LacR is a repressor of lacABCD and LacT an activator of lacTFEG, constituting the lac-gene cluster in Streptococcus pneumoniae.

Appl Environ Microbiol. 2014 Jun 20. pii: AEM.01370-14. [Epub ahead of print]

LacR is a repressor of lacABCD and LacT an activator of lacTFEG, constituting the lac-gene cluster in Streptococcus pneumoniae.

Afzal M1, Shafeeq S2, Kuipers OP3.

Author information

Abstract

Transcriptome comparison of the Streptococcus pneumoniae strain D39 grown in the presence of either lactose or galactose with that of the strain grown in the presence of glucose, revealed the elevated expression of various genes and operons, including the lac gene cluster that is organized into two operons i.e. lac operon-I (lacABCD) and lac operon-II (lacTFEG). Deletion of the DeoR family transcriptional regulator lacR that is present downstream of the lac gene cluster, revealed elevated expression of lac operon-I, even in the absence of lactose. This suggests a function of LacR as a transcriptional repressor of lac operon-I that encodes enzymes involved in the Tagatose-6-P pathway in the absence of lactose or galactose. Deletion of lacR did not affect the expression of lac operon-II that encodes for a lactose-specific PTS. This finding was further confirmed by β-galactosidase assays with PlacA-lacZ and PlacT-lacZ in the presence of either lactose or glucose as a sole carbon source in the medium. This suggests the presence of another transcriptional regulator in the regulation of lac operon-II, which could be the BglG-family transcriptional antiterminator LacT. We demonstrate the role of LacT as a transcriptional activator of lac operon-II in the presence of lactose and CcpA-independent regulation of the lac gene cluster in S. pneumoniae.

Copyright © 2014, American Society for Microbiology. All Rights Reserved.

PMID: 24951784 [PubMed - as supplied by publisher]

Vaccination coverage against hepatitis A and B viruses, Streptococcus pneumoniae, seasonal flu, and A(H1N1)2009 pandemic influenza in HIV-infected patients.

Vaccine. 2014 Jun 18. pii: S0264-410X(14)00804-4. doi: 10.1016/j.vaccine.2014.06.015. [Epub ahead of print]

Vaccination coverage against hepatitis A and B viruses, Streptococcus pneumoniae, seasonal flu, and A(H1N1)2009 pandemic influenza in HIV-infected patients.

Valour F1, Cotte L2, Voirin N3, Godinot M4, Ader F5, Ferry T5, Vanhems P3, Chidiac C5.

Author information

Abstract

BACKGROUND:

Several vaccines are recommended in HIV-infected patients due to an increased risk of vaccine-preventable infections, severe forms of the disease, or shared transmission routes. Few data are available regarding vaccination coverage and its determinants in this population.

METHODS:

A cross-sectional study was performed in HIV-infected patients included in a hospital-based cohort in 2011. Vaccination coverage against hepatitis A virus (HAV), hepatitis B virus (HBV), seasonal and A(H1N1)2009 pandemic influenza, and invasive pneumococcal diseases (IPD) were recorded. Factors associated with vaccination were assessed by multivariate logistic regression.

RESULTS:

2467 patients were included (median age: 47 years; male gender 71.5%; men having sex with men (MSM): 43.9%; CDC stage C: 24.3%; HBV and/or hepatitis C virus co-infection: 14.4%). Median duration of HIV infection was 10 years and 93.1% of patients received combination antiretroviral therapy. At baseline, the median CD4 count was 527 cells/mm3 and HIV viral load was <50 copies/mL in 83.3% of cases. Vaccination coverage for HBV, HAV, seasonal influenza, A(H1N1)2009 pandemic influenza, and IPD were 61.9%, 47.4%, 30.9, 48.3%, and 64.6%, respectively. Factors independently associated with vaccination were a younger (HBV) or an older age (influenza), male gender (HBV, HAV), MSM (HBV), CD4 count >200/mm3 and HIV-RNA <50 copies/mL (IPD, influenza), longer duration of HIV infection (IPD, influenza), and follow-up by an experienced physician (HBV, IPD).

CONCLUSIONS:

Vaccination coverage remained insufficient for all vaccine-preventable infections investigated in this study. Determinants for vaccination were largely not evidence-based, and efforts should be focused on improving physicians' knowledge about guidelines.

Copyright © 2014. Published by Elsevier Ltd.

KEYWORDS:

HAV; HBV; HIV; Influenza; Invasive pneumococcal disease; Vaccination coverage

PMID: 24951870 [PubMed - as supplied by publisher]

Genetic characteristics of Haemophilus influenzae and Streptococcus pneumoniae isolated from children with conjunctivitis-otitis media syndrome.

J Infect Chemother. 2014 Jun 19. pii: S1341-321X(14)00181-0. doi: 10.1016/j.jiac.2014.04.015. [Epub ahead of print]

Genetic characteristics of Haemophilus influenzae and Streptococcus pneumoniae isolated from children with conjunctivitis-otitis media syndrome.

Sugita G1, Hotomi M2, Sugita R3, Kono M1, Togawa A1, Yamauchi K1, Funaki T4, Yamanaka N1.

Author information

Abstract

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.

Copyright © 2014. Published by Elsevier Ltd.

KEYWORDS:

Acute bacterial conjunctivitis; Acute otitis media; Acute rhinosinusitis; Haemophilusinfluenzae; Pulsed-field gel electrophoresis; Streptococcuspneumoniae

PMID: 24953451 [PubMed - as supplied by publisher]

LEVOFLOXACIN AND CEFTRIAXONE IN COMBINATION ATTENUATES LUNG INFLAMMATION IN A MOUSE MODEL OF BACTEREMIC PNEUMONIA BY MULTI-DRUG RESISTANT Streptococcus pneumoniae VIA INHIBITION OF CYTOLYTIC ACTIVITIES OF PNEUMOLYSIN AND AUTOLYSIN.

