Release of Teichoic and Lipoteichoic Acids from 30 Different Strains of Streptococcus pneumoniae during Exposure to Ceftriaxone, Meropenem, Quinupristin/Dalfopristin, Rifampicin and Trovafloxacin

Infection ◽  
2000 ◽  
Vol 28 (1) ◽  
pp. 13-20 ◽  
Author(s):  
C. Heer ◽  
K. Stuertz ◽  
R.R. Reinert ◽  
M. Mäder ◽  
R. Nau
Keyword(s):  
Streptococcus Pneumoniae ◽  
Different Strains ◽  
Lipoteichoic Acids

scholarly journals Interactions of the Streptococcus pneumoniae Toxin-Antitoxin RelBE Proteins with Their Target DNA

2021 ◽  
Vol 9 (4) ◽  
pp. 851
Author(s):  
Inmaculada Moreno-Córdoba ◽  
Wai-Ting Chan ◽  
Concha Nieto ◽  
Manuel Espinosa
Keyword(s):  
Streptococcus Pneumoniae ◽  
Self Regulation ◽  
Mrna Translation ◽  
Dna Supercoiling ◽  
Bacterial Toxin ◽  
Type Ii ◽  
Cellular Functions ◽  
Dna Backbone ◽  
Different Strains ◽  
Palindromic Sequences

Type II bacterial toxin-antitoxin (TA) systems are found in most bacteria, archaea, and mobile genetic elements. TAs are usually found as a bi-cistronic operon composed of an unstable antitoxin and a stable toxin that targets crucial cellular functions like DNA supercoiling, cell-wall synthesis or mRNA translation. The type II RelBE system encoded by the pathogen Streptococcus pneumoniae is highly conserved among different strains and participates in biofilm formation and response to oxidative stress. Here, we have analyzed the participation of the RelB antitoxin and the RelB:RelE protein complex in the self-regulation of the pneumococcal relBE operon. RelB acted as a weak repressor, whereas RelE performed the role of a co-repressor. By DNA footprinting experiments, we show that the proteins bind to a region that encompasses two palindromic sequences that are located around the −10 sequences of the single promoter that directs the synthesis of the relBE mRNA. High-resolution footprinting assays showed the distribution of bases whose deoxyriboses are protected by the bound proteins, demonstrating that RelB and RelB:RelE contacted the DNA backbone on one face of the DNA helix and that these interactions extended beyond the palindromic sequences. Our findings suggest that the binding of the RelBE proteins to its DNA target would lead to direct inhibition of the binding of the host RNA polymerase to the relBE promoter.

scholarly journals In Vitro Activities of Garenoxacin (BMS-284756) against Streptococcus pneumoniae, Viridans Group Streptococci, and Enterococcus faecalis Compared to Those of Six Other Quinolones

2003 ◽  
Vol 47 (11) ◽  
pp. 3542-3547 ◽  
Author(s):  
Patrick Grohs ◽  
Serge Houssaye ◽  
Agnès Aubert ◽  
Laurent Gutmann ◽  
Emmanuelle Varon
Keyword(s):  
Streptococcus Pneumoniae ◽  
Enterococcus Faecalis ◽  
Bactericidal Effect ◽  
Clinical Isolates ◽  
Active Efflux ◽  
Resistant Strains ◽  
Different Strains ◽  
Viridans Group Streptococci ◽  
Derivatives Of

ABSTRACT The activity of garenoxacin, a new quinolone, was determined in comparison with other quinolones against different strains of S. pneumoniae, viridans group streptococci (VGS), and Enterococcus faecalis. Strains were quinolone-susceptible clinical isolates and quinolone-resistant strains with defined mechanisms of resistance obtained from either clinical isolates or derivatives of S. pneumoniae R6. Clinical quinolone-susceptible strains of S. pneumoniae, VGS and E. faecalis showed garenoxacin MICs within a range of 0.03 μg/ml to 0.25 μg/ml. Garenoxacin MICs increased two- to eightfold when one mutation was present in the ParC quinolone resistance-determining region (QRDR), fourfold when one mutation was present in the GyrA QRDR (S. pneumoniae), 8- to 64-fold when two or three mutations were associated in ParC and GyrA QRDR, and 2,048-fold when two mutations were present in both the GyrA and ParC QRDRs (Streptococcus pneumoniae). Increased active efflux had a moderate effect on garenoxacin MICs for S. pneumoniae and VGS. Against S. pneumoniae, garenoxacin behaved like moxifloxacin and sparfloxacin, being more affected by a single gyrA mutation than by a single parC mutation. Although garenoxacin was generally two- to fourfold more active than moxifloxacin against the different wild-type or mutant strains of S. pneumoniae, VGS, and E. faecalis, it was two- to fourfold less active than gemifloxacin. At four times the respective MIC for each strain, the bactericidal effect of garenoxacin, observed at 6 h for S. pneumoniae and at 24 h for S. oralis and E. faecalis, was not influenced by the presence of mutation either in the ParC or in both the ParC and GyrA QRDRs.

