β-Lactams against the Fortress of the Gram-Positive Staphylococcus aureus Bacterium

The biological diversity of the unicellular bacteria-whether assessed by shape, food, metabolism, or ecological niche-surely rivals (if not exceeds) that of the multicellular eukaryotes. The relationship between bacteria whose ecological niche is the eukaryote, and the eukaryote, is often symbiosis or stasis. Some bacteria, however, seek advantage in this relationship. One of the most successful-to the disadvantage of the eukaryote-is the small (less than 1 mu m diameter) and nearly spherical Staphylococcus aureus bacterium. For decades, successful clinical control of its infection has been accomplished using beta-lactam antibiotics such as the penicillins and the cephalosporins. Over these same decades S. aureus has perfected resistance mechanisms against these antibiotics, which are then countered by new generations of beta-lactam structure. This review addresses the current breadth of biochemical and microbiological efforts to preserve the future of the beta-lactam antibiotics through a better understanding of how S. aureus protects the enzyme targets of the beta-lactams, the penicillin-binding proteins. The penicillin-binding proteins are essential enzyme catalysts for the biosynthesis of the cell wall, and understanding how this cell wall is integrated into the protective cell envelope of the bacterium may identify new antibacterials and new adjuvants that preserve the efficacy of the beta-lactams.

Automated summary

The diversity of unicellular bacteria can rival or even exceed that of multicellular eukaryotes in terms of shape, food, metabolism, and ecological niche. The relationship between bacteria that occupy the ecological niche of eukaryotes and eukaryotes is often symbiotic or balanced, but some bacteria, like Staphylococcus aureus, seek advantage in this relationship. Over time, S. aureus has developed resistance mechanisms against beta-lactam antibiotics, requiring the development of new generations of these antibiotics to counteract this resistance.