Aspects épidémiologiques de Staphylococcus aureus résistant à la méticilline dans un centre hospitalier de taille moyenne

Objective – The aim of this study was to assess the incidence of colonization/infection by methicillin-resistant Staphylococcus aureus (MRSA) in our hospital.Method – For two months, cases of MRSA colonization or infection were monitored prospectively. Antibiotic susceptibility patterns and molecular methods were used to type the isolated strains. Morbidity was determined from the incidence of patients colonized/infected by MRSA, according to the type of ward.Results – The overall incidence of patients colonized/infected by MRSA was 1.22%. Incidence depended on the type of ward; it was 1.56 per thousand days of hospitalization in short-term care wards, and 1.65 per thousand days of hospitalization in long-term care wards. MRSA skin colonization or wound infection was most frequently observed (53.1%). Chromosomal DNA macro restriction analysis, with SmaI by pulsed-field gel electrophoresis, revealed that some epidemic MRSA clones were widespread. Most of the 32 MRSA isolates (78.2%) were closely related, and among these strains, 96% displayed the same antibiotype. Community-acquired MRSA accounted for 25% of the MRSA colonization/infection cases. Nevertheless, when considering significant factors of persistent carriage, true community-acquired MRSA cases only accounted for 6.25% of all cases.Conclusion – Computer-triggered warnings in the patient's file, might contribute to the early detection of previously colonized or infected patients readmitted to the hospital.     

Fort pourcentage de souches de Staphylococcus aureus résistantes à la méticilline au CHU de Lomé (Togo)

Objectives – The authors had for aim to estimate the clinical site distribution of Staphylococcus aureus infections according to methicillin susceptibility and to determine the resistance to antibiotics.Material and methods – The study was carried out in the bacteriology laboratory of the University hospital (CHU Tokoin) in Lomé (Togo). About 742 S. aureus isolates were collected from 1997 to 1999. S. aureus isolation and identification were performed by standard methods. We used the disk method for the susceptibility test.Results – Around 67% of the S. aureus isolates were resistant to methicillin (MRSA = 67%). We observed several clinical aspects of S. aureus infections (>13). The percentage of MRSA was 50.8% among outpatients, 61.5% in pediatrics, 65.4% in medical units, and 87.7% in surgery. The percentage of resistance among MRSA for other antibiotics was: Rifampicin = 2%, Ciprofloxacin = 6.1%, Pristinamycin = 18.4%, Gentamicin = 19.8%, Erythromycin = 23.3%, Cotrimoxazole = 34.5%, Chloramphenicol = 36.6%, Lincomycin = 51.9%, Doxycyclin = 72.2%.     

Apport du kit Servitex Staphylocoque MRSA® dans le diagnostic rapide des souches de Staphylococcus aureus résistantes à la méticilline

Objective – An efficient initial antibiotic therapy for patients infected by methicillin resistant Staphylococcus aureus (MRSA) improves the health prognostic in term of morbidity and mortality. The authors wanted to assess the Servitex Staphylocoque MRSA test^®: a rapid (30 min) slide latex agglutination test used to determine methicillin resistance by detecting PBP 2a in Staphylococcus aureus.Method – Sixty five Staphylococcus aureus clinical isolates (53 heterogeneous methicillin resistant S. aureus, nine homogeneous methicillin resistant S. aureus, three methicillin susceptible strains), and two control strains (ATCC 25923, CIP 6525) were studied. These strains were tested by various methods: agar diffusion with 5 μg oxacillin disk tested both at 30°C on Mueller-Hinton medium and at 37°C and on Mueller-Hinton plus 4% NaCl; latex test Servitex MRSA^® tested with two inocula (5 and 10 cfu); and dot blot hybridization with the mecA probe.Results – The methods used to detect methicillin resistance were of similar sensitivity except for the latex test Servitex MRSA^® with a 5 cfu inoculum which detected resistance in only 87% of the cases. A 100% accuracy was restored if a 10 cfu inoculum was used for the latex test Servitex MRSA^®.Comments – Standardization of the initial inoculum appears to be necessary for the reliable detection of methicillin resistance by the latex test. In a clinical laboratory, the use of the latex test is thus restricted to very specific cases if results are to be obtained in less than 48 hours.     

État des lieux et évaluation de la surveillance des Staphylococcus aureus résistants à la méticilline (SARM) : PMSI versus surveillance Raisin

BackgroundThe surveillance of methicillin-resistant Staphylococcus aureus (MRSA) is a national priority. The rate of MRSA infections is one of six indicators tracked by the Department of Health. Since 2002, the French institute for public health surveillance (InVS) has monitored MRSA infections to estimate incidence density. Today, the use of the French administrative database (PMSI) could facilitate this surveillance. The aim of this study was to compare MRSA incidence density computed at a national level using PMSI databases with the results from the InVS taken as the reference.MethodsPMSI databases for the years 2006 to 2009 were used. The reference results were those published by the InVS from 2006 to 2009. MRSA density defined as the number of MRSA infections recorded per year over 1000 hospitals stays was computed. It was then compared with the MRSA incidence density measured by InVS. The time course of MRSA incidence in the PMSI records was modeled using a Poisson regression.ResultsThe incidence density measured by the InVS was higher than the MRSA density computed using the PMSI, but this difference appeared to decrease over time. The PMSI density/InVS MRSA incidence density ratio was 0.8% in 2006 and about 9.2% in 2009. We observed inverted trends with a growing trend in MRSA density identified by the PMSI. Furthermore, the year of study was significantly associated with incidence density (P = 0.01).ConclusionUsing PMSI data as an additional source of information in the hospital MRSA surveillance process makes it possible to detect and analyze patient repeats at the regional and national levels with linkage facilities. Estimation of incidence density for hospitals not participating to this surveillance system will be the next step.     

