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Biomedical subjects

A Bouvet

Publications and source records attributed to A Bouvet.

At least 37 records · Page 2Linked to original sources
PubMed1999

Efficacy of prevention by high-efficiency particulate air filtration or laminar airflow against Aspergillus airborne contamination during hospital renovation.

OBJECTIVE: To evaluate efficacy of laminar airflow facilities plus high-efficiency particulate air (HEPA) filtration and HEPA filtration alone in preventing environmental Aspergillus contamination during hospital renovation. To show the usefulness of environmental surveillance to facilitate protection of patients at risk for invasive pulmonary aspergillosis. DESIGN: Prospective sampling of air and surfaces for Aspergillus conidia during 2-year period. SETTING: A hematological department adjacent to building renovation at a university hospital. RESULTS: 1,047 air samples and 1,178 surface samples were collected from January 1996 to December 1997. Significantly more air samples were positive for Aspergillus species during the period of building renovation than during the periods before and after renovation in a unit without a protected air supply adjacent to the building work area (51.5% vs 31.7%; odds ratio [OR], 2.3; 95% confidence interval [CI95], 1.4-3.7; P<.001). A major increase in the frequency of positive air samples was also found in another adjacent unit that was protected with HEPA filtration alone (from 1.8% to 47.5%; OR, 48.9; CI95, 12-229; P<10(-7)). In addition, in this unit, the mean count of Aspergillus conidia in positive air samples increased significantly during construction (4 colony-forming units [CFU]/m3 to 24.7 CFU/m3; P=.04) and the proportion of positive surface samples showed a significant increase during renovation (from 0.4% to 9.7%; OR, 28.3; CI95, 3.4-623; P=10(-4)). However, none of 142 air samples collected during renovation in the area protected with laminar airflow plus HEPA filtration showed Aspergillus conidia. In a unit distant from the building renovation site, the results of air and surface samples were not affected by renovation. CONCLUSION: This study showed a strong association between building renovation and an increase in environmental Aspergillus contamination. Results confirmed the high efficacy of laminar airflow plus HEPA filtration and a high air-change rate. Although filtration with HEPA was effective during normal conditions, it alone was unable to prevent the rise of Aspergillus contamination related to building renovation. This study emphasized the necessity of an environmental survey of airborne contamination related to construction, to facilitate prevention of nosocomial aspergillosis outbreaks. A standardized protocol for aerobiological surveillance is needed.

Air Microbiology↗
PubMed1999

Exophiala (Wangiella) dermatitidis keratitis after keratoplasty.

We report the first French case of an intraocular infection due to Exophiala (Wangiella) dermatitidis. Two months after a second corneal transplant for congenital hereditary endothelial dystrophy, the patient presented with ocular pain and corneal infiltrates leading to the graft rejection. Diagnosis was established by positive direct examination and cultures of the same fungus from corneal buttons, iris biopsies and ablated sutures.

Adult↗
PubMed1998

Cloning of the canine beta-glucuronidase cDNA, mutation identification in canine MPS VII, and retroviral vector-mediated correction of MPS VII cells.

Mucopolysaccharidosis type VII (MPS VII) is an inherited disease resulting from deficient activity of the lysosomal acid hydrolase beta-glucuronidase (GUSB) and has been reported in humans, mice, cats, and dogs. To characterize canine MPS VII, we have isolated and sequenced the canine GUSB cDNA from normal and affected animals. A single nucleotide substitution was detected in the GUSB cDNA derived from MPS VII dogs. This guanosine to adenine base change at nucleotide position 559 in the canine cDNA sequence causes an arginine to histidine substitution at amino acid position 166. Introduction of the G to A substitution at position 559 in a mammalian expression vector containing the normal canine GUSB cDNA nearly eliminated the GUSB enzymatic activity, demonstrating that this mutation is the cause of canine MPS VII. A retroviral vector expressing the full-length canine beta-glucuronidase cDNA corrected the deficiency in MPS VII cells.

Amino Acid Sequence↗
PubMed1997

Streptococcal pyrogenic exotoxin A, streptolysin O, exoenzymes, serotype and biotype profiles of Streptococcus pyogenes isolates from patients with toxic shock syndrome and other severe infections.

