MpsAB is important for Staphylococcus aureus virulence and growth at atmospheric CO2 levels

Abstract

The mechanisms behind carbon dioxide (CO 2 ) dependency in non-autotrophic bacterial isolates are unclear. Here we show that the Staphylococcus aureus mpsAB operon, known to play a role in membrane potential generation, is crucial for growth at atmospheric CO 2 levels. The genes mpsAB can complement an Escherichia coli carbonic anhydrase (CA) mutant, and CA from E. coli can complement the S. aureus delta- mpsABC mutant. In comparison with the wild type, S. aureus mps mutants produce less hemolytic toxin and are less virulent in animal models of infection. Homologs of mpsA and mpsB are widespread among bacteria and are often found adjacent to each other on the genome. We propose that MpsAB represents a dissolved inorganic carbon transporter, or bicarbonate concentrating system, possibly acting as a sodium bicarbonate cotransporter.

Staphylococcus saccharolyticus: An Overlooked Human Skin Colonizer

“…However, the growth in a CO 2 -rich atmosphere is comparable to the growth under anaerobic conditions. A mechanistic explanation of the effect of CO 2 on bacterial growth was recently published by Fan et al [23]. The authors investigated the growth-promoting effect of CO 2 and the CO 2 -dependency of small colony variants of S. aureus, whose growth defect can be compensated by increased CO 2 /bicarbonate supplementation.…”

Staphylococcus aureus Host Tropism and Its Implications for Murine Infection Models

“…In an attempt to circumvent apparent incompatibilities between human S. aureus strains and laboratory mice, scientists have been on the search for a more suitable animal model. In recent decades, many such S. aureus infection models emerged, involving (i) invertebrates such as the fruit fly ( Drosophila melanogaster ), the roundworm ( Caenorhabditis elegans ) and the honeycomb moth ( Galleria mellonella ); (ii) vertebrates, e.g., zebrafish, rats, rabbits, sheep, dogs, goats, pigs, guinea pigs, and hamsters; as well as (iii) nonhuman primates [ 154 , 155 , 156 , 157 , 158 , 159 ]. However, for a variety of reasons, none of the above has proven to be generally more suitable for S. aureus research.…”

“…From an ethical perspective, the use of invertebrates in virulence models would be preferable; moreover, they could help to make follow-up experiments more targeted [ 156 , 157 ]. However, due to the significant anatomical, physiological, and immunological differences between invertebrates and vertebrates, these models will remain unsuitable for studying more complex host–pathogen interactions [ 160 , 161 ].…”

The MpsB protein contributes to both the toxicity and immune evasion capacity of Staphylococcus aureus

“…We identified three MALs as contributing to serum resistance, with one gene, mpsB, being of particular interest due to its association with the persister or small colony variant (SCV) phenotype associated with chronic S. aureus infections [7]. The MpsABC system participates in cation translocation, and hence the generation of membrane potential, as well as CO 2 transport [7,8]. Mutants of the mpsABC operon exhibited an SCV-like phenotype and have been shown as attenuated in membrane potential and oxygen consumption rates [7].…”

“…The MpsABC system participates in cation translocation, and hence the generation of membrane potential, as well as CO 2 transport [7,8]. Mutants of the mpsABC operon exhibited an SCV-like phenotype and have been shown as attenuated in membrane potential and oxygen consumption rates [7]. MpsABC represents an important functional system of the respiratory chain of S. aureus that acts as an electrogenic unit responsible for the generation of membrane potential [7].…”