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J Etienne

Publications and source records attributed to J Etienne.

At least 37 records · Page 2Linked to original sources
PubMed2003

Relationship between haemolytic and sphingomyelinase activities in a partially purified beta-like toxin from Staphylococcus schleiferi.

beta-Toxins of staphylococcal species possess dual activity in that they can both lyse erythrocytes (by 'hot-cold' lysis) and catalyse hydrolysis of membrane-associated sphingomyelin. However, the precise relationship between these two activities has not been extensively studied. We have partially purified a beta-like toxin from culture supernatants of Staphylococcus schleiferi N860375 which exhibits both 'hot-cold' lysis of erythrocytes and neutral sphingomyelinase activities. This toxin has a strong preference for sheep erythrocytes, the membranes of which are rich in sphingomyelin. Kinetic analysis suggests that haemolysis and sphingomyelinase activities are very closely associated obeying identical Michaelis-Menten kinetics. However, pre-treatment with antibodies to Staphylococcus aureus beta-toxin, Ca(2+), dithiothreitol and phenylmethylsulfonyl fluoride appear to inhibit sphingomyelinase activity significantly more strongly than haemolysis while Mg(2+) activates sphingomyelinase activity more strongly than haemolysis. We attribute these effects to differences in binding properties in the two assays. Micropurification by both sphingosylphosphocholine-agarose affinity chromatography and preparative electrophoresis revealed that the 34-kDa toxin associates non-covalently with individual proteins.

Bacterial Toxins↗
PubMed2003

Repeat capture-recapture studies as part of the evaluation of the surveillance of Legionnaires' disease in France.

We evaluated improvements made to the mandatory notification surveillance system for Legionnaires' disease in France by estimating its sensitivity in 1995 and 1998 using a repeat capture-recapture method. A case of Legionnaires' disease was defined as a person treated for pneumonia in whom legionella had been detected. Patient details were collected from (1) mandatory notifications; (2) the National Reference Centre for Legionella; (3) a postal survey of all hospital laboratories. The three sources were cross-matched and 715 individual cases were identified. A log-linear model, which included an interaction term between mandatory notifications and both the National Reference Centre and Laboratory sources, provided an estimated total of 1124 cases (95% CI 973-1275) in 1998, a twofold increase compared with 1995. The sensitivity of the surveillance system improved from 10% in 1995 to 33% (95% CI 29-38%) in 1998. Capture-recapture methods are important tools in the evaluation of surveillance systems.

Data Collection↗
PubMed2003

In vitro antibacterial activity of moxifloxacin against hospital isolates: a multicentre study.

OBJECTIVE: To evaluate the in vitro antibacterial activity of moxifloxacinin in comparison to that of other fluoroquinolones (ciprofloxacin, ofloxacin and trovafloxacin). METHODS: A total of 2,196 strains was collected in 11 French hospitals in 1998. Minimum inhibitory concentrations (MICs) (mg/L) were determined by agar dilution and agar diffusion was performed with 5-microg discs. Internal quality control was carried out with genetically defined strains. RESULTS: MIC50s and MIC90s of moxifloxacin against nalidixic acid (NAL)-susceptible Enterobacteriaceae (n = 663) were 0.12 and 0.5. As for other quinolones, the activity of moxifloxacin (4-32) was reduced against NAL-intermediate and NAL-resistant strains (n = 222). MIC50s and MIC90s of moxifloxacin were 2 and 4 for ciprofloxacin-susceptible P. aeruginosa (n = 128); moxifloxacin had no activity against ciprofloxacin-resistant strains (n = 56). The activity of moxifloxacin was maintained against NAL-susceptible A. baumannii (n = 11; 0.032-0.125), but reduced against NAL-resistant strains (n = 30; 16-32). H. influenzae (n = 97) and M. catarrhalis (n = 40) were inhibited by low concentrations (0.03-0.06 and 0.06-0.25, respectively). Moxifloxacin had better activity (0.06-0.12) than other tested quinolones against methicillin-susceptible S. aureus strains (n = 110); ciprofloxacin-resistant strains (n = 85) (2-8) were usually methicillin-resistant. Moxifloxacin was moderately active against enterococci (n = 149) (E. faecalis: 0.5-16; E. faecium: 2-4). Streptococci (n = 194) and pneumococci (n = 136), including 70 penicillin G-intermediate or G-resistant strains, were inhibited by low concentrations (0.25-0.5 for each species). Based on the regression curve, tentative zone diameter breakpoints could be > or =21 and <18 mm for MIC breakpoints of < or =1 and >2 mg/L, respectively. CONCLUSIONS: While retaining activity against Enterobacteriaceae, moxifloxacin was moderately active against P. aeruginosa. Its activity was inferior to that of ciprofloxacin for these species. This study confirmed the comparatively high in vitro activity of moxifloxacin against Gram-positive cocci and other pathogens isolated from community-acquired respiratory tract infections.