The determination of protein M and T serotypes, biotypes and pyrogenic (erythrogenic) exotoxin A (SPE A), streptolysin O (SLO), streptokinase (SK), hyaluronidase (HA) and cysteine proteinase release by 212 S. pyogenes isolates from patients with severe invasive group A streptococcal (GAS) infections, among them 74 cases of streptococcal toxic shock syndrome (STSS) has been investigated. M1 or M3 serotypes were expressed by 25% of the isolates (53/212), whereas 59% (125/212) belonged to 15 other different serotypes and 16% (34/212) were untypeable. Of the 74 isolates from STSS patients, 42% (31/74) expressed M1 and to a lesser extent M3 serotypes versus 19% of the non STSS isolates (26/138). Among the ten different biotypes known, biotypes 1 and 3 were prevalent, particularly the former in the case of STSS isolates. SPE A was detectably produced by about 25% (54/212) of the strains. However, as high as 40.5% of the STSS isolates (30/74) versus 17.4% of non STSS isolates (24/138) released SPE A. Moreover, 67% of the SPE A producing strains were of serotype M1 or M3. SK and HA were released by 71% and 10% of the isolates respectively. All strains released SLO (4 to 256 HU/ml) and 85% cysteine proteinase. No relationship between toxin or enzyme titer and the type of disease or clinical origin of the strains was found. Culture supernatants of all isolates showed moderate to high lymphocyte transforming activity with index values ranging from 14.5 to 50.3 including those strains which did not release detectable amounts of SPE A suggesting that SPE C and other mitogenic factor(s) are released by the isolates investigated.

Adolescent↗
PubMed1996

Septicaemia caused by phenotypic variants of group A streptococci.

Clinical isolates (115) of Streptococcus pyogenes responsible for septicaemia were investigated to determine whether invasiveness may be correlated with a large variety of strains, or concerns only particular phenotypes. Irrespective of their clinical origin, the strains studied displayed seven of the ten biotypes described within this species. As already observed in a series of strains isolated from pharyngitis, a restricted association between M-types and biotypes was demonstrated; each M-type corresponded to a sole biotype. However, the proportion of biotypes 3, 5 and 7 was higher in the septicaemia series than in the pharyngitis series, with a larger variety of M-types and with more non-typable strains. Despite these differences, the restricted associations between these characters were concordant in both series. These results demonstrate that streptococcal septicaemias appear to be caused by a wide variety of strains, suggesting that multiple factors may be involved in the invasiveness of the bloodstream during streptococcal infections.

Adolescent↗
PubMed1995

[Tuberculosis in a Parisian pneumology department: 151 cases].

OBJECTIVES: The incidence of tuberculosis has risen since 1992. We studied cases observed in our department to search for factors favouring this increased incidence. METHODS: A retrospective assessment of 151 cases of tuberculosis observed over a 3 year period in a department of pneumology in Paris was performed. RESULTS: Fifty-two percent of the patients were foreigners; 66% lived in a poor socio-economic environment included 18% with no permanent residence; 29% were alcoholics. An association with human immunodeficiency virus infection was seen in 7% of the cases. Another immunodepression factor was found in 15%. Tuberculosis was discovered in a context of respiratory distress in 7% or the patients. Outcome was fatal in 6%. Three months after diagnosis 22% of the patients were lost to follow-up. CONCLUSION: This series emphasizes the major role of socio-economic factors in the rising incidence of tuberculosis and the need for urgent and adapted measures for therapeutic management in an often non-compliant and socially instable population.

AIDS-Related Opportunistic Infections↗
PubMed1995

Human endocarditis due to nutritionally variant streptococci: streptococcus adjacens and Streptococcus defectivus.

Streptococcus adjacens and S. defectivus are two recently individualized species of viridans streptococci. Both species were previously designated as nutritionally variant streptococci and characterized by their growth as small satellite colonies supported by 'helper' bacteria, or requiring complex media enriched with cysteine or with pyridoxal. Structural abnormalities were observed under these conditions and balanced growth can be obtained only with a semi-chemically defined medium, in which the cells are morphologically normal and exhibit a parietal chromophore. The two species are primarily isolated from the oral cavity, or from intestinal and genito-urinary tracts. They are likely to be responsible for most blood-culture-negative endocarditis and account for more than 4% of streptococcal strains isolated from blood cultures during this disease. Cases of endocarditis caused by these bacteria exhibit much higher rates of failure, relapse and mortality than those due to other viridans streptococci. The slow growth rate of the bacteria and the production of large amounts of exopolysaccharide in vivo may account for the difficulties encountered in treatment and suggest that a longer course of antimicrobial therapy may be required for successful cures. Results obtained from experimental models of endocarditis confirmed the efficacy of vancomycin as an alternative therapy in patients when a combination of penicillin and aminoglycoside is ineffective or contraindicated.

Animals↗
PubMed1995

Analysis of enzymatic activities for differentiation of two species of nutritionally variant streptococci, Streptococcus defectivus and Streptococcus adjacens.

Strains of nutritionally variant streptococci, Streptococcus defectivus (n = 10) and Streptococcus adjacens (n = 20), were studied for the production of glycosidic and proteolytic enzyme activities. S. defectivus strains produced neuraminidase and alpha-fucosidase, while S. adjacens strains produced only neuraminidase. The S. adjacens strains produced a very wide range of proteolytic activities with the ability to hydrolyze the majority of aminopeptidase substrates tested, while S. defectivus strains hydrolyzed only a minority of aminopeptidase substrates. These data provide additional phenotypic characteristics which may be useful in distinguishing between these two species and suggest that they may have different nutritional requirements.

Amino Acid Sequence↗
PubMed1994

Epidemiology of Staphylococcus aureus in patients with cystic fibrosis.

