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Biomedical subjects

J L Avril

Publications and source records attributed to J L Avril.

At least 19 recordsLinked to original sources
PubMed1997

Comparative activities of new fluoroquinolones, alone or in combination with amoxicillin, trimethoprim-sulfamethoxazole, or rifampin, against intracellular Listeria monocytogenes.

We studied the activities of the new fluoroquinolones clinafloxacin, levofloxacin, ofloxacin, and sparfloxacin alone or in combination on the intracellular growth of Listeria monocytogenes. Against intracellular growth of the four strains tested, a similar reduction of the bacterial count was obtained with clinafloxacin at the dose of 10 x MIC (delta log10 CFU/ml = -2.19 +/- 0.24), with levofloxacin at 8 x MIC (delta log10 CFU/ml = -2.28 +/- 0.25), and with sparfloxacin at 4 x MIC (delta log10 CFU/ml = -2.16 +/- 0.21) after 24 h of incubation. The combination of the quinolones with trimethoprim-sulfamethoxazole or amoxicillin did not show a substantial increase in activity compared to the fluoroquinolone alone. Antagonism with rifampin was strongly suggested. No modification of the MIC was observed after 20 successive infections of HeLa cells and contact with subinhibitory concentrations of clinafloxacin, levofloxacin, and sparfloxacin for 24 h. We conclude that clinafloxacin, levofloxacin, or sparfloxacin could represent a therapeutic alternative to amoxicillin for the treatment of Listeria infections in adults, especially clinafloxacin, whose MIC is low (0.06 to 0.12 micrograms/ml), and whose best activity against intracellular L. monocytogenes was obtained at a concentration of 1.2 micrograms/ml, which is similar to clinically achievable levels. The results must be confirmed in an experimental model.

Amoxicillin↗
PubMed1996

First European case of gastroenteritis and bacteremia due to Vibrio hollisae.

Vibrio hollisae is a pathogenic Vibrio species known to cause gastroenteritis in humans after the consumption of shellfish. All cases of infection reported previously were restricted to the Atlantic and Pacific coasts of the United States. A case of gastroenteritis and bacteremia in a previously healthy 76-year-old man who ate cockles from the Quiberon Bay in Brittany, France, is described. This is the first report of Vibrio hollisae infection in Europe.

Aged↗
PubMed1995

[Pasteurelloses].

According to the genetic relationships among Gram-negative bacilli the genus Pasteurella is included with the genus Haemophilus and the genus Acinobacillus within the family Pasteurellacae. Pasteurella multocida, the type species, is responsible for the majority of human Pasteurella infections. P. multocida is a member of the normal flora in the upper respiratory tract of many mammals or birds. It causes sporadic or epidemic diseases among different animal species, particularly pneumonia and atrophic rhinitis in swine in intensive breeding stations. The most common human infection with P. multocida is a local cellulitis following dog or cat bites and scratches. Serious local complications are sometimes responsible for prolonged disability. The respiratory tract is the second human source of P. multocida isolates. The frequency of recovery of P. multocida from oropharynx of apparently healthy pig breeders suggests that respiratory pasteurellosis could be an occupational disease. The mechanisms of virulence of P. multocida are unclear. Several factors are involved: capsules preventing phagocytosis, a dermonecrotic toxin causing experimental atrophic rhinitis, hyaluronidase, neuraminidase and proteases. Penicillin is considered to be the drug of choice for Pasteurella infection. Tetracyclin is efficient for bites but has no bactericidal effect. Oxacillin, first-generation cephalosporins, macrolides and aminoglycosides have poor activities. In the case of beta-lactamase producing strains a bactericidal effect could be achieved with fluoroquinolones or third generation cephalosporins.

Animals↗
PubMed1995

[Bactericidal activity of ciprofloxacin and sparfloxacin. Comparison with others active antibiotics against Pasteurella multocida].

Bactericidal activities of ciprofloxacin and sparfloxacin were compared to other antibiotics active against human isolates of Pasteurella multocida. Three human isolates of Pasteurella multocida were used for killing-curve studies with ciprofloxacin and sparfloxacin comparatively to others antibiotics. At 2x the MIC, ciprofloxacin and sparfloxacin exhibited a killing of more than 99.9% of the initial viable cells that was achieved within 6 h of incubation. These activities were faster than those of amoxycillin and cefpodoxime. No regrowth was observed after 24 h of incubation. Doxycycline and clarithromycin used at MICx2 had no bactericidal activities. It was concluded that fluoroquinolones, namely ciprofloxacin and sparfloxacin, can be considered having good bactericidal activity against P. multocida.