Antimicrob Agents Chemother. 2014 Jun 23. pii: AAC.03245-14. [Epub ahead of print]

LEVOFLOXACIN AND CEFTRIAXONE IN COMBINATION ATTENUATES LUNG INFLAMMATION IN A MOUSE MODEL OF BACTEREMIC PNEUMONIA BY MULTI-DRUG RESISTANT Streptococcus pneumoniae VIA INHIBITION OF CYTOLYTIC ACTIVITIES OF PNEUMOLYSIN AND AUTOLYSIN.

Majhi A1, Adhikary R1, Bhattacharyya A1, Mahanti S1, Bishayi B2.

Author information

Abstract

OBJECTIVES:

Whether synergistic antimicrobial combination in vitro would be beneficial in down regulation of pneumococcal virulent genes and associated inflammation of the lung tissue induced by multi-drug resistant S. pneumoniae infection in vivo needs to be elucidated for considering this mode of therapy in case of severe pneumococcal infection.

METHODS:

We investigated the in vivo changes in expression of these virulence determinants using an efficacious combination predetermined by in vitro studies. Balb/C mice were infected with 106 CFU of bacteria. Intravenous levofloxacin at 150 mg/kg and/or ceftriaxone at 50 mg/kg were initiated 18 h post infection; animals were sacrificed from 0 - 24 h after initiation of treatment. Levels of cytokines, chemokines and CRP in serum and in lungs, along with myeloperoxidase, nitric oxide, inflammatory cell count in broncho alveolar lavage fluid (BALF), changes in pneumolysin and autolysin gene expression and COX-2 and iNOS protein expression in lungs were estimated.

RESULTS:

Combination therapy down regulated inflammation and promoted bacterial clearance. Pneumolysin and autolysin expression was down regulated with concomitant decrease in expression of COX-2 and iNOS in lung tissue.

CONCLUSION:

Thus this combination can be considered for therapeutic use even in cases of pneumonia caused by drug resistant isolates.

Copyright © 2014, American Society for Microbiology. All Rights Reserved.

PMID: 24957840 [PubMed - as supplied by publisher]

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A Modified Janus Cassette (Sweet Janus) to Improve Allelic Replacement Efficiency by High-Stringency Negative Selection in Streptococcus pneumoniae.

PLoS One. 2014 Jun 24;9(6):e100510. doi: 10.1371/journal.pone.0100510. eCollection 2014.

A Modified Janus Cassette (Sweet Janus) to Improve Allelic Replacement Efficiency by High-Stringency Negative Selection in Streptococcus pneumoniae.

Li Y, Thompson CM, Lipsitch M.

Author information

Abstract

The Janus cassette permits marker-free allelic replacement or knockout in streptomycin-resistant Streptococcus pneumoniae (pneumococcus) through sequential positive and negative selection. Spontaneous revertants of Janus can lead to high level of false-positives during negative selection, which necessitate a time-consuming post-selection screening process. We hypothesized that an additional counter-selectable marker in Janus would decrease the revertant frequency and reduce false-positives, since simultaneous reversion of both counter-selectable makers is much less likely. Here we report a modified cassette, Sweet Janus (SJ), in which the sacB gene from Bacillus subtilis conferring sucrose sensitivity is added to Janus. By using streptomycin and sucrose simultaneously as selective agents, the frequency of SJ double revertants was about 105-fold lower than the frequency of Janus revertants. Accordingly, the frequency of false-positives in the SJ-mediated negative selection was about 100-fold lower than what was seen for Janus. Thus, SJ enhances negative selection stringency and can accelerate allelic replacement in pneumococcus, especially when transformation frequency is low due to strain background or suboptimal transformation conditions. Results also suggested the sacB gene alone can function as a counter-selectable marker in the Gram-positive pneumococcus, which will have the advantage of not requiring a streptomycin-resistant strain for allelic replacement.

PMID: 24959661 [PubMed - as supplied by publisher]

Preceding human metapneumovirus infection increases adherence of Streptococcus pneumoniae and severity of murine pneumococcal pneumonia.

J Microbiol Immunol Infect. 2014 Jun 12. pii: S1684-1182(14)00073-5. doi: 10.1016/j.jmii.2014.04.008. [Epub ahead of print]

Preceding human metapneumovirus infection increases adherence of Streptococcus pneumoniae and severity of murine pneumococcal pneumonia.

Lai SH1, Liao SL2, Wong KS1, Lin TY3.

Author information

Abstract

BACKGROUND:

Coinfection with respiratory virus and Streptococcus pneumoniae has been frequently reported in several epidemiologic studies. The aim of this study was to explore the effect of preceding human metapneumovirus (hMPV) inoculation on subsequent pneumococcal infection.

METHODS:

Hep-2 and A549 cells were infected with hMPV then inoculated with S. pneumoniae. Bacterial adhesion was measured using colony forming unit and cytometric-fluorescence assays. In vivo bacterial adhesion was examined in hMPV-infected mice after inoculation of fluorescence-conjugated S. pneumoniae. Pulmonary inflammation (bacterial titers, cytokine levels, and histopathology) of hMPV-infected mice was investigated after inoculation with S. pneumoniae.

RESULTS:

In vitro results of bacterial infection with S. pneumoniae on A549 and Hep-2 monolayer cells showed that even though cellular adherence was variable among different serotypes, there was significantly enhanced bacterial adherence in A549 cells with preceding hMPV infection. In addition, in vivo study of hMPV-infected mice showed increased adhesion of S. pneumoniae on the bronchial epithelium with delayed bacterial clearance and exacerbated histopathology. Furthermore, mice with preceding hMPV infection showed repressed recruitment of airway neutrophils with decreased expression of neutrophil chemoattractants during pneumococcal infection.

