Acinetobacter baumannii: An emerging pathogenic threat to public health

Abstract

Over the last three decades, Acinetobacter has gained importance as a leading nosocomial pathogen, partly due to its impressive genetic capabilities to acquire resistance and partly due to high selective pressure, especially in critical care units. This low-virulence organism has turned into a multidrug resistant pathogen and now alarming healthcare providers worldwide. Acinetobacter baumannii (A. baumannii) is a major species, contributing about 80% of all Acinetobacter hospital-acquired infections. It disseminates antibiotic resistance by virtue of its extraordinary ability to accept or donate resistance plasmids. The procedures for breaking the route of transmission are still proper hand washing and personal hygiene (both the patient and the healthcare professional), reducing patient’s biofilm burden from skin, and judicious use of antimicrobial agents. The increasing incidence of extended-spectrum beta-lactamases and carbapenemases in A. baumannii leaves almost no cure for these “bad bugs”. To control hospital outbreaks of multidrug resistant-Acinetobacter infection, we need to contain their dissemination or require new drugs or a rational combination therapy. The optimal treatment for multidrug-resistant A. baumannii infection has not been clearly established, and empirical therapy continues to require knowledge of susceptibility patterns of isolates from one’s own institution. This review mainly focused on general features and introduction to A. baumannii and its epidemiological status, potential sources of infection, risk factors, and strategies to control infection to minimize spread.

Keywords: Acinetobacter; Acinetobacter baumannii; Biofilm; Combination therapy; Hospital-acquired infection; Intensive care unit; Multidrug resistance; Nosocomial Pathogen; Risk factor

Core tip:Acinetobacter, is Gram-negative cocco-bacilli, originally regarded as low virulence bacteria, adopted now with increasing incidences, and recognized as a significant healthcare-associated multidrug-resistant classical pathogen. Acinetobacter baumannii (A. baumannii) accounts for nearly 80% of reported Acinetobacter infections. A. baumannii resist desiccation, and survive for several months on animate and inanimate surfaces. It has excellent colonizing potential, and contact transmission is a big challenge intermittent as well as endemic outbreaks. Strong biofilm formation is a part of virulence pathogenesis strategies of this organisms, and elimination of the identified source often require multiple interventions. This review mainly discusses on relevant epidemiological features of A. baumannii.