scholarly journals Pneumolysin Localizes to the Cell Wall of Streptococcus pneumoniae

2009 ◽  
Vol 191 (7) ◽  
pp. 2163-2168 ◽  
Author(s):  
Katherine E. Price ◽  
Andrew Camilli
Keyword(s):  
Cell Wall ◽  
Streptococcus Pneumoniae ◽  
Otitis Media ◽  
Mouse Models ◽  
Western Blotting ◽  
Causative Agent ◽  
Signal Peptide ◽  
Cell Fractionation ◽  
In Vitro Growth

ABSTRACT Streptococcus pneumoniae is the causative agent of multiple diseases, including otitis media, pneumonia, bacteremia, and meningitis. Pneumolysin (Ply), a member of the cholesterol-dependent cytolytic pore-forming toxins, is produced by virtually all clinical isolates of S. pneumoniae, and strains in which the Ply gene has been deleted are severely attenuated in mouse models of infection. In contrast to all other members of the cholesterol-dependent cytolysin family, Ply lacks a signal peptide for export. Instead, Ply has been hypothesized to be released upon autolysis or, alternatively, via a nonautolytic mechanism that remains ill defined. We determined by use of cell fractionation and Western blotting that, during in vitro growth, exported Ply is localized primarily to the cell wall compartment in 18 different serotypes in the absence of detectable cell lysis. Hemolytic assays revealed that this cell wall-localized Ply is active. Additionally, cell wall-localized Ply is accessible to extracellular protease and is detergent releasable.

scholarly journals RrgA and RrgB Are Components of a Multisubunit Pilus Encoded by the Streptococcus pneumoniae rlrA Pathogenicity Islet

2006 ◽  
Vol 74 (4) ◽  
pp. 2453-2456 ◽  
Author(s):  
Julianna LeMieux ◽  
David L. Hava ◽  
Alan Basset ◽  
Andrew Camilli
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Wall ◽  
Streptococcus Pneumoniae ◽  
Western Blotting ◽  
Surface Proteins ◽  
Domain Swapping ◽  
Cell Fractionation ◽  
Sorting Signal ◽  
Transmission Electron

ABSTRACT The rlrA pathogenicity islet in Streptococcus pneumoniae TIGR4 encodes three surface proteins, RrgA, RrgB, and RrgC, and three sortase enzymes. Using transmission electron microscopy, cell fractionation, cell wall sorting signal domain swapping, and Western blotting, we show that RrgA and RrgB are incorporated into a multisubunit pilus in S. pneumoniae.

scholarly journals The avian haemophili.

1989 ◽  
Vol 2 (3) ◽  
pp. 270-277 ◽  
Author(s):  
P J Blackall
Keyword(s):  
Causative Agent ◽  
Protective Immunity ◽  
In Vitro Growth ◽  
Phenotypic Properties ◽  
Infectious Coryza ◽  
The Common ◽  
Recent Attention

There are four currently recognized taxa to accommodate the avian haemophili: Haemophilus paragallinarum, Pasteurella avium, Pasteurella volantium, and Pasteurella species A (the last three being formerly united as Haemophilus avium). A range of other taxa has also been recognized, but they have been neither named nor assigned to a genus. All of these various taxa, legitimate and otherwise, have the common characteristic of requiring V factor, but not X factor, for in vitro growth. Several recent studies have established the phenotypic properties that allow the differentiation of the recognized taxa, both named and unnamed. The serological properties of H. paragallinarum, the causative agent of infectious coryza of chickens, has received considerable recent attention. In contrast, many questions on the pathogenicity and virulence mechanisms of H. paragallinarum remain unanswered. Another area requiring further work is the identification of those antigens responsible for inducing protective immunity in vaccinated or naturally infected chickens.

scholarly journals Draft Genome Sequence of Pediatric Otitis Media Isolate Streptococcus pneumoniae Strain EF3030, Which Forms In Vitro Biofilms That Closely Mimic In Vivo Biofilms

2019 ◽  
Vol 8 (2) ◽  
Author(s):  
Edgar J. Scott ◽  
Nicole R. Luke-Marshall ◽  
Anthony A. Campagnari ◽  
David W. Dyer
Keyword(s):  
Streptococcus Pneumoniae ◽  
Otitis Media ◽  
Genome Sequence ◽  
Dna Sequences ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Draft Assembly ◽  
Content Type

Here, we report the draft genome sequence of Streptococcus pneumoniae EF3030, a pediatric otitis media isolate active in biofilm assays of epithelial colonization. The final draft assembly included 2,209,198 bp; the annotation predicted 2,120 coding DNA sequences (CDSs), 4 complete rRNA operons, 58 tRNAs, 3 noncoding RNAs (ncRNAs), and 199 pseudogenes.

scholarly journals In Vitro Inhibition of Fungal Antagonists on Fusarium sp., the Disease Causative Agent on Dragon Fruit Plant (Hylocereus undatus (Haw.) Britton & Rose)

