Biomedical subjects

J-P Lavigne

Publications and source records attributed to J-P Lavigne.

7 recordsLinked to original sources

PubMed2006

[Antimicrobial susceptibility of Proteus mirabilis urinary tract isolates from 1999 to 2005 at Nîmes University Hospital].

AIM OF THE STUDY: To analyse antimicrobial resistance trends of Proteus mirabilis urinary tract isolates from 1999 to 2005 at the Nîmes University hospital. MATERIALS AND METHODS: We retrospectively collected non-duplicate urinary tract infections and colonization isolates from inpatients between 1 January 1999 and 31 December 2005. RESULTS: One thousand and eight non-duplicate urinary tract isolates were studied, 63.1% were from females and the mean age was 76 years. The mean resistance rate was 59.0% for amoxicillin (AMX), 48.0% for piperacillin (PIP), 3.9% for cefotaxim, 33.9% for amoxicillin plus clavulanic acid (AMC) and 2.8% for piperacillin plus tazobactam (TZP). A significant increase in resistance was observed for AMC and TZP. The mean resistance rate was 35.0% for norfloxacin, 34.8% for ofloxacin and 23.5% for ciprofloxacin. No significant increase in resistance to fluoroquinolones was seen except for ciprofloxacin whereas a significant increase was observed for aminoglycosides. The mean rate resistance for cotrimoxazole was 33.2% with a significant decrease in the resistance during the study period. CONCLUSION: P. mirabilis stilled sensitive to cefotaxim or ceftazidim and to TZP. The significant increase in the rate resistance to AMC and TZP could be explained by production of beta-lactamases and in particular extended-spectrum beta-lactamases. The increase in resistance observed for fluoroquinolones become a major concern. Amikacine was the most active aminoglycosides. These data suggested for the re-enforcement of the antimicrobial susceptibility surveillance in order to optimise the rational use of antibiotics.

Anti-Bacterial Agents↗

PubMed2006

[Caenorhabditis elegans: in vivo study model of bacterial virulence].

The nematode Caenorhabditis elegans presents many advantages as a model system. The worm has recently emerged as a potentially useful tool for the study of host-pathogen interactions. This paper presents advantages and inconveniences of this model, the variety of bacterial pathogens studied, and its use to monitor virulence of Extraintestinal Escherichia coli strains.

Animals↗

PubMed2006

[Type IV secretion system and their effectors: an update].

Subversion of eukaryotic hosts by bacterial pathogens requires specialized macromolecules secretion systems delivering virulence factors either into the environment or directly into host cells. Transport of molecules across bacterial and eukaryotic membranes is a process requiring multi-component machineries called secretion systems. This review focuses on the Type IV secretion system. This complex is required for genetic exchange (DNA transport) and secretion of effectors (proteins, macromolecules, DNA-proteins complex) into target cells. They transport a wide variety of substrates including large DNA/protein complexes, multi protein toxins, or individual proteins. We describe recent advances on the structure and the function of this secretion system, their effectors and their effects on the functions of eukaryotic cell.

Bacteria↗

PubMed2006

Virulence genotype and nematode-killing properties of extra-intestinal Escherichia coli producing CTX-M beta-lactamases.

This study evaluated the virulence potential of Escherichia coli isolates producing CTX-M beta-lactamases. During a 24-month period, 33 extended-spectrum beta-lactamase (ESBL)-producing E. coli, including 14 CTX-M-producers, were isolated from urinary tract infections at Nîmes University Hospital, France. The prevalence of 14 major virulence factors (VFs) was investigated by PCR and compared with the prevalence in a group of 99 susceptible E. coli isolates. Ten VFs were less prevalent (p <0.05) in the ESBL isolates than the susceptible E. coli, while iutA and traT were more prevalent in ESBL isolates (p <0.05). Moreover, the CTX-M-producing isolates had significantly fewer VFs than TEM-producing isolates. A novel infection model using the nematode Caenorhabditis elegans was developed to assess the virulence properties of extra-intestinal pathogenic E. coli (ExPEC) strains in vivo. C. elegans infection assays, using 14 ESBL-producing E. coli and ten susceptible E. coli isolates, indicated that the ability to kill nematodes correlated with the presence of VFs, and that CTX-M-producing isolates had relatively low virulence in vivo. Overall, the results suggested that hospital-acquired CTX-M-producing E. coli, although adapted for survival in an antibiotic-rich environment such as the hospital milieu, have a relatively low intrinsic virulence potential.

Aged↗

PubMed2005

[Enterococcal bacteremia at Nîmes university hospital].

