbR operator sites from the promoter regions of these genes.

  14. Transport of Streptococcus pneumoniae capsular polysaccharide in MHC Class II tubules.

    Tom Li Stephen

    2007-03-01

    Full Text Available Bacterial capsular polysaccharides are virulence factors and are considered T cell-independent antigens. However, the capsular polysaccharide Sp1 from Streptococcus pneumoniae serotype 1 has been shown to activate CD4(+ T cells in a major histocompatibility complex (MHC class II-dependent manner. The mechanism of carbohydrate presentation to CD4(+ T cells is unknown. We show in live murine dendritic cells (DCs that Sp1 translocates from lysosomal compartments to the plasma membrane in MHCII-positive tubules. Sp1 cell surface presentation results in reduction of self-peptide presentation without alteration of the MHCII self peptide repertoire. In DM-deficient mice, retrograde transport of Sp1/MHCII complexes resulting in T cell-dependent immune responses to the polysaccharide in vitro and in vivo is significantly reduced. The results demonstrate the capacity of a bacterial capsular polysaccharide antigen to use DC tubules as a vehicle for its transport as an MHCII/saccharide complex to the cell surface for the induction of T cell activation. Furthermore, retrograde transport requires the functional role of DM in self peptide-carbohydrate exchange. These observations open new opportunities for the design of vaccines against microbial encapsulated pathogens.

  15. Coordinated Bacteriocin Expression and Competence in Streptococcus pneumoniae Contributes to Genetic Adaptation through Neighbor Predation.

    Wei-Yun Wholey

    2016-02-01

    Full Text Available Streptococcus pneumoniae (pneumococcus has remained a persistent cause of invasive and mucosal disease in humans despite the widespread use of antibiotics and vaccines. The resilience of this organism is due to its capacity for adaptation through the uptake and incorporation of new genetic material from the surrounding microbial community. DNA uptake and recombination is controlled by a tightly regulated quorum sensing system that is triggered by the extracellular accumulation of competence stimulating peptide (CSP. In this study, we demonstrate that CSP can stimulate the production of a diverse array of blp bacteriocins. This cross stimulation occurs through increased production and secretion of the bacteriocin pheromone, BlpC, and requires a functional competence regulatory system. We show that a highly conserved motif in the promoter of the operon encoding BlpC and its transporter mediates the upregulation by CSP. The accumulation of BlpC following CSP stimulation results in augmented activation of the entire blp locus. Using biofilm-grown organisms as a model for competition and genetic exchange on the mucosal surface, we demonstrate that DNA exchange is enhanced by bacteriocin secretion suggesting that co-stimulation of bacteriocins with competence provides an adaptive advantage. The blp and com regulatory pathways are believed to have diverged and specialized in a remote ancestor of pneumococcus. Despite this, the two systems have maintained a regulatory connection that promotes competition and adaptation by targeting for lysis a wide array of potential competitors while simultaneously providing the means for incorporation of their DNA.

  16. Serotypes and antimicrobial resistance of meningeal isolates of Streptococcus pneumonia. Cuba, 2007-2012

    Gilda Toraño-Peraza

    2014-12-01

    Full Text Available An observational study was conducted to know the serotypes and antimicrobial susceptibility of isolates of Streptococcus pneumoniae responsible for meningitis in Cuba, where there is no vaccine yet to prevent invasive pneumococcal disease. The study included the total number of isolates submitted to the "Pedro Kourí" Institute between 2007 and 2012 (N=237. Serotypes identification was performed using capsular swelling test and antimicrobial susceptibility was studied by determining the minimum inhibitory concentration using the broth microdilution method. Predominant serotypes were 6A, 6B, 14, 19F and 23F and other non-vaccinal 18 serogroups/serotypes were identified in 29.1% of the isolates. A tendency to an increased resistance to penicillin (44.3 % was observed; the most common resistance patterns were: penicillin-trimethoprim/sulfamethoxazole and penicillin-erythromycin (21.1% and 10.5%, respectively. The largest number of isolates resistant to penicillin was in serotypes 6B, 14, 19F and 23F and the possibility of resistant non-vaccine serotypes emergence should be considered. The results show that 70.4 % of the isolates studied corresponds to the serotypes included in 13-valent conjugated pneumococcal vaccine, but with 10-valent it would achieve a lower vaccination potential coverage (56.1%. This information must be considered when evaluating the decision to use in Cuba any commercially available vaccine or the proposal of another strategy of vaccination from autochthonous vaccine candidates.

  17. Macrolide-resistant phenotypes of invasive streptococcus pneumoniae isolates in Serbia

    Gajić Ina

    2012-01-01

    Full Text Available Macrolide resistance in Streptococcus pneumoniae has emerged as an important worldwide problem over the past decade. The aim of this study was to investigate macrolide-resistant phenotypes and the antimicrobial susceptibility patterns of invasive pneumococci in Serbia. A total of 68 invasive pneumococcal strains, collected from 2009 to 2011, were sent from regional laboratories to the National Reference Laboratory. Susceptibility testing was performed using the VITEK2 system and phenotypes were determined by triple-test. Overall penicillin and erythromycin nonsusceptibility rates were 26% and 43%, respectively. Resistance rates were higher in children than in adults. Co-resistance to penicillin and erythromycin was detected in 18% strains. Resistance rates to the third generation of cephalosporins, TMP-SXT and tetracycline were 16%, 37% and 29%, respectively. All isolates were fully susceptible to vancomycin, linezolid, fluoroquinolones, telithromycin and rifampicin. Twenty-two isolates (79% an expressed macrolide-lincosamide-streptogramin B (MLSB resistance phenotype and M phenotype was found in 21% of macrolide resistant strains. [Projekat Ministarstva nauke Republike Srbije, br. 175039

  18. Autolytic Activity and Plasma Binding Study of Aap, a Novel Minor Autolysin of Streptococcus pneumoniae

    Ramina Mahboobi

    2016-04-01

    Full Text Available Pneumococcal autolysins are enzymes involved in cell wall turnover and cellular division physiologically. They have been found to be involved in the pneumococcus pathogenesis. The aim of this study was to identify the autolytic activity of Spr1754 as a novel protein of Streptococcus pneumoniae. Moreover, the binding of the recombinant protein to plasma proteins was also determined. The spr1754 gene was amplified by PCR and cloned into the pET21a(+ prokaryotic expression vector. The constructed pET21a(+/spr1754 recombinant plasmid was transformed into E. coli Origami (DE3 and induced using IPTG. The recombinant protein of Spr1754 was purified by Ni-NTA affinity chromatography and confirmed by SDS-PAGE and Western blot analysis using anti-His tag monoclonal antibody. Autolytic activity and the ability of the recombinant protein in binding to plasma proteins were performed using zymogram analysis and western blot, respectively. The spr1754 with expected size was cloned and overexpressed in Escherichia coli Origami (DE3, successfully. After purification of the Spr1754 recombinant protein, the autolytic activity was observed by zymography. Of the four plasma proteins used in this study, binding of lactoferrin to Spr1754 recombinant protein was shown. The Spr1754 recombinant protein has a bifunctional activity, i.e., as being autolysin and lactoferrin binding and designated as Aap (autolytic/ adhesion/ pneumococcus. Nevertheless, characterization of the Aap needs to be followed using gene inactivation and cell wall localization.

  19. Post-operative Streptococcus pneumoniae meningoencephalitis complicating surgery for acromegaly in an identical twin.

    Cote, David J; Iuliano, Sherry L; Smith, Timothy R; Laws, Edward R

    2015-06-01

    This case report provides provocative and useful data regarding two aspects of acromegaly and its management. The patient, who is one of a pair of identical twins, has no known hereditary, genetic or otherwise potentially etiologic factors as compared to her unaffected sister. Secondly, transsphenoidal surgery, which was ultimately successful, was complicated by pneumococcal meningitis, an unusual event with only four previously reported patients, three of whom ended in death or major neurologic deficits. In this case, a 57-year-old woman gradually developed classical signs and symptoms of acromegaly while her identical twin sister remained normal with no evidence of endocrine disease. Endoscopic transsphenoidal surgery was complicated by the development of meningitis 25 days after surgery. This was controlled following a difficult hospital course. Streptococcus pneumoniae meningoencephalitis is a rare but life-threatening complication of transsphenoidal surgery. A high index of suspicion for incipient meningitis should be maintained when patients present with severe headache and increased intracranial pressure, even if they initially lack the typical symptoms and signs. Immediate and aggressive treatment is necessary to avoid significant neurologic deficit.

  20. A Multi-Scale Computational Study on the Mechanism of Streptococcus pneumoniae Nicotinamidase (SpNic

    Bogdan F. Ion

    2014-09-01

    Full Text Available Nicotinamidase (Nic is a key zinc-dependent enzyme in NAD metabolism that catalyzes the hydrolysis of nicotinamide to give nicotinic acid. A multi-scale computational approach has been used to investigate the catalytic mechanism, substrate binding and roles of active site residues of Nic from Streptococcus pneumoniae (SpNic. In particular, density functional theory (DFT, molecular dynamics (MD and ONIOM quantum mechanics/molecular mechanics (QM/MM methods have been employed. The overall mechanism occurs in two stages: (i formation of a thioester enzyme-intermediate (IC2 and (ii hydrolysis of the thioester bond to give the products. The polar protein environment has a significant effect in stabilizing reaction intermediates and in particular transition states. As a result, both stages effectively occur in one step with Stage 1, formation of IC2, being rate limiting barrier with a cost of 53.5 kJ•mol−1 with respect to the reactant complex, RC. The effects of dispersion interactions on the overall mechanism were also considered but were generally calculated to have less significant effects with the overall mechanism being unchanged. In addition, the active site lysyl (Lys103 is concluded to likely play a role in stabilizing the thiolate of Cys136 during the reaction.

  1. Use of serology and urine antigen detection to estimate the proportion of adult community-acquired pneumonia attributable to Streptococcus pneumoniae.

    Watt, J P; Moïsi, J C; Donaldson, R L A; Reid, R; Ferro, S; Whitney, C G; Santosham, M; O'Brien, K L

    2010-12-01

    Streptococcus pneumoniae is a common cause of community-acquired pneumonia (CAP) but existing diagnostic tools have limited sensitivity and specificity. We enrolled adults undergoing chest radiography at three Indian Health Service clinics in the Southwestern United States and collected acute and convalescent serum for measurement of PsaA and PspA titres and urine for pneumococcal antigen detection. Blood and sputum cultures were obtained at the discretion of treating physicians. We compared findings in clinical and radiographic CAP patients to those in controls without CAP. Urine antigen testing showed the largest differential between CAP patients and controls (clinical CAP 13%, radiographic CAP 17%, control groups 2%). Serological results were mixed, with significant differences between CAP patients and controls for some, but not all changes in titre. Based on urine antigen and blood culture results, we estimated that 11% of clinical and 15% of radiographic CAP cases were due to pneumococcus in this population.

  2. Fluoroquinolone resistance in atypical pneumococci and oral streptococci: evidence of horizontal gene transfer of fluoroquinolone resistance determinants from Streptococcus pneumoniae.

    Ip, Margaret; Chau, Shirley S L; Chi, Fang; Tang, Julian; Chan, Paul K

    2007-08-01

    Atypical strains, presumed to be pneumococcus, with ciprofloxacin MICs of > or =4.0 microg/ml and unique sequence variations within the quinolone resistance-determining regions (QRDRs) of the gyrase and topoisomerase genes in comparison with the Streptococcus pneumoniae R6 strain, were examined. These strains were reidentified using phenotypic methods, including detection of optochin susceptibility, bile solubility, and agglutination by serotype-specific antisera, and genotypic methods, including detection of pneumolysin and autolysin genes by PCR, 16S rRNA sequencing, and multilocus sequence typing (MLST). The analysis based on concatenated sequences of the six MLST loci distinguished the "atypical" strains from pneumococci, and these strains clustered closely with S. mitis. However, all these strains and five of nine strains from the viridans streptococcal group possessed one to three gyrA, gyrB, parC, and parE genes whose QRDR sequences clustered with those of S. pneumoniae, providing evidence of horizontal transfer of the QRDRs of the gyrase and topoisomerase genes from pneumococci into viridans streptococci. These genes also conferred fluoroquinolone resistance to viridans streptococci. In addition, the fluoroquinolone resistance determinants of 32 well-characterized Streptococcus mitis and Streptococcus oralis strains from bacteremic patients were also compared. These strains have unique amino acid substitutions in GyrA and ParC that were distinguishable from those in fluoroquinolone-resistant pneumococci and the "atypical" isolates. Both recombinational events and de novo mutations play an important role in the development of fluoroquinolone resistance.

  3. Risk factors for levofloxacin-nonsusceptible Streptococcus pneumoniae in community-acquired pneumococcal pneumonia: a nested case-control study.

    Kang, C-I; Song, J-H; Kim, S H; Chung, D R; Peck, K R; So, T M; Hsueh, P-R

    2014-01-01

    This study was performed to evaluate the clinical features of community-onset levofloxacin-nonsusceptible pneumococcal pneumonia and to identify risk factors for levofloxacin resistance. Using the database of a surveillance study of community-acquired pneumococcal infections in Asian countries, we conducted a nested case-control study to identify risk factors for levofloxacin-nonsusceptible S. pneumoniae in community-acquired pneumonia in adults. Of 981 patients with pneumococcal pneumonia, 46 (4.7 %) had levofloxacin-nonsusceptible S. pneumoniae, of whom 39 evaluable cases were included in the analysis. All cases were from Korea, Taiwan, and Hong Kong. Among patients with levofloxacin-susceptible S. pneumoniae, 490 controls were selected based on patient country. Of the 39 cases of levofloxacin-nonsusceptible pneumococcal pneumonia, 23 (59.0 %) were classified as healthcare-associated, while 164 (33.5 %) of the 490 controls of levofloxacin-susceptible S. pneumoniae (P = 0.001) were classified as healthcare-associated. Multivariate analysis showed that previous treatment with fluoroquinolones, cerebrovascular disease, and healthcare-associated infection were significantly associated with levofloxacin-nonsusceptible pneumococcal pneumonia (all P < 0.05). Levofloxacin-nonsusceptible pneumococci pose an important new public health threat in our region, and more information on the emergence and spread of these resistant strains will be necessary to prevent spread throughout the population.

  4. Enhanced inflammation in aged mice following infection with Streptococcus pneumoniae is associated with decreased IL-10 and augmented chemokine production.

    Williams, Andrew E; José, Ricardo J; Brown, Jeremy S; Chambers, Rachel C

    2015-03-15

    Streptococcus pneumoniae is the most common cause of severe pneumonia in the elderly. However, the impact of aging on the innate inflammatory response to pneumococci is poorly defined. We compared the innate immune response in old vs. young adult mice following infection with S. pneumoniae. The accumulation of neutrophils recovered from bronchoalveolar lavage fluid and lung homogenates was increased in aged compared with young adult mice, although bacterial outgrowth was similar in both age groups, as were markers of microvascular leak. Aged mice had similar levels of IL-1β, TNF, IFN-γ, IL-17, and granulocyte colony-stimulating factor following S. pneumoniae infection, compared with young mice, but increased levels of the chemokines CXCL9, CXCL12, CCL3, CCL4, CCL5, CCL11, and CCL17. Moreover, levels of IL-10 were significantly lower in aged animals. Neutralization of IL-10 in infected young mice was associated with increased neutrophil recruitment but no decrease in bacterial outgrowth. Furthermore, IL-10 neutralization resulted in increased levels of CCL3, CCL5, and CXCL10. We conclude that aging is associated with enhanced inflammatory responses following S. pneumoniae infection as a result of a compromised immunomodulatory cytokine response.

  5. Streptococcus pneumoniae R6 interspecies transformation: genetic analysis of penicillin resistance determinants and genome-wide recombination events.

    Sauerbier, Julia; Maurer, Patrick; Rieger, Martin; Hakenbeck, Regine

    2012-11-01

    Interspecies gene transfer has been implicated as the major driving force for the evolution of penicillin resistance in Streptococcus pneumoniae. Genomic alterations of S. pneumoniae R6 introduced during four successive transformations with DNA of the high-level penicillin-resistant Streptococcus mitis B6 with beta-lactam selection have now been determined and the contribution of genes to high resistance levels was analysed genetically. Essential for high level resistance to penicillins of the transformant CCCB was the combination of murM(B) (6) and the 3' region of pbp2b(B) (6) . Sequences of both genes were detected in clinical isolates of S. pneumoniae, confirming the participation of S. mitis in the global gene pool of beta-lactam resistance determinants. The S. mitis PBP1b gene which contains an authentic stop codon within the transpeptidase domain is now shown to contribute only marginal to resistance, but it is possible that the presence of its transglycosylase domain is important in the context of cognate PBPs. The genome sequence of CCCB revealed 36 recombination events, including deletion and acquisition of genes and repeat elements. A total of 78 genes were affected representing 67 kb or 3.3% of the genome, documenting extensive alterations scattered throughout the genome.

  6. Tn5253 family integrative and conjugative elements carrying mef(I) and catQ determinants in Streptococcus pneumoniae and Streptococcus pyogenes.

    Mingoia, Marina; Morici, Eleonora; Morroni, Gianluca; Giovanetti, Eleonora; Del Grosso, Maria; Pantosti, Annalisa; Varaldo, Pietro E

    2014-10-01

    The linkage between the macrolide efflux gene mef(I) and the chloramphenicol inactivation gene catQ was first described in Streptococcus pneumoniae (strain Spn529), where the two genes are located in a module designated IQ element. Subsequently, two different defective IQ elements were detected in Streptococcus pyogenes (strains Spy029 and Spy005). The genetic elements carrying the three IQ elements were characterized, and all were found to be Tn5253 family integrative and conjugative elements (ICEs). The ICE from S. pneumoniae (ICESpn529IQ) was sequenced, whereas the ICEs from S. pyogenes (ICESpy029IQ and ICESpy005IQ, the first Tn5253-like ICEs reported in this species) were characterized by PCR mapping, partial sequencing, and restriction analysis. ICESpn529IQ and ICESpy029IQ were found to share the intSp 23FST81 integrase gene and an identical Tn916 fragment, whereas ICESpy005IQ has int5252 and lacks Tn916. All three ICEs were found to lack the linearized pC194 plasmid that is usually associated with Tn5253-like ICEs, and all displayed a single copy of a toxin-antitoxin operon that is typically contained in the direct repeats flanking the excisable pC194 region when this region is present. Two different insertion sites of the IQ elements were detected, one in ICESpn529IQ and ICESpy029IQ, and another in ICESpy005IQ. The chromosomal integration of the three ICEs was site specific, depending on the integrase (intSp 23FST81 or int5252). Only ICESpy005IQ was excised in circular form and transferred by conjugation. By transformation, mef(I) and catQ were cotransferred at a high frequency from S. pyogenes Spy005 and at very low frequencies from S. pneumoniae Spn529 and S. pyogenes Spy029.