Anti-Infective Agents↗
PubMed2002

Pan-European study on culture-proven Legionnaires' disease: distribution of Legionella pneumophila serogroups and monoclonal subgroups.

This pan-European study included unrelated strains of Legionella pneumophila obtained from 1335 cases of Legionnaires' disease. The isolates were serotyped into the serogroups 1 to 15 by monoclonal antibodies (MAb) and/or rabbit antisera. Additionally, MAb subgrouping was undertaken for isolates belonging to serogroups 1, 4, and 5. Monoclonal types of serogroup 1 were subdivided as having, or not having, the virulence-associated epitope recognized by the MAb 3/1 (Dresden Panel). This epitope is not present on strains belonging to any other serogroups. Taking all Legionella incidents together, MAb 3/1-positive cases were most frequent (66.8%); 11.7% of the isolates belonged to MAb 3/1-negative serogroup 1 subgroups and 21.5% to other serogroups, with serogroups 3 and 6 predominating. Among all serotypes discriminated in this study, monoclonal subtype Philadelphia was the most frequent. If categories of infection were considered, the proportion of MAb 3/1-negative strains differed significantly ( P<0.0005) between community-acquired cases (139/510; 27.3%) and travel-associated (42/295; 14.2%) or hospital-acquired infections (176/329; 53.5%). Moreover, taking distribution in different European areas into account, the proportion of MAb 3/1-negative strains was significantly higher in the Scandinavian region than in the Mediterranean countries or the UK for both community-acquired (48.7% vs. 18.6% or 12.0%; P<0.0005) and nosocomial cases (87.7% vs. 32.6% or 52.6%; P</=0.0007).

Animals↗
PubMed2002

Designation of the European Working Group on Legionella Infection (EWGLI) amplified fragment length polymorphism types of Legionella pneumophila serogroup 1 and results of intercentre proficiency testing Using a standard protocol.

The utility of amplified fragment length polymorphism (AFLP) analysis as a genotyping method for the epidemiological typing of Legionella pneumophila serogroup 1 has been previously demonstrated. This study (i). reports recommendations for the designation of the European Working Group on Legionella Infections (EWGLI) AFLP types, (ii). describes the EWGLI AFLP types identified for the 130 strains in the EWGLI culture collection, and (iii). reports the results of a newly introduced international programme of proficiency testing. Following preliminary analysis of 20 epidemiologically unrelated isolates, 16 major AFLP types were identified. A coded proficiency panel, comprising 12 additional isolates representing 9 of these 16 AFLP types, was sent to 17 centres in 14 European countries where it was analysed following a previously determined standard protocol. The identity of each coded strain (recorded as AFLP type 001-016 or untypeable) was determined by participants with reference to these 16 AFLP types, either visually or using gel analysis software where available, and reported to the coordinating centre. Nine of the 12 strains, including an epidemiologically related pair and two pairs of unrelated isolates of the same type, were correctly identified to the correct AFLP type by all or all but one of the participants. Seven laboratories correctly identified all 12 isolates, and a further seven laboratories correctly identified 11. Type identification scores ranged from 75% (1 centre), 83% (2 centres), and 92% (7 centres) to 100% (7 centres). The AFLP method as described is robust and rapid and allows the genotypic comparison of isolates of Legionella pneumophila between different testing centres without the need for exchange of the strains studied.

