The Silent Threat: Unveiling Pathogenicity and Antimicrobial Resistance in Nonfermenting Gram-Negative Bacilli

Nonfermenting Gram-negative bacilli (NFGNB) are aerobic bacteria prevalent in healthcare settings and have become important healthcare-associated pathogens due to their capacity to persist in hospital environments and their intrinsic and acquired antibiotic resistance. Due to their significant involvement in multidrug-resistant infections, the World Health Organization has assigned carbapenem-resistant Acinetobacter baumannii and Pseudomonas aeruginosa as priority pathogens. The excessive administration of broad-spectrum antibiotics, notably carbapenems, has driven the global increase in carbapenem-resistant NFGNB, resulting in limited options for treatment and increasing morbidity and mortality. NFGNB, including P. aeruginosa, A. baumannii, Stenotrophomonas maltophilia, and Burkholderia species, are significant opportunistic pathogens associated with serious nosocomial infections, particularly in critically ill and immunocompromised individuals. Their increasing resistance contributes significantly to the worldwide antimicrobial resistance crisis, which is currently acknowledged as a serious public health issue.