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R Leprat

Publications and source records attributed to R Leprat.

10 recordsLinked to original sources
PubMed2003

Is pulsed-field gel electrophoresis a valuable tool to identify nosocomial cases of Legionella pneumophila disease?

Pulsed-field gel electrophoresis (PFGE) was used to type Legionella pneumophila isolates collected from the water systems of Besançon University Hospital and other hospitals in Franche-Comté region between January 2001 and December 2002 and compare them with patient isolates to identify hospital-acquired pneumonia. Genomic DNA was digested with SfiI and subjected to PFGE in a clamped, homogeneous electric field apparatus. Two of 11 Legionella infections were hospital-acquired. Both were with the same type, also present in the ward water. An environmental strain isolated from the water system of Vesoul Hospital, exhibited DNA pattern 6, also found in three patients with community-acquired pneumonia, who had never been in Vesoul hospital and lived in different towns located >60 km away. Patient 11, who lived in Besançon, was infected with a DNA pattern 12 strain. This patient had never been to the Besançon swimming pool, from which a similar strain was collected. Subtype matching of patient and environmental isolates should be interpreted with caution, and it is important to combine a molecular typing method with sound epidemiological data to ensure that the most stringent criteria are used to determine whether a hospital-reservoir is responsible for nosocomial pneumonia.

Cross Infection↗
PubMed1998

[Surveillance of biocontamination of the environment of labile blood products: its role in a quality assurance program].

As part of a quality assurance approach aiming at reducing the risk of bacterial contamination of labile blood components (BC), their environment was submitted to a twofold quality control. A yearly control was carried out by the University Hospital Laboratory of Hygiene (UH-LH). Another control was regularly implemented by our Quality Control Laboratory. In accordance with this quality system, we focused our attention on decontamination procedures, control targets and the definition of an acceptable threshold. The analysis of results over 1 year showed that they can be considered as satisfactory when less than 40 CFU/100 cm2 are found. Quality sheets were developed, aimed at motivating our staff, adapting the decontamination procedures and initiating corrective measures. This quality programme allowed us to develop close collaboration links with the UH-LH and to play a role in the prevention of hospital-acquired infections.

Bacteremia↗
PubMed1995

Risk factors for nosocomial colonization with multiresistant Acinetobacter baumannii.

A six-month prospective survey was carried out in a university hospital to assess the incidence of Acinetobacter baumannii cross-contamination and to identify risk factors for colonization. Clinical isolates obtained during the study period were biotyped and genotyped by pulsed-field gel electrophoresis after ApaI macrorestriction of total DNA. Case-control univariate and multivariate analyses were performed to identify risk factors for Acinetobacter baumannii colonization. One hundred forty-seven patients hospitalized in 36 units were colonized or infected, of whom 52 were in three intensive care units. The urinary (29%) and bronchopulmonary tracts (26%) were the most frequently colonized sites. Nine major restriction patterns were identified: two were exhibited by epidemic multi-resistant strains of biotype 9 which were isolated from 65 patients hospitalized in ten units. Multivariate analysis showed that case-patients were (a) more likely than non-infected controls to be male, to have been previously hospitalized in another unit and to have had longer stays in the unit before colonization and hyperalimentation; and (b) more likely than controls colonized with other gram-negative bacilli to be male, to have had longer hospitalization, to have received treatment with third-generation cephalosporins and to have had a urinary catheter. The high incidence of colonization with Acinetobacter baumannii can thus be attributed to frequent cross-contamination and the use of broad-spectrum antibiotics. Colonized patients appear to be the major source of cross-contamination as epidemic strains spread throughout the hospital.

Acinetobacter Infections↗
PubMed1994

Typing of hospital strains of Xanthomonas maltophilia by pulsed-field gel electrophoresis.

We report the use of pulsed-field gel electrophoresis (PFGE) to characterize Xanthomonas maltophilia isolates from an incident of hospital-acquired infection over a 12-day period in a haematological unit. Ten isolates from five patients (from throat, urine, stool and blood) and two isolates from environmental sites in the unit were compared with 10 epidemiologically unrelated clinical strains, isolated over a 3-month period from several units in two hospitals, by PFGE of DraI digests of chromosomal DNA. The profiles obtained were stable, reproducible and discriminatory. The 10 unrelated strains had different DNA profiles. Each of the five patients in the unit was colonized by a different strain and the isolates from a water faucet and a shower pommel had the same DNA profile as the strains of two patients who had used these fittings. A case-controlled study showed that the only factor that correlated with colonization was the origin of the patient from another unit (P = 0.0122). We conclude that PFGE is a rapid and discriminatory technique for the typing of X. maltophilia where a common origin of infection is suspected.

Adult↗
PubMed1979

Selective inactivation of hemagglutinin and neuraminidase on mumps virus.

The thermal stability and the effect of guanidine on the hemagglutinin and neuraminidase of three strains of mumps virus were compared. The heat inactivation of hemagglutinin resulted in the concomitant loss of neuraminidase. The effect of guanidine at various molarities showed that the neuraminidase was more sensitive than the hemagglutinin and a selective inactivation was obtained after exposure to 1.5 M guanidine. However differences in sensitivity of both activities (hemagglutinin and neuraminidase) to heat and guanidine inactivations were observed among strains and correlated with differential susceptibility to non-specific inhibitors of the strains.

Allantois↗
PubMedDate not supplied

Extracellular neuraminidase production by a strain of Pseudomonas aeruginosa isolated from cystic fibrosis.

Extracellular neuraminidase production was found in a strain of Pseudomonas aeruginosa isolated from a patient with cystic fibrosis. Extracellular neuraminidase was secreted in growth medium during the early stationary phase. The enzyme was produced in brain-heart infusion supplemented with 10% colt serum. The enzyme hydrolyzed the alpha 2 leads to 3 glycosidic linkages from N-acetylneuraminlactose and fetuin, and cleaved also mucins from CF. Activity was optimal pH 6.6-7.0, not modified by addition of calcium and magnesium cations, and insensitive to EDTA inhibition (50% inhibition in the presence of 0.035 mM EDTA). The enzyme was stable at temperatures of 4 degrees C for weeks and 37 degrees C for at least 24 h but was almost completely inactivated within 30 min at 56 degrees C. No N-acetylneuraminic acid aldolase was secreted in growth medium. For the neuraminidase producing strain and non-producing reference strains for P. aeruginosa, we demonstrated an endogeneous neuraminidase acting on endogenous substrate from highly concentrated cell extracts.

Child↗