Bacterial Typing Techniques↗
PubMed2002

[The epidemiology of toxemic infections caused by Staphylococcus aureus in an intensive care setting].

The mission of the National Reference Centre for Staphylococcal Toxemia (CNRTS) is to participate in the epidemiological surveillance of staphylococcal toxemia in France. As these syndromes do not have to be declared, the data collected remain incomplete. Comparison of the clinical data with the results of molecular analysis of the causal strains has nonetheless enabled advances in our understanding of the present-day epidemiology of these syndromes, a clearer knowledge of their pathophysiology and isolation of a hitherto unknown entity, staphylococcal necrotizing pneumonia.

Bacterial Toxins↗
PubMed2002

Isolation and characterization of a protein-tyrosine kinase and a phosphotyrosine-protein phosphatase from Klebsiella pneumoniae.

Two proteins of Klebsiella pneumoniae, termed Yor5 and Yco6, were analyzed for their capacity to participate in the reversible phosphorylation of proteins on tyrosine. First, protein Yco6 was overproduced from its specific gene and purified to homogeneity by affinity chromatography. Upon incubation in the presence of radioactive adenosine triphosphate, it was found to effectively autophosphorylate. Two-dimensional analysis of its phosphoamino acid content revealed that it was modified exclusively at tyrosine. Second, protein Yor5 was also overproduced from the corresponding gene and purified to homogeneity by affinity chromatography. It was shown to contain a phosphatase activity capable of cleaving the synthetic substrate p-nitrophenyl phosphate into p-nitrophenol and free phosphate. In addition, it was assayed on individual phosphorylated amino acids and appeared to dephosphorylate specifically phosphotyrosine, with no effect on phosphoserine or phosphothreonine. Such specificity for phosphotyrosine was confirmed by the observation that Yor5 was able to dephosphorylate protein Yco6 previously autophosphorylated. Together, these data demonstrate that similarly to other bacterial species including Acinetobacter johnsonii and Escherichia coli, the cells of K. pneumoniae contain both a protein-tyrosine kinase and a phosphotyrosine-protein phosphatase. They also provide evidence that this phosphatase can utilize the kinase as an endogenous substrate, which suggests the occurrence of a regulatory mechanism connected with reversible protein phosphorylation on tyrosine. Since Yco6 and Yor5 are both involved in the synthesis of capsular polysaccharide and since capsules are essential to the virulence of K. pneumoniae, we suggest that reversible protein phosphorylation on tyrosine may be part of the cascade of reactions that determine the pathogenicity of bacteria.

Amino Acid Sequence↗
PubMed2002

Clinically and histologically silent Q fever endocarditis accidentally diagnosed by PCR.

A case of Q fever endocarditis was diagnosed in a patient with no sign of active endocarditis by performing PCR targeting eubacterial 16S rDNA on the resected mitral valve. The diagnosis was confirmed by detection of high levels of anti-Coxiella burnetti antibodies, positive immunohistologic analysis of the valve tissue with specific antibodies and culture of C. burnetti from the valve tissue. As this patient had an unexplained aggravation of valve dysfunction, we recommended routine serologic testing for C. burnetti to allow the diagnosis of Q fever endocarditis at a very early stage.

Adult↗
PubMed2001

[Epidemiological context: microbiological value of Synercid].

