Therapeutic Approaches to Streptococcal Infections

A special issue of Antibiotics (ISSN 2079-6382). This special issue belongs to the section "Antibiotics Use and Antimicrobial Stewardship".

Deadline for manuscript submissions: closed (1 July 2021) | Viewed by 7065

Special Issue Editor


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Guest Editor
Medical Biochemistry and Genetics, University of Turku, Turku, Finland
Interests: bacterial adhesion; carbohydrates; adhesin; streptococci; globo-series glycolipids

Special Issue Information

Dear Colleagues,

The infections of streptococci are globally estimated to cause over one million deaths per year. Close encounters of animals and humans also increase the prevalence of both existing and emerging streptococcal zoonoses. Overuse of antibiotics in humans and livestock increase antibiotic resistance, therefore causing a serious threat to public health. This Special Issue welcomes all studies discovering new antimicrobial compounds or vaccines against streptococci. Major emphasis is on the inhibition of mechanisms that are involved in streptococcal host interactions, e.g., adhesion, cytotoxicity, and immune escape. Methodologically, this can be approached using various techniques such as cellular microbiology methods, glycomics, genomics, screening of natural compounds, and rational drug design. A special objective could also be streptococcal studies related to the COVID-19 pandemic.

- Discovery of specialized metabolites as antimicrobial compounds

- Structure-based design of antimicrobial compounds

- Targeting adhesion, colonization, and in vivo virulence factors

- Targeting natural competence of DNA transformation to prevent infections and horizontal transfer of antibiotic resistance

- Application of bioinformatics, genome data-mining, and artificial intelligence

- Prevention of streptococcal infections in relation to the coronavirus pandemic (COVID-19)

Dr. Sauli Haataja

Guest Editor

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Keywords

  • bacterial adhesion
  • host specificity
  • zoonosis
  • streptococci

Published Papers (3 papers)

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Research

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15 pages, 2939 KiB  
Article
Inhibition of Pneumolysin Cytotoxicity by Hydrolysable Tannins
by Santeri Maatsola, Sami Kurkinen, Marica T. Engström, Thomas K. M. Nyholm, Olli Pentikäinen, Juha-Pekka Salminen and Sauli Haataja
Antibiotics 2020, 9(12), 930; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics9120930 - 21 Dec 2020
Cited by 8 | Viewed by 2487
Abstract
Streptococcus pneumoniae causes invasive infections such as otitis media, pneumonia and meningitis. It produces the pneumolysin (Ply) toxin, which forms a pore onto the host cell membrane and has multiple functions in the pathogenesis of S. pneumoniae. The Ply C-terminal domain 4 [...] Read more.
Streptococcus pneumoniae causes invasive infections such as otitis media, pneumonia and meningitis. It produces the pneumolysin (Ply) toxin, which forms a pore onto the host cell membrane and has multiple functions in the pathogenesis of S. pneumoniae. The Ply C-terminal domain 4 mediates binding to membrane cholesterol and induces the formation of pores composed of up to 40 Ply monomers. Ply has a key role in the establishment of nasal colonization, pneumococcal transmission from host to host and pathogenicity. Altogether, 27 hydrolysable tannins were tested for Ply inhibition in a hemolysis assay and a tannin-protein precipitation assay. Pentagalloylglucose (PGG) and gemin A showed nanomolar inhibitory activity. Ply oligomerization on the erythrocyte surface was inhibited with PGG. PGG also inhibited Ply cytotoxicity to A549 human lung epithelial cells. Molecular modelling of Ply interaction with PGG suggests that it binds to the pocket formed by domains 2, 3 and 4. In this study, we reveal the structural features of hydrolysable tannins that are required for interaction with Ply. Monomeric hydrolysable tannins containing three to four flexible galloyl groups have the highest inhibitory power to Ply cytotoxicity and are followed by oligomers. Of the oligomers, macrocyclic and C-glycosidic structures were weaker in their inhibition than the glucopyranose-based oligomers. Accordingly, PGG-type monomers and oligomers might have therapeutic value in the targeting of S. pneumoniae infections. Full article
(This article belongs to the Special Issue Therapeutic Approaches to Streptococcal Infections)
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Review