Amoxicillin↗
PubMed1995

Epidemiologic analysis of glycopeptide-resistant Enterococcus strains in neutropenic patients receiving prolonged vancomycin administration.

Vancomycin-resistant enterococci have been isolated with increasing frequency since 1988. Thus far, most of these resistant enterococci have belonged to the Enterococcus faecium species, and epidemiological studies have shown a wide diversity among interhospital and intrahospital isolates. This report presents an epidemiologic investigation of 25 vancomycin-resistant Enterococcus strains--24 Enterococcus faecium and one Enterococcus gallinarum--isolated from the stools or blood of adult patients receiving intravenous vancomycin prophylaxis during neutropenia and hospitalized in a single hematologic unit. Macrorestriction patterns of total DNA and of ribosomal DNA regions were used to analyze the strains. Strains produced different total DNA restriction fragment length polymorphism patterns after SmaI digestion. Ribotyping was less discriminative than pulsed-field gel electrophoresis. The results confirmed the genetic unrelatedness of the strains. Prolonged vancomycin administration, commonly used in hematologic units, could be involved in the selection of endogenous resistant enterococcal strains.

Anti-Bacterial Agents↗
PubMed1995

[Susceptibility to quinolones of Salmonella isolated from men and animals].

Fluoroquinolones are efficacious antibiotics for the treatment of Salmonella infections in humans. One of these quinolones, enrofloxacin, a precursor of ciprofloxacin, is used to treat respiratory infections in calves and poultry. There is a risk of developing resistant strains of Salmonella in animals, which may then contaminate humans. To evaluate current susceptibilities of Salmonella strains to quinolones, we collected 95 strains belonging to various serotypes in a district of intensive breeding (the Ille-et-Vilaine Département): 54 human strains, 24 bovine strains, and 17 poultry strains. The technique of dilutions in agar medium was used to determine Minimal Inhibitory Concentrations (MICs) for the following antibiotics: nalidixic acid, norfloxacin, pefloxacin, ofloxacin, ciprofloxacin, levofloxacin and clinafloxacin. Our results showed that human Salmonella strains remained very susceptible to quinolones. Only 3 animal strains had nalidixic-acid MICs > 128 mg/l. For these 3 strains, pefloxacin and ciprofloxacin MICs were respectively 1 or 2 mg/l and 0.25 mg/l. For all the other human and animal strains the nalidixic-acid MICs were < 4 mg/l, and their MICs 90 were: 0.12 mg/l for ofloxacin and norfloxacin, 0.06 mg/l for pefloxacin, 0.03 mg/l for ciprofloxacin, 0.016 mg/l for levofloxacin, and 0.004 mg/l for clinafloxacin.

Animals↗
PubMed1995

Clinical evaluation of the Vital system compared with the Hémoline diphasic method for the detection of aerobic blood cultures.

In a collaborative study at two university hospitals, the recovery of microorganisms and the speed of detection of microbial aerobic growth by the Vital system (bioMérieux) and a diphasic conventional blood culture system were compared. The Vital system monitors each blood culture bottle every 15 minutes to detect inactivation of fluorescent suspended in the broth medium due to microbial growth. A total of 1086 comparisons were made between the two systems, yielding a total of 117 isolates. Microorganisms were recovered more often from the Vital aerobic bottles (p < 0.05). The Vital system detected 43% of the microorganisms within the first 12 hours of incubation whereas in the same time the conventional system detected only 5% of the microorganisms. The results demonstrate that the Vital system is a reliable, continuous monitoring, fully automated system and an attractive alternative to conventional blood culture methods.

Bacteremia↗
PubMed1994

Biotyping, ribotyping and esterase electrophoresis as epidemiological tools for Acinetobacter baumannii.

