May Sulfonamide Inhibitors of Carbonic Anhydrases from Mammaliicoccus sciuri Prevent Antimicrobial Resistance Due to Gene Transfer to Other Harmful Staphylococci?

Mammaliicoccus sciuri, previously known as Staphylococcus sciuri, is a Gram-positive bacterium involved in gene transfer phenomena that confer resistance to multiple antibiotics. These plasmid-encoded genes can be easily transferred to other pathogenic staphylococci. Because antibiotic resistance is rising, inhibiting M. sciuri proliferation may be a credible strategy for restricting antimicrobial resistance gene transfer to other pathogenic bacteria. Recently, it has been shown that blocking bacterial carbonic anhydrases (CAs, EC 4.2.1.1), metalloenzymes sustaining bacterial metabolic activities, can reduce pathogen survival and fitness. Here, the recombinant M. sciuri gamma-CA (MscCA gamma) has been cloned and purified, utilizing the DNA recombinant technology. Its kinetic properties for the CO2 hydration reaction, as well as the sulfonamide inhibition profile, were investigated and compared with those reported earlier for MscCA beta (previously described as SauBCA) and the two off-target human CA isoforms (hCA I and hCA II). The recombinant MscCA gamma showed significant hydratase activity. Moreover, the MscCA gamma sulfonamide inhibitory profile was different from that of MscCA beta, implying that a varied amino acid set typifies the catalytic pocket of the two enzymes. These differences provide additional evidence for the possibility of developing novel CA class-specific inhibitors.

Automated summary

Blocking bacterial carbonic anhydrases can reduce pathogen survival and fitness. The recombinant M. sciuri gamma-CA showed significant hydratase activity, with a sulfonamide inhibitory profile different from that of MscCA beta, suggesting the possibility of developing novel CA class-specific inhibitors.