CONCLUSION:

These results suggest that hMPV-infected airway cells, especially the lower airway epithelium, express increased adherence with S. pneumoniae. Furthermore, hMPV-infected mice showed impaired recruitment of airway neutrophils, possibly leading to delayed bacterial clearance and exacerbated pulmonary inflammation, after secondary infection with pneumococcal isolates.

Copyright © 2014. Published by Elsevier B.V.

KEYWORDS:

airway epithelium; animal model; infection and inflammation; pneumonia; viral infection

PMID: 24931548 [PubMed - as supplied by publisher]

Clinical cure rates in subjects treated with azithromycin for community-acquired respiratory tract infections caused by azithromycin-susceptible or azithromycin-resistant Streptococcus pneumoniae: analysis of Phase 3 clinical trial data.

J Antimicrob Chemother. 2014 Jun 11. pii: dku207. [Epub ahead of print]

Clinical cure rates in subjects treated with azithromycin for community-acquired respiratory tract infections caused by azithromycin-susceptible or azithromycin-resistant Streptococcus pneumoniae: analysis of Phase 3 clinical trial data.

Zhanel GG1, Wolter KD2, Calciu C3, Hogan P4, Low DE5, Weiss K6, Karlowsky JA7.

Author information

Abstract

BACKGROUND:

Community-acquired respiratory tract infections (CARTI) are commonly caused by Streptococcus pneumoniae (SPN) and empirically treated with azithromycin. This study assessed clinical cure rates in azithromycin-treated subjects with CARTI caused by azithromycin-susceptible (Azi-S) or azithromycin-resistant (Azi-R) SPN.

METHODS:

1127 subjects with CARTI (402 acute otitis media, 309 community-acquired pneumonia, 255 acute bacterial exacerbations of chronic bronchitis and 161 acute bacterial sinusitis) in 13 Phase 3 clinical trials (1993-2007) had a confirmed pathogen, received azithromycin and were assessed for clinical cure/failure. 34.4% of subjects (388/1127) had a positive culture for SPN; 33.4% (376/1127) had Azi-S or Azi-R SPN.

RESULTS:

28.9% (112/388) of subjects with SPN had Azi-R SPN: 35.7% (40/112) were low-level Azi-R SPN (LLAR; MIC 2-8 mg/L), while 64.3% (72/112) were high-level Azi-R SPN (HLAR; MIC ≥16 mg/L). Among Azi-S and Azi-R SPN CARTI subjects, clinical cure rates were: 86.2% (324/376) overall; 89.4% (236/264) for subjects with Azi-S SPN; 78.6% (88/112) for subjects with Azi-R SPN (P = 0.003, versus Azi-S); 77.5% (31/40) for subjects with LLAR SPN (P < 0.001); and 79.2% (57/72) for subjects with HLAR SPN (P = 0.122).

CONCLUSIONS:

Clinical cure rates in CARTI subjects treated with azithromycin were higher for Azi-S SPN (89.4%) versus Azi-R SPN (78.6%; P = 0.003). However, cure rates were not different for subjects infected with LLAR-SPN versus HLAR-SPN. At the observed prevalence of Azi-R SPN of 28.9%, an additional 3.1 clinical failures would be predicted, as a consequence of azithromycin resistance (LLAR and HLAR), per 100 subjects treated empirically with azithromycin.

© The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

KEYWORDS:

S. pneumoniae; macrolides; outcome; resistance; susceptibility

PMID: 24920652 [PubMed - as supplied by publisher]

Platelet endothelial cell adhesion molecule-1 (PECAM-1), a putative receptor for the adhesion of Streptococcus pneumoniae to the vascular endothelium of the blood-brain barrier.

Infect Immun. 2014 Jun 9. pii: IAI.00046-14. [Epub ahead of print]

Platelet endothelial cell adhesion molecule-1 (PECAM-1), a putative receptor for the adhesion of Streptococcus pneumoniae to the vascular endothelium of the blood-brain barrier.

Iovino F1, Molema G2, Bijlsma JJ1.

Author information

Abstract

The Gram-positive bacterium Streptococcus pneumoniae is the main causative agent of bacterial meningitis. S. pneumoniae is thought to invade the Central Nervous System via the bloodstream by crossing the vascular endothelium of the blood-brain barrier. The exact mechanism by which pneumococci cross endothelial cell barriers before meningitis develops is unknown. Here we investigated the role of PECAM-1/CD31, one of the major endothelial cell adhesion molecules, in S. pneumoniae adhesion to vascular endothelium of the blood-brain barrier. Mice were intravenously infected with pneumococci and sacrificed at various time points to represent stages preceding meningitis. Immunofluorescent analysis of brain tissue of infected mice showed that pneumococci co-localized with PECAM-1. Also in Human Brain Microvascular Endothelial Cells (HBMEC) incubated with S. pneumoniae we observed a clear co-localization between PECAM-1 and pneumococci. Blocking of PECAM-1 reduced the adhesion of S. pneumoniae to endothelial cells in vitro, implying that PECAM-1 is involved in pneumococcal adhesion to the cells. Furthermore, using endothelial cell protein lysates we demonstrated that S. pneumoniae physically binds to PECAM-1 in vitro. Moreover, both in vitro and in vivo PECAM-1 co-localizes with the S. pneumoniae adhesion receptor pIgR. Lastly, immunoprecipitation experiments revealed that PECAM-1 can physically interact with pIgR. In summary, we show for the first time that blood-borne S. pneumoniae co-localizes with PECAM-1 expressed by brain microvascular endothelium and that in addition they co-localize with pIgR. We hypothesize that this interaction may play a role in pneumococcal binding to the blood-brain barrier vasculature prior to invasion into the brain.

Copyright © 2014, American Society for Microbiology. All Rights Reserved.