scholarly journals Mutations in the tacF Gene of Clinical Strains and Laboratory Transformants of Streptococcus pneumoniae: Impact on Choline Auxotrophy and Growth Rate

2008 ◽  
Vol 190 (12) ◽  
pp. 4129-4138 ◽  
Author(s):  
Ana González ◽  
Daniel Llull ◽  
María Morales ◽  
Pedro García ◽  
Ernesto García
Keyword(s):  
Streptococcus Pneumoniae ◽  
Repeat Unit ◽  
Teichoic Acid ◽  
Integral Membrane Protein ◽  
Nutritional Requirement ◽  
Spontaneous Mutant ◽  
Free Medium ◽  
Streptococcus Oralis ◽  
Complex Relationships ◽  
Lipoteichoic Acids

ABSTRACT The nutritional requirement that Streptococcus pneumoniae has for the aminoalcohol choline as a component of teichoic and lipoteichoic acids appears to be exclusive to this prokaryote. A mutation in the tacF gene, which putatively encodes an integral membrane protein (possibly, a teichoic acid repeat unit transporter), has been recently identified as responsible for generating a choline-independent phenotype of S. pneumoniae (M. Damjanovic, A. S. Kharat, A. Eberhardt, A. Tomasz, and W. Vollmer, J. Bacteriol. 189:7105-7111, 2007). We now report that Streptococcus mitis can grow in choline-free medium, as previously illustrated for Streptococcus oralis. While we confirmed the finding by Damjanovic et al. of the involvement of TacF in the choline dependence of the pneumococcus, the genetic transformation of S. pneumoniae R6 by using S. mitis SK598 DNA and several PCR-amplified tacF fragments suggested that a minimum of two mutations were required to confer improved fitness to choline-independent S. pneumoniae mutants. This conclusion is supported by sequencing results also reported here that indicate that a spontaneous mutant of S. pneumoniae (strain JY2190) able to proliferate in the absence of choline (or analogs) is also a double mutant for the tacF gene. Microscopic observations and competition experiments during the cocultivation of choline-independent strains confirmed that a minimum of two amino acid changes were required to confer improved fitness to choline-independent pneumococcal strains when growing in medium lacking any aminoalcohol. Our results suggest complex relationships among the different regions of the TacF teichoic acid repeat unit transporter.

scholarly journals The Capsule Sensitizes Streptococcus pneumoniae to α-Defensins Human Neutrophil Proteins 1 to 3

2008 ◽  
Vol 76 (8) ◽  
pp. 3710-3716 ◽  
Author(s):  
Katharina Beiter ◽  
Florian Wartha ◽  
Robert Hurwitz ◽  
Staffan Normark ◽  
Arturo Zychlinsky ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Performance Liquid Chromatography ◽  
Streptococcus Pneumoniae ◽  
Human Neutrophil ◽  
High Performance ◽  
Positive Charge ◽  
Early Stage ◽  
Innate Immune ◽  
Intracellular Killing ◽  
Lipoteichoic Acids

ABSTRACT Streptococcus pneumoniae is a major cause of morbidity and mortality worldwide. Its polysaccharide capsule causes resistance to phagocytosis and interferes with the innate immune system's ability to clear infections at an early stage. Nevertheless, we found that encapsulated pneumococci are sensitive to killing by a human neutrophil granule extract. We fractionated the extract by high-performance liquid chromatography and identified α-defensins by mass spectrometry as the proteins responsible for killing pneumococci. Analysis of sensitivity to the commercial α-defensins human neutrophil proteins 1 to 3 (HNP1-3) confirmed these findings. We analyzed the sensitivities of different pneumococcal strains to HNP1-3 and found that encapsulated strains are efficiently killed at physiological concentrations (7.5 μg/ml). Surprisingly, nonencapsulated, nonvirulent pneumococci were significantly less sensitive to α-defensins. The proposed mechanisms of α-defensin resistance in nonencapsulated pneumococci is surface charge modification, e.g., by introduction of positive charge by d-alanylation of surface-exposed lipoteichoic acids. These mechanisms are surmounted by the presence of the capsule, which we hypothesize is masking these charge modifications. Hence, α-defensins in the phagolysosome of neutrophils possibly contribute to intracellular killing after antibody-mediated opsonophagocytosis of encapsulated pneumococci.

scholarly journals Enzyme Immunoassay Detecting Teichoic and Lipoteichoic Acids versus Cerebrospinal Fluid Culture and Latex Agglutination for Diagnosis of Streptococcus pneumoniae Meningitis

