Sylvie Parer

Impact of an infection control program in an intensive care unit in France

OBJECTIVE To evaluate the impact of an infection control program in an intensive care unit (ICU). DESIGN Prospective before-after study. Two 6-month study periods were compared; between these periods, an infection control program based on isolation was implemented. SETTING Polyvalent ICU of Montpellier Teaching Hospital.Patients. Any patient who was hospitalized in the ICU for >48 hours and was discharged during 1 of the 2 periods. MAIN OUTCOME MEASURES The main patient-related variables were sex, age at admission, type of patient (surgical, medical, or trauma), Simplified Acute Physiology Score II, length of ICU stay, need for intubation, duration of exposure to invasive devices, onset of nosocomial infection and pathogens responsible, and death. We compared the 2 study periods with respect to the incidence of 4 nosocomial infections (pneumonia, urinary tract infection, bacteremia, and catheter-associated infection), the frequency of infection with the main multidrug-resistant pathogens, and patient survival. RESULTS Patients in periods 1 and 2 were similar with regard to sex, age, physiology score, and exposure to invasive devices. The rates of infection with multidrug-resistant pathogens were significantly lower during period 2 than during period 1 (infection rate: 28.1% of patients in period 1 and 9.6% of patients in period 2 [P = .01]; pneumonia rate: 32.6% of patients in period 1 and 4.2% of patients in period 2 [P = .008]). The mortality rate among patients with nosocomial pneumonia was 38.2% in period 1 and 4.3% in period 2 (P = .009). CONCLUSIONS After implementation of an infection control program, the rate of infection with multidrug-resistant pathogens decreased, as did the mortality rate among patients with nosocomial pneumonia.

Pacemaker surgical site infection caused by Mycobacterium goodii.

We describe what we believe to be the first documented case of Mycobacterium goodii infection in Europe. It is also the second documented report of a pacemaker pocket surgical site infection caused by M. goodii. Although rarely involved in such infections, rapidly growing mycobacteria should be recognized during conventional bacteriological investigations and further identified by molecular tools to provide adequate therapy. In the present case, antimicrobial therapy with doxycycline without removal of the pacemaker was successful.

Pseudomonas aeruginosa and Achromobacter sp. Clonal Selection Leads to Successive Waves of Contamination of Water in Dental Care Units

ABSTRACT Dental care unit waterlines (DCUWs) consist of complex networks of thin tubes that facilitate the formation of microbial biofilms. Due to the predilection toward a wet environment, strong adhesion, biofilm formation, and resistance to biocides, Pseudomonas aeruginosa, a major human opportunistic pathogen, is adapted to DCUW colonization. Other nonfermentative Gram-negative bacilli, such as members of the genus Achromobacter, are emerging pathogens found in water networks. We reported the 6.5-year dynamics of bacterial contamination of waterlines in a dental health care center with 61 dental care units (DCUs) connected to the same water supply system. The conditions allowed the selection and the emergence of clones of Achromobacter sp. and P. aeruginosa characterized by multilocus sequence typing, multiplex repetitive elements-based PCR, and restriction fragment length polymorphism in pulsed-field gel electrophoresis, biofilm formation, and antimicrobial susceptibility. One clone of P. aeruginosa and 2 clones of Achromobacter sp. colonized successively all of the DCUWs: the last colonization by P. aeruginosa ST309 led to the closing of the dental care center. Successive dominance of species and clones was linked to biocide treatments. Achromobacter strains were weak biofilm producers compared to P. aeruginosa ST309, but the coculture of P. aeruginosa and Achromobacter enhanced P. aeruginosa ST309 biofilm formation. Intraclonal genomic microevolution was observed in the isolates of P. aeruginosa ST309 collected chronologically and in Achromobacter sp. clone A. The contamination control was achieved by a complete reorganization of the dental health care center by removing the connecting tubes between DCUs.

