Incidence of class A extended-spectrum beta-lactamases in Champagne-Ardenne (France): a 1 year prospective study.

OBJECTIVES: To assess the frequency and diversity of extended spectrum beta-lactamases (ESBLs) in the Champagne-Ardenne region France, and to identify genetic elements associated with the bla(CTX-M) genes. METHODS: During 2004, all the non-duplicate isolates of Pseudomonas aeruginosa and Acinetobacter baumannii resistant to ceftazidime and of Enterobacteriaceae intermediate or resistant to ceftazidime and/or cefotaxime, screening samples excluded, were collected in 10 public hospitals and 3 private clinics. bla genes were sequenced and bla(CTX-M) environment characterized by PCR mapping. RESULTS: In Enterobacteriaceae (138/21 861; 0.6%), ESBLs were predominantly TEM-24 (n = 52; 37.7%) and CTX-M-15 (n = 37; 26.8%). Three new enzymes were identified, CTX-M-61 (CTX-M-1 group), TEM- and SHV-type. A. baumannii (n = 5) produced VEB-1 and P. aeruginosa (n = 2) SHV-2a. ISEcp1 was detected in 22/27 strains, disrupted in 7 of them. The IS903-like element was downstream of bla(CTX-M-14) and bla(CTX-M-16). ISCR1 was found upstream of bla(CTX-M-2) and bla(CTX-M-9), and ISCR1 and bla(CTX-M-2) were located on a sul1-type class 1 integron. In comparison with 2001-02, ESBL distribution among Enterobacteriaceae showed an increase in CTX-M-type (44.9% vs 3.7% P < 10(-7)) due to Escherichia coli CTX-M-15 and to the almost total disappearance of TEM-3 (0.9% vs 51.2%). E. coli was the most frequent species (50.0% vs 5.1% in 1998) despite a similar prevalence to that in 1998 (0.5% vs 0.2%). CONCLUSIONS: A careful detection of bla(CTX-M)-type spread to other species would help to anticipate clonal endemics such as those observed in Enterobacter aerogenes TEM-24.

[Sick sinus syndrome: comparative study of atrial and ventricular stimulation tests]. / Maladie du sinus: étude comparative des tests de stimulation auriculaire et ventriculaire.

Subjects with a ventriculo-atrial block and normal sinus function exhibit acceleration of the sinus rhythm during incremental right ventricular pacing; this acceleration is nor observed or is hardly visible in patients with sinus node dysfunction. Incremental right ventricular pacing up to 150/min was performed in 16 patients with ventriculo-atrial block (Group A) referred for investigation of sinus node dysfunction and the results compared with the classical tests of atrial pacing (Strauss'graph, atrio-sino-atrial conduction time, sinus node recovery time). The same tests were carried out in 19 patients without sinus node dysfunction (Group B). In the latter group, sinus rhythm exceeded 80/min during right ventricular pacing at 150/min and the rate increased with respect to the basal rhythm was always greater than 10/min. In Group A premature atrial pacing gave abnormal results in 4 cases, sinus node recovery times were abnormal in 15 cases, and rapid right ventricular pacing abnormal in all cases (sinus rhythm less than 80/min and/or rate increase of less than 10/min). There was no relation between the increased sinus node recovery time and the degree of rate increase during rapid ventricular pacing. Incremental right ventricular pacing, therefore, seems to be a new method of investigating sinus node function but complementary studies are required to determine its limitations, the exact mechanism and to try to widen its application to subjects without ventriculo-atrial block.

[Evaluation of cardiac function by external polygraphic recordings. Comparison with angiography]. / Evaluation de la fonction cardiaque au moyen d'enregistrements polygraphiques externes. Comparaison avec l'angiographie.

Good correlations have been reported between angiographic ejection fraction and indices of left ventricular function obtained by external polygraphic recordings. We studied 104 coronary or normal patients undergoing angiography within 24 hours of external polygraphic recordings. The angiographic ejection fraction was compared with three external indices in each case: the Weissler index (PEP/ET), the normalised derivation of a calibrated apex cardiogram (ds/dt/s) and the ejection fraction calculated from the apex cardiogram (EF apex). The angiographic ejection fraction was calculated after measuring left ventricular end diastolic and end systolic volumes in the 30 degrees RAO projection by a method derived from Dodge's. No correlation was found between the angiographic ejection fraction and any of the external indices. Analysis of our results and of those previously reported lead us to the following conclusions: --systolic time intervals are very sensitive to stress, imposing recording conditions which are difficult to meet in hospital surroundings, --a good quality apex cardiogram can only be obtained in a small percentage of patients, --the apex cardiogram reflects a mechanical phenomenon due to displacement of the apex beat and cannot therefore be assimilated to changes in cardiac volume, --the ds/dt/s index is difficult to calculate without a sophisticated computer. Therefore, these methods of external recording are not suitable for routine medical practice.