  7. Detection of pneumolysin and autolysin genes among antibiotic resistant Streptococcus pneumoniae in invasive infections

    Sourav S

    2010-01-01

    Full Text Available Purpose: To detect the presence of autolysin and pneumolysin genes among Streptococcus pneumoniae strains isolated from different disease entities among Indian patients. The study also attempted to determine antimicrobial susceptibility of the isolates. Materials and Methods: A total of 24 S. pneumoniae isolates were checked for the presence of lytA gene coding for autolysin and ply gene coding for pneumolysin using polymerase chain reaction (PCR. All the isolates were subjected to susceptibility testing by disc diffusion method for 10 different therapeutically relevant antibiotics. Minimum inhibition concentration (MIC was determined using broth dilution method for ampicillin, penicillin and ciprofloxacin. Results: Eleven isolates from ocular infections and 13 isolates from different invasive diseases showed susceptibility to most of the antibiotics tested except chloramphenicol and ciprofloxacin. Fifty percentage of the isolates showed resistance to chloramphenicol and ciprofloxacin. A moderate level of resistance of 18% was noted for cefepime and ceftriaxone. Only 6% of resistance was observed for amoxicillin and ceftazidime. MIC levels ranged from 0.015 to 1 μg/mL for ampicillin and only one isolate had an MIC of 1 μg/mL. The MIC levels for penicillin ranged from 0.062 to 4 μg/mL, wherein nine isolates showed high levels of MICs ranging from 2 to 4 μg/mL. Six isolates had a very high resistance levels for ciprofloxacin with MIC ranging from 32-128 μg/mL. The presence of lytA was observed in 23 out of 24 isolates tested whereas only 17 isolates were positive for pneumolysin. Four ocular isolates and one isolate from ear infection were negative for pneumolysin. Conclusion: Emerging resistance observed for cefepime and ceftriaxone might be due their increased and frequent usage nowadays. Presence of pneumolysin appears to be more critical for pathogenesis of invasive infections than the ocular infections. However, presence of lytA gene in

  8. Unravelling the multiple functions of the architecturally intricate Streptococcus pneumoniae β-galactosidase, BgaA.

    Anirudh K Singh

    2014-09-01

    Full Text Available Bacterial cell-surface proteins play integral roles in host-pathogen interactions. These proteins are often architecturally and functionally sophisticated and yet few studies of such proteins involved in host-pathogen interactions have defined the domains or modules required for specific functions. Streptococcus pneumoniae (pneumococcus, an opportunistic pathogen that is a leading cause of community acquired pneumonia, otitis media and bacteremia, is decorated with many complex surface proteins. These include β-galactosidase BgaA, which is specific for terminal galactose residues β-1-4 linked to glucose or N-acetylglucosamine and known to play a role in pneumococcal growth, resistance to opsonophagocytic killing, and adherence. This study defines the domains and modules of BgaA that are required for these distinct contributions to pneumococcal pathogenesis. Inhibitors of β-galactosidase activity reduced pneumococcal growth and increased opsonophagocytic killing in a BgaA dependent manner, indicating these functions require BgaA enzymatic activity. In contrast, inhibitors increased pneumococcal adherence suggesting that BgaA bound a substrate of the enzyme through a distinct module or domain. Extensive biochemical, structural and cell based studies revealed two newly identified non-enzymatic carbohydrate-binding modules (CBMs mediate adherence to the host cell surface displayed lactose or N-acetyllactosamine. This finding is important to pneumococcal biology as it is the first adhesin-carbohydrate receptor pair identified, supporting the widely held belief that initial pneumococcal attachment is to a glycoconjugate. Perhaps more importantly, this is the first demonstration that a CBM within a carbohydrate-active enzyme can mediate adherence to host cells and thus this study identifies a new class of carbohydrate-binding adhesins and extends the paradigm of CBM function. As other bacterial species express surface-associated carbohydrate

  9. Identification and characterization of noncoding small RNAs in Streptococcus pneumoniae serotype 2 strain D39.

    Tsui, Ho-Ching Tiffany; Mukherjee, Dhriti; Ray, Valerie A; Sham, Lok-To; Feig, Andrew L; Winkler, Malcolm E

    2010-01-01

    We report a search for small RNAs (sRNAs) in the low-GC, gram-positive human pathogen Streptococcus pneumoniae. Based on bioinformatic analyses by Livny et al. (J. Livny, A. Brencic, S. Lory, and M. K. Waldor, Nucleic Acids Res. 34:3484-3493, 2006), we tested 40 candidates by Northern blotting and confirmed the expression of nine new and one previously reported (CcnA) sRNAs in strain D39. CcnA is one of five redundant sRNAs reported by Halfmann et al. (A. Halfmann, M. Kovacs, R. Hakenbeck, and R. Bruckner, Mol. Microbiol. 66:110-126, 2007) that are positively controlled by the CiaR response regulator. We characterized 3 of these 14 sRNAs: Spd-sr17 (144 nucleotides [nt]; decreased in stationary phase), Spd-sr37 (80 nt; strongly expressed in all growth phases), and CcnA (93 nt; induced by competence stimulatory peptide). Spd-sr17 and CcnA likely fold into structures containing single-stranded regions between hairpin structures, whereas Spd-sr37 forms a base-paired structure. Primer extension mapping and ectopic expression in deletion/insertion mutants confirmed the independent expression of the three sRNAs. Microarray analyses indicated that insertion/deletion mutants in spd-sr37 and ccnA exerted strong cis-acting effects on the transcription of adjacent genes, indicating that these sRNA regions are also cotranscribed in operons. Deletion or overexpression of the three sRNAs did not cause changes in growth, certain stress responses, global transcription, or virulence. Constitutive ectopic expression of CcnA reversed some phenotypes of D39 Delta ciaR mutants, but attempts to link CcnA to -E to comC as a target were inconclusive in ciaR(+) strains. These results show that S. pneumoniae, which lacks known RNA chaperones, expresses numerous sRNAs, but three of these sRNAs do not strongly affect common phenotypes or transcription patterns.

  10. Etiology of acute otitis media and serotype distribution of Streptococcus pneumoniae and Haemophilus influenzae in Chilean children <5 years of age.

    Rosenblut, Andres; Napolitano, Carla; Pereira, Angelica; Moreno, Camilo; Kolhe, Devayani; Lepetic, Alejandro; Ortega-Barria, Eduardo

    2017-02-01

    The impact of bacterial conjugate vaccines on acute otitis media (AOM) is affected by several factors including population characteristics, bacterial etiology and vaccine conjugation method, carrier, and coverage. This study estimated the baseline etiology, distribution, and antibiotic susceptibility of bacterial serotypes that causes AOM in children aged Haemophilus influenzae (40.3% [56/139]) were predominant among the cultures that showed bacterial growth (85% [139/164]). All Streptococcus pneumoniae positive episodes were serotyped, 19F (21%) and 14 (17%) were the predominant serotypes; all Haemophilus influenzae strains were nontypeable. Streptococcus pneumoniae were resistant to penicillin (5%) and erythromycin (33%); Haemophilus influenzae were resistant to ampicillin (14%) and cefuroxime and cefotaxime (2% each).AOM in Chilean children is predominantly caused by Streptococcus pneumoniae and nontypeable Haemophilus influenzae. Use of a broad spectrum vaccine against these pathogens might aid the reduction of AOM in Chile.

  11. CXCL14 displays antimicrobial activity against respiratory tract bacteria and contributes to clearance of Streptococcus pneumoniae pulmonary infection.

    Dai, Chen; Basilico, Paola; Cremona, Tiziana Patrizia; Collins, Paul; Moser, Bernhard; Benarafa, Charaf; Wolf, Marlene

    2015-06-15

    CXCL14 is a chemokine with an atypical, yet highly conserved, primary structure characterized by a short N terminus and high sequence identity between human and mouse. Although it induces chemotaxis of monocytic cells at high concentrations, its physiological role in leukocyte trafficking remains elusive. In contrast, several studies have demonstrated that CXCL14 is a broad-spectrum antimicrobial peptide that is expressed abundantly and constitutively in epithelial tissues. In this study, we further explored the antimicrobial properties of CXCL14 against respiratory pathogens in vitro and in vivo. We found that CXCL14 potently killed Pseudomonas aeruginosa, Streptococcus mitis, and Streptococcus pneumoniae in a dose-dependent manner in part through membrane depolarization and rupture. By performing structure-activity studies, we found that the activity against Gram-negative bacteria was largely associated with the N-terminal peptide CXCL141-13. Interestingly, the central part of the molecule representing the β-sheet also maintained ∼62% killing activity and was sufficient to induce chemotaxis of THP-1 cells. The C-terminal α-helix of CXCL14 had neither antimicrobial nor chemotactic effect. To investigate a physiological function for CXCL14 in innate immunity in vivo, we infected CXCL14-deficient mice with lung pathogens and we found that CXCL14 contributed to enhanced clearance of Streptococcus pneumoniae, but not Pseudomonas aeruginosa. Our comprehensive studies reflect the complex bactericidal mechanisms of CXCL14, and we propose that different structural features are relevant for the killing of Gram-negative and Gram-positive bacteria. Taken together, our studies show that evolutionary-conserved features of CXCL14 are important for constitutive antimicrobial defenses against pneumonia.

  12. New crystal structures of adenylate kinase from Streptococcus pneumoniae D39 in two conformations.

    Thach, Trung Thanh; Lee, Sangho

    2014-11-01

    Adenylate kinases (AdKs; EC 2.7.3.4) play a critical role in intercellular homeostasis by the interconversion of ATP and AMP to two ADP molecules. Crystal structures of adenylate kinase from Streptococcus pneumoniae D39 (SpAdK) have recently been determined using ligand-free and inhibitor-bound crystals belonging to space groups P21 and P1, respectively. Here, new crystal structures of SpAdK in ligand-free and inhibitor-bound states determined at 1.96 and 1.65 Å resolution, respectively, are reported. The new ligand-free crystal belonged to space group C2, with unit-cell parameters a=73.5, b=54.3, c=62.7 Å, β=118.8°. The new ligand-free structure revealed an open conformation that differed from the previously determined conformation, with an r.m.s.d on Cα atoms of 1.4 Å. The new crystal of the complex with the two-substrate-mimicking inhibitor P1,P5-bis(adenosine-5'-)pentaphosphate (Ap5A) belonged to space group P1, with unit-cell parameters a=53.9, b=62.3, c=63.0 Å, α=101.9, β=112.6, γ=89.9°. Despite belonging to the same space group as the previously reported crystal, the new Ap5A-bound crystal contains four molecules in the asymmetric unit, compared with two in the previous crystal, and shows slightly different lattice contacts. These results demonstrate that SpAdK can crystallize promiscuously in different forms and that the open structure is flexible in conformation.

  13. Absence of tmRNA Has a Protective Effect against Fluoroquinolones in Streptococcus pneumoniae.

    Brito, Liliana; Wilton, Joana; Ferrándiz, María J; Gómez-Sanz, Alicia; de la Campa, Adela G; Amblar, Mónica

    2016-01-01

    The transfer messenger RNA (tmRNA), encoded by the ssrA gene, is a small non-coding RNA involved in trans-translation that contributes to the recycling of ribosomes stalled on aberrant mRNAs. In most bacteria, its inactivation has been related to a decreased ability to respond to and recover from a variety of stress conditions. In this report, we investigated the role of tmRNA in stress adaptation in the human pathogen Streptococcus pneumoniae. We constructed a tmRNA deletion mutant and analyzed its response to several lethal stresses. The ΔssrA strain grew slower than the wild type, indicating that, although not essential, tmRNA is important for normal pneumococcal growth. Moreover, deletion of tmRNA increased susceptibility to UV irradiation, to exogenous hydrogen peroxide and to antibiotics that inhibit protein synthesis and transcription. However, the ΔssrA strain was more resistant to fluoroquinolones, showing twofold higher MIC values and up to 1000-fold higher survival rates than the wild type. Deletion of SmpB, the other partner in trans-translation, also reduced survival to levofloxacin in a similar extent. Accumulation of intracellular reactive oxygen species associated to moxifloxacin and levofloxacin treatment was also highly reduced (∼100-fold). Nevertheless, the ΔssrA strain showed higher intracellular accumulation of ethidium bromide and levofloxacin than the wild type, suggesting that tmRNA deficiency protects pneumococcal cells from fluoroquinolone-mediated killing. In fact, analysis of chromosome integrity revealed that deletion of tmRNA prevented the fragmentation of the chromosome associated to levofloxacin treatment. Moreover, such protective effect appears to relay mainly on inhibition of protein synthesis, since a similar effect was observed with antibiotics that inhibit that process. The emergence and spread of drug-resistant pneumococci is a matter of concern and these results contribute to a better comprehension of the mechanisms

  14. Diverse Ecological Strategies Are Encoded by Streptococcus pneumoniae Bacteriocin-Like Peptides.

    Miller, Eric L; Abrudan, Monica I; Roberts, Ian S; Rozen, Daniel E

    2016-04-13

    The opportunistic pathogen Streptococcus pneumoniae is commonly carried asymptomatically in the human nasopharynx. Due to high rates of cocolonization with other pneumococcus strains, intraspecific competitive interactions partly determine the carriage duration of strains and thereby their potential to cause disease. These interactions may be mediated by bacteriocins, such as the type IIb bacteriocins encoded by the blp (bacteriocin-like peptide) locus. To understand blp diversity and evolution, we undertook a bioinformatic analysis of 4,418 pneumococcal genomes, including 168 newly sequenced genomes. We describe immense variation at all levels of genomic organization: Gene presence/absence, gene order, and allelic diversity. If we make the extreme and naive hypothesis that assumes all genes in this operon can assort randomly, this variation could lead to 10(15) distinct bacteriocin-related phenotypes, each potentially representing a unique ecological strategy; however, we provide several explanations for why this extreme is not realized. Although rarefaction analysis indicates that the number of unique strategies is not saturated, even after sampling thousands of genomes, we show that the variation is neither unbounded nor random. We delimit three bacteriocin groups, which contain group-specific bacteriocins, immunity genes, and blp operon gene order, and argue that this organization places a constraint on realized ecological strategies. We additionally show that ecological strategy diversity is significantly constrained by pneumococcal phylogeny and clonal structure. By examining patterns of association between alleles within the blp operon, we show that bacteriocin genes, which were believed to function in pairs, can be found with a broad diversity of partner alleles and immunity genes; this overall lack of allelic fidelity likely contributes to the fluid structure of this operon. Our results clarify the diversity of antagonistic ecological strategies in the

  15. Absence of tmRNA Has a Protective Effect against Fluoroquinolones in Streptococcus pneumoniae

    Brito, Liliana; Wilton, Joana; Ferrándiz, María J.; Gómez-Sanz, Alicia; de la Campa, Adela G.; Amblar, Mónica

    2017-01-01

    The transfer messenger RNA (tmRNA), encoded by the ssrA gene, is a small non-coding RNA involved in trans-translation that contributes to the recycling of ribosomes stalled on aberrant mRNAs. In most bacteria, its inactivation has been related to a decreased ability to respond to and recover from a variety of stress conditions. In this report, we investigated the role of tmRNA in stress adaptation in the human pathogen Streptococcus pneumoniae. We constructed a tmRNA deletion mutant and analyzed its response to several lethal stresses. The ΔssrA strain grew slower than the wild type, indicating that, although not essential, tmRNA is important for normal pneumococcal growth. Moreover, deletion of tmRNA increased susceptibility to UV irradiation, to exogenous hydrogen peroxide and to antibiotics that inhibit protein synthesis and transcription. However, the ΔssrA strain was more resistant to fluoroquinolones, showing twofold higher MIC values and up to 1000-fold higher survival rates than the wild type. Deletion of SmpB, the other partner in trans-translation, also reduced survival to levofloxacin in a similar extent. Accumulation of intracellular reactive oxygen species associated to moxifloxacin and levofloxacin treatment was also highly reduced (∼100-fold). Nevertheless, the ΔssrA strain showed higher intracellular accumulation of ethidium bromide and levofloxacin than the wild type, suggesting that tmRNA deficiency protects pneumococcal cells from fluoroquinolone-mediated killing. In fact, analysis of chromosome integrity revealed that deletion of tmRNA prevented the fragmentation of the chromosome associated to levofloxacin treatment. Moreover, such protective effect appears to relay mainly on inhibition of protein synthesis, since a similar effect was observed with antibiotics that inhibit that process. The emergence and spread of drug-resistant pneumococci is a matter of concern and these results contribute to a better comprehension of the mechanisms

  16. Structural reevaluation of Streptococcus pneumoniae Lipoteichoic acid and new insights into its immunostimulatory potency.

    Gisch, Nicolas; Kohler, Thomas; Ulmer, Artur J; Müthing, Johannes; Pribyl, Thomas; Fischer, Kathleen; Lindner, Buko; Hammerschmidt, Sven; Zähringer, Ulrich

    2013-05-31

    Streptococcus pneumoniae is a Gram-positive human pathogen with a complex lipoteichoic acid (pnLTA) structure. Because the current structural model for pnLTA shows substantial inconsistencies, we reinvestigated purified and, more importantly, O-deacylated pnLTA, which is most suitable for NMR spectroscopy and electrospray ionization-MS spectrometry. We analyzed pnLTA of nonencapsulated pneumococcal strains D39Δcps and TIGR4Δcps, respectively. The data obtained allowed us to (re)define (i) the position and linkage of the repeating unit, (ii) the putative α-GalpNAc substitution at the ribitiol 5-phosphate (Rib-ol-5-P), and (iii) the length of (i.e. the number of repeating units in) the pnLTA chain. We here also describe for the first time that the terminal sugar residues in the pnLTA (Forssman disaccharide; α-D-GalpNAc-(1→3)-β-D-GalpNAc-(1→)), responsible for the cross-reactivity with anti-Forssman antigen antibodies, can be heterogeneous with respect to its degree of phosphorylcholine substitution in both O-6-positions. To assess the proinflammatory potency of pnLTA, we generated a (lipopeptide-free) Δlgt mutant of strain D39Δcps, isolated its pnLTA, and showed that it is capable of inducing IL-6 release in human mononuclear cells, independent of TLR2 activation. This finding was quite in contrast to LTA of the Staphylococcus aureus SA113Δlgt mutant, which did not activate human mononuclear cells in our experiments. Remarkably, this is also contrary to various other reports showing a proinflammatory potency of S. aureus LTA. Taken together, our study refines the structure of pnLTA and indicates that pneumococcal and S. aureus LTAs differ not only in their structure but also in their bioactivity.

  17. Mismatch repair in Streptococcus pneumoniae: relationship between base mismatches and transformation efficiencies.

    Claverys, J P; Méjean, V; Gasc, A M; Sicard, A M

    1983-10-01

    Genetic transformation in Streptococcus pneumoniae involves the insertion of single-stranded pieces of donor DNA into a recipient genome. Efficiencies of transformation strongly depend on the mutations (markers) carried by donor DNA. Markers are classified according to their transforming efficiencies into very high, high, intermediate, and low efficiency. The last is approximately 1/20th as efficient as the first. This marker effect is under the control of the Hex system, which is thought to correct mismatches at the donor-recipient heteroduplex stage in transformation. To investigate this effect, wild type, mutant, and revertant DNA sequences at five genetic sites within the amiA locus were determined. The results show that low-efficiency markers arise from transitional changes A . T to G . C. The transversion A . T to T . A corresponds to an intermediate-efficiency marker. Transversions G . C to T . A and G . C to C . G lead to high-efficiency markers. Among the eight possible mismatches that could exist transiently at the heteroduplex stage in transformation, only two--namely, A/G and C/C--are not corrected by the Hex system. It is noteworthy that the four possible base pairs (A . T, T . A, G . C, and C . G) have been encountered at the very same site (amiA6 site), which constitutes a good illustration of the marker effect. DNA sequence analysis also reveals that short deletions (33 or 34 bases long) are integrated with very high efficiencies. These results confirm that the Hex system corrects point mismatches harbored in donor-recipient heteroduplexes thousands of bases long. The correction pattern of the Hex system toward multiple-base mismatches has also been investigated. Its behavior toward double-base mismatches is complex, suggesting that neighboring sequences may affect the detection of mispaired bases.