MECHANISM OF ACTION: Synercid', an antibiotic designed around the concept of molecular synergism, is composed of 70% dafopristin or spectrogramin A and 30% quinupristin or spectrogramin B. First, dafopristin binds to the ribosomal 50S unit changing the conformation of the ribosome. This increases the affinity of quinupristin that in turn binds to the bacterial ribosome. This double binding interrupts protein synthesis and blocks bacterial growth. ACTIVITY: In vitro, Synercid is particularly active against Gram positive cocci, irrespective of the strain's resistance phenotype. It is notably active against meti-sensitive and meti-resistant S. aureus, S. pneumoniae, S. pyogenes and Enterococcus faecium. MECHANISMS OF RESISTANCE TO MACROLIDES/LINCOSAMIDES/STREPTOGRAMINS: The most frequently encountered mechanism is a modification of the ribosomal target. Two other mechanisms can also be operating: enzyme inactivation or efflux phenomenon. Another mechanism of resistance, LSA phenotype, remains poorly understood. Only a very small proportion of the patients are concerned by resistance (9 patients in a study enrolling 880 patients).

Anti-Bacterial Agents↗
PubMed2001

Cardiac and hemodynamic effects of intravenous dofetilide in patients with heart failure.

This study assesses the effects of dofetilide, a new selective Ikr blocker with class III properties, on left ventricular function and hemodynamics of heart failure and compares these effects with those of placebo and amiodarone. Because available antiarrhythmic drugs may depress myocardial performance, an invasive hemodynamic study was performed to assess the safety of this agent. Hemodynamic and angiographic data were obtained at baseline and after 30 minutes of double-blind infusion of dofetilide (8 microg/kg; n = 12), placebo (n = 12), or amiodarone (5 mg/kg; n = 6) in heart failure patients (New York Heart Association class II or III, ejection fraction <35%). Intravenous dofetilide preserved the inotropic indexes and the end-systolic volume index despite a slight but significant decrease in heart rate, whereas intravenous amiodarone increased end-diastolic and end-systolic volume indexes. Amiodarone induced a negative inotropic effect illustrated by a rightward shift of the pressure-volume loop and a reduction in pressure-derived indexes of contractility. Intravenous dofetilide acutely prolonged QT interval more than intravenous amiodarone; however, dofetilide did not slow the overall relaxation rate and reduced QT dispersion. In an acute setting, compared with intravenous amiodarone, intravenous dofetilide preserves cardiac function offering a hemodynamic advantage to treat arrhythmias in patients with impaired left ventricular function.

Adult↗
PubMed2001

Phage conversion of Panton-Valentine leukocidin in Staphylococcus aureus: molecular analysis of a PVL-converting phage, phiSLT.

Staphylococcal Panton-Valentine leukocidin (PVL) is an important virulence factor, which causes leukocytolysis and tissue necrosis. Our previous report on the existence of the PVL genes (lukS-PV and lukF-PV) on the genome of prophage phiPVL in the Staphylococcus aureus strain V8 suggested the horizontal transmission of PVL genes by temperate bacteriophage among S. aureus (Kaneko, et al., 1998. Gene 215, 57-67). Here, we demonstrated the phage conversion of S. aureus leading to the production of PVL by discovery of a novel PVL-carrying phage, phiSLT (Staphylococcal Leukocytolytic Toxin) from a clinical isolate of S. aureus. phiSLT was able to lysogenize several clinical isolates of PVL-negative S. aureus strains as well as strain RN4220 at the conserved 29-bp sequence (attB) and all the lysogenized S. aureus strains had the ability to produce PVL. phiSLT had an elongated head of about 100x50 nm and a flexible tail of 400 nm long, that was quite different from phiPVL which had an isometric hexagonal head of about 60 nm diameter. The linear double-stranded phiSLT genome comprised 42,942 bp with 29-bp attachment core sequences and contained 62 open reading frames. Only 6.4 kbp region containing lysis cassette, PVL genes, attP, integrase, and orf204 of phiSLT was identical to that of phiPVL, while other regions were different from those of phiPVL. Thus, it can be concluded that PVL genes are carried by different temperate phages, which have the same attachment site.

Amino Acid Sequence↗
PubMed2001

Myocarditis, a rare but severe manifestation of Q fever: report of 8 cases and review of the literature.

