Nosocomial imipenem-resistant Acinetobacter baumannii infections: Epidemiology and risk factors

Abstract

The incidence, clinical characteristics, risk factors, antimicrobial susceptibility, and outcomes of nosocomial imipenem-resistant A. baumannii (IRAB) infections during a 5-y period (2003-2007) were retrospectively analyzed. A total of 720 patients with 925 episodes of A. baumannii infection were included in the study. A. baumannii infections were seen mostly in intensive care units. The incidence was 6.2 per 1000 admissions. The most common infections were pneumonias and bloodstream infections. Imipenem resistance among Acinetobacter strains increased significantly each y of the study (from 43.3% to 72.9%). Mortality was related to the presence of imipenem resistance, stay in intensive care unit, female gender, old age, and pneumonia. Haemodialysis, malignancy, and mechanical ventilation were significant risk factors for IRAB infections. Imipenem resistance was higher in strains isolated from patients with pneumonia. IRAB strains showed higher resistance rates to other antibiotics than imipenem-susceptible strains. The most active antimicrobial agents against A. baumannii were cefoperazone-sulbactam and netilmicin. The incidence of A. baumannii infections and imipenem resistance increased during the study period. IRAB infections should be considered in patients on mechanical ventilation and haemodialysis and in patients with malignancies.

Increasing Trend of Imipenem-Resistance Among Acinetobacter baumannii Isolated From Hospital Acquired Pneumonia in Northeast of Iran

“…A. baumannii is an opportunistic pathogen, which affects different groups of people, especially those admitted to the ICU (22). Furthermore, our results found that the trend A. baumannii resistant strains to imipenem was increasing, in confirming this finding, some studies have also reported this phenomenon (9,30,31). In a study of 298 positive cultures of A. baumannii isolated from American soldiers in the Iraq war who were hospitalized at military hospitals between 2003 and 2008, showed that 46 (15%) were resistant to imipenem (32).…”

Patient Demographics and Characteristics of Infection with Carbapenem-Resistant <i>Acinetobacter baumannii</i> in a Teaching Hospital from the United States

“…The biggest risk factor for developing carbapenem-resistant A. baumannii was prior hospitalization. This risk factor has also been reported by other group [5] and could be indicative of exposures in the hospital environment or of the use of antibiotics that leads to development of resistance. Samples from the patients on respiratory ventilators and from those with polymicrobial infections [31] also had high odds of developing carbapenem resistant A. baumannii and suggest that cross contamination and colonization of respiratory equipment could be a concern.…”

“…In addition, A. baumannii infections have been identified in troops returning from military engagements in the Middle East [4]. A. baumannii has been identified as the causative agent in many serious medical conditions such as sepsis and nosocomial pneumonia [5,6]. Although in general the virulence of this species is low; its colonization poses a threat in a health care setting.…”

Effects of silver nanoparticles in combination with antibiotics on the resistant bacteria <em>Acinetobacter baumannii</em>

“…4 The majority of such bacteria are extensively drug resistant, which may include resistance to carbapenems and all other antibiotics except polymyxins and tigecycline. 5 Polymyxin B is effective against drug-resistant A. baumannii, but systemic application carries risk of toxicity, primarily kidney toxicity and neurotoxicity. 6,7 A. baumannii infection is common in patients with severe infections, and is often accompanied by other bacterial and/or fungal infections.…”