2018 ◽  
Vol 5 (2) ◽  
pp. 224
Author(s):  
Dewa Ayu Andriastini ◽  
Yan Ramona ◽  
Meitini Wahyuni Proborini
Keyword(s):  
Causative Agent ◽  
Biocontrol Agent ◽  
Antagonistic Activity ◽  
Assay Method ◽  
In Vitro Growth ◽  
Dragon Fruit ◽  
Fusarium Sp ◽  
In Vitro Inhibition ◽  
Hylocereus Undatus

A research on in vitro inhibition of fungal antagonists, isolated from dragon fruit plantation in Sembung village, Bali, on Fusarium sp. (the disease causative agent of dragon fruit plant) was conducted with the main objective to investigate the effectiveness of these fungal antagonists to inhibit the in vitro growth of the pathogen. Dual assay method was applied in this experiment. The results showed that three potential fungal antagonists were successfully isolated in this research and they were identified as Trichoderma harzianum, Aspergillus niger, dan Paecilomyces lilacinus. All these fungal antagonists showed antagonistic activity against Fusarium sp. which was statistically significant (p<0.05) when compared to control. This indicated that all antagonist isolates were potential to be developed as biocontrol agent candidates.

scholarly journals Insight into the Lytic Functions of the Lactococcal Prophage TP712

Viruses ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 881 ◽  
Author(s):  
Escobedo ◽  
Campelo ◽  
Wegmann ◽  
García ◽  
Rodríguez ◽  
...  
Keyword(s):  
Cell Wall ◽  
Signal Peptide ◽  
Catalytic Domain ◽  
Experimental Conditions ◽  
Binding Domains ◽  
Cell Wall Binding ◽  
Additional Cell ◽  
Translational Start ◽  
Bacterial Peptidoglycan

The lytic cassette of Lactococcus lactis prophage TP712 contains a putative membrane protein of unknown function (Orf54), a holin (Orf55), and a modular endolysin with a N-terminal glycoside hydrolase (GH_25) catalytic domain and two C-terminal LysM domains (Orf56, LysTP712). In this work, we aimed to study the mode of action of the endolysin LysTP712. Inducible expression of the holin-endolysin genes seriously impaired growth. The growth of lactococcal cells overproducing the endolysin LysTP712 alone was only inhibited upon the dissipation of the proton motive force by the pore-forming bacteriocin nisin. Processing of a 26-residues signal peptide is required for LysTP712 activation, since a truncated version without the signal peptide did not impair growth after membrane depolarization. Moreover, only the mature enzyme displayed lytic activity in zymograms, while no lytic bands were observed after treatment with the Sec inhibitor sodium azide. LysTP712 might belong to the growing family of multimeric endolysins. A C-terminal fragment was detected during the purification of LysTP712. It is likely to be synthesized from an alternative internal translational start site located upstream of the cell wall binding domain in the lysin gene. Fractions containing this fragment exhibited enhanced activity against lactococcal cells. However, under our experimental conditions, improved in vitro inhibitory activity of the enzyme was not observed upon the supplementation of additional cell wall binding domains in. Finally, our data pointed out that changes in the lactococcal cell wall, such as the degree of peptidoglycan O-acetylation, might hinder the activity of LysTP712. LysTP712 is the first secretory endolysin from a lactococcal phage described so far. The results also revealed how the activity of LysTP712 might be counteracted by modifications of the bacterial peptidoglycan, providing guidelines to exploit the biotechnological potential of phage endolysins within industrially relevant lactococci and, by extension, other bacteria.

scholarly journals Management of Infections Due to Antibiotic-Resistant Streptococcus pneumoniae

1998 ◽  
Vol 11 (4) ◽  
pp. 628-644 ◽  
Author(s):  
Sheldon L. Kaplan ◽  
Edward O. Mason
Keyword(s):  
Streptococcus Pneumoniae ◽  
Otitis Media ◽  
Acute Otitis Media ◽  
Antibiotic Resistant ◽  
New Antibiotics ◽  
Resistant Strains ◽  
Systemic Infections ◽  
Drug Resistant Strains ◽  
Common Infection

SUMMARY Antibiotic-resistant strains of Streptococcus pneumoniae are becoming more prevalent throughout the world; this has resulted in modifications of treatment approaches. Management of bacterial meningitis has the greatest consensus. Strategies for treating other systemic infections such as pneumonia, bacteremia, and musculoskeletal infections are evolving, in part related to the availability of new antibiotics which are active in vitro against isolates resistant to penicillin and the extended-spectrum cephalosporins. However, there are currently very limited data related to the clinical efficacy of these new agents. The studies upon which current recommendations are based are reviewed. Otitis media represents the single most common infection due to S. pneumoniae. Recommendations for treatment of acute otitis media due to drug-resistant strains and the rationale for these recommendations are discussed.

Sign in / Sign up

Export Citation Format

Share Document