PMID: 24914219 [PubMed - as supplied by publisher]

Emergence of Streptococcus pneumoniae Serogroups 15 and 35 in Nasopharyngeal Cultures from Young Children with Acute Otitis Media

Pediatr Infect Dis J. 2014 Jun 6. [Epub ahead of print]

Emergence of Streptococcus pneumoniae Serogroups 15 and 35 in Nasopharyngeal Cultures from Young Children with Acute Otitis Media.

Martin JM1, Hoberman A, Paradise JL, Barbadora KA, Shaikh N, Bhatnagar S, Shope T, Block SL, Haralam MA, Kurs-Lasky M, Colborn DK, Green M.

Author information

Abstract

BACKGROUND::

Surveillance of children with acute otitis media (AOM) for nasopharyngeal colonization with Streptococcus pneumoniae before, during, and after the introduction of 7-valent pneumococcal conjugate vaccine (PCV7) indicated the near-complete elimination of PCV7 strains and the emergence of pneumococcal serotype 19A.

METHODS::

To determine effects of the introduction of 13-valent pneumococcal conjugate vaccine (PCV13) on pneumococcal nasopharyngeal colonization, we obtained nasopharyngeal cultures from 228 children 6 through 23 of age months presenting with a new episode of AOM during 2012 and 2013 and enrolled in an ongoing clinical trial of antimicrobial efficacy. All children had received at least 2 doses of PCV13. The S. pneumoniae isolates were subjected to serotyping and testing for antimicrobial susceptibility. We compared the findings with results obtained in three earlier studies.

RESULTS::

We found nasopharyngeal colonization with S. pneumoniae in 113 (50%) of the children with AOM. PCV7 and PCV13 serotypes accounted for 2% and 12%, respectively of the pneumococcal isolates. Of the 14 PCV13 isolates, 8 were serotype 19A. Nonvaccine serotypes accounted for 69% of the isolates. Most frequently occurring were subtypes of serotype 15 (23%) and serotype 35B (9%). Overall, 33% of the isolates were penicillin-nonsusceptible, a proportion not significantly different from proportions found in our three earlier studies (26%, 36%, and 37%, respectively). Serotypes 15 and 35B accounted for 51% of penicillin-nonsusceptible isolates.

CONCLUSION::

Expansion of contents of pneumococcal vaccine administered to children is followed by not-fully-predictable changes in nasopharyngeal pneumococcal colonization. Continued surveillance is required to help inform future vaccine development.

PMID: 24911895 [PubMed - as supplied by publisher]

Determination of Kinetics and the Crystal Structure of a Novel Type 2 Isopentenyl Diphosphate: Dimethylallyl Diphosphate Isomerase from Streptococcus pneumoniae.

Chembiochem. 2014 Jun 6. doi: 10.1002/cbic.201402046. [Epub ahead of print]

Determination of Kinetics and the Crystal Structure of a Novel Type 2 Isopentenyl Diphosphate: Dimethylallyl Diphosphate Isomerase from Streptococcus pneumoniae.

de Ruyck J1, Janczak MW, Neti SS, Rothman SC, Schubert HL, Cornish RM, Matagne A, Wouters J, Poulter CD.

Author information

Abstract

Isopentenyl diphosphate isomerase (IDI) is a key enzyme in the isoprenoid biosynthetic pathway and is required for all organisms that synthesize isoprenoid metabolites from mevalonate. Type 1 IDI (IDI-1) is a metalloprotein that is found in eukaryotes, whereas the type 2 isoform (IDI-2) is a flavoenzyme found in bacteria that is completely absent from human. IDI-2 from the pathogenic bacterium Streptococcus pneumoniae was recombinantly expressed in Escherichia coli. Steady-state kinetic studies of the enzyme indicated that FMNH2 (KM =0.3 μM) bound before isopentenyl diphosphate (KM =40 μM) in an ordered binding mechanism. An X-ray crystal structure at 1.4 Å resolution was obtained for the holoenzyme in the closed conformation with a reduced flavin cofactor and two sulfate ions in the active site. These results helped to further approach the enzymatic mechanism of IDI-2 and, thus, open new possibilities for the rational design of antibacterial compounds against sequence-similar and structure-related pathogens such as Enterococcus faecalis or Staphylococcus aureus.

© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

KEYWORDS:

X-ray structures; bisubstrates; flavoproteins; isoprenoids; steady-state kinetics

PMID: 24910111 [PubMed - as supplied by publisher]

Penicillin-Binding Protein 2x of Streptococcus pneumoniae: The Mutation Ala707Asp Within the C-terminal PASTA2 Domain Leads to Destabilization.

Microb Drug Resist. 2014 Jun;20(3):250-7. doi: 10.1089/mdr.2014.0082. Epub 2014 May 19.

Penicillin-Binding Protein 2x of Streptococcus pneumoniae: The Mutation Ala707Asp Within the C-terminal PASTA2 Domain Leads to Destabilization.

Schweizer I1, Peters K, Stahlmann C, Hakenbeck R, Denapaite D.

Author information

Abstract

Streptococcus pneumoniae penicillin-binding protein 2x (PBP2x) is an enzyme involved in the last stages of peptidoglycan assembly and essential for bacterial growth and survival. PBP2x localizes to the division site, a process that depends on its Penicillin-Binding Protein And Serine-Threonine-kinase Associated (PASTA) domains, which was previously demonstrated via GFP-PBP2x in living cells. During this study a mutant strain was isolated in which the GFP-PBP2x fusion protein did not localize at division sites and it contained reduced amounts of the full-length GFP-PBP2x. We now show that this defect is due to a point mutation within the C-terminal PASTA2 domain of PBP2x. The mutant protein was analyzed in detail in terms of beta-lactam binding, functionality, and localization in live cells. We demonstrate that the mutation affects the GFP-tagged PBP2x variant severely and renders it susceptible to the protease/chaperone HtrA.

PMID: 24841912 [PubMed - in process]

Community-acquired pneumonia caused by carbapenem-resistant Streptococcus pneumoniae: re-examining its prevention and treatment.

