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A Andremont

Publications and source records attributed to A Andremont.

At least 19 recordsLinked to original sources
PubMed2005

[How should potential selection for bacterial antibiotic resistance be defined?].

Evolution of bacterial resistance to antibiotics could be better controlled if we knew how to define the potential of evolution of bacterial resistance towards a given antibiotic, prospectively. No unique method allows to do it. Pieces of answers can be obtained by using diverse methods using bacteriological, ecological pharmaco-epidemiological techniques and experimental models. Association of the results obtained with these various techniques is mandatory to understand the evolution potential of resistance towards a given antibiotic when it is used in the clinical setting.

Anti-Bacterial Agents↗
PubMed2005

Comment définir le potentiel de sélection de la résistance bactérienne aux antibiotiques ?

Evolution of bacterial resistance to antibiotics could be better controlled if we knew how to define the potential of evolution of bacterial resistance towards a given antibiotic, prospectively. No unique method allows to do it. Pieces of answers can be obtained by using diverse methods using bacteriological, ecological pharmaco-epidemiological techniques and experimental models. Association of the results obtained with these various techniques is mandatory to understand the evolution potential of resistance towards a given antibiotic when it is used in the clinical setting.

Journal Article↗
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

Candidemia in French hospitals: incidence rates and characteristics.

OBJECTIVE: To determine the incidence of candidemia in French hospitals. MATERIALS AND METHODS: A representative sample of 25 French hospitals [nine teaching hospitals (TH), ten general hospitals (GH) and six cancer referral centers (CRC)] was randomly selected. The incidence rates of candidemia per number of admissions and per patient-days of hospitalization were determined and extrapolated to the national level. RESULTS: From January 1, 1995 to December 31, 1995, the overall incidence rate per 1000 admissions was 0.29, ranging from 0.71/1000 in CRC, to 0.17/1000 in GH. The overall incidence for 1000 patient-days was 0.035 and the highest incidence was also observed in CRC (0.116/1000), followed by TH (0.052/1000). Candida albicans (53%) was the most common species isolated, a central venous catheter (26%) was the most common portal of entry and 50% of the candidaemic patients had a neoplasm. CONCLUSION: This study should enable us to optimize surveillance, prevention and treatment of these potentially life-threatening infections.

Candida↗
PubMed2002

Hand contamination before and after different hand hygiene techniques: a randomized clinical trial.

The efficacy of alcohol-based handrubs (ABH) for hand hygiene (HH) compared with handwashing (HW) remains to be established in the clinical setting. Factors associated with severe hand contamination before HH techniques were medical ward, physician and not wearing gloves. Forty-three healthcare workers [HCW, 26 nurses (N), nine nurse assistants (NA) and eight physicians (P)] each performed six HH techniques in random order, immediately after a patient care activity: HW with non-antiseptic soap for 10 (US10) and 30 (US30) s; HW with antiseptic (polyvidone iodine- or chlorhexidine-based) soap for 10 (AS10), 30 (AS30) or 60 (AS60) s; and ABH (Sterillium, Bode Chemie, Germany). The fingertips of the dominant hand were pressed on to agar for culture before and after each HH technique. Five hundred and sixteen specimens were obtained. Log(10)-transformed bacterial count reductions after HH were 0.74, 0.51, 1.13, 1.14, 1.21 and 1.40 for US10, US30, AS10, AS30, AS60 and ABH, respectively; both AS and ABH were significantly better than US. Qualitative assessment showed that 11 of the 256 pre-HH specimens (4.3%) had pathogenic bacteria, and that two of these 11 remained positive after HH (US in both instances).

Adult↗
PubMed2002

Impact of quinupristin/dalfopristin (RP59500) on the faecal microflora in healthy volunteers.

