[__ Science __ ] Alexander Fleming & God’s Signature in Microbiology

[AIG.com]

The molecular complexities of staphylococci mechanisms indicate the signature of a divine Designer who has placed his signature on his art piece, staphylococci.

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[Barbarian]

A Very Early-Branching Staphylococcus aureus Lineage Lacking the Carotenoid Pigment Staphyloxanthin​

Abstract​

Here we discuss the evolution of the northern Australian Staphylococcus aureus isolate MSHR1132 genome. MSHR1132 belongs to the divergent clonal complex 75 lineage. The average nucleotide divergence between orthologous genes in MSHR1132 and typical S. aureus is approximately sevenfold greater than the maximum divergence observed in this species to date. MSHR1132 has a small accessory genome, which includes the well-characterized genomic islands, νSAα and νSaβ, suggesting that these elements were acquired well before the expansion of the typical S. aureus population. Other mobile elements show mosaic structure (the prophage φSa3) or evidence of recent acquisition from a typical S. aureus lineage (SCCmec, ICE6013 and plasmid pMSHR1132). There are two differences in gene repertoire compared with typical S. aureus that may be significant clues as to the genetic basis underlying the successful emergence of S. aureus as a pathogen. First, MSHR1132 lacks the genes for production of staphyloxanthin, the carotenoid pigment that confers upon S. aureus its characteristic golden color and protects against oxidative stress. The lack of pigment was demonstrated in 126 of 126 CC75 isolates. Second, a mobile clustered regularly interspaced short palindromic repeat (CRISPR) element is inserted into orfX of MSHR1132. Although common in other staphylococcal species, these elements are very rare within S. aureus and may impact accessory genome acquisition. The CRISPR spacer sequences reveal a history of attempted invasion by known S. aureus mobile elements.

Turns out, the evolution of the CspA gene is critical to the formation of staphyloxanthin, which is an important contributor to the virulence of Staphylococcus aureus.

Mol Microbiol
2020 Apr;113(4):826-840

One evolutionarily selected amino acid variation is sufficient to provide functional specificity in the cold shock protein paralogs of Staphylococcus aureus ​

Abstract ​

Bacterial genomes encode several families of protein paralogs. Discrimination between functional divergence and redundancy among paralogs is challenging due to their sequence conservation. Here, we investigated whether the amino acid differences present in the cold shock protein (CSP) paralogs of Staphylococcus aureus were responsible for functional specificity. Since deletion of cspA reduces the synthesis of staphyloxanthin (STX), we used it as an in vivo reporter of CSP functionality. Complementation of a ΔcspA strain with the different S. aureus CSP variants showed that only CspA could specifically restore STX production by controlling the activity of the stress-associated sigma B factor (σB ). To determine the amino acid residues responsible for CspA specificity, we created several chimeric CSPs that interchanged the amino acid differences between CspA and CspC, which shared the highest identity. We demonstrated that CspA Pro58 was responsible for the specific control of σB activity and its associated phenotypes. Interestingly, CspC gained the biological function of CspA when the E58P substitution was introduced. This study highlights how just one evolutionarily selected amino acid change may be sufficient to modify the specific functionality of CSP paralogs.

If God designed the pigment vital to the virulence of Staph. aureus, He did so, using evolutionary processes.

 

[Truthfrees]

The molecular complexities of staphylococci mechanisms indicate the signature of a divine Designer who has placed his signature on his art piece, staphylococci.

Continue reading...

cool - thanks for the info

 

[Barbarian]

It should be noted also that Flemming correctly predicted the evolution of resistance to penicillin if doctors overused it unnecessarily, using Darwinian theory.