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Characterization of nisin F and its role in the control of respiratory tract and skin infections

Thesis (PhD (Microbiology))--University of Stellenbosch, 2009.

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Main Author: De Kwaadsteniet, Michele
Other Authors: Dicks, Leon Milner Theodore
Format: Thesis
Language:English
Published: Stellenbosch : University of Stellenbosch 2009
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access_status_str Open Access
author De Kwaadsteniet, Michele
author2 Dicks, Leon Milner Theodore
author_browse De Kwaadsteniet, Michele
Dicks, Leon Milner Theodore
author_facet Dicks, Leon Milner Theodore
De Kwaadsteniet, Michele
author_sort De Kwaadsteniet, Michele
collection Thesis
dc_rights_str_mv University of Stellenbosch
description Thesis (PhD (Microbiology))--University of Stellenbosch, 2009.
format Thesis
id oai:scholar.sun.ac.za:10019.1/1285
institution Stellenbosch University (South Africa)
language English
last_indexed 2026-06-10T12:45:50.231Z
license_str Other — see source repository
provenance_str_mv Harvested via OAI-PMH from SUNScholar — Stellenbosch University Repository
publishDate 2009
publishDateRange 2009
publishDateSort 2009
publisher Stellenbosch : University of Stellenbosch
publisherStr Stellenbosch : University of Stellenbosch
record_format dspace
source_str SUNScholar — Stellenbosch University Repository
spelling oai:scholar.sun.ac.za:10019.1/1285 Characterization of nisin F and its role in the control of respiratory tract and skin infections De Kwaadsteniet, Michele Dicks, Leon Milner Theodore University of Stellenbosch. Faculty of Science. Dept. of Microbiology. Dissertations -- Microbiology Theses -- Microbiology Nisin Respiratory infections -- Treatment Drug resistance in microorganisms Antibiotics -- Therapeutic use Skin -- Infections -- Treatment Staphylococcus aureus Bacteriocins Thesis (PhD (Microbiology))--University of Stellenbosch, 2009. Multidrug resistant strains of Staphylococcus aureus is presenting an increasing threat, especially immune compromised individuals. Many of these strains have developed resistance to newly approved drugs such as quinupristin-dalfopristin, linezolid and daptomycin. The search for alternative treatment, including bacteriocins (ribosomally synthesized antimicrobial peptides) of lactic acid bacteria is increasing . Lactococcus lactis subsp. lactis F10, isolated from freshwater catfish, produced a new nisin variant active against clinical strains of S. aureus. The operon encoding nisin F is located on a plasmid and the structural gene has been sequenced. The lantibiotic is closely related to nisin Z, except at position 30 where valine replaced isoleucine. The antimicrobial activity of nisin F against S. aureus was tested in the respiratory tract of Wistar rats. Non-immunosuppressed and immunosuppressed rats were intranasally infected with S. aureus K and then treated with either nisin F or sterile physiological saline. Nisin F protected immunosuppressed rats against S. aureus, as symptoms of an infection were only detected in the trachea and lungs of immunosuppressed rats treated with saline. The safety of intranasally administered nisin F was also evaluated and proved to have no adverse side effects. The potential of nisin F as an antimicrobial agent to treat subcutaneous skin infections was evaluated by infecting C57BL/6 mice with a bioluminescent strain of S. aureus (Xen 36). Immunosuppressed mice were treated with either nisin F or sterile physiological saline 24 h and 48 h after infection with subcutaneously injected S. aureus Xen 36. Histology and bioluminescence flux measurements revealed that nisin F was ineffective in the treatment of deep dermal staphylococcal infections. Non-infected and infected mice treated with nisin F had an influx of polymorphonuclear cells in the deep stroma of the skin tissue. This suggested that nisin F, when injected subcutaneously, may have modulated the immune system. Nisin F proved an effective antimicrobial agent against S. aureus-related infections in the respiratory tract, but not against subcutaneous infections. The outcome of nisin F treatment thus depends on the route of administration and site of infection. Doctoral 2009-03-11T08:22:06Z 2010-06-01T08:17:23Z 2009-03-11T08:22:06Z 2010-06-01T08:17:23Z 2009-03 Thesis http://hdl.handle.net/10019.1/1285 en University of Stellenbosch application/pdf Stellenbosch : University of Stellenbosch
spellingShingle Dissertations -- Microbiology
Theses -- Microbiology
Nisin
Respiratory infections -- Treatment
Drug resistance in microorganisms
Antibiotics -- Therapeutic use
Skin -- Infections -- Treatment
Staphylococcus aureus
Bacteriocins
De Kwaadsteniet, Michele
Characterization of nisin F and its role in the control of respiratory tract and skin infections
title Characterization of nisin F and its role in the control of respiratory tract and skin infections
title_full Characterization of nisin F and its role in the control of respiratory tract and skin infections
title_fullStr Characterization of nisin F and its role in the control of respiratory tract and skin infections
title_full_unstemmed Characterization of nisin F and its role in the control of respiratory tract and skin infections
title_short Characterization of nisin F and its role in the control of respiratory tract and skin infections
title_sort characterization of nisin f and its role in the control of respiratory tract and skin infections
topic Dissertations -- Microbiology
Theses -- Microbiology
Nisin
Respiratory infections -- Treatment
Drug resistance in microorganisms
Antibiotics -- Therapeutic use
Skin -- Infections -- Treatment
Staphylococcus aureus
Bacteriocins
url http://hdl.handle.net/10019.1/1285
work_keys_str_mv AT dekwaadstenietmichele characterizationofnisinfanditsroleinthecontrolofrespiratorytractandskininfections