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Cloning of genes affecting capsule expression in Staphylococcus aureus strain M
Author(s) -
Lee Chia Y.
Publication year - 1992
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1992.tb00872.x
Subject(s) - biology , plasmid , complementation , mutant , staphylococcus aureus , prophage , gene , strain (injury) , microbiology and biotechnology , cloning (programming) , clone (java method) , transduction (biophysics) , genetics , bacteriophage , escherichia coli , bacteria , biochemistry , anatomy , computer science , programming language
Summary Staphylococcus aureus strain M produces large amounts of capsular polysaccharide. It produces a non‐encapsulated variant at a frequency of 0.01% at 37° C. At high temperature (43° C), the frequency of capsule loss was shown to be 1–38%. A 19kb plasmid and a prophage were found to be carried by the M strain, but curing of these elements did not affect capsular production. To clone the capsular (cap) genes, a plasmid library of S. aureus M was constructed directly in S. aureus RN4200. The library was then infected with phage 80α. After transduction of the phage lysates to a Cap ‐ mutant derived from M strain, a recombinant plasmid was obtained which complemented the mutant to a Cap + phenotype. Chromosomal walking experiments were used to clone additional nearby cap genes. Complementation tests using a collection of Cap ‐ mutants showed that most of the mutants were complemented by a 19.4 kb DNA fragment, suggesting that the majority of the cap genes affecting capsule production are clustered together.