The effect of 5 days' administration of quinupristin/dalfopristin (RP59500) on the faecal microflora was evaluated in healthy volunteers. Twenty healthy volunteers received 7.5 mg/kg of quinupristin/dalfopristin infused over 1 h twice daily for 5 days and four received a matched placebo. Faecal samples were collected before, during and after treatment (days -1/-2, 6, 8, 14/15, 35 +/- 2, 60 +/- 4, 90 +/- 4). In the treated volunteers, anaerobes, including sporulating and Gram-negative bacteria, decreased slightly during treatment, whereas numbers of enterococci and Enterobacteriaceae increased significantly (P < 0.01). Counts of anaerobes and enterococci resistant to erythromycin or to quinupristin/dalfopristin increased significantly (P < 0.01) during treatment and returned slowly to their baseline levels after the end of treatment. Mean faecal antibiotic concentrations reached 291 +/- 184 and 42 +/- 22 microg/g of faeces for quinupristin and dalfopristin, respectively, by the fifth day of treatment. Counts of yeasts were not influenced significantly by the treatment. No emergence of glycopeptide-resistant enterococci, Staphylococcus aureus, Pseudomonas aeruginosa or Clostridium difficile was observed. No episode of diarrhoea was reported. In conclusion, quinupristin/dalfopristin administration was associated with a temporary shift towards resistance of the endogenous flora and a temporary increase in counts of enterobacteria and enterococci. However, no decrease in colonization resistance towards exogenous potentially pathogenic bacteria was observed and the observed modifications disappeared within 12 weeks after the end of quinupristin/dalfopristin administration.

Adult↗
PubMed2001

Duration of colonization by methicillin-resistant Staphylococcus aureus after hospital discharge and risk factors for prolonged carriage.

To investigate persistent carriage of methicillin-resistant Staphylococcus aureus (MRSA), we conducted a prospective 10-month study of MRSA carriage in previous carriers who were readmitted to our hospital. Four screening specimens, 2 from the skin and 2 from the nares, were obtained within 3 days after admission, in addition to diagnostic specimens requested by physicians. Of the 78 patients included in our study, 31 (40%) were persistent carriers of MRSA, with an estimated median time of 8.5 months to MRSA clearance. In the multivariate analysis, the only factor significantly associated with persistent carriage was the presence of a break in the skin at readmission (odds ratio, 4.34; P=.004); however, a trend was found for admission from a chronic-care institution (odds ratio, 3.65; P=.06). Our data confirm that prolonged carriage of MRSA can occur after hospital discharge, support routine screening for MRSA at readmission of previously MRSA-positive patients, and suggest that a particularly high index of suspicion for MRSA carriage should be maintained if these patients have a break in the skin.

Adult↗
PubMed2001

Bronchopulmonary disposition of the ketolide telithromycin (HMR 3647).

Telithromycin (HMR 3647) is the first member of a new family of antimicrobials, the ketolides, developed specifically for the treatment of community-acquired respiratory tract infections. Telithromycin has proven in vitro activity against both common and atypical respiratory tract pathogens. The penetration of telithromycin into bronchopulmonary tissues and subsequent elimination from these sites were evaluated in four groups (groups A, B, C, and D) of six healthy male subjects who received telithromycin at 800 mg once daily for 5 days. Subjects in groups A, B, C, and D underwent fiberoptic bronchoscopy and bronchoalveolar lavage 2, 8, 24, and 48 h after receipt of the last dose, respectively. The concentration of telithromycin in the alveolar macrophages, epithelial lining fluid (ELF), and plasma was determined by the agar diffusion method with Bacillus subtilis ATCC 6633 as the test organism. The concentration of telithromycin in alveolar macrophages markedly exceeded that in plasma, reaching up to 146 times the concentration in plasma 8 h after dosing (median concentration, 81 mg/liter). Telithromycin was retained in alveolar macrophages 24 h after dosing (median concentration, 23 mg/liter), and it was still quantifiable 48 h after dosing (median concentration, 2.15 mg/liter). Telithromycin median concentrations in ELF also markedly exceeded concentrations in plasma (median concentration in ELF, 3.7 mg/liter 8 h after dosing). Telithromycin achieves high and sustained concentrations in ELF and in alveolar macrophages, while it maintains adequate levels in plasma, providing an ideal pharmacokinetic profile for effective treatment of community-acquired respiratory tract infections caused by either common or atypical, including intracellular, respiratory tract pathogens.

