UNLABELLED: To enhance the research capabilities of investigators interested in Staphylococcus aureus, the Nebraska Center for Staphylococcal Research (CSR) has generated a sequence-defined transposon mutant library consisting of 1,952 strains, each containing a single mutation within a nonessential gene of the epidemic community-associated methicillin-resistant S. aureus (CA-MRSA) isolate USA300. To demonstrate the utility of this library for large-scale screening of phenotypic alterations, we spotted the library on indicator plates to assess hemolytic potential, protease production, pigmentation, and mannitol utilization. As expected, we identified many genes known to function in these processes, thus validating the utility of this approach. Importantly, we also identified genes not previously associated with these phenotypes. In total, 71 mutants displayed differential hemolysis activities, the majority of which were not previously known to influence hemolysin production. Furthermore, 62 mutants were defective in protease activity, with only 14 previously demonstrated to be involved in the production of extracellular proteases. In addition, 38 mutations affected pigment formation, while only 7 influenced mannitol fermentation, underscoring the sensitivity of this approach to identify rare phenotypes. Finally, 579 open reading frames were not interrupted by a transposon, thus providing potentially new essential gene targets for subsequent antibacterial discovery. Overall, the Nebraska Transposon Mutant Library represents a valuable new resource for the research community that should greatly enhance investigations of this important human pathogen.
IMPORTANCE: Infections caused by Staphylococcus aureus cause significant morbidity and mortality in both community and hospital environments. Specific-allelic-replacement mutants are required to study the biology of this organism; however, this process is costly and time-consuming. We describe the construction and validation of a sequence-defined transposon mutant library available for use by the scientific community through the Network on Antimicrobial Resistance in Staphylococcus aureus (NARSA) strain repository. In addition, complementary resources, including a website (http://app1.unmc.edu/fgx/) and genetic tools that expedite the allelic replacement of the transposon in the mutants with useful selectable markers and fluorescent reporter fusions, have been generated. Overall, this library and associated tools will have a significant impact on studies investigating S. aureus pathogenesis and biology and serve as a useful paradigm for the study of other bacterial systems.
Gene Knockout Techniques, Gene Library, Genetics, Microbial, Genotype, Humans, Methicillin-Resistant Staphylococcus aureus, Mutagenesis, Insertional, Nebraska, Phenotype
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License.
Fey, Paul D.; Endres, Jennifer L.; Yajjala, Vijaya Kumar; Widhelm, Todd J.; Boissy, Robert J.; Bose, Jeffrey L.; and Bayles, Kenneth W., "A genetic resource for rapid and comprehensive phenotype screening of nonessential Staphylococcus aureus genes." (2013). Journal Articles: Pathology and Microbiology. 14.
A Genetic resource supp 2.pdf (5312 kB)
A Genetic resource supp 3.pdf (2375 kB)
A Genetic resource supp 4.pdf (119 kB)
A Genetic resource supp 5.pdf (123 kB)
A Genetic resource supp 6.pdf (110 kB)
A Genetic resource supp 7.pdf (77 kB)
A Genetic resource supp 8.pdf (109 kB)