  18. Clustering of serotypes in a longitudinal study of Streptococcus pneumoniae carriage in three day care centres

    Tanskanen Antti

    2008-12-01

    Full Text Available Abstract Background Streptococcus pneumoniae (pneumococcus causes a wide range of clinical manifestations that together constitute a major burden of disease worldwide. The main route of pneumococcal transmission is through asymptomatic colonisation of the nasopharynx. Studies of transmission are currently of general interest because of the impact of the new conjugate-polysaccharide vaccines on nasopharyngeal colonisation (carriage. Here we report the first longitudinal study of pneumococcal carriage that records serotype specific exposure to pneumococci simultaneously within the two most important mixing groups, families and day care facilities. Methods We followed attendees (N = 59 with their family members (N = 117 and the employees (N = 37 in three Finnish day care centres for 9 months with monthly sampling of nasopharyngeal carriage. Pneumococci were cultured, identified and serotyped by standard methods. Results Children in day care constitute a core group of pneumococcal carriage: of the 36 acquisitions of carriage with documented exposure to homologous pneumococci, the attendee had been exposed in her/his day care centre in 35 cases and in the family in 9 cases. Day care children introduce pneumococci to the family: 66% of acquisitions of a new serotype in a family were associated with simultaneous or previous carriage of the same type in the child attending day care. Consequently, pneumococcal transmission was found to take place as micro-epidemics driven by the day care centres. Each of the three day care centres was dominated by a serotype of its own, accounting for 100% of the isolates of that serotype among all samples from the day care attendees. Conclusion The transmission of pneumococci is more intense within than across clusters defined by day care facilities. The ensuing micro-epidemic behaviour enhances pneumococcal transmission.

  19. Distinct effects on diversifying selection by two mechanisms of immunity against Streptococcus pneumoniae.

    Yuan Li

    Full Text Available Antigenic variation to evade host immunity has long been assumed to be a driving force of diversifying selection in pathogens. Colonization by Streptococcus pneumoniae, which is central to the organism's transmission and therefore evolution, is limited by two arms of the immune system: antibody- and T cell- mediated immunity. In particular, the effector activity of CD4(+ T(H17 cell mediated immunity has been shown to act in trans, clearing co-colonizing pneumococci that do not bear the relevant antigen. It is thus unclear whether T(H17 cell immunity allows benefit of antigenic variation and contributes to diversifying selection. Here we show that antigen-specific CD4(+ T(H17 cell immunity almost equally reduces colonization by both an antigen-positive strain and a co-colonized, antigen-negative strain in a mouse model of pneumococcal carriage, thus potentially minimizing the advantage of escape from this type of immunity. Using a proteomic screening approach, we identified a list of candidate human CD4(+ T(H17 cell antigens. Using this list and a previously published list of pneumococcal Antibody antigens, we bioinformatically assessed the signals of diversifying selection among the identified antigens compared to non-antigens. We found that Antibody antigen genes were significantly more likely to be under diversifying selection than the T(H17 cell antigen genes, which were indistinguishable from non-antigens. Within the Antibody antigens, epitopes recognized by human antibodies showed stronger evidence of diversifying selection. Taken together, the data suggest that T(H17 cell-mediated immunity, one form of T cell immunity that is important to limit carriage of antigen-positive pneumococcus, favors little diversifying selection in the targeted antigen. The results could provide new insight into pneumococcal vaccine design.

  20. Cloning of the hexA mismatch-repair gene of Streptococcus pneumoniae and identification of the product.

    Martin, B; Prats, H; Claverys, J P

    1985-01-01

    The hexA mismatch repair gene of Streptococcus pneumoniae has been cloned into multicopy plasmid vectors. The cloned hexA gene is expressed as judged from its ability to complement various chromosomal hexA- alleles. Its direction of transcription was defined and the functional limits were localized by original methods relying on homology-dependent integration of nonautonomous chimeric plasmids carrying chromosomal inserts into the chromosome. Comparison of the proteins encoded by recombinant plasmids and by restriction fragments allowed us to identify an Mr 94 000 protein as the probable product of the hexA gene.

  1. The association of serotype and pulsed-field gel electrophoresis genotype in isolates of Streptococcus pneumoniae isolated in Israel

    M. Bar-Meir

    2015-05-01

    Full Text Available The relationship between Streptococcus pneumoniae isolates causing invasive infections in children admitted to a single center in central Israel was examined by pulsed-field gel electrophoresis (PFGE and serotyping. Although there was a close correlation between serotype and PFGE clone, the genetic diversity varied by serotype, with some genotypes comprising multiple serotypes. Additionally, clones C and D were associated with higher penicillin minimum inhibitory concentrations. Serotyping alone may be insufficient for epidemiological mapping of pneumococcal isolates in the era of pneumococcal conjugate polysaccharide vaccines.

  2. Affinity of ceftobiprole for penicillin-binding protein 2b in Streptococcus pneumoniae strains with various susceptibilities to penicillin.

    Davies, Todd A; He, Wenping; Bush, Karen; Flamm, Robert K

    2010-10-01

    Wild-type penicillin-binding protein (PBP) 2b from penicillin-susceptible Streptococcus pneumoniae had high affinity for ceftobiprole and penicillin (50% inhibitory concentrations [IC(50)s] of ≤0.15 μg/ml) but not ceftriaxone (IC(50) of >8 μg/ml). In clinical isolates, ceftobiprole and PBP 2b affinities were reduced 15- to 30-fold with a Thr-446-Ala substitution and further still with an additional Ala-619-Gly PBP 2b substitution. Ceftobiprole remained active (MICs of ≤1 μg/ml) against all strains tested and behaved more like penicillin than ceftriaxone with respect to PBP 2b binding.

  3. Identification and Characterization of Noncoding Small RNAs in Streptococcus pneumoniae Serotype 2 Strain D39 ▿ †

    Tsui, Ho-Ching Tiffany; Mukherjee, Dhriti; Ray, Valerie A.; Sham, Lok-To; Andrew L Feig; Winkler, Malcolm E.

    2009-01-01

    We report a search for small RNAs (sRNAs) in the low-GC, Gram-positive human pathogen Streptococcus pneumoniae. Based on bioinformatic analyses by Livny et al. (J. Livny, A. Brencic, S. Lory, and M. K. Waldor, Nucleic Acids Res. 34:3484-3493, 2006), we tested 40 candidates by Northern blotting and confirmed the expression of nine new and one previously reported (CcnA) sRNAs in strain D39. CcnA is one of five redundant sRNAs reported by Halfmann et al. (A. Halfmann, M. Kovacs, R. Hakenbeck, an...

  4. Serotype Distribution and Antimicrobial Sensitivity Profile of Streptococcus pneumoniae Carried in Healthy Toddlers before PCV13 Introduction in Niamey, Niger

    Sanda, Abdel-Kader A.; Soussou, Amadou M.

    2017-01-01

    Background To mitigate the burden of pneumococcal infections in Niger, a 13-valent pneumococcal vaccine, PCV13, was introduced for routine child vaccination in July 2014. In order to provide pre-vaccine baseline data and allow appreciation of changes on carriage due to vaccination, we analyzed retrospectively pneumococcal isolates obtained from healthy, 0 to 2 year old children prior to the vaccine introduction. Methods From June 5, 2007, to May 26, 2008, 1200 nasopharyngeal swabs were collected from healthy 0 to 2 year old children and analyzed by standard microbiological methods. Serotyping was done by SM-PCR and the data were analyzed with R version 2.15.0 (2012-03-30). Results Streptococcus pneumoniae was detected in 654/1200 children (54.5%) among whom 339 (51.8%) were males. The ages of the study subjects varied from few days to 26 months (mean = 7.1, median = 6, 95% CI [6.8–7.4]). Out of 654 frozen isolates, 377 (54.8%) were able to be re-grown and analyzed. In total, 32 different serogroups/serotypes were detected of which, the most prevalent were 6/(6A/6B/6C/6D) (15.6%), 23F (10.6%), 19F (9.3%), 14 (9%), 19A (5.6%), 23B (4.0%), 25F/38 (3.7%), 18/(18A/18B/18C/18F) (2.9%) and PCR non-typeable (16.4%). Eleven serogroups/serotypes accounting for 57.3% (216/377) were of PCV13 types. Of the 211/377 (56%) isolates tested for drug sensitivity, 23/211 (10.9%), 24/211 (11.4%), 9/211(4.3%) and 148/210 (70.5%) were respectively resistance to oxacillin, chloramphenicol, erythromycin and tetracycline. Thirteen of the oxacillin resistant isolates were additionally multidrug-resistant. No resistance was however detected to gentamycin500μg and to fluoroquinolones (ø Norfloxacin5μg 3 months and presence in family of more than one sibling aged 3 months and presence in family of children aged < 6 years were significant factors for pneumococcal carriage. The present data should help understanding post vaccine introduction changes in pneumococcal carriage and infections

  5. Systematic review and meta-analysis of a urine-based pneumococcal antigen test for diagnosis of community-acquired pneumonia caused by Streptococcus pneumoniae.

    Sinclair, Alison; Xie, Xuanqian; Teltscher, Marty; Dendukuri, Nandini

    2013-07-01

    Standard culture methods for diagnosis of Streptococcus pneumoniae pneumonia take at least 24 h. The BinaxNOW urine-based test for S. pneumoniae (BinaxNOW-SP) takes only 15 min to conduct, potentially enabling earlier diagnosis and targeted treatment. This study was conducted to assess whether the use of BinaxNOW-SP at the time of hospital admission would provide adequate sensitivity and specificity for diagnosis of community-acquired pneumonia (CAP) in adult patients. We searched PubMed, EMBASE/OVID, Cochrane Collaboration, Centre for Reviews and Dissemination, INAHTA, and CADTH for diagnostic or etiologic studies of hospitalized predominately adult patients with clinically defined CAP that reported the diagnostic performance of BinaxNOW-SP versus cultures. Two authors independently extracted study details and diagnostic two-by-two tables. We found that 27 studies met our inclusion criteria, and three different reference standards were used between them. A bivariate meta-analysis of 12 studies using a composite of culture tests as the reference standard estimated the sensitivity of BinaxNOW-SP as 68.5% (95% credibility interval [CrI], 62.6% to 74.2%) and specificity as 84.2% (95% CrI, 77.5% to 89.3%). A meta-analysis of all 27 studies, adjusting for the imperfect and variable nature of the reference standard, gave a higher sensitivity of 74.0% (CrI, 66.6% to 82·3%) and specificity of 97.2% (CrI, 92.7% to 99.8%). The analysis showed substantial heterogeneity across studies, which did not decrease with adjustment for covariates. We concluded that the higher pooled sensitivity (compared to culture) and high specificity of BinaxNOW-SP suggest it would be a useful addition to the diagnostic workup for community-acquired pneumonia. More research is needed regarding the impact of BinaxNOW-SP on clinical practice.

  6. Influence of clavulanic acid on the activity of amoxicillin against an experimental Streptococcus pneumoniae-Staphylococcus aureus mixed respiratory infection.

    Smith, G M; Boon, R J; Beale, A S

    1990-01-01

    An experimental respiratory infection caused by Streptococcus pneumoniae was established in weanling rats by intrabronchial instillation. Treatment of this infection with amoxicillin rapidly eliminated the pneumococci from the lung tissue. A beta-lactamase-producing strain of Staphylococcus aureus, when inoculated in a similar manner, did not persist adequately in the lungs long enough to permit a reasonable assessment of the therapy, but staphylococcal survival was extended in the lungs of rats infected 24 h previously with S. pneumoniae. Amoxicillin therapy was relatively ineffective against the pneumococci in this polymicrobial infection and had no effect on the growth of S. aureus. In contrast, amoxicillin-clavulanic acid eliminated the pneumococci from the lung tissue and brought about a reduction in the numbers of staphylococci. The data illustrate the utility of this model for the study of polymicrobial lung infections and demonstrate the role of amoxicillin-clavulanic acid in the treatment of polymicrobial infections involving beta-lactamase-producing bacteria. PMID:2327767

  7. Seasonal Variation of Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae Bacteremia According to Acquisition and Patient Characteristics

    Gradel, Kim Oren; Nielsen, Stig Lønberg; Pedersen, Court

    2016-01-01

    Seasonal variation analysis. METHODS In 3 Danish health regions (2.3 million total inhabitants), patients with bacteremia were identified from 2000 through 2011 using information from laboratory information systems. Analyses were confined to Escherichia coli, Staphylococcus aureus, and Streptococcus...... pneumoniae. Additional data were obtained from the Danish National Hospital Registry for the construction of admission histories and calculation of the Charlson comorbidity index (CCI). Bacteremias were categorized as community acquired, healthcare associated (HCA), and hospital acquired. We defined multiple....... coli, 6,924 S. aureus, and 4,884 S. pneumoniae bacteremia cases. For E. coli, the seasonal variation was highest for community-acquired cases (PTT ratio, 1.24; 95% CI, 1.17-1.32), was diminished for HCA (PTT ratio, 1.14; 95% CI, 1.04-1.25), and was missing for hospital-acquired cases. No seasonal...

  8. Rationale for revised penicillin susceptibility breakpoints versus Streptococcus pneumoniae: coping with antimicrobial susceptibility in an era of resistance.

    Weinstein, Melvin P; Klugman, Keith P; Jones, Ronald N

    2009-06-01

    In January 2008, the Clinical and Laboratory Standards Institute published revised susceptibility breakpoints for penicillin and Streptococcus pneumoniae, and shortly thereafter, the United States Food and Drug Administration similarly revised its breakpoints via changes in the package insert for penicillin. The revised susceptibility breakpoint is penicillin at a dosage of 12 million units-24 million units per day. The susceptibility breakpoint of penicillin at a dosage of > or =18 million units per day. Herein, we review the scientific basis for the revisions to the breakpoints, which were supported by microbiologic, pharmacokinetic and/or pharmacodynamic, and clinical data. Clinicians, once again, should feel comfortable prescribing penicillin for pneumococcal pneumonia and other pneumococcal infections outside the central nervous system.

  9. Pneumonia and empyema caused by Streptococcus intermedius that shows the diagnostic importance of evaluating the microbiota in the lower respiratory tract.

    Noguchi, Shingo; Yatera, Kazuhiro; Kawanami, Toshinori; Yamasaki, Kei; Fukuda, Kazumasa; Naito, Keisuke; Akata, Kentarou; Nagata, Shuya; Ishimoto, Hiroshi; Taniguchi, Hatsumi; Mukae, Hiroshi

    2014-01-01

    The bacterial species in the Streptococcus anginosus group (S. constellatus, S. anginosus, S. intermedius) are important causative pathogens of bacterial pneumonia, pulmonary abscesses and empyema. However, the bacteria in this group are primarily oral resident bacteria and unable to grow significantly on ordinary aerobic culture media. We experienced a case of pneumonia and empyema caused by Streptococcus intermedius detected using a 16S rRNA gene sequencing analysis of bronchoalveolar lavage fluid and pleural effusion, but not sputum. Even when applying the molecular method, sputum samples are occasionally unsuitable for identifying the causative pathogens of lower respiratory tract infections.

  10. Outbreak of Pneumonia in the Setting of Fatal Pneumococcal Meningitis among US Army Trainees: Potential Role of Chlamydia pneumoniae Infection

    2011-06-02

    physical stress may contribute to an increased risk for infections with Streptococcus pneumoniae , Streptococcus pyogenes, Mycoplasma pneumoniae ...Chlamydia pneumoniae , Mycoplasma pneumoniae , Streptococcus pneumoniae , Bordetella pertussis, and Legionella pneumophila[10] in addition to undergoing...postexposure chemoprophylaxis. Mil Med 2003;168:1-6 7. Balicer RD, Zarka S, Levine H, et al. Control of Streptococcus pneumoniae serotype 5 epidemic of

  11. Resistance of Streptococcus pneumoniae to antimicrobials in São Paulo, Brazil: clinical features and serotypes Resistência antimicrobiana de Streptococcus pneumoniae em São Paulo, Brasil: quadro clínico e sorotipos

    Anna Sara S. Levin

    1996-06-01

    Full Text Available To study resistance to antimicrobials, serotypes and clinical features of S. pneumoniae in S. Paulo, Brazil, 50 patients with a positive culture were evaluated: 7 were considered carriers and 43 had pneumococcal infections. Pneumonia and meningitis were the most commom infections. Mortality was 34% and underlying diseases were present in 70%. Relative resistance to penicillin occurred in 24% and complete resistance was not detected. Resistance to tetracycline was 32% and to sulfamethoxazole/trimethoprim 32%; one strain had intermediate susceptibility to erythromycin; no resistance was present for chloramphenicol, rifampin or vancomycin. Resistance to at least one of the drugs tested occurred in 62%. Results by the E-test for penicillin were similar to those by the agar dilution method. There were 24 different serotypes and 74% of the strains belonged to the 23-valent vaccine including all the penicillin-resistant strains. In this study S. pneumoniae caused severe infections and presented a high resistance rate to commonly used antimicrobials. Routine surveillance of resistance and the use of vaccination, as well as the restriction of inappropriate use of antimicrobials, are recommended in São Paulo, Brazil.Com a finalidade de estudar resistência a antimicrobianos, sorotipos e quadro clínico de Streptococcus pneumoniae em São Paulo, Brasil, foram avaliados 50 pacientes com culturas positivas: 7 foram considerados portadores e 43 infectados. Pneumonia e meningite foram as infecções mais freqüentes. A letalidade foi de 34% e doenças de base estiveram presentes em 70%. Resistência relativa a penicilina ocorreu em 24% e a resistência completa não foi detectada. Resistência a tetraciclina ocorreu em 32% e a sulfametoxazol/trimetoprim em 32% e houve uma cepa com sensibilidade intermediária a eritromicina. Não houve resistência a cloranfenicol, rifampicina ou vancomicina. Em 62% dos casos houve resistência a pelo menos uma das drogas

  12. [Serotype distribution of Streptococcus pneumoniae isolated from invasive infections at the Hospital de Niños of Santa Fe].

    Mayoral, C; Baroni, M R; Giani, R; Virgolini, S; Zurbriggen, L; Regueira, M

    2008-01-01

    The serotype distribution of Streptococcus pneumoniae varies through time. The introduction of pneumococcal conjugate vaccines showed a decreased prevalence of pneumococcal invasive isolates belonging to serotype 14 and an increase of serotypes not therein included. In 1993, the Hospital de Niños of Santa Fe began surveillance of the serotype distribution of invasive S. pneumoniae disease. In the period 2003-2005, 76 isolates were analysed by studying the correlation between serotype and pathology, age and MIC of penicillin. Serotype 14 was the most frequent followed by serotypes 1, 6B, 18C, 7F, 19 F and 5. Serotype 14 showed a statistically significant correlation with MICs of penicillin ranging from 0,5 to 2 mg/l. Although this serotype was more frequently observed in pneumonia than in meningitis, there was not a significant association with any particular pathology. Serotypes 14 and 1, were prevalent among children under and over 2 years old, respectively. Most of these isolates with MICs of penicillin = 2 mg/l, were from patients with pneumonia and not with meningitis. The serotype distribution was similar to that during the period 1993-99, with the exception of serotypes 18C, 4, 12F and 22F which had never been found before. The emergence of these serotypes makes it essential to continue surveillance to determine which conjugated vaccine formulation would be suitable to prevent the most frequent pneumococcal invasive infections.