Seven hundred and thirty-four isolates of Staphylococcus aureus, recovered from the sputum of 238 cystic fibrosis patients in six French hospitals, were characterized by esterase electrophoretic typing, capsular polysaccharide serotyping and phage typing and tested against 14 antibiotics for sensitivity. Thirty-four esterase electrophoretic types were found with a genotypic diversity coefficient of 0.91. Five hundred and forty-eight (78.7%) isolates produced capsular polysaccharide and 350 (50.3%) were type 8. Four hundred and sixty isolates (66.6%) were phage typable and 202 (28.2%) were lysed by group III bacteriophages. No esterase electrophoretic type, capsular type or phage type was specific to cystic fibrosis. Isolates belonged to a wide range of types, similar to strains acquired outside hospitals. Eighty-five patients had three or more consecutive isolates over at least 6 months. The ability of S. aureus to persist for long periods of time has been demonstrated in 73% of them. Methicillin-resistance was encountered among 73 strains (9.8%) which were also multiresistant. Two hundred and eighty-nine (39.9%) strains were sensitive to all antibiotics tested except to penicillin. Pristinamycin and co-trimoxazole were the most effective antibiotics. These results could contribute to the elaboration of a rational approach to the prophylaxis and therapy of respiratory staphylococcal infections in cystic fibrosis patients.

Bacterial Capsules↗
PubMed1994

Restricted association between biotypes and serotypes within group A streptococci.

Investigating individual variations between different isolates of group A streptococci, we observed a close correlation between biotypes and serotypes in 46 strains from pharyngitis patients. Biotyping, carried out with a commercially available rapid identification gallery, delineated 10 different associations of characteristics, designated biotypes 1 to 10, observed both in the manufacturer's (127 strains) and our personal (98 strains) collections of group A strains. Only the most frequent biotypes (biotypes 1 to 6) were observed in the pharyngitis cohort, but the overall frequencies of the biotypes did not display striking differences compared with the control collections. Serotyping of the pharyngitis strains showed that each M type was restricted to a sole biotype. For example, M types 1, 4, and 28 were found only in biotype 1 and M type 6 was found only in biotype 6 strains. This association was not due to an epidemiologic bias, since it was also observed in a control series consisting of reference strains and isolates from distant countries (the United States and Czech Republic versus France). An exception was for M type 78, which exhibited biotype 3 or biotype 4. Investigation of the heterogeneity of the strains at the DNA level showed no significant variations of the ribotype patterns between strains of different biotypes, confirming that group A streptococci belong to a unique and homogeneous species. This previously undescribed association between serotypes and biotypes is of interest for a rapid and preliminary characterization of strains isolated in individual patients or during an outbreak. A possible pathogenic association of some biotypic characteristics with specific M proteins is envisaged.

Adolescent↗
PubMed1993

Identification of pig chromosomes in pig-mouse somatic cell hybrid bivariate flow karyotypes.

To identify pig chromosomes in pig-mouse somatic cell hybrids, dual-laser flow karyotypes and GTG-banded metaphase spreads of pig, mouse, and 7 pig-mouse hybrid cell lines were compared. Pig chromosomes no. 1, 2, 5, 6, 10, 11, 13, 14, 16, 18, X and Y were tentatively assigned to individual peaks in the pig flow karyotype on the basis of DNA content vs. relative chromosome length. In the 7 hybrid cell lines, 7 out of 8 peaks distinct from those of the mouse cell line could be correlated with the presence of pig chromosomes no. 5, 9, 10, 11 or 16, 14, 15, and 18, whereas 1 peak appeared to correspond to the presence of 1 middle-size chromosome (3, 4, or 7). Other pig chromosomes present in the hybrids could not be detected with certainty due to superposition with mouse peaks and mouse chromosome rearrangements.

Animals↗
PubMed1993

New latex reagent using monoclonal antibodies to capsular polysaccharide for reliable identification of both oxacillin-susceptible and oxacillin-resistant Staphylococcus aureus.

A new latex agglutination test (Pastorex Staph-Plus, Sanofi Diagnostics Pasteur), consisting of a mixture of latex particles coated with fibrinogen and immunoglobulin G for the detection of clumping factor and protein A and latex particles sensitized with monoclonal antibodies directed to Staphylococcus aureus serotype 5 and 8 capsular polysaccharides, was compared with three commercially available rapid agglutination methods for the identification of 220 isolates of S. aureus (61 oxacillin resistant) and 128 isolates of coagulase-negative staphylococci. The sensitivity for identification of S. aureus was high with the Pastorex Staph-Plus test (98.6%) compared with those of the other tests, which ranged from 91.8 to 84.5%. Test sensitivities for the identification of oxacillin-resistant S. aureus were as follows: Pastorex Staph-Plus, 95.1%; Pastorex Staph, 73.8%; Staphyslide, 72.1%; and StaphAurex, 49.2%.

Antibodies, Monoclonal↗