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10 pages, 283 KiB  
Review
Antimicrobial Resistance among Beta-Hemolytic Streptococcus in Brazil: An Overview
by Rosana Rocha Barros
Antibiotics 2021, 10(8), 973; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics10080973 - 12 Aug 2021
Cited by 8 | Viewed by 2702
Abstract
Streptococcus pyogenes, Streptococcus agalactiae and Streptococcus dysgalactiae subsp. equisimilis (SDSE) are the beta-hemolytic streptococci species with the most clinical relevance to humans. These species are responsible for several infections, ranging from mild to life-threatening diseases. Although resistance to recommended drugs [...] Read more.
Streptococcus pyogenes, Streptococcus agalactiae and Streptococcus dysgalactiae subsp. equisimilis (SDSE) are the beta-hemolytic streptococci species with the most clinical relevance to humans. These species are responsible for several infections, ranging from mild to life-threatening diseases. Although resistance to recommended drugs has not been so critical as detected in other species, it has occurred in diverse regions. In Brazil, it is possible to observe an increasing macrolide and lincosamide resistance trend due to the spread of polyclonal strains. Macrolide–lincosamide–streptogramin B (MLS) resistance phenotypes have been prevalent among S. agalactiae and S. pyogenes, while M phenotype (resistance only to macrolides) has prevailed among SDSE resistant isolates. Fluoroquinolone resistance is rare in this country, reported only in S.agalactiae and S.pyogenes. This is due to nucleotide substitutions in gyrA and parC genes. Reduced penicillin susceptibility and vancomycin resistance, detected in other regions, have not yet been reported in Brazil. Tetracycline is not a therapeutical option, and resistance has occurred at high levels, especially among S.agalactiae. These findings highlight the need for continuous monitoring in order to track the occurrence of antimicrobial resistance among beta-hemolytic streptococci species circulating in this country. Full article
(This article belongs to the Special Issue Therapeutic Approaches to Streptococcal Infections)

Other

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6 pages, 256 KiB  
Perspective
Microbicidal Activity of Hypothiocyanite against Pneumococcus
by Edriss Yassine and Balázs Rada
Antibiotics 2021, 10(11), 1313; https://0-doi-org.brum.beds.ac.uk/10.3390/antibiotics10111313 - 28 Oct 2021
Cited by 1 | Viewed by 1375
Abstract
Infections caused by Streptococcus pneumoniae (pneumococcus, Spn) manifest in several forms such as pneumonia, meningitis, sinusitis or otitis media and are associated with severe morbidity and mortality worldwide. While current vaccines and antibiotics are available to treat Spn infections, the rise of [...] Read more.
Infections caused by Streptococcus pneumoniae (pneumococcus, Spn) manifest in several forms such as pneumonia, meningitis, sinusitis or otitis media and are associated with severe morbidity and mortality worldwide. While current vaccines and antibiotics are available to treat Spn infections, the rise of antibiotic resistance and limitations of the vaccines to only certain Spn serotypes urge the development of novel treatments against Spn. Hypothiocyanite (OSCN-) is a natural antimicrobial product produced by the body’s own innate immune system to fight a variety of pathogens. We recently showed that OSCN- is also capable of killing Spn in vitro. OSCN- is an oxidative agent attacking microbes in a nonspecific manner, is safe for the host and also has anti-inflammatory effects that make it an ideal candidate to treat a variety of infections in humans. However, OSCN- has a short life span that makes its use, dosage and administration more problematic. This minireview discusses the antimicrobial mechanism of action of OSCN- against Spn and elaborates on the potential therapeutic use of OSCN- against Spn and other infectious agents, either alone or in combination with other therapeutic approaches. Full article
(This article belongs to the Special Issue Therapeutic Approaches to Streptococcal Infections)
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