Myocarditis has only rarely been described as a manifestation of acute Q fever. Among our series of 1276 patients in whom acute Q fever was diagnosed during 1985--1999, myocarditis was diagnosed in 8. Two patients (25.0%) developed cardiac symptoms during the course of interstitial pneumonia, 2 (25.0%) initially presented with unexplained fever, and 1 (12.5%) presented with febrile cutaneous rash. In 3 patients, cardiac symptoms were inaugural: 1 patient experienced heart failure, and 2 experienced precordial pain. Dilated cardiomyopathy was documented in 7 patients, and 2 (1 of whom had undergone heart transplantation) died despite therapy. In addition, 1 patient was scheduled for heart transplantation because of cardiac insufficiency. When the patients in this study were compared with 32 control patients with acute Q fever, no specific epidemiological or clinical features were associated with this disease except worse prognosis (P=.006). Moreover, among the 12 patients from our series who died as a result of acute Q fever, 2 patients, who were significantly younger than the other 9 patients (P=.03), had myocarditis. Our study highlights the severity of Coxiella burnetii myocarditis.

Adolescent↗
PubMed2001

The surgical management of congenital liver cysts.

BACKGROUND: Most series that report the results of surgical treatment for congenital liver cysts focus more on the technical aspects of the operation than on the late outcome of these patients. In this paper, we emphasize the importance of appropriate patient selection and adequate surgical technique for successful long-term outcome. METHODS: Twenty-four consecutive patients with congenital liver cysts were selected for surgical treatment. According to our own classification, 13 patients had simple liver cysts, nine had multicystic liver disease, and two had type I polycystic liver disease. All of these patients were treated by the fenestration technique. An open approach was used for five patients (group 1) treated between 1984 and 1990. In 19 patients (group 2) treated since 1991, a laparoscopic approach was used. The incidence of complicated liver cysts was 40% in group 1 and 68% in group 2. RESULTS: There were no treatment-related deaths in this series. The mean postoperative hospital stay was significantly shorter for patients who underwent successful laparoscopic fenestration (p < 0.05). In the open group (group 1), there were no postoperative complications, and all patients were alive and free of symptoms during a mean follow-up of 130 months, without any sign of cyst recurrence. In the laparoscopic group (group 2), four patients were converted to open surgery. One of these patients had an inaccessible posterior cyst; another had bile within the cystic cavity. A further two cases had complicated liver cysts with an uncertain diagnosis between congenital and neoplastic cysts. Four patients (21%) developed peri- or postoperative complications. During a mean follow-up time of 38.5 months, none of the patients with simple liver cysts incurred late symptoms or signs of cyst recurrence. In the six patients with multicystic liver disease, one developed disease-related cyst progression (17%) and required reoperation. One of the two patients with type I polycystic liver disease (50%) developed asymptomatic disease-related cyst progression. CONCLUSIONS: When patients are carefully selected and a proper surgical technique is employed, excellent long-term results with a low morbidity rate can be achieved in patients with congenital liver cysts. Patients with multicystic liver disease or type I polycystic liver disease are more prone to late cyst recurrence. A tailored approach is thus indicated for patients with congenital liver cystic disease. However, the laparoscopic approach appears to be the gold standard for the treatment of highly symptomatic or complicated simple liver cysts.

Adult↗
PubMed2001

egc, a highly prevalent operon of enterotoxin gene, forms a putative nursery of superantigens in Staphylococcus aureus.