Administration, Oral↗
PubMed2001

Genetic diversity of Pseudomonas aeruginosa strains isolated from ventilated patients with nosocomial pneumonia, cancer patients with bacteremia, and environmental water.

Random amplified polymorphic DNA typing was used to study the genetic diversity of Pseudomonas aeruginosa strains from (i) ventilated patients with nosocomial pneumonia who were hospitalized in intensive care units, (ii) cases of bacteremia in cancer patients with severe neutropenia, and (iii) rivers and swimming pools. Genetic diversity was determined by three phylogenetic methods and by statistical analysis of population genetics. The population studied undergoes epidemic clonality with a high rate of genetic recombination. P. aeruginosa bacteremia and pneumonia are not caused by specific clones within this species.

Bacteremia↗
PubMed2001

Characterization of AfaE adhesins produced by extraintestinal and intestinal human Escherichia coli isolates: PCR assays for detection of Afa adhesins that do or do not recognize Dr blood group antigens.

Operons of the afa family are expressed by pathogenic Escherichia coli strains associated with intestinal and extraintestinal infections in humans and animals. The recently demonstrated heterogeneity of these operons (L. Lalioui, M. Jouve, P. Gounon, and C. Le Bouguénec, Infect. Immun. 67:5048-5059, 1999) was used to develop a new PCR assay for detecting all the operons of the afa family with a single genetic tool. This PCR approach was validated by investigating three collections of human E. coli isolates originating from the stools of infants with diarrhea (88 strains), the urine of patients with pyelonephritis (97 strains), and the blood of cancer patients (115 strains). The results obtained with this single test and those previously obtained with several PCR assays were closely correlated. The AfaE adhesins encoded by the afa operons are variable, particularly with respect to the primary sequence encoded by the afaE gene. The receptor binding specificities have not been determined for all of these adhesins; some recognize the Dr blood group antigen (Afa/Dr(+) adhesins) on the human decay-accelerating factor (DAF) as a receptor, and others (Afa/Dr(-) adhesins) do not. Thus, the afa operons detected in this study were characterized by subtyping the afaE gene using specific PCRs. In addition, the DAF-binding capacities of as-yet-uncharacterized AfaE adhesins were tested by various cellular approaches. The afaE8 subtype (Afa/Dr(-) adhesin) was found to predominate in afa-positive isolates from sepsis patients (75%); it was frequent in afa-positive pyelonephritis E. coli (55.5%) and absent from diarrhea-associated strains. In contrast, Afa/Dr(+) strains (regardless of the afaE subtype) were associated with both diarrhea (100%) and extraintestinal infections (44 and 25% in afa-positive pyelonephritis and sepsis strains, respectively). These data suggest that there is an association between the subtype of AfaE adhesin and the physiological site of the infection caused by afa-positive strains.

Adhesins, Escherichia coli↗
PubMed2000

Intranasal immunization with protein-linked phosphorylcholine protects mice against a lethal intranasal challenge with streptococcus pneumoniae.

Immunization against phosphorylcholine (PC) linked to a protein protects mice against Streptococcus pneumoniae when used parenterally, and against Salmonella typhimurium when used orally after entrapment in D,L-Lactide-co-Glycolide microspheres. Here, we immunized BALB/c mice intranasally with a serotype 3 S. pneumoniae strain. Immunization was followed by a rise in anti-PC IgA and IgG titers in serum and in pulmonary secretions, but not by any rise in anti ds-DNA antibody nor any glomerular Ig deposition. The survival rates were 91 and 76% in the two groups of mice, respectively. These rates were significantly higher than those in control mice immunized intranasally either with Thyr loaded in microspheres (0%), blank microspheres (22%), free Thyr (17%), and saline (18%). This demonstrates that the mucosal route is effective for vaccination against S. pneumoniae pneumonia with PC linked to a protein carrier. It constitutes another important step forward in the development of the concept that PC can be used as a mucosal immunogen for protection against the different diseases caused by PC-bearing bacteria.

