Exposure to stress minimizes the zone of antimicrobial action: a phenotypic demonstration with six Acinetobacter baumannii strains

Aim: To phenotypically study the role of domestic environmental stress in the emergence of antimicrobial resistance in Acinetobacter baumannii. Materials and Methods: Six strains of A. baumannii were initially subjected to AST and then were exposed to various stresses (temperature, pH and random combinations). Stressed cells were subcultured and then subjected for AST. The ZOIs before and after exposure to stress were compared. Statistical analysis was done using Student t-test at p < 0.10. Results: Exposure to stresses and combination of stresses resulted in substantial reduction in the ZOIs. Stress hardening was associated with further reduction in ZOIs. Conclusion: Exposure to domestic environmental stress imparted a significant and substantial reduction in the susceptibility of A. baumannii strains to antibiotics.