Prise en charge de la sarcopénie en réanimation

Muscle atrophy in ICU is systematic and responsible for multiple functional consequences. The causes are multiple, including in particular the effect of bed rest, impaired innervation, hormonal imbalances, and reduced efficiency of energy substrates. The determination of the development of sarcopenia can be achieved by repeated clinical assessment, as urinary 3-methylhistidine/créatinine ratio, reflecting the degradation of myofibrillar proteins. Therapeutically, in addition to measures of metabolic and nutritional modulation, an active or passive mobilization is recommended.     

Gestion des complications digestives de la nutrition entérale en réanimation

The digestive complications of enteral nutrition (EN) are frequent in critically ill patients. However, the complications clinically significant, with major discomfort, with prognosis impairment, or increasing nurse's workload, are finally less frequent. On the other hand, they are often associated with enteral discontinuation and undernutrition. The understanding of the EN-related gastroparesis and diarrhoea mechanisms is essential in their control. Protocols implementation, adapted to every intensive care unit, discussed with the crew, is the only means to limit these complications and to reduce the opportunities to interrupt EN.     

Résistance aux antibiotiques de Staphylococcus aureus isolé des infections communautaires et hospitalières à Casablanca

Objective – The resistance patterns to 11 antibiotics of 156 community acquired and 189 nosocomial Staphylococcus aureus isolated during two periods at the IbnRochd University Hospital of Casablanca were determined.Material and methods – Detection of methicillin resistance was performed using the agar screen technique with 6 mg/L of oxacillin and resistance to other antibiotics was studied using the NCCLS disk diffusion method.Results – Methicillin resistance levels were 1.9% and 45% for community and nosocomial isolates respectively. MRSA isolates were multiresistant (gentamicin 84.7%, cotrimoxazole 51.2%, erythromycin 44.7%, fusidic acid 45.9%, ciprofloxacin 83.5%). MRSA isolates were mostly isolated from the surgery department (46.2%) during the first period and from the ICU (61%) during the second period. MRSA were isolated mainly from blood (34.1%), pus (34.6%), and respiratory tract (27.1%).     

Colonisation par bactéries multirésistantes à l'admission en service de réanimation

Objectives – To estimate the prevalence of nasal and anal carriage of multiresistant bacteria on admission in ICU and to identify patients with high risk of colonization.Method – We used a prospective observation study on 163 patients admitted over six months.Results – 9.8% of patients were MRB carriers on admission. Determining a previous antibiotic therapy in the previous three months was possible in 57% of the cases. Items with a significant relative risk (RR) of colonization were: hospitalization in the previous year (RR = 6.11; p < 0.01), treatement by antibiotics within the last three months (RR = 3.64; p < 0.05), living or working in an institution (RR = 6.68; p < 0.001).Comments – The patients living or working in an institution were identified as having a high risk for colonization (56.2% carriers). The patients hospitalized in the previous year were not specific enough (53.4%) but 87.5% of carriers were hospitalized for more than one month.     

Automatisation du contrôle strict de la glycémie en réanimation

Since the publication of the first Leuven study highlighting the association between tight glycemic control and reduced mortality in surgical intensive care patients, many protocols have been developed and used in clinical practice. Recent multicentrer studies that did not find the positive results of the landmark study lead us to question the methods used to achieve tight glycemic control. New computerized protocols must take in account the nurse workload, the risk for severe hypoglycaemia and the unnecessary variation in clinical care. There are two opposite approaches: the “closed-loop” approach coming from research in diabetes but necessitating reliable near-continuous glucose sensors and involving legal and regulatory concerns and the “human in the loop” approach easier to implement in clinical practice. Whatever the approach, a standardized multifactorial evaluation in order to select the most efficient computer protocols is required.     

Place de la calorimétrie indirecte et des formules estimant la dépense énergétique des malades de réanimation

Energy expenditure in critically ill patients is variable according to initial injury, severity, nutritional status and comorbidities. Hypermetabolism progressively increases over the first week following the onset of sepsis. And many other determinants of energy expenditure (pharmacotherapy, mechanical ventilation, nutrition) are described. It is very difficult to estimate energy expenditure daily in critically ill patients. Of importance, a cumulative negative caloric balance of more than 10 000 kcal is associated with a worsened outcome in severely ill patients. And overfeeding could also affect outcome in intensive care units. Predictive equations for estimating energy requirements were developed with anthropometric parameters, like Harris-Benedict equation, or with specific or ventilatory parameters, like Ireton-Jones equation. Finally, indirect calorimetry is considered to be the gold standard for determining energy expenditure in individuals. It could be used for “extreme” situations like in morbidly obese, in post-injury period, or with new therapeutics. However, complex access to indirect calorimetry restricts its use. International guidelines (caloric requirements between 20–30 kcal/kg BW per day) could be applied in 75 % of our patients.