Impact of intensive care unit relocation and role of tap water on an outbreak of Pseudomonas aeruginosa expressing OprD-mediated resistance to imipenem

BACKGROUND

To assess the impact of the incidental relocation of an intensive care unit (ICU) on the risk of colonizations/infections with Pseudomonas aeruginosa exhibiting OprD-mediated resistance to imipenem (PA-OprD).

AIM

The primary aim was to compare the proportion of PA-OprD among P. aeruginosa samples before and after an incidental relocation of the ICU. The role of tap water as a route of contamination for colonization/infection of patients with PA-OprD was assessed as a secondary aim.

METHODS

A single-centre, observational, before/after comparison study was conducted from October 2013 to October 2015. The ICU was relocated at the end of October 2014. All P. aeruginosa-positive samples isolated from patients hospitalized ≥48 h in the ICU were included. Tap water specimens were collected every three months in the ICU. PA-OprD strains isolated from patients and tap water were genotyped using pulse-field gel electrophoresis.

FINDINGS

A total of 139 clinical specimens of P. aeruginosa and 19 tap water samples were analysed. The proportion of PA-OprD strains decreased significantly from 31% to 7.7% after the relocation of the ICU (P = 0.004). All PA-OprD clinical specimens had a distinct genotype. Surprisingly, tap water was colonized with a single PA-OprD strain during both periods, but this single clone has never been isolated from clinical specimens.

CONCLUSION

Relocation of the ICU was associated with a marked decrease in P. aeruginosa strains resistant to imipenem. The polyclonal character of PA-OprD strains isolated from patients and the absence of tap-water-to-patient contamination highlight the complexity of the environmental impact on the endogenous colonization/infection with P. aeruginosa.

[Fatal Panton-Valentine leukocidine-associated Staphylococcus aureus necrotizing pneumonia]

Panton-Valentine leukocidin-producing Staphylococcus aureus necrotizing pneumonia is an unusual cause of community-acquired pneumonia associated with a high fatality rate. The specificities of its presentation must be known by the critical care doctor, in order to quickly make the diagnosis and start the right antibiotics and discuss adjunctive therapy with intravenous immunoglobin. Moreover, the management of close contacts (household and healthcare workers) of patient with such a pneumonia is not well-known. The present case report underlines the clinical presentation of this pneumonia, the specificities of its treatment, and specifies the management of close contacts.

Introduction of highly resistant bacteria into a hospital via patients repatriated or recently hospitalized in a foreign country

We describe the prevalence of carriage and variables associated with introduction of highly drug-resistant microorganisms (HDRMO) into a French hospital via patients repatriated or recently hospitalized in a foreign country. The prevalence of HDRMO was 11% (15/132), with nine carbapenamase-producing Enterobacteriaceae, nine carbapenem-resistant Acinetobacter baumannii and six glycopeptide-resistant enterococci. Half of the admitted patients (63/132, 48%) were colonized with extended spectrum beta-lactamase-producing Enterobacteriaceae (ESBLPE). Among the four episodes with secondary cases, three involved A. baumannii.

Enterobacteriaceae bacteremia: risk factors for ESBLPE

OBJECTIVES

The increasing prevalence of extended spectrum beta-lactamase producing enterobacteriaceae (ESBLPE) requires defining the use of carbapenems in first intention. We analyzed the associations between enterobacteriaceae bacteremia (EbBact) and ESBLPE carriage during 10 years in a 950-bed teaching hospital.

METHODS

We analyzed a 10-year (July 2001 to June 2011) prospective collection of bacteremia cases including 2 databases: (1) EbBact and (2) a computerized database of patients carrying EBLSE. Only one episode of EbBact was analyzed per patient and hospital stay. Factors associated with ESBLPE bacteremia were assessed by univariate and multivariate logistic regression analysis.

RESULTS

Overall, 2355 cases of EbBact were identified, among which 135 (5.7%) were ESBLPE (2001-05: 1.4%, 2006-09: 7.6%, 2010-11: 14.2%). ESBLPE bacteremia was observed in 52 of the 88 (59%) patients carrying ESBLPE and in 83/2267 (3.7%) patients not known to be colonized with ESBLPE. Factors associated with ESBLPE bacteremia in patients not known to be colonized were: female gender (ORa=0.56, CI95% [0.34-0.91]), hospitalization in the ICU (ORa=2.51 [1.27-5.05]) or medical/surgical wards (ORa=1.83 [1.04-3.38]), the period (2006-09, ORa=4.08 [2.21-8.16]; 2010-11, ORa=8.17 [4.14-17.06] compared to 2001-05), and history of EbBact (ORa=2.29 [0.97-4.79]).

CONCLUSION

In case of EbBact, patients known to be colonized with ESBLPE present with ESBLPE bacteremia in more than half of the cases, requiring carbapenems as empirical antibiotic treatment. The global prevalence of ESBLPE among patients presenting with EbBact not known to be colonized with ESBLPE was 3.7%.

[Enterovirus nosocomial infections in a neonatal care unit: from diagnosis to evidence, from a clinical observation of a central nervous system infection]

Although enteroviruses generally cause asymptomatic or mild disease, neonates are at higher risk for severe illnesses, among which systemic disease characterized by multiorgan involvement is a potentially fatal condition. Enterovirus neonatal infections may be the source of nosocomial infections in neonatology or in pediatric intensive care units. We report central nervous system infections due to Echovirus 11 in two neonates and the molecular evidence of nosocomial transmission of this strain in a neonatal unit by enterovirus genotyping and phylogenetic analysis. This report illustrates the importance of including enterovirus genome detection in the sepsis screening concomitantly with bacteriological investigations performed at admission of a neonate. Rapid diagnosis and subsequent genotyping could have a beneficial impact on clinical practices at the individual level (reducing the length of antibiotic therapy) and public health policy at the collective level by reinforcing hygiene measures to prevent nosocomial infections, with nurseries and neonatal units being at greater risks.