An epidemiological survey was carried out over a one-week period to assess the spread of Acinetobacter baumannii in a medical intensive care unit. Fifty strains were isolated from patients colonized or infected by the organism and from a hospital environment. These strains belonged to biotypes 9 or 18. The rRNA gene restriction patterns (using EcoRI and PvuII as restriction endonucleases) and the esterase electrophoretic profiles were determined on 31 strains, using as comparison strain isolates from another intensive care unit of our hospital and from two other French hospitals. Four EcoRI ribotypes, four PvuII ribotypes and six esterase profiles were identified. All biotype 9 strains isolated in our hospital presented the same ribotype after EcoRI digestion, the same ribotype after PvuII digestion and the same zymotype. The same observation was made on most of the biotype 18 strains. Biotyping is an appropriate method for screening of strains, and ribotyping and esterase electrophoresis could be used as additional methods to delineate outbreaks of nosocomial infections caused by A. baumannii.

Acinetobacter↗
PubMed1994

Inhibition of intracellular growth of Listeria monocytogenes by antibiotics.

We studied the activities of 15 antibiotics on the intracellular growth of Listeria monocytogenes in a HeLa cell line. After 24 h of contact with the infected cells, the antibiotics most effective against the intracellular growth of the 10 strains tested were amoxicillin, temafloxacin, and sparfloxacin, which nevertheless failed to totally eliminate the intracellular bacteria. Rifampin and co-trimoxazole had variable effects, depending on the isolates studied. The most active combinations were amoxicillin-sparfloxacin, co-trimoxazole-gentamicin, and sparfloxacin-co-trimoxazole. The results suggest the value of using a cell culture technique to study the activities of antibiotics against certain bacteria with intracellular sites of multiplication.

Anti-Bacterial Agents↗
PubMed1994

Pasteurella multocida: oropharyngeal carriage and antibody response in breeders.

The presence of Pasteurella multocida in the oropharynx of 58 pig, cattle or rabbit breeders whose livestock had suffered from pasteurellosis was investigated using a selective medium. Blood samples for serological studies were collected at the same moment. Nineteen breeders were found to host one P multocida subsp multocida strain. Oropharyngeal carriage of P multocida was found to be more frequent in pig breeders (42% of individuals) than in cattle (10%) or rabbit (0%) breeders. Genomic polymorphism among 10 D2 strains was found by restriction endonuclease analysis using pulsed-field gel electrophoresis (REA-PFGE). Antibodies to P multocida were found in the sera of 32 of these 58 breeders, whereas only 2 of the 70 controls had antibodies. These results, recorded from healthy individuals, show that P multocida, acting as an opportunistic bacterium, may be responsible for occupational diseases. Nevertheless, the strong prevalence of specific antibodies makes the presence of antibodies in the sera of these breeders an insufficient indication of a current patent infection.

Adult↗
PubMed1993

Continuous ambulatory peritoneal dialysis: evaluation of three new culture methods.

Out of 900 dialysates analysed over 15 months at the Rennes Regional Hospital, 116 cloudy specimens with a leucocyte count of more than 100/mm3 were studied. Three methods of laboratory diagnosis based on physical or chemical disruption of leucocytes were evaluated: saponin incorporated in the agar medium, sonication, and the Isolator lysis centrifugation system. Sensitivity was improved (52%) for the three methods combined compared with the standard method (37%). The Isolator system (51%, P < 0.05) gave the best results. Direct microscopic examination nevertheless remains essential for its indicative value (sensitivity 33% of positive dialysates). The leucocyte count was correlated with the percentage of culture positivity (43% from 100-200/mm3 compared with 62% from 500-1000/mm3); 80% of organisms were Gram-positive bacteria and most were coagulase-negative staphylococci. Opportunistic pathogens such as Corynebacterium jeikeium were frequently isolated.

Corynebacterium Infections↗
PubMed1992

Esterase electrophoresis compared with biotyping for epidemiological typing of Acinetobacter baumannii strains.

Forty-nine Acinetobacter baumannii strains belonging to three biotypes and isolated from four hospitals were differentiated by electrophoretic typing of their esterases. Six main kinds of esterases were distinguished by their spectra of hydrolytic activity toward seven synthetic substrates. The electrophoretic variations of these enzymes were used to define ten zymotypes among the three biotypes. Esterase electrophoresis appeared to be more sensitive than biotyping, and could represent an additional marker for epidemiological analysis.

Acinetobacter↗
PubMed1992

Septicemia and hepatic abscess caused by Pediococcus acidilactici.

A case of postoperative Pediococcus acidilactici septicemia with parallel isolation of the organism from hepatic specimens is presented. Laboratory methods to identify this vancomycin-resistant gram-positive cocci are described. Very few cases of documented infections due to this bacterium have been reported in the literature.

Humans↗