Physiological role of bicarbonate in microbes: A double-edged sword?

HCO is involved in pH homoeostasis and plays a multifaceted role in human health. HCO has been recognized for its antimicrobial properties and is pivotal in bacterial antibiotic susceptibility. Notably, the interconversion between CO and HCO, facilitated by the enzyme carbonic anhydrase (CA), is crucial in tissues infected by pathogens. Studies have highlighted the antimicrobial potency of CA inhibitors, emphasizing the importance of this enzyme in this area. The potential of HCO as an antibiotic adjuvant is evident; its ability to increase virulence in pathogens such as and requires meticulous scrutiny. HCO modulates bacterial behaviours in diverse manners: it promotes O157:H7 colonization in the human gut by altering specific gene expression and, with , amplifies the effect of tobramycin on planktonic cells while promoting biofilm formation. These multifaceted effects necessitate profound mechanistic exploration before HCO can be considered a promising clinical adjuvant.