Reducing Staphylococcus aureus resistance to lysostaphin using CRISPR-dCas9.
Biotechnol Bioeng
; 116(12): 3149-3159, 2019 12.
Article
em En
| MEDLINE
| ID: mdl-31433061
ABSTRACT
Bacteriolytic enzymes (cell lytic enzymes) are promising alternatives to antibiotics especially in killing drug-resistant bacteria. However, some bacteria slowly become resistant to various classes of peptidoglycan hydrolases, for reasons not well studied, in the presence of growth-supporting nutrients, which are prevalent at sites of infection. Here, we show that Staphylococcus aureus, a human and animal pathogen, while susceptible to the potent staphylolytic enzyme lysostaphin (Lst) in buffered saline, is highly resistant in the rich medium tryptic soy broth (TSB). Through a series of biochemical analysis, we identified that the resistance was due to prevention of Lst-cell binding mediated by the wall teichoic acids (WTAs) present on the cell surface. Inhibition or deletion of the gene tarO responsible for the first step of WTA biosynthesis greatly reduced S. aureus resistance to Lst in TSB. To overcome the resistance, we took advantage of the gene regulation potential of CRISPR-dCas9 and demonstrated that downregulation of tarO, tarH, and/or tarG gene expression, the latter two encoding enzymes that anchor WTAs in the outer layer of cell wall peptidoglycan, sensitized S. aureus to Lst and enabled eradication of the bacterium in TSB in 24 hr. As a result, we elucidate a key mechanism of Lst resistance in metabolically active S. aureus and provide a potential approach for treating life-threatening or hard-to-treat infections caused by Gram-positive pathogens.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Staphylococcus aureus
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Regulação Bacteriana da Expressão Gênica
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Deleção de Genes
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Farmacorresistência Bacteriana
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Sistemas CRISPR-Cas
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Lisostafina
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article