National trends in hospital, long-term care and outpatient Acinetobacter baumannii resistance rates

Abstract

Introduction. Acinetobacter baumannii is a top-priority pathogen of the World Health Organization (WHO) and the Centers for Disease Control (CDC) due to antibiotic resistance. Gap Statement. Trends in A. baumannii resistance rates that include community isolates are unknown. Aim. Identify trends in A. baumannii resistance rates across the Veterans Affairs (VA) Healthcare System, including isolates from patients treated in hospitals, long-term care facilities and outpatient clinics nationally. Methodology. We included A. baumannii clinical cultures collected from VA patients from 2010 to 2018. Cultures were categorized by location: VA medical centers (VAMCs), long-term care (LTC) units [community living centers (CLCs)], or outpatient. We assessed carbapenem resistance, multidrug resistance (MDR) and extensive drug resistance (XDR). Time trends were assessed with Joinpoint regression. Results. We identified 19 376 A . baumannii cultures (53% VAMCs, 4% CLCs, 43% outpatient). Respiratory cultures were the most common source of carbapenem-resistant (43 %), multidrug-resistant (49 %) and extensively drug-resistant (21 %) isolates. Over the study period, the number of A. baumannii cultures decreased significantly in VAMCs (11.9% per year). In 2018, carbapenem resistance was seen in 28% of VAMC isolates and 36% of CLC isolates, but only 6% of outpatient isolates, while MDR was found in 31% of VAMC isolates and 36% of CLC isolates, but only 8 % of outpatient isolates. Carbapenem-resistant, multidrug-resistant and extensively drug-resistant A. baumannii isolates decreased significantly in VAMCs and outpatient clinics over time (VAMCs: by 4.9, 7.2 and 6.9%; outpatient: by 11.3, 10.5 and 10.2% per year). Resistant phenotypes remained stable in CLCs. Conclusion. In the VA nationally, the prevalence of A. baumannii is decreasing, as is resistance. Carbapenem-resistant and multidrug-resistant A. baumannii remain common in VAMCs and CLCs. The focus of infection control and antimicrobial stewardship efforts to prevent transmission of resistant A. baumannii should be in hospital and LTC settings.

Decreasing Antibiotic Resistance Trends Nationally in Gram-Negative Bacteria Across United States Veterans Affairs Medical Centers, 2011–2020

“…While it should be reiterated that these comparisons are not direct, as CDC relied on modeling estimates that were not used in this study, the overall estimated trend differences suggest favorable resistance profiles at VAMCs. Earlier surveillance reports in the VHA also suggest an attenuation of AR in VAMCs, as AR decreases were seen in Acinetobacter from 2010 to 2018, there were stable rates of ESCR Klebsiella pneumoniae bloodstream infections from 2007 to 2013, and decreases in carbapenem-resistant K. pneumoniae were observed from 2006 to 2015 [ 15 , 36 , 37 ].…”

“…Data on overall US resistance trends are largely derived from CDC modeling estimates, with smaller surveillance studies at times reporting differing trends [ 1 , 14 ]. Since 2012, decreases in carbapenem-resistant Acinetobacter have been observed; however, there have been conflicting reports on trends in multi-drug-resistant P. aeruginosa [ 1 , 15 – 17 ]. For Enterobacterales, extended-spectrum cephalosporin-resistant infections have increased in both community and healthcare settings, with varied trends reported for carbapenem-resistant infections [ 1 , 16 – 18 ].…”

Structure–function correlates of fibrinogen binding by Acinetobacter adhesins critical in catheter-associated urinary tract infections

“…Acinetobacter baumannii is a gram-negative, opportunistic pathogen able to colonize a variety of human host tissues ( 1 ). Among the most common infections caused by A. baumannii are urinary tract, bloodstream, indwelling catheter, and respiratory infections ( 1 , 2 ). In addition to its opportunistic versatility, antibiotic and multidrug resistance is a significant concern for A. baumannii.…”