  13. The crystal structure of alanine racemase from Streptococcus pneumoniae, a target for structure-based drug design

    Davlieva Milya

    2011-05-01

    Full Text Available Abstract Background Streptococcus pneumoniae is a globally important pathogen. The Gram-positive diplococcus is a leading cause of pneumonia, otitis media, bacteremia, and meningitis, and antibiotic resistant strains have become increasingly common over recent years.Alanine racemase is a ubiquitous enzyme among bacteria and provides the essential cell wall precursor, D-alanine. Since it is absent in humans, this enzyme is an attractive target for the development of drugs against S. pneumoniae and other bacterial pathogens. Results Here we report the crystal structure of alanine racemase from S. pneumoniae (AlrSP. Crystals diffracted to a resolution of 2.0 Å and belong to the space group P3121 with the unit cell parameters a = b = 119.97 Å, c = 118.10 Å, α = β = 90° and γ = 120°. Structural comparisons show that AlrSP shares both an overall fold and key active site residues with other bacterial alanine racemases. The active site cavity is similar to other Gram positive alanine racemases, featuring a restricted but conserved entryway. Conclusions We have solved the structure of AlrSP, an essential step towards the development of an accurate pharmacophore model of the enzyme, and an important contribution towards our on-going alanine racemase structure-based drug design project. We have identified three regions on the enzyme that could be targeted for inhibitor design, the active site, the dimer interface, and the active site entryway.

  14. Association between fluoroquinolone usage and a dramatic rise in ciprofloxacin-resistant Streptococcus pneumoniae in Canada, 1997-2006.

    Adam, Heather J; Hoban, Daryl J; Gin, Alfred S; Zhanel, George G

    2009-07-01

    This study evaluated the prevalence of fluoroquinolone usage and investigated the association between usage and resistance in respiratory isolates of Streptococcus pneumoniae in Canada. Fluoroquinolone susceptibility testing was conducted on S. pneumoniae collected from 25 medical centres across Canada over nine study years. Fluoroquinolone prescriptions and consumption figures were derived from data in the IMS Health, Canada CompuScript Audit. Between 1997 and 2006, 11825 S. pneumoniae isolates were collected. Ciprofloxacin resistance rates increased significantly (P or = 65 years). Outpatient ciprofloxacin and respiratory fluoroquinolone prescriptions increased by 55.6% (38.2 prescriptions/1000 population to 59.4 prescriptions/1000 population; Pfluoroquinolone consumption increased by 10.6% [1.1 defined daily doses (DDDs)/1000/day to 1.2 DDDs/1000/day; P=0.02] and 38.2% (0.5 to 0.7 DDDs/1000/day; P=0.02), respectively, from 2001 to 2006. A strong association between ciprofloxacin use and resistance (R(2)=0.89) was identified. Fluoroquinolone resistance in S. pneumoniae increased significantly in Canada from 1997 to 2006 in conjunction with increased ciprofloxacin and respiratory fluoroquinolone consumption. Ciprofloxacin usage appears to be the biggest driver of resistance; however, total fluoroquinolone usage is also important.

  15. [Activity of cefpodoxime and other oral beta-lactams against Haemophilus influenzae and Streptococcus pneumoniae with different susceptibilities to penicillin].

    Fenoll, A; Robledo, O; Lerma, M; Giménez, M J; Cebrián, L; Casal, J; Aguilar, L; Gómez-Lus, M L

    2006-03-01

    This study explores the influence on the intrinsic activity of different oral beta-lactams of beta-lactamase production in Haemophilus influenzae and penicillin resistance in Streptococcus pneumoniae. Three substudies were performed: a) a general susceptibility study, analyzing 550 strains received by the Spanish Laboratorio de Referencia de Neumococos throughout February and March 2005; b) a study on the influence of penicillin resistance on the activity of beta-lactams, analyzing 251 penicillin-susceptible strains (MICor=2 mg/l) randomly chosen among those received by the Spanish Laboratorio de Referencia de Neumococos throughout 2005; and c) an H. influenzae susceptibility study analyzing 150 strains received by Instituto Valenciano de Microbiologia throughout 2005. A total of 71% of S. pneumoniae strains were susceptible to penicillin, 21% exhibited intermediate resistance and 8% strains presented full resistance. H. influenzae beta-lactamase production rate was 18.6%. Of the non-beta-lactamase-producing strains, 3% were not susceptible to ampicillin. Cefpodoxime and cefixime exhibited the highest intrinsic activity against H. influenzae, while amoxicillin and cefpodoxime were the most active compounds against S. pneumoniae. All H. influenzae strains were susceptible to oral cephalosporins and amoxicillin/clavulanic acid. The increase in penicillin resistance in S. pneumoniae influenced cefixime, cefaclor and cefuroxime to a higher degree than amoxicillin and cefpodoxime.

  16. Regulation of virulence gene expression resulting from Streptococcus pneumoniae and nontypeable Haemophilus influenzae interactions in chronic disease.

    Emily K Cope

    Full Text Available Chronic rhinosinusitis (CRS is a common inflammatory disease of the sinonasal cavity mediated, in part, by polymicrobial communities of bacteria. Recent molecular studies have confirmed the importance of Streptococcus pneumoniae and nontypeable Haemophilus influenzae (NTHi in CRS. Here, we hypothesize that interaction between S. pneumoniae and NTHi mixed-species communities cause a change in bacterial virulence gene expression. We examined CRS as a model human disease to validate these polymicrobial interactions. Clinical strains of S. pneumoniae and NTHi were grown in mono- and co-culture in a standard biofilm assay. Reverse transcriptase real-time PCR (RTqPCR was used to measure gene expression of key virulence factors. To validate these results, we investigated the presence of the bacterial RNA transcripts in excised human tissue from patients with CRS. Consequences of physical or chemical interactions between microbes were also investigated. Transcription of NTHi type IV pili was only expressed in co-culture in vitro, and expression could be detected ex vivo in diseased tissue. S. pneumoniae pyruvate oxidase was up-regulated in co-culture, while pneumolysin and pneumococcal adherence factor A were down-regulated. These results were confirmed in excised human CRS tissue. Gene expression was differentially regulated by physical contact and secreted factors. Overall, these data suggest that interactions between H. influenzae and S. pneumoniae involve physical and chemical mechanisms that influence virulence gene expression of mixed-species biofilm communities present in chronically diseased human tissue. These results extend previous studies of population-level virulence and provide novel insight into the importance of S. pneumoniae and NTHi in CRS.

  17. Fatal purpura fulminans and Waterhouse-Friderichsen syndrome from fulminant Streptococcus pneumoniae sepsis in an asplenic young adult.

    Hale, Andrew J; LaSalvia, Mary; Kirby, James E; Kimball, Allison; Baden, Rachel

    2016-01-01

    Asplenic patients are at increased risk for sepsis and fulminant infection. Sepsis in these patients is typically secondary to encapsulated bacteria, with Streptococcus pneumoniae being the most frequent pathogen. Rare complications of severe sepsis include purpura fulminans and bilateral adrenal hemorrhage (Waterhouse-Friderichsen syndrome). We present the case of a 36-year-old woman, healthy except for splenectomy years prior for idiopathic thrombocytopenic purpura treatment, who presented with fever. Upon presentation to our hospital, three hours after symptoms onset, she had purpura fulminans and shock. Despite timely antimicrobials and maximal resuscitative efforts, her disease progressed and she expired 12 hours after symptoms onset. Autopsy revealed bilateral adrenal hemorrhage; acute adrenal crisis likely contributed to her refractory shock. Prior to her presentation, she had not received guideline-based post-splenectomy care. Sepsis in asplenic patients can be fulminant and rapidly fatal. Streptococcus pneumoniae remains the most frequent cause, despite decreasing rates in recent years related to widespread pneumococcal vaccination. Guideline-based vaccinations and "pill-in-pocket" therapy can be life-saving for asplenic patients. Purpura fulminans represents an extreme manifestation of disseminated intravascular coagulation, is more common in asplenic patients, and portends a poor prognosis. Waterhouse-Friderichsen syndrome can be seen concurrently with purpura fulminans and further portends a poor prognosis; pre-mortem diagnosis requires a high index of suspicion.

  18. [Studies on expression, purification, crystal growth and optimization of putative transcription factor LytR from Streptococcus pneumoniae].

    Min, Xun; Zhong, Wen; Zhao, Shasha; Dong, Jie; Dong, Shanshan; Zhou, Aie; Yan, Wenjuan; Wang, Deqiang

    2013-08-01

    The aim of the present study was to obtain the crystal of transcription factor LytR of streptococcus pneumoniae for X-ray crystal structure and function analysis. The LytR gene of D39 strains from Streptococcus pneumoniae (S. pn) was cloned into the prokaryotic expression vector pET32a(+), then overexpression was obtained in the E. coli BL21 (DE3) through transformation of the recombinant plasmid that had been verified by colony PCR and sequencing. Soluble fusion protein with His-tag highly expressed by the induction of 0.5 mmol/L IPTG and was purified by a three step procedure, the purity of the purified LytR recombinant protein was over 90%. Preliminary screening of crystallization conditions was performed using the hanging-drop vapour-diffusing method with Hampton Crystal screen and PEG screen kits. The protein crystals X-ray diffraction data were collected from a single crystal and more stick crystals whose X-ray diffraction reached 4.0 A were obtained. These works laid the foundation for further research on the 3D structure of putative transcription factor LytR and its biological aspects.

  19. Experimental otitis media in gerbils and chinchillas with Streptococcus pneumoniae, Haemophilus influenzae, and other aerobic and anaerobic bacteria.

    Fulghum, R S; Brinn, J E; Smith, A M; Daniel, H J; Loesche, P J

    1982-05-01

    To ascertain the usefulness of Mongolian gerbils as an inbred model for otitis media, 52 Mongolian gerbils (Meriones unguiculatus, strain MONT/Tum) were compared with 26 chinchillas (Chinchilla laniger) for susceptibility to Streptococcus pneumoniae type 3. Haemophilus influenzae type b, and a polymicrobic culture including anaerobes (Streptococcus intermedius, Propionibacterium acnes, Staphylococcus epidermidis, and Corynebacterium sp.). Organisms were inoculated percutaneously into the superior chamber of the middle ear bulla. The gerbils and chinchillas shared similar susceptibilities and responses to the inoculated organisms as determined by X-ray, otoscopic, histopathological, and microbiological determinations at 5 to 7 days. Koch's postulate studies proved the role of S. pneumoniae and H. influenzae in the pathology found in both animal models. The animals were also susceptible to the polymicrobic culture, although the relative virulence of the individual members of this mixture was low, suggesting that these species potentiated as a polymicrobic mixture. The Corynebacterium sp. appeared to elicit the greatest histopathological response in chronic (8-week) studies in gerbils. The gerbils were found to be useful as an alternative animal model for the study of otitis media of bacterial etiology.

  20. TRAIL+ monocytes and monocyte-related cells cause lung damage and thereby increase susceptibility to influenza-Streptococcus pneumoniae coinfection.

    Ellis, Gregory T; Davidson, Sophia; Crotta, Stefania; Branzk, Nora; Papayannopoulos, Venizelos; Wack, Andreas

    2015-09-01

    Streptococcus pneumoniae coinfection is a major cause of influenza-associated mortality; however, the mechanisms underlying pathogenesis or protection remain unclear. Using a clinically relevant mouse model, we identify immune-mediated damage early during coinfection as a new mechanism causing susceptibility. Coinfected CCR2(-/-) mice lacking monocytes and monocyte-derived cells control bacterial invasion better, show reduced epithelial damage and are overall more resistant than wild-type controls. In influenza-infected wild-type lungs, monocytes and monocyte-derived cells are the major cell populations expressing the apoptosis-inducing ligand TRAIL. Accordingly, anti-TRAIL treatment reduces bacterial load and protects against coinfection if administered during viral infection, but not following bacterial exposure. Post-influenza bacterial outgrowth induces a strong proinflammatory cytokine response and massive inflammatory cell infiltrate. Depletion of neutrophils or blockade of TNF-α facilitate bacterial outgrowth, leading to increased mortality, demonstrating that these factors aid bacterial control. We conclude that inflammatory monocytes recruited early, during the viral phase of coinfection, induce TRAIL-mediated lung damage, which facilitates bacterial invasion, while TNF-α and neutrophil responses help control subsequent bacterial outgrowth. We thus identify novel determinants of protection versus pathology in influenza-Streptococcus pneumoniae coinfection.

  1. Compensatory evolution of pbp mutations restores the fitness cost imposed by β-lactam resistance in Streptococcus pneumoniae.

    Andrea G Albarracín Orio

    2011-02-01

    Full Text Available The prevalence of antibiotic resistance genes in pathogenic bacteria is a major challenge to treating many infectious diseases. The spread of these genes is driven by the strong selection imposed by the use of antibacterial drugs. However, in the absence of drug selection, antibiotic resistance genes impose a fitness cost, which can be ameliorated by compensatory mutations. In Streptococcus pneumoniae, β-lactam resistance is caused by mutations in three penicillin-binding proteins, PBP1a, PBP2x, and PBP2b, all of which are implicated in cell wall synthesis and the cell division cycle. We found that the fitness cost and cell division defects conferred by pbp2b mutations (as determined by fitness competitive assays in vitro and in vivo and fluorescence microscopy were fully compensated by the acquisition of pbp2x and pbp1a mutations, apparently by means of an increased stability and a consequent mislocalization of these protein mutants. Thus, these compensatory combinations of pbp mutant alleles resulted in an increase in the level and spectrum of β-lactam resistance. This report describes a direct correlation between antibiotic resistance increase and fitness cost compensation, both caused by the same gene mutations acquired by horizontal transfer. The clinical origin of the pbp mutations suggests that this intergenic compensatory process is involved in the persistence of β-lactam resistance among circulating strains. We propose that this compensatory mechanism is relevant for β-lactam resistance evolution in Streptococcus pneumoniae.

  2. A novel computational method identifies intra- and inter-species recombination events in Staphylococcus aureus and Streptococcus pneumoniae.

    Lisa Sanguinetti

    Full Text Available Advances in high-throughput DNA sequencing technologies have determined an explosion in the number of sequenced bacterial genomes. Comparative sequence analysis frequently reveals evidences of homologous recombination occurring with different mechanisms and rates in different species, but the large-scale use of computational methods to identify recombination events is hampered by their high computational costs. Here, we propose a new method to identify recombination events in large datasets of whole genome sequences. Using a filtering procedure of the gene conservation profiles of a test genome against a panel of strains, this algorithm identifies sets of contiguous genes acquired by homologous recombination. The locations of the recombination breakpoints are determined using a statistical test that is able to account for the differences in the natural rate of evolution between different genes. The algorithm was tested on a dataset of 75 genomes of Staphylococcus aureus and 50 genomes comprising different streptococcal species, and was able to detect intra-species recombination events in S. aureus and in Streptococcus pneumoniae. Furthermore, we found evidences of an inter-species exchange of genetic material between S. pneumoniae and Streptococcus mitis, a closely related commensal species that colonizes the same ecological niche. The method has been implemented in an R package, Reco, which is freely available from supplementary material, and provides a rapid screening tool to investigate recombination on a genome-wide scale from sequence data.

  3. [Genetic analysis of multidrug-resistant Streptococcus pneumoniae including meropenem resistance that was isolated from elderly residents with pneumonia in nursing-care facilities].

    Ota, Kazuko; Chiba, Naoko; Sato, Kentaro; Nara, Syoetu; Kato, Satoko; Kanazawa, Hisao; Ikejima, Shin; Takahashi, Yoshihiro; Iwata, Satoshi; Ubukata, Kimiko

    2014-07-01

    From February to December 20XX, penicillin-resistant Streptococcus pneumoniae (PRSP) showing MICs of 16-32 microg/mL to cefotaxime (CTX) and 4-8 microg/mL to meropenem (MEPM) were isolated from 6 patients hospitalized at the general hospital S (2 cases) and hospital A (4 cases), close to the hospital S. Five elderly patients among these six cases came from nursing care facilities or nursing care-related medical facilities. All elderly persons (mean age: 81.7 years) were diagnosed as having pneumonia at the time of admission and the problematic PRSP was isolated from sputum samples collected on admission. Notably, all of these PRSP isolates simultaneously showed high resistance to macrolide agents mediated by an erm (B) gene and to fluoroquinolone agents via mutations in the gyrA and parC genes. Eventually, they were identified as multidrug-resistant S. pneumoniae (MDRSP) with high resistance to many agents. The capsule type of all strains was serotype 19F and multilocus sequence typing (MLST) revealed that they belonged to clonal complex (CC) 7993, which has not been reported before. It was thus concluded that the MDRSP that had spread within the nursing facilities was transmitted to the general hospitals via the elderly inpatients with pneumonia caused by these agents. Although one case finally had a poor outcome, the pneumococcal infection was not the direct trigger of the event. The current ratio of MDRSP is concluded to be very low. However, general hospitals that accept patients for therapeutic purposes from nursing-care facilities have to share epidemiological information in a timely manner with the nursing homes to prevent nosocomial infections.

  4. Activity of ceftobiprole against Streptococcus pneumoniae isolates exhibiting high-level resistance to ceftriaxone.

    Davies, Todd A; Flamm, Robert K; Lynch, A Simon

    2012-06-01

    Tracking Resistance in the US Today (TRUST) 2008 surveillance data showed that 6% of Streptococcus pneumoniae were non-susceptible to ceftriaxone [minimum inhibitory concentration (MIC) ≥ 2 μg/mL] and that 8% of the ceftriaxone-non-susceptible isolates exhibited high-level resistance (MIC ≥ 8 μg/mL). Here we describe the activity of ceftobiprole against ceftriaxone-resistant isolates and characterise the genotypic traits associated with resistance. Thirty isolates with ceftriaxone MICs ≥ 8 μg/mL were analysed by sequencing of penicillin-binding protein (PBP) and murM genes. Sequencing of pbp1a, pbp2b and pbp2x showed nine PBP patterns, with the most common (n=17) being: PBP1a T371S (STMK motif), P432T (SRNVP motif); PBP2b T446A (SSNT motif), A619G (KTGTA motif); and PBP2x T338A and M339F (STMK motif), L364F, I371T, R384G, M400T, L546V (LKSGT motif); six isolates had the same pattern without the PBP2b A619G change. For these 23 isolates, MICs were 8 μg/mL for ceftriaxone, 4-8 μg/mL for penicillin and 0.5-2 μg/mL for ceftobiprole. The remaining seven isolates with higher MICs (ceftriaxone 8-32 μg/mL, penicillin 4-32 μg/mL and ceftobiprole 2-4 μg/mL) had fewer PBP active-site motif substitutions. The majority of isolates (17/30) had murM alleles similar to the wild-type, whilst the rest had alleles reflecting a mosaic structure. No murM alleles were associated with higher MICs. Against these 30 isolates, ceftobiprole was 4-16-fold more active than ceftriaxone. Widely described PBP and MurM substitutions probably account for the high ceftriaxone MICs (8 μg/mL) in the majority of isolates. However, seven isolates with ceftriaxone MICs of 8-32 μg/mL had fewer PBP substitutions in active-site motifs, suggesting either that there is another resistance mechanism or that unique PBP mutations may contribute to high-level β-lactam resistance.

  5. Expression of Streptococcus pneumoniae Bacteriocins Is Induced by Antibiotics via Regulatory Interplay with the Competence System.

