European Journal of Biomedical and Pharmaceutical Sciences

ACINETOBACTER BAUMANNII: AN EMERGING UNIQUE MULTI-DRUG RESISTANT PATHOGEN

Nilay Chatterjee, Kumkum Bhattacharyya and Somasri Dam*

ABSTRACT

Acinetobacter baumannii complex emerged as a nosocomial opportunistic pathogen in intensive care unit probably as a consequence at least in part, of increasing use of broad spectrum antibiotics in hospital. It causes outbreaks of infection and health care–associated infections, including bacteremia, pneumonia, meningitis, urinary tract infection, and wound infection. Ventilator-associated pneumonia and bloodstream infections are most common, and mortality rates can reach 35%. Dealing with multi-drug resistant Acinetobacter baumannii is a great challenge for physician and clinical microbiologists not only due to its ability to survive in a hospital milieu but also because of the increase of mortality and morbidity associated with this pathogen. The changing trend in antibiotic susceptibility pattern from sensitive to resistance to commonly used antimicrobial agents creates problem in management of infections caused by A. baumannii. Polymyxins show reliable antimicrobial activity against A. baumannii isolates. Available clinical reports, although consisting of small-sized studies, support their effectiveness and mitigate previous concerns for toxicity. Minocycline, and particularly its derivative, tigecycline, have shown high antimicrobial activity against A. baumannii, though relevant clinical evidence is still scarce. This review summarizes the recent advances, with particular focus on evolutionary and genomic aspects, virulence factors, pathogenesis, antibiotic resistance, therapeutic regiments of Acinetobacter baumannii and also proposes new avenues of research.

Keywords: Acinetobacter baumannii, Polymyxin, nosocomial, MDR.