The recently described staphylococcal enterotoxins (SE) G and I were originally identified in two separate strains of Staphylococcus aureus. We have previously shown that the corresponding genes seg and sei are present in S. aureus in tandem orientation, on a 3.2-kb DNA fragment (Jarraud, J. et al. 1999. J. Clin. Microbiol. 37:2446-2449). Sequence analysis of seg-sei intergenic DNA and flanking regions revealed three enterotoxin-like open reading frames related to seg and sei, designated sek, sel, and sem, and two pseudogenes, psi ent1 and psi ent2. RT-PCR analysis showed that all these genes, including seg and sei, belong to an operon, designated the enterotoxin gene cluster (egc). Recombinant SEG, SEI, SEK, SEL, and SEM showed superantigen activity, each with a specific V beta pattern. Distribution studies of genes encoding superantigens in clinical S. aureus isolates showed that most strains harbored such genes and in particular the enterotoxin gene cluster, whatever the disease they caused. Phylogenetic analysis of enterotoxin genes indicated that they all potentially derived from this cluster, identifying egc as a putative nursery of enterotoxin genes.

3' Untranslated Regions↗
PubMed2001

Molecular techniques open up new vistas for typing of coagulase-negative staphylococci.

Several methods were used to type 64 clinical isolates of coagulase-negative staphylococci (CNS) derived from hospitals in Morocco. The clinical isolates originated principally from blood cultures and wound sources. These isolates provided the opportunity to substantially compare the proficiency of developing molecular techniques with conventional phenotypic tests for use in the identification of clinical staphylococci. The following molecular methods were examined: Utility ribotyping analysis (Ribotyping); PCR analysis performed with 16S-23S ribosomal-DNA intergenic spacer (ITS-PCR); PCR-based random amplified polymorphic DNA (RAPD). The results obtained by the molecular techniques were contrasted to those of conventional phenotypic tests. Conventional phenotypic tests allowed the outright recognition of the majority of isolates (50/64). These 50 isolates were subdivided into 33 novobiocin-susceptible and 17 novobiocin-resistant strains of CNS. However, 2 other novobiocin-susceptible and 12 other novobiocin-resistant isolates remained unclassified by these tests. There was a good agreement between the conventional phenotypic tests and RAPD for the 33 novobiocin-susceptible isolates. But, the RAPD technique permitted the assignment of the two unidentified novobiocin-susceptible isolates to the Staphylococcus hominis species. A complete correlation was obtained between the three molecular tools for recognition of the 12 novobiocin-resistant isolates that were not identified by phenotypic typing; these were in fact identified as 5 Staphylococcus cohnii and 4 Staphylococcus equorum. Three isolates remained unidentified by all three systems of molecular techniques.

Bacterial Proteins↗
PubMed2001

[Severe staphylococcal pneumonia in children].

Between 1986 and 1999, 8 cases of severe pneumonia due Staphylococcus aureus strains producing the Panton and Valentine leukotoxin (PVL) were referred to the French reference centre for staphylococcal toxaemia. All but one patient were children and to determine the clinical features of these pneumonia we conducted a prospective surveillance during 1999. Staphylococcal pneumonia was defined according to usual standards. All the strains were tested for the gene coding PVL, the cases associated with PVL positive strains were considered as study group. Nosocomial pneumonia were excluded. 52 cases were referred and 16 were PVL positive. These pneumonia occurred in younger patients (median age = 14.8 vs. 70.1) which were previously healthy (40% of underlying disease in control) Remarkable features were the presence of viral infection in the preceding day (75% vs. 9%), the frequency of shock (81% vs. 53%), respiratory distress (75% vs. 53%) and hemoptysia (38% vs. 3%). Leucopenia was present in 79% of cases. Mortality was higher in the PVL group (75% vs. 47%). Severe staphylococcal pneumonia with shock, leucopenia, hemoptysia and high mortality rate have been previously described in children and young adults. We established the relationship between this syndrome and the PVL production by S. aureus. We believe that viral infection constitute the prerequisite altering the respiratory epithelium which secondary allows S. aureus invasion. The necrotizing action of the PVL leads to the massive haemorrhagic necrotic pneumonia. Staphylococcal necrotizing pneumonia is a new entity which frequency is probably underestimated. Further studies are needed to determinate the prognosis factors, the role of S. aureus carriage and of viral infections. The description of this new syndrome could lead to changes in the management of staphylococcal pneumonia in children.

Carrier State↗