1998 ◽  
Vol 36 (8) ◽  
pp. 2346-2348 ◽  
Author(s):  
Kristin Stuertz ◽  
Imke Merx ◽  
Helmut Eiffert ◽  
Erich Schmutzhard ◽  
Michael Mäder ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Streptococcus Pneumoniae ◽  
Enzyme Immunoassay ◽  
Antimicrobial Therapy ◽  
Latex Agglutination ◽  
Viral Pathogens ◽  
Cerebrospinal Fluid Culture ◽  
Culture Negative ◽  
Lipoteichoic Acids ◽  
Fluid Culture

A newly developed enzyme immunoassay (EIA) was used to detect the presence of pneumococcal teichoic and lipoteichoic acids in cerebrospinal fluid (CSF) from patients with Streptococcus pneumoniae meningitis who were being treated with antibiotics. All initial CSF samples, which on culture grew S. pneumoniae, were positive in the EIA. A total of 14 subsequent culture-negative samples gave clear signals in the EIA up to day 15 after the onset of antibiotic treatment. For 11 CSF specimens, culture, microscopy, and latex agglutination were negative while the EIA detected pneumococcal antigens. The EIA did not react either with CSF of patients with meningitis caused by bacteria other than S. pneumoniae or by viral pathogens. In conclusion, this EIA can be a valuable tool for the diagnosis of S. pneumoniaemeningitis from CSF samples in cases in which prior antimicrobial therapy minimizes the usefulness of culture or other antigen detection tests.

WhyD tailors surface polymers to prevent bacteriolysis and direct cell elongation in Streptococcus pneumoniae

2022 ◽  
Author(s):  
Josué Flores-Kim ◽  
Genevieve S Dobihal ◽  
Thomas G Bernhardt ◽  
David Z Rudner
Keyword(s):  
Cell Wall ◽  
Streptococcus Pneumoniae ◽  
Cell Elongation ◽  
Clinical Importance ◽  
Cell Wall Synthesis ◽  
Teichoic Acids ◽  
Direct Cell ◽  
Penicillin Treatment ◽  
Dramatic Shift ◽  
Lipoteichoic Acids

Penicillin and related antibiotics disrupt cell wall synthesis in bacteria and induce lysis by misactivating cell wall hydrolases called autolysins. Despite the clinical importance of this phenomenon, little is known about the factors that control autolysins and how penicillins subvert this regulation to kill cells. In the pathogen Streptococcus pneumoniae (Sp), LytA is the major autolysin responsible for penicillin-induced bacteriolysis. We recently discovered that penicillin treatment of Sp causes a dramatic shift in surface polymer biogenesis in which cell wall-anchored teichoic acids (WTAs) increase in abundance at the expense of lipid-linked lipoteichoic acids. Because LytA binds to these polymers, this change recruits the enzyme to its substrate where it cleaves the cell wall and elicits lysis. In this report, we identify WhyD (SPD_0880) as a new factor that controls the level of WTAs in Sp cells to prevent LytA misactivation and lysis. We show that WhyD is a WTA hydrolase that restricts the WTA content of the wall to areas adjacent to active PG synthesis. Our results support a model in which the WTA tailoring activity of WhyD directs PG remodeling activity required for proper cell elongation in addition to preventing autolysis by LytA.

Transformation of restriction endonuclease phenotype in Streptococcus pneumoniae

1982 ◽  
Vol 152 (1) ◽  
pp. 183-190
Author(s):  
C C Muckerman ◽  
S S Springhorn ◽  
B Greenberg ◽  
S A Lacks
Keyword(s):  
Streptococcus Pneumoniae ◽  
Restriction Endonuclease ◽  
Genetic Basis ◽  
Laboratory Strain ◽  
The Other ◽  
Unique Restriction ◽  
Different Strains ◽  
Spontaneous Conversion

The genetic basis of the unique restriction endonuclease DpnI, that cleaves only at a methylated sequence, 5'-GmeATC-3', and of the complementary endonuclease DpnII, which cleaves at the same sequence when it is not methylated, was investigated. Different strains of Streptococcus pneumoniae isolated from patients contained either DpnI (two isolates) or DpnII (six isolates). The latter strains also contained DNA methylated at the 5'-GATC-3' sequence. A restrictable bacteriophage, HB-3, was used to characterize the various strains and to select for transformants. One laboratory strain contained neither DpnI nor Dpn II. It was probably derived from a DpnI-containing strain, and its DNA was not methylated at 5'-GATC-3'. Cells of this strain were transformed to the DpnI restriction phenotype by DNA from a DpnI-containing strain and to the DpnII restriction phenotype by DNA from a DpnII-containing strain. Neither cross-transformation, that is, transformation to one phenotype by DNA from a strain of the other phenotype, nor spontaneous conversion was observed. Extracts of transformants to the new restriction phenotype were shown to contain the corresponding endonuclease.

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