Bacterial heteroresistance: an evolving novel way to combat antibiotics

Heteroresistance is a phenomenon where a subset of bacterial cells shows higher resistance towards antibiotic while the majority are susceptible to the same. Till date, a few reports have been emerged with prevalence of heteroresistance in several bacterial species towards different classes of antibiotics. It is hard to treat heteroresistant bacterial infections as it is difficult in identifying and studying these subpopulations. The organisms with stable heteroresistance can sustain the resistance ability even in the absence of antibiotics while unstable heteroresistance can revert to susceptibility in the absence of antibiotics. The bacterial heteroresistance is due to genetically unsteady amplification of tandem genes or could also be due to physiological mechanism. The major challenge is to detect and distinguish isolates into susceptible or resistant to antibiotics due to instability and low frequency in their appearance that can give misinterpretation in the therapy. This review concentrates on bacterial heteroresistance with their associated mechanisms followed by modified and advanced evaluation procedures. Also, complications allied with the treatment failure due to bacterial heteroresistance and concerns over its prevalence in food chain.