Regional differences and trends in antimicrobial susceptibility of Acinetobacter baumannii☆
Introduction
In hospitals worldwide today a host of bacterial pathogens have emerged and evolved that confound the ability to treat efficiently and in a cost-effective manner the infectious processes they cause [1], [2], [3], [4]. Increasingly over the past 10 years these pathogens are Gram-negative bacilli, including multidrug-resistant (MDR) isolates with a multitude of evolving antibiotic resistance mechanisms [5], [6]. Less commonly involved in hospital infections, but with increasing frequency, is a pathogen once considered a commensal but now considered a major hospital-associated pathogen, namely Acinetobacter baumannii [7], [8], [9], [10]. A. baumannii is intrinsically resistant to many classes of antibiotics and is frequently MDR, leaving few effective antimicrobial agents that are clinically beneficial [11], [12]. Although A. baumannii can be isolated from a variety of clinical specimens from hospitalised patients, it is commonly isolated in intensive care units (ICUs) from intubated patients [13], [14]. As A. baumannii can frequently be MDR, it is critical that appropriate susceptibility testing be performed after culture as empirical therapy may be problematic due to resistance. Surveillance programmes to monitor susceptibility can assist in delineating resistance in these isolates over time and across multiple regions globally [15], [16], [17], which may assist in choosing appropriate empirical therapy as needed and better understanding evolving resistance. This report documents the in vitro activity of clinically relevant antibiotics against a global collection of A. baumannii isolated in 48 countries from 2011 to 2014 as part of the Study for Monitoring Antimicrobial Resistance Trends (SMART) ongoing surveillance initiative.
Section snippets
Clinical isolates
For the SMART programme, participating sites each collected up to 100 consecutive aerobic or facultatively anaerobic Gram-negative pathogens from intra-abdominal infections (IAIs) and up to 50 pathogens from urinary tract infections (UTIs) per year. Only one isolate per patient per species was accepted. Isolates were identified using local site procedures, and then all isolates except those from China were sent to one of two central laboratories [International Health Management Associates
Results
Isolates from 2013 to 2014 were analysed for recent prevalence, MDR rates and susceptibility as a compromise between showing the most current data available (i.e. 2014 alone) and having large enough sample sizes for robust subset analyses such as by patient location. In these two years, 1011 isolates of A. baumannii were collected from IAIs (n = 721) and UTIs (n = 276), with 307 of the isolates coming from patients in ICUs and 615 from non-ICU wards. Overall, the proportion of A. baumannii among
Discussion
Since large-scale surveillance data on combined resistance in A. baumannii are rare [6], [15], [20], the SMART surveillance programme offers a unique opportunity to assess the epidemiology, susceptibility and MDR rates of this organism using recent global isolates collected and tested in a consistent way. This current SMART report confirmed what smaller studies at the country or individual hospital level have found in the past, i.e. generally high antimicrobial resistance and multidrug
Conclusions
Data reported in this study continue to document both single drug and multidrug resistance in IAI and UTI isolates of A. baumannii. Susceptibility varied somewhat by region but was low everywhere. MDR rates were high in every region, even in North America, the region with the lowest rate. Resistance was higher in ICUs than non-ICU wards, but even in the latter MDR rates were concerningly high, especially in Europe and the Middle East. These findings underscore the need for new agents that could
Acknowledgements
The authors thank all of the participants in the Study for Monitoring Antimicrobial Resistance Trends (SMART) programme for their continuing contributions to its success.
Funding: The SMART surveillance programme, including data analysis and publication, is funded by Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc. (Kenilworth, NJ). The sponsor approved the overall study design, but collection and testing of isolates, data analysis and manuscript preparation were independently
References (33)
- et al.
Antimicrobial susceptibility among Gram-negative isolates collected from intensive care units in North America, Europe, the Asia-Pacific Rim, Latin America, the Middle East, and Africa between 2004 and 2009 as part of the Tigecycline Evaluation and Surveillance Trial
Clin Ther
(2012) - et al.
Antimicrobial susceptibility of Gram-negative organisms isolated from patients hospitalized with pneumonia in US and European hospitals: results from the SENTRY Antimicrobial Surveillance Program, 2009–2012
Int J Antimicrob Agents
(2014) MYSTIC Europe 2007: activity of meropenem and other broad-spectrum agents against nosocomial isolates
Diagn Microbiol Infect Dis
(2009)Global antibacterial resistance: the never-ending story
J Glob Antimicrob Resist
(2013)- et al.
Emerging broad-spectrum resistance in Pseudomonas aeruginosa and Acinetobacter baumannii: mechanisms and epidemiology
Int J Antimicrob Agents
(2015) - et al.
Ventilator-associated pneumonia due to extensive drug-resistant Acinetobacter baumannii: risk factors, clinical features, and outcomes
Am J Infect Control
(2014) - et al.
Changes in MIC within a global collection of Acinetobacter baumannii collected as part of the Tigecycline Evaluation and Surveillance Trial, 2004 to 2009
Clin Ther
(2012) - et al.
Summary trends for the Meropenem Yearly Susceptibility Test Information Collection program: a 10-year experience in the United States (1999–2008)
Diagn Microbiol Infect Dis
(2009) - et al.
In vitro activity of tigecycline and comparators against Gram-positive and Gram-negative isolates collected from the Middle East and Africa between 2004 and 2011
Int J Antimicrob Agents
(2014) - et al.
Antibiotic resistance of Acinetobacter baumannii in Iran: a systemic review of the published literature
Osong Public Health Res Perspect
(2015)
OXA- and GES-type β-lactamases predominate in extensively drug-resistant Acinetobacter baumannii isolates from a Turkish university hospital
Clin Microbiol Infect
Spread of imipenem-resistant Acinetobacter baumannii co-expressing OXA-23 and GES-11 carbapenemases in Lebanon
Int J Infect Dis
High prevalence of multidrug-resistance in Acinetobacter baumannii and dissemination of carbapenemase-encoding genes blaOXA-24-like and blaNDM-1 in Algiers hospitals
Asian Pac J Trop Med
Antimicrobial susceptibility of Gram-negative organisms isolated from patients hospitalized in intensive care units in United States and European hospitals (2009–2011)
Diagn Microbiol Infect Dis
Improvement of MALDI-TOF MS profiling for the differentiation of species within the Acinetobacter calcoaceticus–Acinetobacter baumannii complex
Syst Appl Microbiol
Identification of Acinetobacter species: is Bruker Biotyper MALDI-TOF mass spectrometry a good alternative to molecular techniques?
Infect Genet Evol
Cited by (0)
- ☆
The results of this report were presented in part at the 55th Interscience Conference on Antimicrobial Agents and Chemotherapy/28th International Congress of Chemotherapy (ICAAC/ICC), 17–21 September 2015, San Diego, CA.