Int J Gen Med. 2014 May 21;7:253-7. doi: 10.2147/IJGM.S63744. eCollection 2014.

Community-acquired pneumonia caused by carbapenem-resistant Streptococcus pneumoniae: re-examining its prevention and treatment.

Doi A1, Iwata K2, Takegawa H3, Miki K4, Sono Y1, Nishioka H5, Takeshita J6, Tomii K7, Haruta T8.

Author information

Abstract

A 73-year-old man with no significant past medical history or any history of health care visits was hospitalized for pneumonia. Sputum culture revealed multidrug-resistant Streptococcus pneumoniae, even to carbapenems. The patient was later treated successfully with levofloxacin. Throat cultures from his two grandchildren revealed S. pneumoniae with the same susceptibility pattern. Analysis for resistant genes revealed gPRSP (pbp1a + pbp2x + pbp2b gene variants) in both the patient and his grandchildren, none of whom had received pneumococcal vaccines of any kind. This case illustrates the importance of the emergence of carbapenem-resistant S. pneumoniae. Non-rational use of carbapenems for community-acquired infections may be counterproductive. This case also highlights the importance of pneumococcal vaccinations in children and the elderly.

KEYWORDS:

Streptococcus pneumoniae; carbapenem resistance; pneumonia

PMID: 24899822 [PubMed] PMCID: PMC4038523 Free PMC Article

TBX21 participates in innate immune response by regulating Toll-like receptor 2 expression in Streptococcus pneumoniae infections.

Mol Oral Microbiol. 2014 Jun 5. doi: 10.1111/omi.12061. [Epub ahead of print]

TBX21 participates in innate immune response by regulating Toll-like receptor 2 expression in Streptococcus pneumoniae infections.

Woo CH1, Shin SG, Koh SH, Lim JH.

Author information

Abstract

Nasopharyngeal carriage of Streptococcus pneumoniae (pneumococcus) plays an important role in the development of invasive diseases, and is also critically involved in setting up respiratory bacterial and viral infections. We previously reported that pneumococcus, one of the commonly carried bacteria in the nasopharynx, regulates nontypeable Haemophilus influenzae (NTHi)-induced inflammation by upregulating the expression of Toll-like receptor 2 (TLR2). However, the underlying molecular mechanisms by which TLR2 expression is regulated during pneumococcal infections have not yet been well characterized. TBX21 is an important transcription factor of adaptive immunity, but there is an increasing body of evidence pointing to a role in regulating innate immunity. The expression of TBX21 was reported in epithelial cells, but the expression and role of TBX21 in respiratory epithelium, especially for regulating TLR2, has not yet been studied. In this study, we found that pneumococcus upregulates TBX21 expression in the respiratory epithelium. The effect of pneumococcus on TBX21 expression was dependent on its cytoplasmic toxin, pneumolysin. In addition, epithelial TBX21 expression was not regulated by the gram-negative bacterium NTHi, peptidoglycan or endotoxin. Deficiency of TBX21 in mice or knocking down TBX21 in epithelial cells suppressed pneumococcus-induced TLR2 expression, but not that of TLR4 or TLR9. These results indicate that the adaptive immune regulator TBX21 participates in regulating innate immune responses, through regulation of TLR2 expression during pneumococcal infections. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.

KEYWORDS:

Pneumococcus; Pneumolysin; TBX21; TLR2

PMID: 24903905 [PubMed - as supplied by publisher]

Streptococcus pneumoniae Interacts with pIgR Expressed by the Brain Microvascular Endothelium but Does Not Co-Localize with PAF Receptor.

PLoS One. 2014 May 19;9(5):e97914. doi: 10.1371/journal.pone.0097914. eCollection 2014.

Streptococcus pneumoniae Interacts with pIgR Expressed by the Brain Microvascular Endothelium but Does Not Co-Localize with PAF Receptor.

Iovino F1, Molema G2, Bijlsma JJ1.

Author information

Abstract

Streptococcus pneumoniae is thought to adhere to the blood-brain barrier (BBB) endothelium prior to causing meningitis. The platelet activating factor receptor (PAFR) has been implicated in this adhesion but there is a paucity of data demonstrating direct binding of the bacteria to PAFR. Additionally, studies that inhibit PAFR strongly suggest that alternative receptors for pneumococci are present on the endothelium. Therefore, we studied the roles of PAFR and pIgR, an established epithelial pneumococcal receptor, in pneumococcal adhesion to brain endothelial cells in vivo. Mice were intravenously infected with pneumococci and sacrificed at various time points before meningitis onset. Co-localization of bacteria with PAFR and pIgR was investigated using immunofluorescent analysis of the brain tissue. In vitro blocking with antibodies and incubation of pneumococci with endothelial cell lysates were used to further probe bacteria-receptor interaction. In vivo as well as in vitro pneumococci did not co-localize with PAFR. On the other hand the majority of S. pneumoniae co-localized with endothelial pIgR and pIgR blocking reduced pneumococcal adhesion to endothelial cells. Pneumococci physically interacted with pIgR in endothelial cell lysates. In conclusion, bacteria did not associate with PAFR, indicating an indirect role of PAFR in pneumococcal adhesion to endothelial cells. In contrast, pIgR on the BBB endothelium may represent a novel pneumococcal adhesion receptor.

PMID: 24841255 [PubMed - in process] PMCID: PMC4026408 Free PMC Article

Role of SIRT1 in Streptococcus pneumoniae-induced human β-defensin-2 and interleukin-8 expression in A549 cell.

Mol Cell Biochem. 2014 Jun 4. [Epub ahead of print]

Role of SIRT1 in Streptococcus pneumoniae-induced human β-defensin-2 and interleukin-8 expression in A549 cell.

Lin L1, Wen SH, Guo SZ, Su XY, Wu HJ, Chong L, Zhang HL, Zhang WX, Li CC.