Administration, Intranasal↗
PubMed2000

[Consequences of antibiotic therapy to the intestinal ecosystem].

Ecological impact of antibiotherapy results from the interaction between microorganisms in the ecosystems and antibiotics at which they are exposed. The amount of antibiotics use in the world is continuously increasing. The fraction devoted to human care is only about half the total amount. There are multiple other fields of usage, in agriculture, breeding and veterinary medicine. Bacterial ecosystems exposed at antibiotherapy in man are mainly the skin and the gastrointestinal and respiratory tracts. The gastrointestinal system is quantitatively predominant and the consequences of the bacterial imbalance induced by antibiotics are potentially severe. It is the reason why it is the most extensively studied, in the literature and in the present review. The origin of resistant bacteria will be briefly discussed.

Animals↗
PubMed2000

Targeted delivery of antibiotics using liposomes and nanoparticles: research and applications.

This review examines current technologies for increasing the bioavailability of antibiotics by means of liposomes or nanoparticles. The main focus is on liposomes. These carriers were preferentially developed because their composition is compatible with biological constituents. Biodegradable polymers in the form of colloidal particles have also been used and show promise for future applications in antimicrobial chemotherapy. The in vivo behaviour of both types of carriers and consequently their therapeutic potential, are determined by their route of administration. Conventional carrier strategies permit the mononuclear phagocyte system to be targeted by intravenous injection of antibiotics. Stealthy strategies avoid major uptake by these cells and extend the systemic presence of these carriers. The purpose of this review is to provide background information in antibiotic targeting gathered from papers published over the last twenty years. It seems clear that such drug carriers (liposomes, nanoparticles) allow increased drug concentration at infected sites but reduce drug toxicity.

Aminoglycosides↗
PubMed2000

Prevalence of virulence genes and clonality in Escherichia coli strains that cause bacteremia in cancer patients.

Phenotypic analysis of Escherichia coli strains causing bacteremia in cancer patients suggests that they possess specific virulence properties. To investigate this hypothesis, we compared the frequency of the virulence-related genes cnf1, cnf2, papC, hlyC, and iut in 155 E. coli strains isolated from hospitalized cancer patients with epidemiologically unrelated cases of bacteremia to their frequency in 70 E. coli strains isolated from the feces of healthy unrelated volunteers. Of the blood isolates, 24, 37, and 26% were positive for cnf1, papC, and hlyC, respectively, versus only 6, 17, and 6% of the fecal isolates (P < 0.05 in all instances). By contrast, 47% of both isolates carried the iut gene. The patients' clinical characteristics did not significantly influence these frequencies. The presence on various pathogenicity islands (PAIs) of a combination of the cnf1, papC, and hlyC genes on the chromosome was strongly suggested by Southern blotting of pulsed-field gel electrophoresis (PFGE) patterns with specific DNA probes. The phylogenetic relatedness among 60 strains carrying three, two, one, or no virulence genes and 6 ECOR strains included as references was determined by neighbor joining, the unweighted pair-group method with arithmetic mean, and Wagner analysis of the randomly amplified polymorphic DNA (RAPD) patterns generated by 11 primers. Identification of a major cluster including 96.4% of the strains carrying the cnf1, papC, and hlyC genes and ECOR subgroup B2 strains suggested that the virulent E. coli strains causing bacteremia in cancer patients are closely related to ECOR B2 strains. The presence in the E. coli population surveyed of a strong linkage disequilibrium, and especially of a highly significant correlation between PFGE and RAPD genetic distances, confirms that clonal propagation has a major impact on the E. coli population structure. Nevertheless, low bootstrap values in the phylogenetic tree suggested that frequent genetic exchange inhibits the individualization of discrete genetic lineages, which are stable on an evolutionary scale.

Animals↗