Risk factors for colonization and infection by Pseudomonas aeruginosa in patients hospitalized in intensive care units in France

Abstract

Pseudomonas aeruginosa (P.aeruginosa) remains a prominent nosocomial pathogen responsible for high morbi-mortality in intensive care units (ICUs). P.aeruginosa transmission is known to be partly endogenous and exogenous. Main factors have been highlighted but the precise role of environment in regard to antibiotics use remained unclear.ObjectiveTo assess the role of environment, medical care and individual risks factors for P. aeruginosa colonization and infection.Study design and settingA French multicentric prospective study involved ten ICUs for a five months period. Every adult patient newly hospitalized in ICUs with no P. aeruginosa carriage up to 48 hours after admission was included and weekly screened before discharge or death. Screening swabs were either rectal, sputum or oropharyngeal samples. Hydric environment was also sampled each week. Data on patient clinical features, environmental and device exposures, and antibiotics supports were regularly collected. Multivariate analysis was performed with a multistate model.ResultsThe overall prevalence of P. aeruginosa carriage was 15.3% (201/1314). Risk factors associated with patient colonization were: use of inactive antibiotics against P. aeruginosa (HR = 1.60 [1.15–2.21] p<0.01), tap water contamination at the entry in the room (HR = 1.66 [1.01–2.27] p<0.05) and mechanical invasive ventilation (HR = 4.70 [2.66–8.31] p<0.0001). Active antibiotics prevented from colonization (HR = 0.67 [0.48–0.93] p = 0.02) and from infection (HR = 0.64 [0.41–1.01] p = 0.05). Interaction between hydric environment antibiotics support was not statistically associated with patient colonization.ConclusionHydric contamination and antibiotics pressure seem to remain key independent risk factors in P. aeruginosa colonization. These results advocate the need to carry on preventive and targeted interventions toward healthcare associated infections.

Structural equation modeling the “control of gut overgrowth” in the prevention of ICU-acquired Gram-negative infection

“…This is possibly not paradoxical as antibiotics used for PPAP typically lack activity against Pseudomonas and Acinetobacter. In this regard, the cumulative days of exposure to antibiotics without activity against Pseudomonas have been reported as being a risk factor for acquiring P. aeruginosa and Acinetobacter in the ICU [24][25][26]. Moreover, concomitant systemic antibiotic therapy fails to prevent the acquisition of respiratory tract colonization with Gram-negative bacteria [27] and more than triples the risk of subsequent infection among ICU patients receiving an enteral decolonization regimen with gentamicin against KPC-producing Klebsiella pneumonia [28] and CRE-producing Acinetobacter [29].…”

A live auxotrophic vaccine confers mucosal immunity and protection against lethal pneumonia caused by Pseudomonas aeruginosa

“…While several candidates to receive α-PA vaccination have been discussed [8], those patients scheduled for cardiac surgery [52] and those undergoing mechanical ventilation [53] appear to be the most obvious target individuals. Another important infection group are those undergoing chemotherapy [54] or AIDS patients [55].…”

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

“…The high rate of systemic antibiotics already initiated before study inclusion (79% of patients received agents effective against Pseudomonas) potentially reduces the effect of a vaccine. The fact that most patients were receiving antibiotics prior to vaccine dosing was expected because prior antibiotic exposure is consistently identified as a risk factor for nosocomial P. aeruginosa pneumonia [20]. Moreover, overall, approximately 98% received concomitant antibiotics during the trial, and it will be therefore not possible to explore potential interactions between vaccination and antibiotic exposure on P. aeruginosa isolates.…”