Author information

Abstract

Streptococcus pneumoniae is an important pathogen of pneumonia in human. Human alveolar epithelium acts as an effective barrier and is an active participant in host defense against invasion of bacterial by production of various mediators. Sirtuin 1 (SIRT1), the prototypic class III histone deacetylase, is involved in the molecular control of lifespans and immune responses. This study aimed at examining the role of SIRT1 in mediating S. pneumoniae-induced human β-defensin-2 (hBD2) and interleukin-8(IL-8) expression in the alveolar epithelial cell line A549 and the underlying mechanisms involved. A549 cells were infected with S. pneumoniae for indicated times. Exposure of A549 cells to S. pneumoniae increased the expressions of SIRT1 protein, hBD2 and IL-8 mRNA, and protein. The SIRT1 activator resveratrol enhanced S. pneumoniae-induced gene expression of hBD2 but decreased IL-8 mRNA levels. Blockade of SIRT1 activity by the SIRT1 inhibitors nicotinamide reduced S. pneumoniae-induced hBD2 mRNA expression but increased its stimulatory effects on IL-8 mRNA. S. pneumoniae-induced activation of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK). SIRT1 expression was attenuated by selective inhibitors of ERK and p38 MAPK. The hBD2 mRNA production was decreased by pretreatment with p38 MAPK inhibitor but not with ERK inhibitor, whereas the IL-8 mRNA expression was controlled by phosphorylation of ERK. These results suggest that SIRT1 mediates the induction of hBD2 and IL-8 gene expression levels in A549 cell by S. pneumoniae. SIRT1 may play a key role in host immune and defense response in A549.

PMID: 24894820 [PubMed - as supplied by publisher]

Effectiveness of the standard and an alternative set of Streptococcus pneumoniae multi locus sequence typing primers.

BMC Microbiol. 2014 Jun 3;14(1):143. [Epub ahead of print]

Effectiveness of the standard and an alternative set of Streptococcus pneumoniae multi locus sequence typing primers.

Adamiak P, Vanderkooi OG, Kellner JD, Schryvers AB, Bettinger JA, Alcantara J.

Abstract

BACKGROUND:

Multi-locus sequence typing (MLST) is a portable, broadly applicable method for classifying bacterial isolates at an intra-species level. This methodology provides clinical and scientific investigators with a standardized means of monitoring evolution within bacterial populations. MLST uses the DNA sequences from a set of genes such that each unique combination of sequences defines an isolate's sequence type. In order to reliably determine the sequence of a typing gene, matching sequence reads for both strands of the gene must be obtained. This study assesses the ability of both the standard, and an alternative set of, Streptococcus pneumoniae MLST primers to completely sequence, in both directions, the required typing alleles.

RESULTS:

The results demonstrated that for five (aroE, recP, spi, xpt, ddl) of the seven S. pneumoniae typing alleles, the standard primers were unable to obtain the complete forward and reverse sequences. This is due to the standard primers annealing too closely to the target regions, and current sequencing technology failing to sequence the bases that are too close to the primer. The alternative primer set described here, which includes a combination of primers proposed by the CDC and several designed as part of this study, addresses this limitation by annealing to highly conserved segments further from the target region. This primer set was subsequently employed to sequence type 105 S. pneumoniae isolates collected by the Canadian Immunization Monitoring Program ACTive (IMPACT) over a period of 18 years.

CONCLUSIONS:

The inability of several of the standard S. pneumoniae MLST primers to fully sequence the required region was consistently observed and is the result of a shift in sequencing technology occurring after the original primers were designed. The results presented here introduce clear documentation describing this phenomenon into the literature, and provide additional guidance, through the introduction of a widely validated set of alternative primers, to research groups seeking to undertake S. pneumoniae MLST based studies.

PMID: 24889110 [PubMed - as supplied by publisher] Free full text

Streptococcus pneumoniae Arginine Synthesis Genes Promote Growth and Virulence in Pneumococcal Meningitis.

J Infect Dis. 2014 Jun;209(11):1781-91. doi: 10.1093/infdis/jit818. Epub 2013 Dec 13.

Streptococcus pneumoniae Arginine Synthesis Genes Promote Growth and Virulence in Pneumococcal Meningitis.

Piet JR1, Geldhoff M, van Schaik BD, Brouwer MC, Valls Seron M, Jakobs ME, Schipper K, Pannekoek Y, Zwinderman AH, van der Poll T, van Kampen AH, Baas F, van der Ende A, van de Beek D.

Author information

Abstract

Streptococcus pneumoniae (pneumococcus) is a major human pathogen causing pneumonia, sepsis and bacterial meningitis. Using a clinical phenotype based approach with bacterial whole-genome sequencing we identified pneumococcal arginine biosynthesis genes to be associated with outcome in patients with pneumococcal meningitis. Pneumococci harboring these genes show increased growth in human blood and cerebrospinal fluid (CSF). Mouse models of meningitis and pneumonia showed that pneumococcal strains without arginine biosynthesis genes were attenuated in growth or cleared, from lung, blood and CSF. Thus, S. pneumoniae arginine synthesis genes promote growth and virulence in invasive pneumococcal disease.

KEYWORDS:

Streptococcus pneumoniae; arginine synthesis; bacterial meningitis; virulence; whole genome sequencing

PMID: 24338350 [PubMed - in process]

An unexpected Streptococcus pneumoniae strain.