    Kjos, Morten; Miller, Eric; Slager, Jelle; Lake, Frank B; Gericke, Oliver; Roberts, Ian S; Rozen, Daniel E; Veening, Jan-Willem

    2016-02-01

    Pneumococcal bacteriocins (pneumocins) are antibacterial toxins that mediate intra-species competition within the human host. However, the triggers of pneumocin expression are poorly understood. Using RNA-sequencing, we mapped the regulon of the pneumocin cluster (blp) of Streptococcus pneumoniae D39. Furthermore, by analogy with pneumococcal competence, we show that several antibiotics activate the blp-genes. Using real-time gene expression measurements we show that while the promoter driving expression of the two-component regulatory system blpR/H is constitutive, the remaining blp-promoters that control pneumocin expression, immunity and the inducer peptide BlpC, are pH-dependent and induced in the late exponential phase. Intriguingly, competence for genetic transformation, mediated by the paralogous ComD/E two-component quorum system, is induced by the same environmental cues. To test for interplay between these regulatory systems, we quantified the regulatory response to the addition of synthetic BlpC and competence-stimulating peptide (CSP). Supporting the idea of such interplay, we found that immediately upon addition of CSP, the blp-promoters were activated in a comD/E-dependent manner. After a delay, blp-expression was highly induced and was strictly dependent on blpRH and blpC. This raised the question of the mechanism of BlpC export, since bioinformatic analysis showed that the genes encoding the putative exporter for BlpC, blpAB, are not intact in strain D39 and most other strains. By contrast, all sequenced pneumococcal strains contain intact comAB genes, encoding the transport system for CSP. Consistent with the idea that comAB mediate BlpC export, we finally show that high-level expression of the blp-genes requires comAB. Together, our results demonstrate that regulation of pneumocin expression is intertwined with competence, explaining why certain antibiotics induce blp-expression. Antibiotic-induced pneumocin expression might therefore have

  6. Prevalence of antimicrobial resistance of Streptococcus pneumoniae in Chinese children: four hospitals surveillance

    沈叙庄; 陆权; 叶启慈; 张国成; 俞桑洁; 张泓; 邓秋莲; 杨永弘

    2003-01-01

    Objective To investigate the nasal carriage of antibiotic-resistant pneumococci in children of <5 years old in the following four cities, Beijing, Shanghai, Guangzhou and Xi'an.Methods A total of 647 pneumococci strains were isolated and detected. Minimal inhibition concentrations (MICs) of antibiotics were determined by E-test. Disk diffusion test was used for the measurement of antimicrobial susceptibility.Results Prevalence of penicillin non-susceptible Streptococcus pneumoniae in the four cities was 41%, with Guangzhou (60.8%) ranking first, followed by Xi'an (45%), Shanghai (37%) and Beijing (25.9%). The majority of penicillin non-susceptibility isolates (23.9%-53.8%) had a low level of resistance (MIC 0.64-1.5 μg/ml). The most sensitive antimicrobials in terms of percentage of susceptible organisms were amoxicillin-clavulanic acid (99.4%), followed by ceftriaxone (92.1%); cefurxime and cefaclor were slightly more sensitive than penicillin with susceptibility of 74.8% and 77.9%. Erythromycin, tetracycline and TMP-SMZ were highly resistant (83.6%, 82.1% and 76.2% respectively). Among erythromycin resistant isolates, 100% were resistant to azithromycin, 98.6% to clarithromycin, 97.2% to roxithromycin and spiramycin, and 96.6% to clindamycin. 97.2% (141/145) were typical of the macrolides-lincosamides-streptogramons B (MLSB ) resistance phenotype, and 2.8% (4/145) were M phenotype. The group of PRSP was with significantly higher rates of non-susceptibility for ceftriaxone (18.4%), cefurxime (58.6%), cefaclor (53.4%), compared with the group of PEN-S (0.5%, 1.8% and 0.2%, respectively) and the rate of multi-drug resistance in the isolates of PRSP group (92.9%) was significantly higher than that of PEN-S group (59.2%).Conclusion The rates of penicillin and multi-drug resistance among isolates of pneumococci carried nasally in are high children and the high prevalence of multi-drug resistance in the Chinese population may be becoming one of the most serious

  7. Antibiotic selection pressure and macrolide resistance in nasopharyngeal Streptococcus pneumoniae: a cluster-randomized clinical trial.

    Alison H Skalet

    Full Text Available BACKGROUND: It is widely thought that widespread antibiotic use selects for community antibiotic resistance, though this has been difficult to prove in the setting of a community-randomized clinical trial. In this study, we used a randomized clinical trial design to assess whether macrolide resistance was higher in communities treated with mass azithromycin for trachoma, compared to untreated control communities. METHODS AND FINDINGS: In a cluster-randomized trial for trachoma control in Ethiopia, 12 communities were randomized to receive mass azithromycin treatment of children aged 1-10 years at months 0, 3, 6, and 9. Twelve control communities were randomized to receive no antibiotic treatments until the conclusion of the study. Nasopharyngeal swabs were collected from randomly selected children in the treated group at baseline and month 12, and in the control group at month 12. Antibiotic susceptibility testing was performed on Streptococcus pneumoniae isolated from the swabs using Etest strips. In the treated group, the mean prevalence of azithromycin resistance among all monitored children increased from 3.6% (95% confidence interval [CI] 0.8%-8.9% at baseline, to 46.9% (37.5%-57.5% at month 12 (p = 0.003. In control communities, azithromycin resistance was 9.2% (95% CI 6.7%-13.3% at month 12, significantly lower than the treated group (p < 0.0001. Penicillin resistance was identified in 0.8% (95% CI 0%-4.2% of isolates in the control group at 1 year, and in no isolates in the children-treated group at baseline or 1 year. CONCLUSIONS: This cluster-randomized clinical trial demonstrated that compared to untreated control communities, nasopharyngeal pneumococcal resistance to macrolides was significantly higher in communities randomized to intensive azithromycin treatment. Mass azithromycin distributions were given more frequently than currently recommended by the World Health Organization's trachoma program. Azithromycin use in this setting

  8. Comparative genome analysis of high-level penicillin resistance in Streptococcus pneumoniae.

    Tait-Kamradt, Amelia G; Cronan, Melissa; Dougherty, Thomas J

    2009-06-01

    Streptococcus pneumoniae strains with very high levels of penicillin resistance (minimum inhibitory concentration [MIC] >or=8 microg/ml) emerged in the 1990 s. Previous studies have traced the changes in penicillin binding proteins (PBP) that result in decreased penicillin susceptibility, and the role of several PBP genes in high-level resistance. In the present study, we investigated the changes that occurred at the two highest levels of penicillin resistance using NimbleGen's Comparative Genome Sequencing (CGS) technology. DNA from a highly resistant (Pen MIC 16 microg/ml) pneumococcus was used to serially transform the R6 strain to high-level resistance. Four distinct levels of penicillin resistance above the susceptible R6 strain (MIC 0.016 microg/ml) were identified. Using CGS technology, the entire genome sequences of the two highest levels of resistant transformants were examined for changes associated with the resistance phenotypes. At the third level of resistance, changes in PBPs 1a, 2b, and 2x were found, very similar to previous reports. At the fourth resistance level, two additional changes were observed in the R6 transformants. More changes were observed in PBP2x, as well as in peptidoglycan GlcNAc deacetylase (pdgA), which had a missense mutation in the coding region. Genetic transformation with polymerase chain reaction (PCR) products generated from the high-level resistant parent containing either the additional PBP2x or mutant pdgA gene did not increase the MIC of the third-level transformant. Only when both PCR products were simultaneously transformed into the third-level transformant did colonies emerge that were at the highest level of resistance (16-32 microg/ml), equivalent to the highly resistant parent strain. This is the first instance of the involvement of a variant pdgA gene in penicillin resistance. It is also clear from these experiments and the literature that there are multiple paths to the pneumococcus achieving high

  9. Computational studies on the resistance of penicillin-binding protein 2B (PBP2B) of wild-type and mutant strains of Streptococcus pneumoniae against β-lactam antibiotics.

    Ramalingam, Jothi; Vennila, Jannet; Subbiah, Parthasarathy

    2013-09-01

    Mutations within transpeptidase domain of penicillin-binding protein 2B of the strains of Streptococcus pneumoniae leads to resistance against β-lactam antibiotics. To uncover the important residues responsible for sensitivity and resistance, the recently determined three dimensional structures of penicillin-binding protein 2B of both wild-type R6 (sensitive) and mutant 5204 (resistant) strains along with the predicted structures of other mutant strains G54, Hungary19A-6 and SP195 were considered for the interaction study with β-lactam antibiotics using induced-fit docking of Schrödinger. Associated binding energies of the complexes and their intermolecular interactions in the binding site clearly show that the wild-type R6 as sensitive, mutant strains 5204 and G54 as highly resistant, and the mutant strains Hungary19A-6 and SP195 as intermediate resistant. The study also reveals that the mutant strains Hungary19A-6 and SP195 exhibit intermediate resistant because of the existence of mutations till the intermediate 538th and 516th positions, respectively, and not till the end of the C-terminus. Furthermore, our investigations show that if the mutations are extended till the end of the C terminus, then the antibiotic resistance of induced-mutated strains increases from intermediate to high as in the strains 5204 and G54. The binding patterns obtained in the study are useful in designing potential inhibitors against multidrug resistant S. pneumoniae.

  10. Affinity of ceftaroline and other beta-lactams for penicillin-binding proteins from Staphylococcus aureus and Streptococcus pneumoniae.

    Kosowska-Shick, K; McGhee, P L; Appelbaum, P C

    2010-05-01

    We compared the affinities of ceftaroline for all penicillin-binding proteins (PBPs) with those of ceftriaxone and cefotaxime in 6 Staphylococcus aureus and 7 Streptococcus pneumoniae isolates with various resistance phenotypes. Ceftaroline MICs were pneumoniae. Ceftaroline affinities for penicillin-susceptible S. pneumoniae strains were in the order PBP2X and -3 > PBP1A, -1B, and -2A > PBP2B, and ceftaroline had >or=4-fold higher 50% inhibitory concentrations (IC(50)s) (0.1 to 4 microg/ml) for PBP2X, -2A, -2B, and -3 than those for the other cephalosporins tested. Among 3 penicillin-resistant S. pneumoniae strains, ceftaroline had a high affinity for PBP2X (IC(50), 0.1 to 1 microg/ml), a primary target for cephalosporin PBP binding activity, and high affinities for PBP2B (IC(50), 0.5 to 4 microg/ml) and PBP1A (IC(50), 0.125 to 0.25 microg/ml) as well, both of which are also known as major targets for PBP binding activity of cephalosporins. Ceftaroline PBP affinities in methicillin-susceptible S. aureus strains were greater than or equal to those of the 3 other beta-lactams tested. Ceftaroline bound to PBP2a in methicillin-resistant S. aureus (IC(50), 0.01 to 1 microg/ml) with up to 256-fold-higher affinity than those of other agents. Ceftaroline demonstrated very good PBP affinity against all S. aureus and S. pneumoniae strains tested, including resistant isolates.

  11. Ascorbic acid-dependent gene expression in Streptococcus pneumoniae and the activator function of the transcriptional regulator UlaR2

    Afzal, Muhammad; Shafeeq, Sulman; Kuipers, Oscar P

    2015-01-01

    In this study, we have explored the impact of ascorbic acid on the transcriptome of Streptococcus pneumoniae D39. The expression of several genes and operons, including the ula operon (which has been previously shown to be involved in ascorbic acid utilization), the AdcR regulon (which has been prev

  12. Cellobiose-Mediated Gene Expression in Streptococcus pneumoniae : A Repressor Function of the Novel GntR-Type Regulator BguR

    Shafeeq, Sulman; Kuipers, Oscar P.; Kloosterman, Tomas G.; Leite, Luciana C.C.

    2013-01-01

    The human pathogen Streptococcus pneumoniae has the ability to use the carbon-and energy source cellobiose due to the presence of a cellobiose-utilizing gene cluster (cel locus) in its genome. This system is regulated by the cellobiose-dependent transcriptional activator CelR, which has been previou

  13. Opposing Signals from Pathogen-Associated Molecular Patterns and IL-10 Are Critical for Optimal Dendritic Cell Induction of In Vivo Humoral Immunity to Streptococcus pneumoniae

    2003-07-01

    patterns and IL-10 for optimization of DC induction of an in vivo humoral immune response. Bone marrow-derived, CD8 DC pulsed with Streptococcus ... pneumoniae in vitro induce in vivo protein- and polysaccharide-specific Ig isotype responses upon adoptive transfer into naive mice. Following bacterial

  14. Recognition of Streptococcus pneumoniae and muramyl dipeptide by NOD2 results in potent induction of MMP-9, which can be controlled by lipopolysaccharide stimulation.

    Vissers, Marloes; Hartman, Yvonne; Groh, Laszlo; de Jong, Dirk J; de Jonge, Marien I; Ferwerda, Gerben

    2014-12-01

    Matrix metallopeptidase 9 (MMP-9) is a protease involved in the degradation of extracellular matrix collagen. Evidence suggests that MMP-9 is involved in pathogenesis during Streptococcus pneumoniae infection. However, not much is known about the induction of MMP-9 and the regulatory processes involved. We show here that the Gram-positive bacteria used in this study induced large amounts of MMP-9, in contrast to the Gram-negative bacteria that were used. An important pathogen-associated molecular pattern (PAMP) for Gram-positive bacteria is muramyl dipeptide (MDP). MDP is a very potent inducer of MMP-9 and showed a dose-dependent MMP-9 induction. Experiments using peripheral blood mononuclear cells (PBMCs) from Crohn's disease patients with nonfunctional NOD2 showed that MMP-9 induction by Streptococcus pneumoniae and MDP is NOD2 dependent. Increasing amounts of lipopolysaccharide (LPS), an important PAMP for Gram-negative bacteria, resulted in decreasing amounts of MMP-9. Moreover, the induction of MMP-9 by MDP could be counteracted by simultaneously adding LPS. The inhibition of MMP-9 expression by LPS was found to be regulated posttranscriptionally, independently of tissue inhibitor of metalloproteinase 1 (TIMP-1), an endogenous inhibitor of MMP-9. Collectively, these data show that Streptococcus pneumoniae is able to induce large amounts of MMP-9. These high MMP-9 levels are potentially involved in Streptococcus pneumoniae pathogenesis.

  15. Serum level of YKL-40 is elevated in patients with Streptococcus pneumoniae bacteremia and is associated with the outcome of the disease

    Kronborg, Gitte; Ostergaard, Christian; Nielsen, Henrik;

    2002-01-01

    YKL40 is secreted by activated macrophages and neutrophils. Elevated serum concentrations of YKL40 are found in patients with diseases characterized by inflammation or ongoing fibrosis. The aim of this study was to evaluate serum YKL-40 levels in patients with Streptococcus pneumoniae bacteremia...

  16. Regulation of Arginine Acquisition and Virulence Gene Expression in the Human Pathogen Streptococcus pneumoniae by Transcription Regulators ArgR1 and AhrC

    Kloosterman, Tomas G.; Kuipers, Oscar P.

    2011-01-01

    In this study, we investigated for the first time the transcriptional response of the human pathogen Streptococcus pneumoniae to fluctuating concentrations of arginine, an essential amino acid for this bacterium. By means of DNA microarray analyses, several operons and genes were found, the expressi

  17. Site-specific contributions of glutamine-dependent regulator GlnR and GlnR-regulated genes to virulence of Streptococcus pneumoniae.

    Hendriksen, W.T.; Kloosterman, T.G.; Bootsma, H.J.; Estevao, S.; Groot, R. de; Kuipers, O.P.; Hermans, P.W.M.

    2008-01-01

    The transcriptional regulator GlnR of Streptococcus pneumoniae is involved in the regulation of glutamine and glutamate metabolism, controlling the expression of the glnRA and glnPQ-zwf operons, as well as the gdhA gene. To assess the contribution of the GlnR regulon to virulence, D39 wild-type and

  18. Site-specific contributions of glutamine-dependent regulator GlnR and GlnR-regulated genes to virulence of Streptococcus pneumoniae

    W.T. Hendriksen (Wouter); T.G. Kloosterman (Tomas); H.J. Bootsma (Hester); S. Estevão (Silvia); R. de Groot (Ronald); O.P. Kuipers (Oscar); P.W.M. Hermans (Peter)

    2008-01-01

    textabstractThe transcriptional regulator GlnR of Streptococcus pneumoniae is involved in the regulation of glutamine and glutamate metabolism, controlling the expression of the glnRA and glnPQ-zwf operons, as well as the gdhA gene. To assess the contribution of the GlnR regulon to virulence, D39 wi

  19. Site-specific contributions of glutamine-dependent regulator GlnR and GlnR-regulated genes to virulence of Streptococcus pneumoniae

    Hendriksen, Wouter T.; Kloosterman, Tomas G.; Bootsma, Hester J.; Estevao, Silvia; de Groot, Ronald; Kuipers, Oscar P.; Hermans, Peter W. M.

    2008-01-01

    The transcriptional regulator GlnR of Streptococcus pneumoniae is involved in the regulation of glutamine and glutamate metabolism, controlling the expression of the glnRA and glnPQ-zwf operons, as well as the gdhA gene. To assess the contribution of the GlnR regulon to virulence, D39 wild-type and

  20. 儿童链球菌性肺炎流行病学研究%Epidemiological study of children's streptococcus pneumonia

    周志男; 孙美平

    2011-01-01

    儿童链球菌性肺炎是导致5岁以下儿童死亡的重要因素之一.降低儿童链球菌性肺炎的发病率和死亡率,对实现联合国千年发展的第四个目标至关重要.本文综述近年儿童链球菌性肺炎相关文献(来自联合国、世界卫生组织的官方网站以及ScienceDirect和PubMeb等医药数据库),分析儿童链球菌性肺炎的流行病学现状并提出参考建议.%Children's streptococcus pneumonia is the major factor of children's death under age 5. Decreasing of the morbidity and mortality of children's streptococcus pneumonia is significant to achieve the Millennium Development Goals 4 of WHO. Based on relevant literatures (from United Nations, World Health Organization' official website, relevant databases like Science Direct and Pub Med, et al. ) on children's streptococcus pneumonia published in recent years, this review analyzes the present epidemiology of children's streptococcus pneumonia and provides some recommendations.

  1. Further understanding of streptococcus pneumoniae respiratory tract infection%肺炎链球菌呼吸道感染的再认识

    刘青; 施毅

    2013-01-01

    Streptococcus pneumoniae is still an important pathogen of community-acquired respiratory tract infections.Streptococcus pneumoniae has been studied widely and deeply.However,in recent years,there is a new understanding of microbiological characteristics,epidemiology,resistance mechanisms and the guidelines of streptococcus pneumoniae treatment.The paper introduces the new progress including the status of streptococcus pneumoniae respiratory tract infection,revised penicillin breakpoints,fluoroquinolone resistant characteristics,and biofilm resistance mechanisms.%肺炎链球菌至今仍然是社区获得性呼吸道感染的重要病原体,有关肺炎链球菌的研究已经比较广泛而深入.但近年来,在肺炎链球菌的微生物学特性、流行病学、耐药机制及治疗指南等方面都有了新的认识.本文着重介绍近几年肺炎链球菌感染研究的新进展,主要从肺炎链球菌呼吸道感染的现状、青霉素折点的调整、氟喹诺酮耐药特点、生物膜耐药机制及治疗等方面进行阐述.

