From " Complete genomes of two clinical Staphylococcus aureus strains: Evidence for the rapid evolution of virulence and drug resistance"
The size of the sequenced S. aureus genomes varies from 2.800 Mbp to 2.903 Mbp, encoding 2565–2721 proteins.It has been calculated that approx. 75% of the genome is conserved among all S. aureus isolates representing the core genome.
Comparative Genomics of Staphylococcus aureus
Genes of Staphylococcus aureus Genome subsp.aureus Col
Genome Staphylococcus aureus NCTC 8325
Staphylococcus aureus genome sequence
Staphylococcus aureus strain NCTC 8325 annotation list of ORFs
Gene assigned a role category
Harmony
From "Harmony Goals"
Pulsed-Field Gel Electrophoresis
Harmony PFGE protocol
Multilocus Sequence Typing
PFGE method
Organism-------Staphylococcus aureus
Recommended lysis
enzyme:lysozyme,lysostaphin,proteinase K
Restriction enzyme----------------SmaI, CspI
Approximate no. of-----------10–15, 15–20
restriction Fragments
Fragments size-------------10–700, 30–500
range (kb)
Organism-------Staphylococcus(coagulase negative)
Recommended lysis
enzyme:lysozyme,lysostaphin,proteinase K
Restriction enzyme----------------SmaI
Approximate no. of----------- 15–20
restriction Fragments
Fragments size-------------5–400
range (kb)
Identification of Staphylococcus species
Staphylococcus species
Staphylococci belong to the family Micrococcaceae, which includes the genus Micrococcus in addition to Staphylococcus.
Staphylococci grow rapidly on multiple culture media, in a wide range of environments, including up to 10 percent sodium chloride, and in a broad range of temperatures. Staphylococcus aureus is a nonmotile, nonspore forming, facultative anaerobic grampositive coccus that commonly colonizes healthy humans and is a frequent cause of disease.
It is frequently identified as growing in clusters or clumps.
This is a result of the effect of bound coagulase (“clumping factor”), which binds fibrinogen, converts it to insoluble fibrin, and results in aggregation.
Staphylococcus aureus is the only Staphylococcus found in humans which produces coagulase; other staphylococcal species are commonly identified as coagulase-negative staphylocci.
Staphylococcus aureus produces at least five cytolytic toxins, two exfoliative toxins, eight enterotoxins, and toxic shock syndrome toxin. Some of these toxins act as superantigens, which recruit host defense cells that liberate cytokines and, therefore, produce systemic effects.
Heating will kill the S. aureus organisms, but not inactivate the enterotoxins, because they are stable to heating at 100°C (112°F) for 30 minutes and are resistant to breakdown by gastric acids.
Of growing public health concern is the rapid spread of antibiotic resistance within S. aureus isolates.
Some S. aureus isolates have been identified recently with reduced sensitivity to vancomycin. The mechanism of this resistance is unknown.
Genes that confer resistance can be transferred between organisms by plasmid transfer, transduction and cell-to-cell contact.
