Small colony variants phenotype and biofilm formation: Implication in persistent Staphylococcus aureus infection

Abstract

Staphylococcus aureus survival strategy for persistence can be attributed to their metabolic versatility under unfavorable conditions by switching to small colony variants (SCVs) phenotype and forming biofilm; these attributes contribute to their widespread dissemination, difficulty to detect in routine microbiological screening and challenging eradication particularly in clinical setting, resulting to persistent nature of their infections. The SCVs can survive intracellularly, misinterpreted as  coagulase negative Staphylococcus aureus (CoNS) and down regulate some virulence factors. Biofilm formation provides protection against antibiotics and immune responses; the matrix serve as a physical barrier and transfer of resistant determinant via conjugation occur among the encased bacteria because of their proximity. Thus; SCVs and biofilm aid evasion of antibiotics and immune response resulting to persistent infection. Therefore, understanding the process associated with the ability of bacteria to persist could significantly aid in the development of a better therapeutic options that will ultimately reduce the risk of morbidity and mortality.