J Chemother. 2014 Jun;26(3):173-5. doi: 10.1179/1973947813Y.0000000125. Epub 2013 Dec 6.
An unexpected Streptococcus pneumoniae strain.
Cenderello G, Pontali E, Torresin A, Milano G, Ansaldi F, Feasi M, Usiglio D, Mori M, Icardi G, Cassola G.
Abstract
This clinical driven report describes the unexpected detection of a multidrug resistant (MDR) Streptococcus pneumoniae strain. Italy is usually considered a country characterized by a low prevalence of MDR S. pneumoniae. We describe the occurrence of bacterial meningitis sustained by a MDR S. pneumoniae strain in Italy. The first-line treatment was started with ceftriaxone and dexamethasone, but after the identification of such a resistant strain a second-line regimen was needed. The new regimen was chosen on both susceptibility and pharmacokinetic criteria. Linezolid and levofloxacin were started and a dramatic improvement was observed. A more sensitive anamnesis revealed some elements known to be associated to a MDR S. pneumoniae occurrence (immunesuppression, former antibiotic therapy). So this case should pinpoint our attention on risk factors of MDR for a careful choice of antibiotic therapy in serious pneumococcal infections.
KEYWORDS:
Immunecompromised host,; Linezolid treatment; S.pneumoniae MDR strain,; S.pneumoniae meningitis,

PMID: 24090710 [PubMed - in process]

Streptococcus pneumoniae Phosphotyrosine Phosphatase CpsB and Alterations in Capsule Production Resulting from Changes in Oxygen Availability.

J Bacteriol. 2014 Jun;196(11):1992-2003. doi: 10.1128/JB.01545-14. Epub 2014 Mar 21.

Streptococcus pneumoniae Phosphotyrosine Phosphatase CpsB and Alterations in Capsule Production Resulting from Changes in Oxygen Availability.

Geno KA1, Hauser JR, Gupta K, Yother J.

Author information

Abstract

Streptococcus pneumoniae produces a protective capsular polysaccharide whose production must be modulated for bacterial survival within various host niches. Capsule production is affected in part by a phosphoregulatory system comprised of CpsB, CpsC, and CpsD. Here, we found that growth of serotype 2 strain D39 under conditions of increased oxygen availability resulted in decreased capsule levels concurrent with an ∼5-fold increase in Cps2B-mediated phosphatase activity. The change in Cps2B phosphatase activity did not result from alterations in the levels of either the cps2B transcript or the Cps2B protein. Recombinant Cps2B expressed in Escherichia coli similarly exhibited increased phosphatase activity under conditions of high-oxygen growth. S. pneumoniae D39 derivatives with defined deletion or point mutations in cps2B demonstrated reduced phosphatase activity with corresponding increases in levels of Cps2D tyrosine phosphorylation. There was, however, no correlation between these phenotypes and the level of capsule production. During growth under reduced-oxygen conditions, the Cps2B protein was essential for parental levels of capsule, but phosphatase activity alone could be eliminated without an effect on capsule. Under increased-oxygen conditions, deletion of cps2B did not affect capsule levels. These results indicate that neither Cps2B phosphatase activity nor Cps2D phosphorylation levels per se are determinants of capsule levels, whereas the Cps2B protein is important for capsule production during growth under conditions of reduced but not enhanced oxygen availability. Roles for factors outside the capsule locus, possible interactions between capsule regulatory proteins, and links to other cellular processes are also suggested by the results described in this study.

PMID: 24659769 [PubMed - in process] PMCID: PMC4010992 [Available on 2014/12/1]

Mechanism for transfer of transposon Tn2010 carrying macrolide resistance genes in Streptococcus pneumoniae and its effects on genome evolution.

J Antimicrob Chemother. 2014 Jun;69(6):1470-3. doi: 10.1093/jac/dku019. Epub 2014 Feb 13.

Mechanism for transfer of transposon Tn2010 carrying macrolide resistance genes in Streptococcus pneumoniae and its effects on genome evolution.

Zhou W1, Yao K2, Zhang G1, Yang Y2, Li Y3, Lv Y3, Feng J4.

Abstract

OBJECTIVES:

The objective of this study was to identify the mechanism responsible for the horizontal transfer of transposon Tn2010 in Streptococcus pneumoniae, and the genomic alterations introduced by the transfer process.

METHODS:

Tn2010 was identified using PCR in 15 clinical isolates of S. pneumoniae with erythromycin resistance. S. pneumoniae and Enterococcus faecalis isolates were used as recipient cells in mating and transformation experiments to test the conjugative transferability and transformability of Tn2010. Whole-genome sequencing was used to assess the effects of the Tn2010 transfer on recipient genomes. The biological cost of the horizontal acquisition of Tn2010 and additional genomic changes was investigated by growth competition experiments.

RESULTS:

Tn2010 was transformed at a frequency of 3 × 10(-7) transformants per cfu, whereas no transconjugants were detected using S. pneumoniae or E. faecalis as recipient cells. Genome analysis showed that many other recombinations were scattered throughout the genome of the transformants in addition to transposon Tn2010. The transformants demonstrated a negligible fitness cost compared with the wild-type strain.

CONCLUSIONS:

Tn2010 tended to be transferred by transformation rather than conjugation in S. pneumoniae, and the spread of Tn2010 could have a profound effect on the evolution of the genome. The acquisition of Tn2010 with negligible fitness cost may facilitate spread of the transposon.

© The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

KEYWORDS:

fitness cost; recombination; transformation

PMID: 24532683 [PubMed - in process]

Type I Interferon Signaling Regulates Activation of the Absent in Melanoma 2 Inflammasome during Streptococcus pneumoniae Infection.

Infect Immun. 2014 Jun;82(6):2310-7. doi: 10.1128/IAI.01572-14. Epub 2014 Mar 18.

Type I Interferon Signaling Regulates Activation of the Absent in Melanoma 2 Inflammasome during Streptococcus pneumoniae Infection.

Fang R1, Hara H, Sakai S, Hernandez-Cuellar E, Mitsuyama M, Kawamura I, Tsuchiya K.