  2. PENICILLIN-BINDING PROTEIN 2X OF STREPTOCOCCUS-PNEUMONIAE - EXPRESSION IN ESCHERICHIA-COLI AND PURIFICATION OF A SOLUBLE ENZYMATICALLY ACTIVE DERIVATIVE

    LAIBLE, G; KECK, W; LURZ, R; MOTTL, H; FRERE, JM; JAMIN, M; HAKENBECK, R

    1992-01-01

    A 2.5-kb DNA fragment including the structural gene coding for the penicillin-binding protein 2x (PBP 2x) of Streptococcus pneumoniae has been cloned into the vector pJDC9 and expressed in Escherichia coli. Mapping of RNA polymerase binding sites by electron microscopy indicated that the pbpX promot

  3. Clinical application of a ligation-independent pathway of multiplex ligation-dependent probe amplification for the determination of quinolone susceptibility of Streptococcus pneumoniae.

    Uno, Naoki; Araki, Nobuko; Kaku, Norihito; Kosai, Kosuke; Hasegawa, Hiroo; Yanagihara, Katsunori

    2016-09-01

    We previously uncovered a ligation-independent pathway of multiplex ligation-dependent probe amplification (MLPA) through which products of MLPA could be amplified without both hybridization and ligation reactions. Here, we utilized this pathway to detect an antibiotic resistance mutation of quinolones in Streptococcus pneumoniae.

  4. 烟台地区肺炎链球菌的耐药性检测%Surveillance of antimicrobial resistance of streptococcus pneumoniae in Yantai area

    吴金英; 李少君; 徐新波; 韩颖杰; 杨少虹; 苏兆兰

    2009-01-01

    目的 监测烟台地区肺炎链球菌的耐药性,为临床合理应用抗菌药物提供理论依据.方法 收集烟台地区部分医院临床分离的肺炎链球菌,用E-试验、K-B法检测此菌对青霉素等10种抗菌药物的敏感度.结果 102株肺炎链球菌中71株(70%)对青霉素不敏感.未检出对头孢噻肟、阿莫西林、左旋氧氟沙星和万古霉素耐药的菌株.对克林霉素、红霉素、四环素和复方新诺明耐药率很高,分别为97%、100%、100%和96%.结论 烟台地区青霉素不敏感肺炎链球菌检出率高,对大环内酯类药物耐药状况极为严峻.%Objective To monitor the antimicrobial resistance of streptococcus pneumoniae in Yantai area so as to provide theoretical basis for rational use of antibiotics. Methods The clinical streptococcus pneumoniae isolates were collected from some hospitals in Yantai area. E-test and K-B disk diffusion method were used to determine the susceptibility of streptococcus pneumoniae to 10 antimicrobial agents. Results Seventy-one streptococcus pneumoniae isolates(71/102, 70%) were insensitive to penicillin. None of cefotaxime-, amoxicillin- , levofloxacin-, and vancomycin-resistant strains was found. The resistance rate of streptococcus pneumoniae was relatively highly resistant to clindamyein, erythromycin, tetracycline and TMP-SMZ, 97%, 100%, 100% and 96% respectively. Conclusion Penicillin non-susceptible streptococcus pneumoniae is highly prevalent in Yantai area. The situation is serious about macrolide-resistance of streptococcus pneumoniae.

  5. Genetic characteristics of Haemophilus influenzae and Streptococcus pneumoniae isolated from children with conjunctivitis-otitis media syndrome.

    Sugita, Gen; Hotomi, Muneki; Sugita, Rinya; Kono, Masamitsu; Togawa, Akihisa; Yamauchi, Kazuma; Funaki, Toshinari; Yamanaka, Noboru

    2014-08-01

    Acute conjunctivitis is the most common ocular disorders among children and frequently concomitant with acute otitis media (AOM) as conjunctivitis-otitis syndrome. In this study, we evaluated prevalence of causative pathogens and PCR-based genotypes of Haemophilus influenzae and Streptococcus pneumoniae among children with conjunctivitis-otitis media syndrome. Nontypeable H. influenzae (NTHi) is identified most often at 61.8% in conjunctiva exudates followed by S. pneumoniae at 28.2% and Moraxella catarrhalis at 19.1%. Genetic β-lactamase nonproducing ampicillin resistant (gBLNAR) strains of NTHi and genetic penicillin resistant S. pneumoniae (gPRSP) were identified at 72.1% and at 74.2% among conjunctiva isolates by polymerase chain reaction (PCR), respectively. Pneumococcal strains having either ermB or mefE genes were identified at 93.5% among conjunctiva isolates. The restriction fragment of patterns of 89.7% pairs of H. influenzae isolates and 100% pairs of pneumococcal isolates from conjunctiva exudates, middle ear fluids (MEFs) and nasopharyngeal swabs were identical. In contrast to the previous reports, most prevalent strains from conjunctivitis-otitis media syndrome was BLNAR H. influenzae in this study. The causative pathogen responsible for acute conjunctivitis will be originated from the nasopharynx. In the absence of MEFs one can possibly rely on the nasopharyngeal culture to guide an appropriate treatment.

  6. In Vitro Resistance Development to Nemonoxacin in Streptococcus pneumoniae: A Unique Profile for a Novel Nonfluorinated Quinolone

    Roychoudhury, Siddhartha; Makin, Kelly; Twinem, Tracy; Leunk, Robert

    2016-01-01

    Selection of resistant strains in Streptococcus pneumoniae was studied in vitro with nemonoxacin, a novel nonfluorinated quinolone (NFQ), in comparison with quinolone benchmarks, ciprofloxacin, garenoxacin, and gatifloxacin. In stepwise resistance selection studies, a 256-fold loss of potency was observed after three to four steps of exposure to ciprofloxacin or garenoxacin. In contrast, the loss of potency was limited to eightfold after three steps of exposure to nemonoxacin and repeated attempts to isolate highly resistant organisms after four steps of exposure yielded isolates that could not be subcultured in liquid medium. The quinolone resistance-determining regions of the target genes, parC, parE, gyrA, and gyrB, were analyzed through DNA sequencing. Known mutations, especially in the hotspots of parC and gyrA, were selected with exposure to garenoxacin, ciprofloxacin, and gatifloxacin. In contrast, mutations selected with nemonoxacin were limited to GyrA, GyrB, and ParE, sparing ParC, which is known as a key driver of resistance in clinical isolates of S. pneumoniae. This observation is consistent with previous data using other NFQs, which showed no loss of potency due to ParC mutations in clinical isolates. This apparently unique feature of nemonoxacin is potentially attributable to the structural uniqueness of the NFQs, distinguishing them from the fluoroquinolones that are commonly prescribed for infections by S. pneumoniae. PMID:27267788

  7. A novel gene amplification causes upregulation of the PatAB ABC transporter and fluoroquinolone resistance in Streptococcus pneumoniae.

    Baylay, Alison J; Ivens, Alasdair; Piddock, Laura J V

    2015-01-01

    Overexpression of the ABC transporter genes patA and patB confers efflux-mediated fluoroquinolone resistance in Streptococcus pneumoniae and is also linked to pneumococcal stress responses. Although upregulation of patAB has been observed in many laboratory mutants and clinical isolates, the regulatory mechanisms controlling expression of these genes are unknown. In this study, we aimed to identify the cause of high-level constitutive overexpression of patAB in M184, a multidrug-resistant mutant of S. pneumoniae R6. Using a whole-genome transformation and sequencing approach, we identified a novel duplication of a 9.2-kb region of the M184 genome which included the patAB genes. This duplication did not affect growth and was semistable with a low segregation rate. The expression levels of patAB in M184 were much higher than those that could be fully explained by doubling of the gene dosage alone, and inactivation of the first copy of patA had no effect on multidrug resistance. Using a green fluorescent protein reporter system, increased patAB expression was ascribed to transcriptional read-through from a tRNA gene upstream of the second copy of patAB. This is the first report of a large genomic duplication causing antibiotic resistance in S. pneumoniae and also of a genomic duplication causing antibiotic resistance by a promoter switching mechanism.

  8. Nasopharyngeal Carriage, Capsular and Molecular Serotyping and Antimicrobial Susceptibility of Streptococcus pneumoniae among Asymptomatic Healthy Children in Egypt.

    El-Nawawy, Ahmed A; Hafez, Soad F; Meheissen, Marwa A; Shahtout, Nehal M; Mohammed, Essam E

    2015-12-01

    Streptococcus pneumoniae is a major cause of childhood morbidity and mortality worldwide with increasing antimicrobial resistance. 600 randomly chosen asymptomatic healthy children aged 2-60 months attending Alexandria University Children's Hospital were evaluated for prevalence of nasopharyngeal (NP) carriage of S. pneumoniae. Prevalence of NP carriage was 29.2% (n = 175/600) Capsular serotyping was done using Quellung reaction. Vaccine covered serotypes (VST) represented 67.4% while non-vaccine serotypes (NVST) were 32.6%. The most common VST isolated were 19F (24.6%), 6B (14.3%) and 6A (10.9%). Confirmation of serotyping was performed by multiplex PCR which showed 100% concordance with the Quellung reaction. Antimicrobial susceptibility testing showed penicillin non-susceptibility of 15% (using non-meningitis penicillin MIC breakpoints) and 55% (using meningitis penicillin MIC breakpoints). Highest resistance was found in sulphamethoxazole-trimethoprim (55%), tetracyclins (49%), erythromycin (40%) and clindamycin (25%). This study revealed the epidemiological importance to evaluate regularly the prevalence, serotypes and the increasing antimicrobial resistance of S. pneumoniae in the community.

  9. Entry of Sanfetrinem into Human Polymorphonuclear Granulocytes and Its Cell-Associated Activity against Intracellular, Penicillin-Resistant Streptococcus pneumoniae

    Cuffini, Anna Maria; Tullio, Vivian; Bonino, Alessandro; Allocco, Alessandra; Palarchio, Angela Ianni; Carlone, Nicola A.

    1998-01-01

    The entry of antibiotics into phagocytes is necessary for activity against intracellular pathogens. The ability of sanfetrinem, the first member of a new class of antibiotics, to penetrate human polymorphonuclear granulocytes and its consequences upon subsequent phagocytosis and killing of ingested penicillin-resistant Streptococcus pneumoniae have been evaluated. Sanfetrinem penetrated into human polymorphonuclear leukocytes (PMNs) at all concentrations tested, with cellular concentration/extracellular concentration ratios of 6.6 to 5.03 and 4.21 when sanfetrinem was used at 0.25 to 0.5 and 1 μg/ml, respectively, within 30 min of incubation. The uptake was complete within 5 min and was not energy dependent, since it was not affected by cell viability, environmental temperature, or the addition of a metabolic inhibitor. At a concentration of one-half the MIC, sanfetrinem significantly enhanced human PMN phagocytosis and increased intracellular bactericidal activity against penicillin-resistant S. pneumoniae. Following preexposure of PMNs to a concentration of one-half the MIC of sanfetrinem, there was a significant increase in both phagocytosis and killing compared with that for the controls, indicating the ability of sanfetrinem to interact with biological membranes and remain active within PMNs. Preexposure of streptococci to sanfetrinem made penicillin-resistant S. pneumoniae more susceptible to the bactericidal mechanisms of human PMNs than untreated organisms. PMID:9661015

  10. Serotipos prevalentes de Streptococcus pneumoniae colonizadores de nasofaringe, en niños del Distrito Federal Prevalence of Streptococcus pneumoniae serotypes on nasopharyngeal colonization in children of Mexico City

    Fortino Solórzano-Santos

    2005-07-01

    Full Text Available OBJETIVO: Determinar frecuencia, serotipos y susceptibilidad a ocho antimicrobianos en Streptococcus pneumoniae aislados de la nasofaringe de una muestra representativa de niños menores de cinco años de edad residentes en el Distrito Federal. MATERIAL Y MÉTODOS: Estudio transversal, hecho de febrero de 2002 a enero de 2003. Se incluyeron niños de 2 meses a 5 años. A los seleccionados se les tomó una muestra de exudado faríngeo con hisopo de alginato de calcio. Bajo técnicas ya establecidas se realizó identificación, tipificación y susceptibilidad a ocho antimicrobianos de los aislamientos de S. pneumoniae. Se utilizó estadística descriptiva, prueba de Ji cuadrada y razón de momios (IC 95% para los factores de riesgo. RESULTADOS: Se estudiaron 573 niños. En 122/573 (21.4% niños se aisló S. pneumoniae. Los serotipos más frecuentes fueron el 23F, 35, 19F, 11A y 15A; 46% de los serotipos encontrados no son cubiertos con la vacuna heptavalente. Se encontró 12% de susceptibilidad reducida a la penicilina, con 3% de cepas con alta resistencia; la resistencia a eritromicina fue >30% y para trimetoprim-sulfametoxazol (TMP/SMX >40%. No hubo cepas resistentes a vancomicina, cefotaxima, amoxicilina-clavulanato, cloranfenicol o ampicilina. CONCLUSIONES: El porcentaje de serotipos de S. pneumoniae en portadores nasofaríngeos no cubiertos por la vacuna heptavalente es alto, y la resistencia a macrólidos y TMP/SMX es elevada, lo que debe alertar al grupo médico.OBJECTIVE: To determine the frequency, serotypes and susceptibility profiles to eight antimicrobials in Streptococcus pneumoniae nasopharyngeal isolates from a representative sample of children under 5 years of age, residents of Mexico City. PATIENTS AND METHODS: A cross-sectional survey was conducted in 573 children aged 2 months to 5 years. A nasopharyngeal sample was taken. S. pneumoniae identification, capsular serotyping and antimicrobial susceptibility to eight antimicrobials

  11. [Comparison of culture and real-time PCR methods in the detection of Streptococcus pneumoniae and Haemophilus influenzae in acute otitis media effusion specimens].

    Eser, Ozgen Köseoğlu; Alp, Sehnaz; Ergin, Alper; Ipçi, Kaan; Alp, Alpaslan; Gür, Deniz; Hasçelik, Gülşen

    2012-10-01

    Streptococcus pneumoniae and Haemophilus influenzae are the major etiologic agents of acute otitis media. This study was aimed to compare the detection rate of S.pneumoniae and H.influenzae by culture and real-time polymerase chain reaction (Rt-PCR) in the middle ear effusions of patients diagnosed as acute otitis media. A total of 60 middle ear effusion samples collected from children with acute otitis media were included in the study. The samples were inoculated and incubated in BACTEC Ped Plus blood culture bottles and BACTEC 9120 system (BD Diagnostic Systems, MD), respectively, and the isolates were identified by conventional methods. For the molecular diagnosis of H.influenzae and S.pneumoniae, ply pneumolysin gene and HIB capsule region, respectively were amplified by Rt-PCR (LightCycler, Roche Diagnostics, Germany). H.influenzae and S.pneumoniae were isolated from 5 (8.3%) and 3 (5%) of the patient samples with conventional culture methods, respectively. In addition in 11.6% of the samples other microorganisms (Staphylococcus epidermidis, Streptococcus intermedius, Streptococcus sanguinis, Moraxella catarrhalis, Pseudomonas aeruginosa, Candida albicans) were also isolated. On the other hand H.influenzae and S.pneumoniae were detected in 38 (63.3%) and 24 (40%) of the samples with Rt-PCR, respectively. There was about eight fold increase in the detection frequency of H.influenzae and S.pneumoniae with Rt-PCR compared to culture methods. When culture was accepted as the gold standard method, the sensitivity, specificity and positive predictive value of Rt-PCR in the detection of H.influenzae and S.pneumoniae were estimated as 80%, 51% and 98.2%, respectively. As a result, Rt-PCR was shown to be a sensitive method and could be preferred for the rapid diagnosis of H.influenzae and S.pneumoniae in the etiological diagnosis of acute otitis media, especially in culture negative cases.

  12. Características clínico-microbiológicas de la meningitis por Streptococcus pneumoniae resistente a la penicilina Streptococcus pneumoniae meningitis resistant to penicillin clinical and microbiological characteristics

    Demóstenes Gómez-Barreto

    1999-10-01

    Full Text Available OBJETIVO: Evaluar la susceptibilidad antimicrobiana de Streptococcus pneumoniae aislado del líquido cefalorraquídeo de niños con meningitis, así como describir y comparar las características clínicas y microbiológicas, el tratamiento y la evolución del padecimiento entre niños infectados con cepas sensibles y resistentes a la penicilina y la cefalosporina. MATERIAL Y MÉTODOS: Treinta y ocho niños con meningitis neumocócica fueron incluidos prospectivamente en el Programa Institucional de Vigilancia de las Infecciones Neumocócicas, durante el lapso 1994-1998. Los datos clínicos y de laboratorio se colectaron de cada expediente. RESULTADOS: Del total de niños, 63% era menor de dos años de edad, 28.9% mostró cepas insensibles a la penicilina, 18.4% tenía resistencia intermedia, y 10.5% tenía resistencia elevada. El 2.6% mostró también resistencia a la cefotaxima. La única característica (por la prueba exacta de Fisher asociada con la resistencia fue: enfermedad de base previa al proceso (pOBJECTIVE: To evaluate the susceptibility to antibiotics of Streptococcus pneumoniae isolated from cerebrospinal fluid of children with meningitis. To describe and compare the clinical and microbiological characteristics, treatment and outcome among children infected with strains either susceptible or resistant to penicillin and cephalosporin. MATERIAL AND METHODS: A total of 38 children with pneumococcal meningitis were prospectively enrolled in the Institutional Surveillance Program for Pneumococcal Infections during 1994-1998. Clinical and laboratory data were collected by chart review. RESULTS: Of the 38 children, 24 (63% were less than 2 years of age, 11 (28.9% had drug-resistant S. pneumoniae, 18.4% had intermediate resistance, 10.5% high level resistance and 2.6% also showed high level resistance to cefotaxime. The only associated factors (by Fisher’s exact test associated to resistance were: previous use of antibiotics (p=0

  13. Heat-shock protein ClpL/HSP100 increases penicillin tolerance in Streptococcus pneumoniae.

    Tran, Thao Dang-Hien; Kwon, Hyog-Young; Kim, Eun-Hye; Kim, Ki-Woo; Briles, David E; Pyo, Suhkneung; Rhee, Dong-Kwon

    2011-01-01

    Penicillin resistance and tolerance has been an increasing threat to the treatment of pneumococcal pneumoniae. However, no penicillin tolerance-related genes have been claimed. Here we show that a major heat shock protein ClpL/HSP100 could modulate the expression of a cell wall synthesis enzyme PBP2x, and subsequently increase cell wall thickness and penicillin tolerance in Streptococus pneumoniae.

  14. Time and dose-dependent risk of pneumococcal pneumonia following influenza: a model for within-host interaction between influenza and Streptococcus pneumoniae.