PURPOSE OF THE STUDY: The aim of this study was the description of enterococcal bacteremia and the evaluation of their resistance evolution to antibiotics and the virulence profile of these isolates. PATIENTS AND METHODS: We have studied all the bacteremia caused by Enterococcus spp. from the 1st of July 2003 until the 30th of June 2004 at Nîmes university hospital. For each isolate, population, clinical and microbiological data were collected. Multiplex PCR allowed for the identification of glycoprotein resistant phenotypes and furthermore, to identify the main virulence genes found in the enterococci. RESULTS: Thirty-three strains were identified from 33 patients (60.6% male) with a median age of 68 years (median: 3-96). The vital prognostic was calculated in 63.6% of the cases (MacCabe > or =1); seven patients died during their hospitalization (21.2%). The infections were nosocomial in 60.6% of the cases. No epidemic was observed. The principal comorbidities were cardiovascular and digestive pathologies. In addition, 54.5% of patients had had a surgical intervention. Enterococcus faecalis (87.9%) was the cause of infection in the majority of cases followed by Enterococcus faecium. Most of the infections were monomicrobial (75.8%). E. faecalis was sensitive to amoxicillin and to glycopeptides but was resistant to norfloxacin, erythromycin and pristinamycin. The same observations were made for the E. faecium with the exception of amoxicillin. E. faecalis had the maximum number of virulence genes and E. faecium the least. CONCLUSION: The enterococcal bacteremia had mainly a nosocomial origin. The isolates came from digestive tract flora but also from catheters. The mortality rate was 21.2%. A developing sensitivity to erythromycin and pristinamycin was observed in comparison to the data of the ONERBA (2002-2003). Only one isolate was resistant to glycopeptide. This was the first European E. faecium containing the vanD allele. This isolate proved fatal to the patient. The dark evolution of enterococcal bacteremia and their frequent nosocomial origin induce to promote studies intended for better knowing the risk factors of such infections.

Adolescent↗

PubMed2005

Total laparoscopic aortobifemoral bypass.

AIM: To assess the feasibility of aortobifemoral bypass by a laparoscopic approach. MATERIAL AND METHODS: During November 2002 through July 2003 a total of 21 patients with aorto-iliac occlusive disease underwent total laparoscopic aortobifemoral bypass surgery. RESULTS: The median operative time was 240 (range 150-420) min with a median aortic cross-clamp time of 60 (30-120) min. Operating time was reduced with experience. The median blood loss was 500 (100-2500) ml. One conversion to open surgery for acute dilation of the small bowel was necessary. Post-operative complications occurred in five patients (coagulation problems, disseminated intravascular coagulation secondary to thrombosis of the left limb, cerebro-vascular accident, dyspnoea, lymph leak) and there was no peri-operative death. Median hospital stay was 7 (5-30) days. CONCLUSION: Aorto-bifemoral bypass using a total laparoscopic approach can be performed safely. As all new techniques, a learning curve is observed. This new technique should be evaluated in a larger randomised trial to assess its clinical value in comparison to conventional surgery.

Adult↗

PubMed2003

Prosthetic vascular infection complicated or not by aortoenteric fistula: comparison of treatment with and without cryopreserved allograft (homograft).

OBJECTIVES: in patients with vascular prosthesis infection, to compare surgical outcome and long-term results of cryopreserved allograft implantations to conventional surgery. DESIGN: retrospective study. MATERIAL AND METHODS: two asynchronous series of 44 [series I: 1980-1994; 8 patients with aortoenteric fistula (AEF)] and 22 (series II: 1994-1997; 4 patients with AEF) patients were treated for prosthesis infection. All patients had prosthesis excision. In series I, there were 4 in situ reparations, 26 extra-anatomic bypass, 13 excision only, and one death at laparotomy. In series II, in situ cryopreserved allografts were implanted in all patients. RESULTS: operative mortality was 16% in series I and 13.6% in series II. For AEF patients, mortality was 37% in series I and 50% in series II. Among hospital survivors, infection-related late mortality was 13.5% in series I and 5% in series II. For AEF patients, late mortality was 20% in series I and 50% in series II. Incidence of reoperations was 54% in series I and 10.5% in series II (p<0.01). Hospital stay was 47.2+/-26.4 days in series I and 16.6+/-11.5 days in series II (p<0.001). CONCLUSIONS: compared to conventional treatment, incidence of reoperations and length of hospital stay are significantly decreased after cryopreserved allograft implantation. However, closure of aortic stump and extra-anatomic bypass gives better results for patients with AEF.

Aged↗