Staphylococcus aureus in a neonatal care center: methicillin-susceptible strains should be a main concern

BackgroundIn the context of a methicillin-susceptible Staphylococcus aureus (MSSA) outbreak, we aimed to improve our knowledge of S. aureus (SA) epidemiology in the neonatal care center (NCC) of a tertiary care teaching hospital.MethodsWe performed a complete one-year review of SA carrier, colonized or infected patients. Monthly prevalence and incidence of SA intestinal carriage, colonization and infection were calculated and the types of infection analysed. During the MSSA outbreak, strains were studied for antimicrobial resistance, content of virulence genes and comparative fingerprint in Pulsed-Field Gel Electrophoresis. Hand hygiene and catheter-related practices were assessed by direct observational audits. Environmental investigation was performed in search of a SA reservoir.ResultsEpidemiological analyses showed 2 or 3 prevalence peaks on a background of SA endemicity. In the NCC, during 2009, overall MSSA prevalence did not decrease below 5.5%, while mean MRSA prevalence was about 1.53%. Analysis of infection cases revealed that the outbreak corresponded to the emergence of catheter-related infections and was probably related to the relaxation in infection control practices in a context of high colonization pressure. Health care workers’ white coats appeared as a potential environmental reservoir that could perpetuate SA circulation in the ward.ConclusionThis report emphasizes the importance of integrating MSSA along with methicillin-resistant SA in a program of epidemiological surveillance in the NCC.

An Outbreak of Heterogeneous Glycopeptide-Intermediate Staphylococcus aureus Related to a Device Source in an Intensive Care Unit

OBJECTIVE The emergence of Staphylococcus aureus with reduced susceptibility to glycopeptides (glycopeptide-intermediate S. aureus [GISA] and heterogeneous GISA [h-GISA]) leads to intensive care unit (ICU) outbreaks that frequently result in ward closure. We investigated the role of hospital hygiene in the transmission and eradication of an h-GISA outbreak. DESIGN The study is a description of an original environmental investigation around a series of 12 cases. SETTING AND PATIENTS The outbreak occurred in a 20-bed polyvalent/trauma ICU in a 2,800-bed tertiary care university hospital in France. INTERVENTIONS Specimens were obtained for surveillance and diagnostic cultures from all patients in the unit. Surface sampling was also performed. Geographic cohorting, contact isolation, emphasis on adherence to infection control practices, and environmental cleaning were implemented. RESULTS Twelve patients with h-GISA infection (n = 5) or colonization (n = 7) were identified. The mean interval between admission and h-GISA detection was 23.6 days (range, 10-89 days), with a median of 16.5 days. Environmental investigation identified an unexpected reservoir, namely, SpO(2) sensors. The outbreak was controlled by a combination of measures, including eradication of this reservoir, avoiding total ward closure. CONCLUSIONS Targeted surface sampling helps to secure the environment through active investigation of various reservoirs while maintaining normal activity on the ward. In our study, this method led to the detection of an unsuspected reservoir, the eradication of which helped control the h-GISA epidemic. Further applications of this original investigative procedure should allow confirmation of its relevance and efficiency.

Comparative diffusion assay to assess efficacy of topical antimicrobial agents against Pseudomonas aeruginosa in burns care

BackgroundSeverely burned patients may develop life-threatening nosocomial infections due to Pseudomonas aeruginosa, which can exhibit a high-level of resistance to antimicrobial drugs and has a propensity to cause nosocomial outbreaks. Antiseptic and topical antimicrobial compounds constitute major resources for burns care but in vitro testing of their activity is not performed in practice.ResultsIn our burn unit, a P. aeruginosa clone multiresistant to antibiotics colonized or infected 26 patients over a 2-year period. This resident clone was characterized by PCR based on ERIC sequences. We investigated the susceptibility of the resident clone to silver sulphadiazine and to the main topical antimicrobial agents currently used in the burn unit. We proposed an optimized diffusion assay used for comparative analysis of P. aeruginosa strains. The resident clone displayed lower susceptibility to silver sulphadiazine and cerium silver sulphadiazine than strains unrelated to the resident clone in the unit or unrelated to the burn unit.ConclusionsThe diffusion assay developed herein detects differences in behaviour against antimicrobials between tested strains and a reference population. The method could be proposed for use in semi-routine practice of medical microbiology.