    Shrestha, Sourya; Foxman, Betsy; Dawid, Suzanne; Aiello, Allison E; Davis, Brian M; Berus, Joshua; Rohani, Pejman

    2013-09-06

    A significant fraction of seasonal and in particular pandemic influenza deaths are attributed to secondary bacterial infections. In animal models, influenza virus predisposes hosts to severe infection with both Streptococcus pneumoniae and Staphylococcus aureus. Despite its importance, the mechanistic nature of the interaction between influenza and pneumococci, its dependence on the timing and sequence of infections as well as the clinical and epidemiological consequences remain unclear. We explore an immune-mediated model of the viral-bacterial interaction that quantifies the timing and the intensity of the interaction. Taking advantage of the wealth of knowledge gained from animal models, and the quantitative understanding of the kinetics of pathogen-specific immunological dynamics, we formulate a mathematical model for immune-mediated interaction between influenza virus and S. pneumoniae in the lungs. We use the model to examine the pathogenic effect of inoculum size and timing of pneumococcal invasion relative to influenza infection, as well as the efficacy of antivirals in preventing severe pneumococcal disease. We find that our model is able to capture the key features of the interaction observed in animal experiments. The model predicts that introduction of pneumococcal bacteria during a 4-6 day window following influenza infection results in invasive pneumonia at significantly lower inoculum size than in hosts not infected with influenza. Furthermore, we find that antiviral treatment administered later than 4 days after influenza infection was not able to prevent invasive pneumococcal disease. This work provides a quantitative framework to study interactions between influenza and pneumococci and has the potential to accurately quantify the interactions. Such quantitative understanding can form a basis for effective clinical care, public health policies and pandemic preparedness.

  15. Molecular Analysis of Rising Fluoroquinolone Resistance in Belgian Non-Invasive Streptococcus pneumoniae Isolates (1995-2014.

    Pieter-Jan Ceyssens

    Full Text Available We present the results of a longitudinal surveillance study (1995-2014 on fluoroquinolone resistance (FQ-R among Belgian non-invasive Streptococcus pneumoniae isolates (n = 5,602. For many years, the switch to respiratory fluoroquinolones for the treatment of (atypical pneumonia had no impact on FQ-R levels. However, since 2011 we observed a significant decrease in susceptibility towards ciprofloxacin, ofloxacin and levofloxacin with peaks of 9.0%, 6.6% and 3.1% resistant isolates, respectively. Resistance to moxifloxacin arised sporadically, and remained <1% throughout the entire study period. We observed classical topoisomerase mutations in gyrA (n = 25, parC (n = 46 and parE (n = 3 in varying combinations, arguing against clonal expansion of FQ-R. The impact of recombination with co-habiting commensal streptococci on FQ-R remains marginal (10.4%. Notably, we observed that a rare combination of DNA Gyrase mutations (GyrA_S81L/GyrB_P454S suffices for high-level moxifloxacin resistance, contrasting current model. Interestingly, 85/422 pneumococcal strains display MICCIP values which were lowered by at least four dilutions by reserpine, pointing at involvement of efflux pumps in FQ-R. In contrast to susceptible strains, isolates resistant to ciprofloxacin significantly overexpressed the ABC pump PatAB in comparison to reference strain S. pneumoniae ATCC 49619, but this could only be linked to disruptive terminator mutations in a fraction of these. Conversely, no difference in expression of the Major Facilitator PmrA, unaffected by reserpine, was noted between susceptible and resistant S. pneumoniae strains. Finally, we observed that four isolates displayed intermediate to high-level ciprofloxacin resistance without any known molecular resistance mechanism. Focusing future molecular studies on these isolates, which are also commonly found in other studies, might greatly assist in the battle against rising pneumococcal drug resistance.

  16. Genetic diversity of fluoroquinolone-nonsusceptible Streptococcus pneumoniae clinical isolates and the first identification of serotype 20B in China.

    Guo, Q; Zhuo, C; Xu, Y; Huang, W; Wang, C; Zhang, S; Huang, J; Hu, F; Zhu, D; Yang, F; Wang, M

    2014-03-01

    The purpose of this study was to investigate the genetic characteristics of fluoroquinolone-nonsusceptible Streptococcus pneumoniae clinical isolates in China. A total of 377 S. pneumoniae clinical isolates, including 307 pediatric strains and 70 adult strains, were collected from eight centers in China. The minimal inhibitory concentrations (MICs) of 10 antimicrobial agents were determined by agar dilution. Multilocus sequence typing (MLST), serotyping, and quinolone resistance-determining region (QRDR) variations were conducted in levofloxacin-nonsusceptible isolates by polymerase chain reaction (PCR)-based methods. Seven levofloxacin-nonsusceptible isolates were found, with an overall resistance rate of 1.9 % (7/377) and 8.6 % (6/70) in adults. Sequence analyses of parC, gyrA, and parE QRDRs in levofloxacin-resistant isolates demonstrated mutations in dual target sites at the hot spots. These seven strains represented multiple clones: two strains were serotype 19F (Taiwan(19F)-14) and MLST clonal complex (CC) 271/320, two were typed as 23F (Spain(23F)-1) and CC81, two were determined as serotype 20B and a new sequence type of ST6935, and one non-serotypeable pediatric strain belonged to a new sequence type of ST6946. Two serotype 19F strains possessed a variety of characteristic alterations of viridans group streptococci in gyrA (Ser114Gly) or parC (Ser52Gly, Asn91Asp). Fluoroquinolone-nonsusceptible S. pneumoniae isolates showed a substantial degree of genetic diversity and belonged to pre-existing epidemic clones together with native clones. S. pneumoniae strains with serotype 20B was recovered for the first time to be associated with levofloxacin resistance in China.

  17. Comparison of the Denka Seiken slide agglutination method to the quellung test for serogrouping of Streptococcus pneumoniae isolates.

    Shutt, Cheryl K; Samore, Matthew; Carroll, Karen C

    2004-03-01

    This study compared a slide agglutination test (Denka Seiken, Tokyo, Japan) to the "gold standard" quellung reaction (Pneumotest; Statens Serum Institut, Copenhagen, Denmark) for the serogrouping of pneumococci. Two hundred clinical isolates of Streptococcus pneumoniae were used for the comparison. Each assay was performed according to the manufacturer's instructions. There was an overall agreement of 95.7% between the two methods. Only 4 of 10 isolates of serogroup 22 were detected with the slide agglutination assay. Two isolates that were untypeable by the Pneumotest method were typed as serogroups 6 and 31 by the slide agglutination method. The Pneumotest method was unable to type 22 isolates, and the slide agglutination method was unable to type 16 isolates. The slide agglutination method compares favorably with the Pneumotest method and is easier to perform and to interpret.

  18. The critical role of myeloperoxidase in Streptococcus pneumoniae clearance and tissue damage during mouse acute otitis media.

    Xiang, Yun; Jin, Chunfang; Wang, Wei; Wang, Zimeng; Huang, Yifei; Fan, Fangmei; Ma, Yurong; Zhang, Xuemei; Xu, Wenchun; Yin, Yibing; He, Yujuan

    2017-04-01

    We have recently reported that neutrophils play a pivotal role in innate defense against Streptococcus pneumoniae ( Spn) during mouse acute otitis media (AOM). However, the underlying mechanism remains unclear. By constructing models of pneumococcal AOM in C57BL/6 mice and using a specific inhibitor in vivo, we investigated the role of myeloperoxidase (MPO), one of the most important protein components of neutrophils. Experiment results showed a significant increase in MPO production of the recruited neutrophils in Spn-infected mice. Neutrophils killed Spn in a MPO-dependent manner. MPO facilitated the generation of reactive oxygen species (ROS), and consequently promoted Spn clearance at an early stage and exacerbated tissue damage. Moreover, MPO induced neutrophil apoptosis and necrosis, which, in turn, worsened tissue damage. In summary, our study demonstrates that neutrophil MPO plays a paradoxical role in bacterial clearance and tissue damage in pneumococcal AOM.

  19. Impacto de la enfermedad por streptococcus pneumoniae en población adulta mayor en bogotá, colombia, 2008

    Castañeda-Orjuela, Carlos; Alvis-Guzmán, Nelson Alvis-Guzmán2; de la Hoz-Restrepo, Fernando

    2012-01-01

    Objetivo  Estimar el impacto de la enfermedad por Streptococcus pneumoniae en la población mayor de 60 años en Bogotá D.C. Colombia. Métodos Se realizó un estudio de impacto de enfermedad por neumococo combinando una búsqueda sistemática de literatura con el análisis de fuentes de datos rutinarios de mortalidad, consultas y hospitalizaciones debidas neumonías y meningitis en adultos mayores de 60 años. Resultados Se estimó para 2008 en la población bogotana mayor de 60 años la ocurrencia de 6...

  20. [Real-time PCR detection of Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae DNA in clinical specimens].

    Vacková, Z; Lžičařová, D; Stock, N K; Kozáková, J

    2015-10-01

    The study aim was to implement a molecular real-time polymerase chain reaction (PCR) assay recommended by the CDC (Centers for Disease Control and Prevention) for the detection of Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae in clinical (culture negative) specimens from patients with suspected invasive bacterial disease. Clinical specimens are referred to the National Reference Laboratory (NRL) for Meningococcal Infections, Unit for Airborne Bacterial Infections, Centre for Epidemiology and Microbiology, National Institute of Public Health from various regions of the Czech Republic. Clinical specimens are, in particular, cerebrospinal fluid, anti-coagulated blood or serum and, exceptionally, post-mortem specimens. The NRL has implemented molecular diagnosis of these bacterial pathogens involved in meningitis and sepsis from clinical specimens since 1999. The first diagnostic method was semi-nested PCR followed by electrophoretic analysis. In 2014, a molecular qualitative real-time PCR assay was implemented.

  1. In Vitro antimicrobial susceptibilities of Streptococcus pneumoniae isolated from two teaching hospitals in Taiwan, 1989-1995.

    Su, J Y; Chang, S C; Luh, K T; Hsieh, W C

    1995-08-01

    The susceptibility of 46 pneumococcal isolates collected during October 1989 to May 1995 from National Taiwan University Hospital and Taipei Municipal Yang Ming Hospital was studied. Among these isolates, the resistant rate of penicillin G was 21.7%; the penicillin G-resistant strains were more frequently resistant than the penicillin-sensitive strains to other beta-lactam antimicrobial drugs. The minimum bactericidal concentrations (MBCs) of penicillin G for all isolates were equal to, or one dilution higher than, minimum inhibitory concentrations (MICs). Three strains were false positive for penicillin resistance among isolates of Streptococcus pneumoniae screened with oxacillin. On the other hand, resistance to penicillin G was often independent of resistance to erythromycin. Vancomycin was the most active agent tested.

  2. Chemical Synthesis Elucidates the Immunological Importance of a Pyruvate Modification in the Capsular Polysaccharide of Streptococcus pneumoniae Serotype 4.

    Pereira, Claney L; Geissner, Andreas; Anish, Chakkumkal; Seeberger, Peter H

    2015-08-17

    Carbohydrate modifications are believed to strongly affect the immunogenicity of glycans. Capsular polysaccharides (CPS) from bacterial pathogens are frequently equipped with a pyruvate that can be placed across the 4,6-, 3,4-, or 2,3-positions. A trans-2,3-linked pyruvate is present on the CPS of the Gram-positive bacterium Streptococcus pneumoniae serotype 4 (ST4), a pathogen responsible for pneumococcal infections. To assess the immunological importance of this modification within the CPS repeating unit, the first total synthesis of the glycan was carried out. Glycan microarrays containing a series of synthetic antigens demonstrated how antibodies raised against natural ST4 CPS specifically recognize the pyruvate within the context of the tetrasaccharide repeating unit. The pyruvate modification is a key motif for designing minimal synthetic carbohydrate vaccines for ST4.

  3. A Self-deleting Cre-lox-ermAM Cassette, CHESHIRE, for marker-less gene deletion in Streptococcus pneumoniae

    Weng, Liming; Biswas, Indranil; Morrison, Donald A.

    2009-01-01

    Although targeted mutagenesis of Streptococcus pneumoniae is readily accomplished with the aid of natural genetic transformation and chimeric donor DNA constructs assembled in vitro, the drug resistance markers often employed for selection of recombinant products can themselves be undesirable by-products of the genetic manipulation. A new cassette carrying the erythromycin-resistance marker ermAM is described that can be used as a temporary marker for selection of desired recombinants. The cassette may subsequently be removed at will by virtue of an embedded fucose-regulated Cre recombinase gene and terminal lox66 and lox71 Cre recognition sites, with retention of 34 bp from the cassette as an inert residual double-mutant lox72 site. PMID:19850089

  4. Abnormal physiological properties and altered cell wall composition in Streptococcus pneumoniae grown in the presence of clavulanic acid.

    Severin, A; Severina, E; Tomasz, A

    1997-01-01

    Subinhibitory concentrations of clavulanate caused premature induction of stationary-phase autolysis, sensitization to lysozyme, and reductions in the MICs of deoxycholate and penicillin for Streptococcus pneumoniae. In the range of clavulanate concentrations producing these effects, this beta-lactam compound was selectively bound to PBP 3. Cell walls isolated from pneumococci grown in the presence of clavulanate showed increased sensitivity to the hydrolytic action of purified pneumococcal autolysin in vitro. High-performance liquid chromatography analysis of the peptidoglycan isolated from the clavulanate-grown cells showed major qualitative and quantitative changes in stem peptide composition, the most striking feature of which was the accumulation of peptide species carrying intact D-alanyl-D-alanine residues at the carboxy termini. The altered biological and biochemical properties of the clavulanate-grown pneumococci appear to be the consequences of suppressed D,D-carboxypeptidase activity. PMID:9055983

  5. Rapid detection of Streptococcus pneumoniae by real-time fluorescence quantitation PCR%实时荧光定量PCR快速诊断肺炎链球菌

    颜善活; 孙雷; 符可鹏; 卓永光; 杨善业; 樊祖茜; 黄永霞

    2013-01-01

    目的 建立实时荧光定量聚合酶链反应(PCR),用于肺炎链球菌检测和流行病学调查.方法 以肺炎链球菌自溶素(lyt)和溶血素(ply)的基因为目的序列分别设计引物和探针,将其分别与10株肺炎链球菌、13株非肺炎链球菌DNA以及不同浓度梯度的肺炎链球菌DNA进行荧光定量PCR,并将引物和探针应用于200例临床标本检测,同时通过传统的微生物培养鉴定的方法来验证荧光定量PCR的特异性和敏感性.结果 10株肺炎链球菌均获得了明显的扩增产物,13株非肺炎链球菌DNA无明显的扩增信号,其检测敏感性可达100 fg;200例临床标本,实时荧光定量PCR检测出42例肺炎链球菌阳性(阳性率为21%),而培养法阳性16例(阳性率为8%).结论 实时荧光定量PCR是一种敏感、特异、快速的检测肺炎链球菌方法,可用于肺炎链球菌的诊断和流行病学调查.%Objective To establish real-time fluorescence quantitation polymerase chain reaction ( PCR) for the detection and epidemiological studies of Streptococcus pneumoniae. Methods The autolysin (lyt) gene and hemolysin (ply) gene sequences were selected to develop primers and probe. A total of 10 strains of Streptococcus pneumoniae,13 strains of non-Streptococcus pneumoniae DISA and the different concentration strains of Streptococcus pneumoniae DNA were detected by real-time fluorescence quantitation PCR, and 200 clinical specimens were detected by primers and probe. The specificity and sensitivity were also analyzed. Results The 10 strains of Streptococcus pneumoniae were measured to obtain amplification products. However, 13 strains of non-Streptococcus pneumoniae DNA had no obvious amplification, and the sensitivity was 100fg. Among the 200 clinical specimens, real-time fluorescence quantitation PCR detected 42 cases of Streptococcus pneumoniae-positive (the positive rate was 21% ), while the culture method detected 16 cases of Streptococcus pneumoniae

  6. Immunization with Pneumococcal Surface Protein K of Nonencapsulated Streptococcus pneumoniae Provides Protection in a Mouse Model of Colonization.

    Keller, Lance E; Luo, Xiao; Thornton, Justin A; Seo, Keun-Seok; Moon, Bo Youn; Robinson, D Ashley; McDaniel, Larry S

    2015-11-01

    Current vaccinations are effective against encapsulated strains of Streptococcus pneumoniae, but they do not protect against nonencapsulated Streptococcus pneumoniae (NESp), which is increasing in colonization and incidence of pneumococcal disease. Vaccination with pneumococcal proteins has been assessed for its ability to protect against pneumococcal disease, but several of these proteins are not expressed by NESp. Pneumococcal surface protein K (PspK), an NESp virulence factor, has not been assessed for immunogenic potential or host modulatory effects. Mammalian cytokine expression was determined in an in vivo mouse model and in an in vitro cell culture system. Systemic and mucosal mouse immunization studies were performed to determine the immunogenic potential of PspK. Murine serum and saliva were collected to quantitate specific antibody isotype responses and the ability of antibody and various proteins to inhibit epithelial cell adhesion. Host cytokine response was not reduced by PspK. NESp was able to colonize the mouse nasopharynx as effectively as encapsulated pneumococci. Systemic and mucosal immunization provided protection from colonization by PspK-positive (PspK(+)) NESp. Anti-PspK antibodies were recovered from immunized mice and significantly reduced the ability of NESp to adhere to human epithelial cells. A protein-based pneumococcal vaccine is needed to provide broad protection against encapsulated and nonencapsulated pneumococci in an era of increasing antibiotic resistance and vaccine escape mutants. We demonstrate that PspK may serve as an NESp target for next-generation pneumococcal vaccines. Immunization with PspK protected against pneumococcal colonization, which is requisite for pneumococcal disease.

  7. Characterisation of a collection of Streptococcus pneumoniae isolates from patients suffering from acute exacerbations of chronic bronchitis: in vitro susceptibility to antibiotics and biofilm formation in relation to antibiotic efflux and serotypes/serogroups.

    Vandevelde, Nathalie M; Tulkens, Paul M; Diaz Iglesias, Yvan; Verhaegen, Jan; Rodriguez-Villalobos, Hector; Philippart, Ivan; Cadrobbi, Julie; Coppens, Nathalie; Boel, An; Van Vaerenbergh, Kristien; Francart, Hugo; Vanhoof, Raymond; Liistro, Giuseppe; Jordens, Paul; d'Odemont, Jean-Paul; Valcke, Yvan; Verschuren, Franck; Van Bambeke, Françoise

    2014-09-01

    The correlation between Streptococcus pneumoniae serotypes, biofilm production, antibiotic susceptibility and drug efflux in isolates from patients suffering from acute exacerbations of chronic bronchitis (AECB) remains largely unexplored. Using 101 isolates collected from AECB patients for whom partial (n=51) or full (n=50) medical details were available, we determined serotypes (ST)/serogroups (SG) (Quellung reaction), antibiotic susceptibility patterns [MIC (microdilution) using EUCAST and CLSI criteria] and ability to produce biofilm in vitro (10-day model; crystal violet staining). The majority of patients were 55-75 years old and pneumoniae. Moreover, 54% showed high severity scores (GOLD 3-4), and comorbidities were frequent including hypertension (60%), cancer (24%) and diabetes (20%). Alcohol and/or tobacco dependence was >30%. Isolates of SG6-11-15-23, known for large biofilm production and causing chronic infections, were the most prevalent (>15% each), but other isolates also produced biofilm (SG9-18-22-27 and ST8-20 being most productive), except SG7, SG29 and ST5 (fluoroquinolones and 2% for telithromycin. ST19A isolates showed resistance to all antibiotics, ST14 to all except moxifloxacin, and SG9 and SG19 to all except telithromycin, moxifloxacin and ceftriaxone (SG19 only). Solithromycin and telithromycin MICs were similar. No correlation was observed between biofilm production and MIC or efflux (macrolides, fluoroquinolones). S. pneumoniae serotyping may improve AECB treatment by avoiding antibiotics with predictable low activity, but it is not predictive of biofilm production.

