Infections in intensive care unit adult patients harboring multidrug-resistant Pseudomonas aeruginosa: implications for prevention and therapy

Abstract

The purpose of this paper was to report the burden and characteristics of infection by multidrug-resistant Pseudomonas aeruginosa (MDR-PA) in clinical samples from intensive care unit (ICU) adults, and to identify predictors. This was a retrospective observational study at four medical-surgical ICUs. The case cohort comprised adults with documented isolation of an MDR-PA strain from a clinical specimen during ICU stay. Multivariate analysis was performed to identify predictors for MDR-PA infection. During the study period, 5667 patients were admitted to the ICU and P. aeruginosa was isolated in 504 (8.8%). MDR-PA was identified in 142 clinical samples from 104 patients (20.6%); 62 (43.6%) of these samples appeared to be true infections. One hundred and eighteen (83.1%) isolates were susceptible only to amikacin and colistin, and 13 (9.2%) were susceptible only to colistin. Overall, the MIC to meropenem was 16 μg/mL and the MIC was >32 μg/mL, with 60.4% of respiratory samples being MIC >32 μg/mL to meropenem. Independent predictors for MDR-PA infection were fever/hypothermia [odds ratio (OR) 9.09], recent antipseudomonal cephalosporin therapy (OR 6.31), vasopressors at infection onset (OR 4.40), and PIRO (predisposition, infection, response, and organ dysfunction) score >2 (OR 2.06). This study provides novel information that may be of use for the clinical management of patients harboring MDR-PA and for the control of the spread of this organism.

Understanding resistance in Pseudomonas

“…In turn, this may have serious implications in the clinical setting that virulent strains with MDR phenotypes may settle as the primary pathogens in infected, highrisk patients. Fever/hypothermia, PIRO score > 2, vasopressors at infection onset, and recent antipseudomonal cephalosporin exposure have been found to be independent predictors of MDR-PA infections [7,8].…”

Postmortem microbiology sampling following death in hospital: an ESGFOR task force consensus statement

“…It has been estimated that there were 12 000 A. baumannii infections per year in the USA, including 7300 multidrug-resistant infections that resulted in more than 500 deaths. In the USA, there are 51 000 Pseudomonas infections per year, with an estimated 6700 multidrug-resistant infections and around 440 deaths associated with this pathogen 52. Similar rates53 are estimated in Europe.…”

“…Carbapenem-resistant Enterobacteriaceae, multidrug-resistant Acinetobacter and multidrug-resistant Pseudomonas aeruginosa are among the top concerns 52. Similarly, these three pathogens are classified among the critical priorities in the WHO priority pathogens list 32.…”

Efficacy, immunogenicity, and safety of IC43 recombinant Pseudomonas aeruginosa vaccine in mechanically ventilated intensive care patients—a randomized clinical trial

“…Despite the availability of new classes of antibiotics, multidrug resistance to P. aeruginosa has doubled over the past 30 years and improvements in the management of MDR PA pneumonia are a global challenge and unmet clinical need [17,18]. This is the first large randomized trial to evaluate a vaccination strategy in complex medically ill ICU patients requiring MV and aiming to decrease all-cause mortality at day 28.…”