Peripheral Venous Catheter and Bloodstream Infection Caused by Pseudomonas aeruginosa after a Contaminated Preoperative Shower

was reduced in the presence of organic load (Figure 1). On patient wards, application of Sterilox HG resulted in significant reductions in total aerobic and facultative bacterial counts (mean CFU, 39 vs 0.73; P = .0003) and in positive C. difficile cultures (8/66 [12%] vs 0/66; P = .006). Spraying of Sterilox HG on sets of equipment was simple and required only approximately 15 seconds per application. Application of Sterilox HG did not result in production of noticeable noxious fumes but was described as producing an odor similar to that of swimming pool water. There were no reported complaints from nursing staff or patients.

Impact de l'environnement sur les microbiotes : focus sur l'hospitalisation et les microbiotes cutanés et chirurgicaux

Resume Les microbiotes bacteriens colonisent les differentes cavites du corps humain et remplissent des fonctions essentielles. Ils constituent des ecosystemes complexes dont l’equilibre est constamment deplace selon les conditions locales et environnementales. Il en resulte des variations de composition pouvant quelquefois evoluer vers des dysbioses, parfois generatrices de processus pathologiques. Les facteurs exterieurs influent particulierement sur les microbiotes les plus exposes, tels que le microbiote cutane. Du fait des nombreuses pressions medicales et medicamenteuses, l’hopital constitue un environnement particulier pouvant modifier les ecosystemes bacteriens aussi bien a l’echelle individuelle (microbiotes des patients et des soignants) qu’a l’echelle collective (ecosystemes des services). En chirurgie notamment, les multiples pressions antibiotiques, antiseptiques et traumatiques liees a la prise en charge des patients provoquent des perturbations microbiotiques qui semblent importantes a considerer dans la physiopathologie des infections du site operatoire.

Dynamics of the surgical microbiota along the cardiothoracic surgery pathway

Human skin associated microbiota are increasingly described by culture-independent methods that showed an unexpected diversity with variation correlated with several pathologies. A role of microbiota disequilibrium in infection occurrence is hypothesized, particularly in surgical site infections. We study the diversities of operative site microbiota and its dynamics during surgical pathway of patients undergoing coronary-artery by-pass graft (CABG). Pre-, per-, and post-operative samples were collected from 25 patients: skin before the surgery, superficially and deeply during the intervention, and healing tissues. Bacterial diversity was assessed by DNA fingerprint using 16S rRNA gene PCR and Temporal Temperature Gel Electrophoresis (TTGE). The diversity of Operational Taxonomic Units (OTUs) at the surgical site was analyzed according to the stage of surgery. From all patients and samples, we identified 147 different OTUs belonging to the 6 phyla Firmicutes, Actinobacteria, Proteobacteria, Bacteroidetes, Cyanobacteria, and Fusobacteria. High variations were observed among patients but common themes can be observed. The Firmicutes dominated quantitatively but were largely encompassed by the Proteobacteria regarding the OTUs diversity. The genera Propionibacterium and Staphylococcus predominated on the preoperative skin, whereas very diverse Proteobacteria appeared selected in peri-operative samples. The resilience in scar skin was partial with depletion in Actinobacteria and Firmicutes and increase of Gram-negative bacteria. Finally, the thoracic operative site presents an unexpected bacterial diversity, which is partially common to skin microbiota but presents particular dynamics. We described a complex bacterial community that gathers pathobionts and bacteria deemed to be environmental, opportunistic pathogens and non-pathogenic bacteria. These data stress to consider surgical microbiota as a “pathobiome” rather than a reservoir of individual potential pathogens.

Atypical Pneumonia Linked to Community-Acquired Staphylococcus aureus Cross-Transmission in the Nursery

We report the observation of a necrotizing pneumonia due to methicillin-resistant Staphylococcus aureus harboring the Panton-Valentine leukocidin-encoding gene in a previously healthy neonate, with favorable clinical outcome in spite of extensive radiologic lesions. The case was linked to a cluster of 3 neonates colonized by Panton-Valentine leukocidin-producing, methicillin-resistant S. aureus through cross-transmission in the nursery, underlining the need to comply with standard infection control precautions in the maternity ward.