  8. Treatment of Streptococcus pneumoniae disease in children%儿童肺炎链球菌性疾病的治疗

    陆权

    2011-01-01

    肺炎链球菌性疾病(尤其侵袭性肺炎链球菌性疾病)是5岁以下儿童较常见的感染性疾病,肺炎链球菌对抗菌药物的耐药性给临床治疗带来新的挑战.本文综述儿科肺炎链球菌性疾病、肺炎链球菌的耐药现状,并重点评论肺炎链球菌性疾病的治疗策略,包括肺炎链球菌性肺炎、中耳炎、鼻窦炎、脑膜炎和其他侵袭性肺炎链球菌性疾病,积极防治肺炎链球菌性疾病将加速联合国千年发展目标的实现.%Streptococcus pneumoniae disease(PD) especially as invasive pneumococcal disease (IPD)is more common in children younger than 5. The resistance of Streptococcus pneumoniae against antibacterial agents brings new challenges for clinical treatment. This paper reviews PD and Streptococcus pneumoniae resistance, especially focuses on the strategies of treatment for PD including pneumococcal pneumonia, otitis media, sinusitis, meningitis and other invasive pneumococcal diseases. Active prevention and control of pneumococcal disease will speed up the implementation of the United Nations Millennium Development Goals.

  9. ANALYSIS OF STREPTOCOCCUS PNEUMONIA 'S DRUG RESISTANCE TO MACROLIDES%肺炎链球菌对大环内酯类耐药性分析

    郁宝慧

    2015-01-01

    目的 探索郯城县区肺炎链球菌分离株对大环内酯类耐药性及其治疗情况.方法 收集郯城县社区和临床分离的肺炎链球菌 ,根据CLSI标准,用K-B法、Etest法检测肺炎链球菌对红霉素和克林霉素的耐药性及对红霉素的耐药表型.结果 493株肺炎链球菌中红霉素不敏感菌株489株 ,对克林霉素不敏感菌株482株,其中 ermB基因介导的红霉素耐药菌株482株 ,占98.6% , mefE基因介导的红霉素耐药菌株7株,占1.4%.结论 郯城县区对红霉素和克林霉素近乎全部耐药 ,ermB基因介导的靶位改变是郯城县区肺炎链球菌对大环内酯类抗菌药物的主要耐药机制.%Objective To explore streptococcus pneumonia's drug resistance to macrolides . Methods Samples of streptococcus pneumonia were collected from the communities in Tancheng County and the iso-lated ones from clinical treatment .According to the CLSI standard ,K-B method and Etest were used to detect streptococcus pneumonia ' s drug resistance to erythromycin and clindamycin and the resistance phenotype of erythromycin . Results In the 493 strains of streptococcus pneumonia ,489 strains were not sensi-tive to erythromycin ,482 strains were not sensitive to clindamycin .482 drug-resistant strains were mediated by ermB gene ,accounting for 98 .6% of all the strains .7 drug-resistant strains were mediated by mefE gene ,accounting for 1 .4% .Conclusion Erythro-mycin and clindamycin has no obvious effect on streptococcus pneumoniae in this county . T he target change of mediating by ErmB gene is the main mechanism of streptococcus pneumonia 's resistance to mac-rolides .

  10. Streptococcus pneumoniae isolates in healthy children attending day-care centers in 12 states in Mexico Aislamientos de S. pneumoniae en niños sanos de estancias infantiles en 12 estados de México

    Luz Elena Espinosa-de los Monteros

    2007-08-01

    Full Text Available OBJECTIVE: The aim of this study was to determine the prevalence of asymptomatic nasopharyngeal carriage of Streptococcus pneumoniae, which is a major factor in the transmission of this bacterium. MATERIAL AND METHODS: Nasopharyngeal cultures were performed on children attending 32 day-care centers in 12 states in Mexico. RESULTS: Streptococcus pneumoniae was isolated from the nasopharynx of 829 out of 2 777(29.9% subjects aged two months to six years. All children lived in urban areas and 80% spent more than six hours daily in a day-care center. Streptococcus pneumoniae serotypes most frequently identified were: 19F (23%, 6B (15.6%, 23F (11.2% and 6A (14.9%. Thirty-six percent of the isolates were susceptible to penicillin. CONCLUSIONS: Serotype distribution suggests the possible benefits that could be obtained from the heptavalent pneumococcal conjugate vaccine.OBJETIVO: La intención de este estudio fue determinar la prevalencia de portadores nasofaríngeos asintomáticos de Streptococcus pneumoniae, el cual es el principal factor en la transmisión de esta bacteria. MATERIAL Y MÉTODOS: Los cultivos nasofaríngeos fueron realizados en niños que asisten a 32 estancias infantiles en 12 estados de México. RESULTADOS: Streptococcus pneumoniae fue aislado de la nasofaringe de 829 (29.9% niños de los 2 777 incluidos en el estudio con un rango de edad de 2 meses a 6 años. Todos los niños vivían en áreas urbanas y 80% permanecían más de seis horas diarias en la estancia infantil. Los serotipos de Streptococcus pneumoniae más frecuentemente identificados fueron: 19F (23%, 6B (15.6%, 23F (11.2% y 6 A (14.9%. Treinta y seis por ciento de los aislamientos fueron susceptibles a penicilina. CONCLUSIONES: La distribución de serotipos nos da una idea de los posibles beneficios que podrían obtenerse de la vacuna neumocóccica conjugada heptavalente.

  11. Conformational Analysis of the Streptococcus pneumoniae Hyaluronate Lyase and Characterization of Its Hyaluronan-specific Carbohydrate-binding Module*

    Suits, Michael D. L.; Pluvinage, Benjamin; Law, Adrienne; Liu, Yan; Palma, Angelina S.; Chai, Wengang; Feizi, Ten; Boraston, Alisdair B.

    2014-01-01

    For a subset of pathogenic microorganisms, including Streptococcus pneumoniae, the recognition and degradation of host hyaluronan contributes to bacterial spreading through the extracellular matrix and enhancing access to host cell surfaces. The hyaluronate lyase (Hyl) presented on the surface of S. pneumoniae performs this role. Using glycan microarray screening, affinity electrophoresis, and isothermal titration calorimetry we show that the N-terminal module of Hyl is a hyaluronan-specific carbohydrate-binding module (CBM) and the founding member of CBM family 70. The 1.2 Å resolution x-ray crystal structure of CBM70 revealed it to have a β-sandwich fold, similar to other CBMs. The electrostatic properties of the binding site, which was identified by site-directed mutagenesis, are distinct from other CBMs and complementary to its acidic ligand, hyaluronan. Dynamic light scattering and solution small angle x-ray scattering revealed the full-length Hyl protein to exist as a monomer/dimer mixture in solution. Through a detailed analysis of the small angle x-ray scattering data, we report the pseudoatomic solution structures of the monomer and dimer forms of the full-length multimodular Hyl. PMID:25100731

  12. The response regulator YycF inhibits expression of the fatty acid biosynthesis repressor FabT in Streptococcus pneumoniae

    Maria Luz Mohedano

    2016-08-01

    Full Text Available The YycFG (also known as WalRK, VicRK, MicAB or TCS02 two-component system (TCS is highly conserved among Gram-positive bacteria with a low G+C content. In Streptococcus pneumoniae the YycF response regulator has been reported to be essential due to its control of pcsB gene expression. Previously we showed that overexpression of yycF in S. pneumoniae TIGR4 altered the transcription of genes involved in cell wall metabolism and fatty acid biosynthesis, giving rise to anomalous cell division and increased chain length of membrane fatty acids. Here, we have overexpressed the yycFG system in TIGR4 wild-type strain and yycF in a TIGR4 mutant depleted of YycG, and analyzed their effects on expression of proteins involved in fatty acid biosynthesis during activation of the TCS. We demonstrate that transcription of the fab genes and levels of their products were only altered in the YycF overexpressing strain, indicating that the unphosphorylated form of YycF is involved in the regulation of fatty acid biosynthesis. In addition, DNA-binding assays and in vitro transcription experiments with purified YycF and the promoter region of the FabTH-acp operon support a direct inhibition of transcription of the FabT repressor by YycF, thus confirming the role of the unphosphorylated form in transcriptional regulation.

  13. Prevalence of Ile-460-Val/ParE substitution in clinical Streptococcus pneumoniae isolates that were less susceptible to fluoroquinolones.

    Kawamura-Sato, Kumiko; Hasegawa, Tadao; Torii, Keizo; Ito, Hideo; Ohta, Michio

    2005-07-01

    A total of 73 clinical isolates of Streptococcus pneumoniae were measured for susceptibilities to nine fluoroquinolones, and nucleotide sequences of the quinolone resistance-determining regions (QRDRs) were determined. MIC90s of sparfloxacin, tosufloxacin, grepafloxacin, and gatifloxacin were less than 0.5 mg/L and the MIC90 of ciprofloxacin was 2 mg/L, although MIC values of some isolates to ciprofloxacin were more than 2 mg/L. We found that 60 of 73 isolates had only Ile-460-Val/ParE substitution and two isolates had an additional substitution of Ser-114-Gly/GyrA, while none of the isolates had any other substitutions in QRDRs of either ParC/E or GyrA/B. The isolates carrying Ile-460-Val/ParE substitution were more resistant to the fluoroquinolones norfloxacin and ciprofloxacin than the isolates with no amino acid substitution and the differences in MIC values were significant, suggesting that Ile-460-Val/ParE substitution in recent clinical S. pneumoniae isolates should be involved in the low-level fluoroquinolone resistance.

  14. The selection of resistance to and the mutagenicity of different fluoroquinolones in Staphylococcus aureus and Streptococcus pneumoniae.

    Sierra, J M; Cabeza, J G; Ruiz Chaler, M; Montero, T; Hernandez, J; Mensa, J; Llagostera, M; Vila, J

    2005-09-01

    Two quinolone-susceptible Staphylococcus aureus and five quinolone-susceptible Streptococcus pneumoniae isolates were used to obtain in-vitro quinolone-resistant mutants in a multistep resistance selection process. The fluoroquinolones used were ciprofloxacin, moxifloxacin, levofloxacin, gemifloxacin, trovafloxacin and clinafloxacin. The mutagenicity of these quinolones was determined by the Salmonella and the Escherichia coli retromutation assays. All quinolone-resistant Staph. aureus mutants had at least one mutation in the grlA gene, while 86.6% of quinolone-resistant Strep. pneumoniae mutants had mutations in either or both the gyrA and parC genes. Moxifloxacin and levofloxacin selected resistant mutants later than the other quinolones, but this difference was more obvious in Staph. aureus. Accumulation of the fluoroquinolones by Staph. aureus did not explain these differences, since levofloxacin and moxifloxacin accumulated inside bacteria to the same extent as clinafloxacin and trovafloxacin. The results also showed that moxifloxacin and levofloxacin had less mutagenic potency in both mutagenicity assays, suggesting a possible relationship between the selection of resistance to quinolones and the mutagenic potency of the molecule. Furthermore, gemifloxacin selected efflux mutants more frequently than the other quinolones used. Thus, the risk of developing quinolone resistance may depend on the density of the microorganism at the infection site and the concentration of the fluoroquinolone, and also on the mutagenicity of the quinolone used, with moxifloxacin and levofloxacin being the least mutagenic.

  15. The Response Regulator YycF Inhibits Expression of the Fatty Acid Biosynthesis Repressor FabT in Streptococcus pneumoniae

    Mohedano, Maria L.; Amblar, Mónica; de la Fuente, Alicia; Wells, Jerry M.; López, Paloma

    2016-01-01

    The YycFG (also known as WalRK, VicRK, MicAB, or TCS02) two-component system (TCS) is highly conserved among Gram-positive bacteria with a low G+C content. In Streptococcus pneumoniae the YycF response regulator has been reported to be essential due to its control of pcsB gene expression. Previously we showed that overexpression of yycF in S. pneumoniae TIGR4 altered the transcription of genes involved in cell wall metabolism and fatty acid biosynthesis, giving rise to anomalous cell division and increased chain length of membrane fatty acids. Here, we have overexpressed the yycFG system in TIGR4 wild-type strain and yycF in a TIGR4 mutant depleted of YycG, and analyzed their effects on expression of proteins involved in fatty acid biosynthesis during activation of the TCS. We demonstrate that transcription of the fab genes and levels of their products were only altered in the YycF overexpressing strain, indicating that the unphosphorylated form of YycF is involved in the regulation of fatty acid biosynthesis. In addition, DNA-binding assays and in vitro transcription experiments with purified YycF and the promoter region of the FabTH-acp operon support a direct inhibition of transcription of the FabT repressor by YycF, thus confirming the role of the unphosphorylated form in transcriptional regulation. PMID:27610104

  16. LocZ Is a New Cell Division Protein Involved in Proper Septum Placement in Streptococcus pneumoniae

    Holečková, Nela; Molle, Virginie; Buriánková, Karolína; Benada, Oldřich; Kofroňová, Olga; Ulrych, Aleš; Branny, Pavel

    2014-01-01

    ABSTRACT How bacteria control proper septum placement at midcell, to guarantee the generation of identical daughter cells, is still largely unknown. Although different systems involved in the selection of the division site have been described in selected species, these do not appear to be widely conserved. Here, we report that LocZ (Spr0334), a newly identified cell division protein, is involved in proper septum placement in Streptococcus pneumoniae. We show that locZ is not essential but that its deletion results in cell division defects and shape deformation, causing cells to divide asymmetrically and generate unequally sized, occasionally anucleated, daughter cells. LocZ has a unique localization profile. It arrives early at midcell, before FtsZ and FtsA, and leaves the septum early, apparently moving along with the equatorial rings that mark the future division sites. Consistently, cells lacking LocZ also show misplacement of the Z-ring, suggesting that it could act as a positive regulator to determine septum placement. LocZ was identified as a substrate of the Ser/Thr protein kinase StkP, which regulates cell division in S. pneumoniae. Interestingly, homologues of LocZ are found only in streptococci, lactococci, and enterococci, indicating that this close phylogenetically related group of bacteria evolved a specific solution to spatially regulate cell division. PMID:25550321

  17. The interactome of Streptococcus pneumoniae and its bacteriophages show highly specific patterns of interactions among bacteria and their phages.

    Mariano, Rachelle; Wuchty, Stefan; Vizoso-Pinto, Maria G; Häuser, Roman; Uetz, Peter

    2016-04-22

    Although an abundance of bacteriophages exists, little is known about interactions between their proteins and those of their bacterial hosts. Here, we experimentally determined the phage-host interactomes of the phages Dp-1 and Cp-1 and their underlying protein interaction network in the host Streptococcus pneumoniae. We compared our results to the interaction patterns of E. coli phages lambda and T7. Dp-1 and Cp-1 target highly connected host proteins, occupy central network positions, and reach many protein clusters through the interactions of their targets. In turn, lambda and T7 targets cluster to conserved and essential proteins in E. coli, while such patterns were largely absent in S. pneumoniae. Furthermore, targets in E. coli were mutually strongly intertwined, while targets of Dp-1 and Cp-1 were strongly connected through essential and orthologous proteins in their immediate network vicinity. In both phage-host systems, the impact of phages on their protein targets appears to extend from their network neighbors, since proteins that interact with phage targets were located in central network positions, have a strong topologically disruptive effect and touch complexes with high functional heterogeneity. Such observations suggest that the phages, biological impact is accomplished through a surprisingly limited topological reach of their targets.

  18. In vitro activity of ceftobiprole and seven other antimicrobial agents against invasive Streptococcus pneumoniae isolates in Spain.

    Ríos Dueñas, E; Rodríguez-Avial, I; Picazo, J J

    2011-12-01

    The in vitro activity of ceftobiprole was compared with that of seven antimicrobial agents against invasive Streptococcus pneumoniae isolated from adult patients (>15 years old). Characterization of erythromycin-resistant strains and serotype distribution of all pneumococci were also evaluated. Seventy invasive S. pneumoniae strains were isolated from December 2007 to January 2009. Serotyping was carried out by Quellung reaction. Antibiotic susceptibility was tested by broth microdilution (CLSI guidelines). The comparator agents were penicillin, cefotaxime, erythromycin, clindamycin, telithromycin, tetracycline and moxifloxacin. Phenotypic characterization of macrolide resistance was performed by the double disk method. Macrolide resistance genes [erm(B) and mef(A/E)] and the promoter of erm(B) were detected by PCR. Twenty-five different serotypes were detected of which 87% were non-PCV7 types. The percentages of resistance to erythromycin, clindamycin and tetracycline were 20%, 8.6% and 16%, respectively. A penicillin MIC ≥0.12 mg/L was observed in 14 of the 70 invasive pneumococci strains. The cefotaxime and ceftobiprole MIC(50)/MIC(90) of these 14 strains were 1/4 and 0.03/1 mg/L, respectively. Ceftobiprole showed higher in vitro activity than penicillin and cefotaxime with all isolates being inhibited by ≤1 mg/L. Its high in vitro activity should make ceftobiprole a very promising drug for the treatment of pneumococcal infections.

  19. Role of an iron-dependent transcriptional regulator in the pathogenesis and host response to infection with Streptococcus pneumoniae.

    Radha Gupta

    Full Text Available Iron is a critical cofactor for many enzymes and is known to regulate gene expression in many bacterial pathogens. Streptococcus pneumoniae normally inhabits the upper respiratory mucosa but can also invade and replicate in lungs and blood. These anatomic sites vary considerably in both the quantity and form of available iron. The genome of serotype 4 pneumococcal strain TIGR4 encodes a putative iron-dependent transcriptional regulator (IDTR. A mutant deleted at idtr (Δidtr exhibited growth kinetics similar to parent strain TIGR4 in vitro and in mouse blood for up to 48 hours following infection. However, Δidtr was significantly attenuated in a murine model of sepsis. IDTR down-regulates the expression of ten characterized and putative virulence genes in nasopharyngeal colonization and pneumonia. The host cytokine response was significantly suppressed in sepsis with Δidtr. Since an exaggerated inflammatory response is associated with a poor prognosis in sepsis, the decreased inflammatory response could explain the increased survival with Δidtr. Our results suggest that IDTR, which is dispensable for pneumococcal growth in vitro, is associated with regulation of pneumococcal virulence in specific host environments. Additionally, IDTR ultimately modulates the host cytokine response and systemic inflammation that contributes to morbidity and mortality of invasive pneumococcal disease.

  20. Identification of Streptococcus pneumoniae: Development of a Standardized Protocol for Optochin Susceptibility Testing Using Total Lab Automation

    Panitz, Jessica; Burckhardt, Florian; Zimmermann, Stefan

    2017-01-01

    Purpose. Optochin susceptibility is one parameter used in the laboratory to identify Streptococcus pneumoniae. However, a single standardized procedure does not exist. Optochin is included neither in the current EUCAST breakpoint tables nor in the CLSI performance standards for antimicrobial susceptibility testing. We wanted to establish an evidence-based protocol for optochin testing for our Total Lab Automation. Methods. We tested seven different agars and four different reading time points (7 h, 12 h, 18 h, and 24 h). To accommodate for serotype diversity, all tests were done with 99 different strains covering 34 different serotypes of S. pneumoniae. We calculated a multivariable linear regression using data from 5544 inhibition zones. Results. Reading was possible for all strains at 12 h. Agar type and manufacturer influenced the size of the inhibition zones by up to 2 mm and they varied considerably depending on serotype (up to 3 mm for serotype 3). Depending on agar and reading time point, up to 38% of inhibition zones were smaller than the cut-off of 14 mm; that is, the result of the test was false-negative. Conclusions. Shortening incubation time from 24 h to 12 h for optochin susceptibility testing is feasible. Agar and incubation time have to be chosen carefully to avoid false-negative results.