Nosocomial bacteremia due to Acinetobacter baumannii: epidemiology, clinical features and treatment

Abstract

Acinetobacter baumannii is an important cause of nosocomial infections in many hospitals. It is difficult to control and infection caused is difficult to treat due to its high resistance in the environment and its ability to develop resistance to antimicrobials. Bacteremia, followed by respiratory tract and surgical wound infections, is the most significant infection caused by A. baumannii. The known risk factors for A. baumannii bacteremia are invasive procedures and the use of broad-spectrum antimicrobials. Consequently, episodes of bacteremia due to A. baumannii occur most frequently in critically-ill patients admitted to an intensive care unit. The clinical manifestations of bacteremia by A. baumannii are not specific. The most common sources of bacteremia are intravascular catheters and the respiratory tract. A. baumannii bacteremia is associated with a high crude mortality rate, but it is difficult to distinguish morbidity and mortality attributable to A. baumannii from that attributable to the common and severe co-morbidity in these patients. A. baumannii is a bacterium that appears to have a propensity for developing multiple antimicrobial resistance extremely rapidly. These data are disturbing because the therapeutic possibilities decrease while inappropriate antimicrobial treatment contributes to patient mortality. Generally, imipenem is the most active agent against A. baumannii. However, the description of imipenem-resistant A. baumannii strains is becoming increasingly common. The usual treatment for A. baumannii bacteremia is an active beta-lactam alone, preferably one with a limited spectrum. Before beginning treatment of a bacteremia by A. baumannii, it is very important to carry out a clinical evaluation of the patient to eliminate the possibility of a pseudobacteremia, and thereby avoid unnecessary treatment.

Antimicrobial susceptibility of Acinetobacter clinical isolates and emerging antibiogram trends for nosocomial infection management

“…The prevalence of imipenem resistance in Acinetobacter species increased from zero in 1991 to 50% in 2001, as shown in a study conducted in a Spanish hospital (17) . The resistant rates to ampicillin/sulbactam, imipenem, and meropenem were 51.6%, 26.3%, and 29.6%, respectively, of Acinetobacter isolates from 30 European centers (18) .…”

Spread of Novel Aminoglycoside Resistance Gene aac ( 6 ′)- Iad among Acinetobacter Clinical Isolates in Japan

“…Outbreaks have been increasingly reported in the past 2 decades, particularly from intensive care units, where patients undergo invasive procedures and receive broad-spectrum antimicrobial agents, resulting in higher mortality rates (5,27). Furthermore, because Acinetobacter spp.…”

Factores de riesgo para la adquisición y características microbiológicas de las bacteriemias por Acinetobacter baumannii multi-resistente en pediatría: Estudio de casos y controles

“…En el estudio presentado, coincidiendo con lo publicado en otras series, la bacteriemia por ABM fue más frecuente en pacientes con mayor tiempo de internación en UCI 19,20 .…”

“…El motivo de aparición de las bacteriemias primarias por ABM aún no está claro. Algunos autores proponen el origen intestinal, por traslocación bacteriana, fenómeno frecuente en pacientes críticamente enfermos 20 .…”