Author information

Abstract

Streptococcus pneumoniae, a Gram-positive bacterial pathogen, causes pneumonia, meningitis, and septicemia. Innate immune responses are critical for the control and pathology of pneumococcal infections. It has been demonstrated that S. pneumoniae induces the production of type I interferons (IFNs) by host cells and that type I IFNs regulate resistance and chemokine responses to S. pneumoniae infection in an autocrine/paracrine manner. In this study, we examined the effects of type I IFNs on macrophage proinflammatory cytokine production in response to S. pneumoniae. The production of interleukin-18 (IL-18), but not other cytokines tested, was significantly decreased by the absence or blockade of the IFN-α/β receptor, suggesting that type I IFN signaling is necessary for IL-18 production. Type I IFN signaling was also required for S. pneumoniae-induced activation of caspase-1, a cysteine protease that plays a central role in maturation and secretion of IL-18. Earlier studies proposed that the AIM2 and NLRP3 inflammasomes mediate caspase-1 activation in response to S. pneumoniae. From our results, the AIM2 inflammasome rather than the NLRP3 inflammasome seemed to require type I IFN signaling for its optimal activation. Consistently, AIM2, but not NLRP3, was upregulated in S. pneumoniae-infected macrophages in a manner dependent on the IFN-α/β receptor. Furthermore, type I IFN signaling was found to contribute to IL-18 production in pneumococcal pneumonia in vivo. Taken together, these results suggest that type I IFNs regulate S. pneumoniae-induced activation of the AIM2 inflammasome by upregulating AIM2 expression. This study revealed a novel role for type I IFNs in innate responses to S. pneumoniae.

PMID: 24643540 [PubMed - in process] PMCID: PMC4019145 [Available on 2014/12/1]

Recent trends in pediatric bacterial meningitis in Japan - A country where Haemophilus influenzae type b and Streptococcus pneumoniae conjugated vaccines have just been introduced

J Infect Chemother. 2014 May 20. pii: S1341-321X(14)00173-1. doi: 10.1016/j.jiac.2014.04.007. [Epub ahead of print]

Recent trends in pediatric bacterial meningitis in Japan - A country where Haemophilus influenzae type b and Streptococcus pneumoniae conjugated vaccines have just been introduced.

Shinjoh M1, Iwata S2, Yagihashi T3, Sato Y4, Akita H5, Takahashi T3, Sunakawa K6.

Author information

Abstract

To investigate the trends in incidence and the characteristics of bacterial meningitis in Japan where Haemophilus influenzae type b (Hib) vaccine and 7-valent pneumococcal conjugated vaccine (PCV7) were introduced in 2008 and 2010, respectively, which was 5-20 years after their introduction in western countries. The nationwide Japanese survey of pediatric and neonatal bacterial meningitis was performed in 2011 and 2012. We analyzed the epidemiological and clinical data, and compared the information obtained in the previous nationwide survey database. We also investigated the risk factors for disease outcome. In the 2011-2012 surveys, 357 patients were evaluated. H. influenzae, Streptococcus pneumoniae, Streptococcus agalactiae and Escherichia coli were the main organisms. The number of patients hospitalized with bacterial meningitis per 1000 admissions decreased from 1.31 in 2009 to 0.43 in 2012 (p < 0.001). The incidence of H. influenzae and S. pneumoniae meningitis also decreased from 0.66 to 0.08 (p < 0.001), and 0.30 to 0.06 (p < 0.001), respectively. Only 0-2 cases with Neisseria meningitidis were reported each year throughout 2001-2012. The median patient age was 10-12 months in 2001-2011, and became lower in 2012 (2 month old) (p < 0.001). The fatality rate for S. agalactiae is the highest (5.9% (11/187)) throughout 2001-2012 among the four organisms. Risk factors for death and sequelae were convulsions at onset, low CSF glucose, S. agalactiae etiology, and persistent positive CSF culture. Hib vaccine and PCV7 decreased the rate of bacterial meningitis. Earlier introduction of these vaccines may have prevented bacterial meningitis among Japanese children.

Copyright © 2014 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

KEYWORDS:

Bacterial meningitis; Children; Hib; PCV

PMID:  

24855913

[PubMed - as supplied by publisher]

Contributions to Protection from Streptococcus pneumoniae Infection Using Monovalent Recombinant Protein Vaccine Candidates PcpA, PhtD and PlyD1 in an Infant Murine Model During Challenge

Clin Vaccine Immunol. 2014 May 21. pii: CVI.00052-14. [Epub ahead of print]

Contributions to Protection from Streptococcus pneumoniae Infection Using Monovalent Recombinant Protein Vaccine Candidates PcpA, PhtD and PlyD1 in an Infant Murine Model During Challenge.

Verhoeven D1, Perry S1, Pichichero ME2.

Author information

Abstract

A vaccine consisting of several conserved proteins with different functions directing pathogenesis of pneumonia and sepsis would be preferred for protection against infection by Streptococcus pneumoniae. Infants will be the major population targeted for next generation pneumococcal vaccines. Here, we investigated the potential efficacy provided by from three recombinant pneumococcal vaccine candidate proteins; pneumococcal histidine triad D (PhtD), detoxified pneumolysin (PlyD1), and pneumococcal choline-binding protein A (PcpA), toward reducing pneumonia and sepsis in an infant mouse vaccine model. We found vaccination with PhtD and PcpA provided high IgG antibody titers after vaccination in infant mice, similar to adult mice comparators. PlyD1-specific total IgG was significantly lower in infant mice with minimal boosting with the second and third vaccinations. Similar isotypes of IgG for PhtD and PlyD1 were generated in infant compared to adult mice. Although lower total specific IgG was elicited to all three proteins in infant compared to adult mice, the infant mice were protected from bacteremic pneumonia and sepsis mortality (PlyD1) and had lower lung bacterial burdens (PcpA and PhtD) after challenge. The observed immune responses coupled with bacterial reductions elicited by each of the monovalent proteins support further testing in human infant clinical trials.

Copyright © 2014, American Society for Microbiology. All Rights Reserved.

PMID:  

24850621

[PubMed - as supplied by publisher]