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B Jaulhac

Publications and source records attributed to B Jaulhac.

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

One-step reverse transcriptase PCR method for detection of Borrelia burgdorferi mRNA in mouse Lyme arthritis tissue samples.

A one-step reverse transcriptase PCR (RT-PCR) method for detection of Borrelia burgdorferi mRNA in infected C3H mice is described. This simple procedure, less prone to nucleic acid cross-contamination than the standard method, was found to be 10-fold more sensitive than a classical two-step RT-PCR assay. By using one-step RT-PCR, flagellin mRNAs were detected in synovial and heart tissues from all seven infected mice tested.

Animals↗
PubMed1998

Comparison of sample preparation methods for detection of Legionella pneumophila in culture-positive bronchoalveolar lavage fluids by PCR.

A prospective study was conducted on 25 Legionella pneumophila culture-positive and 98 culture-negative bronchoalveolar lavage fluid samples to compare two DNA preparation methods: a rapid modified Chelex-based protocol and a proteinase K method. PCR was found to be more sensitive with the Chelex-based method (P = 0.03). N difference was found concerning the inhibition rate.

Bacteriological Techniques↗
PubMed1997

Seroreactivity to Borrelia burgdorferi antigens in early rheumatoid arthritis: a case-control study.

This study investigates the seroreactivity to Borrelia burgdorferi antigens of patients suffering from rheumatoid arthritis (RA) for < 5 yr. Subjects were matched with controls for age, sex and area of residence in order to minimize the risk of differential exposure to B. burgdorferi. A total of 57 pairs were tested by immunofluorescence assay (IFA) and Western blotting. Only two RA patients showed positive IFA results, and another was positive by Western blot analysis. No significant difference in Lyme seropositivity was detected between cases and controls using either serological test. Furthermore, no significant difference in antibody response was observed to specific or non-specific proteins (e.g. Osp C, 93 kDa protein, flagellin, heat shock proteins). These results do not support the previous suggestions that B. burgdorferi may be involved in the aetiology of RA, or that RA favours the production of antibodies that cross-react with B. burgdorferi proteins.

Adult↗
PubMed1997

Prevalence of Bartonella henselae and Bartonella clarridgeiae in stray cats.

The aim of the present work was to determine by blood culture the prevalence of blood infection with Bartonella species in a well-defined, European, urban stray cat population. Therefore, 94 stray cats were trapped from 10 cat colonies. Blood samples of these cats were cultured on both blood agar and liquid medium in order to raise the likelihood of bacterial detection. Fifty blood samples (53%) gave a positive culture result for Bartonella species. Isolate identification was performed by sequencing the first 430 bases of the 16S ribosomal DNA. Three types of sequences were thus obtained. The first type (17 isolates; 34%) was identical to that of B. henselae Houston-1 and the corresponding strains were referred as B. henselae type I. The second sequence type (18 isolates; 36%) was identical to that initially described as "BA-TF," and the corresponding strains were referred to as B. henselae type II. The third sequence type (15 isolates; 30%) was identical to that of the Bartonella clarridgeiae type strain (ATCC 51734). Our study points out the major role of stray cats as a reservoir of Bartonella spp. which can be transmitted to pet cats and, consequently, to humans. The study also highlights the high prevalence of B. clarridgeiae (16%) in the blood of stray cats.

Animals↗
PubMed1996

Detection of Borrelia burgdorferi by DNA amplification in synovial tissue samples from patients with Lyme arthritis.

OBJECTIVE: To compare the detection rates of chromosomal flagellin gene from Borrelia burgdorferi in synovial tissue (ST) and synovial fluid (SF) using polymerase chain reaction (PCR) techniques. METHODS: B burgdorferi DNA was sought in SF and ST from 12 consecutive patients with Lyme arthritis and from 29 patients with noninfectious diseases (controls). RESULTS: No DNA amplification was observed in samples obtained from the 29 control patients, whereas B burgdorferi DNA was detected in all ST and/or SF samples from the 12 patients with Lyme arthritis. Results from 1 ST sample were not interpretable because of PCR inhibitors. Among the 11 remaining patients, 10 had positive ST samples, whereas only 4 had positive SF samples (P < 0.05). CONCLUSION: These data suggest that detection of chromosomal B burgdorferi DNA may be more efficient in ST than SF.

Adolescent↗
PubMed1996

Identification of Mycobacterium shimoidei in a tuberculosis-like cavity by 16S ribosomal DNA direct sequencing.

A new, well-documented case of Mycobacterium shimoidei infection is reported. This bacterium was isolated from a patient with preexisting pulmonary lesions who developed a tuberculosis-like cavity in the lung. Isolation of fewer than ten strains, not epidemiologically related, has been reported worldwide; all originated from human pulmonary samples. Identification of the strain described here was first accomplished by 16S rDNA direct sequencing after in vitro amplification. This method allows rapid identification of unusual bacteria. The identification was confirmed by specific phenotypical tests and by chromatographic methods.

Adult↗
PubMed1996

Diagnostic value of the indirect immunofluorescence assay in cat scratch disease with Bartonella henselae and Afipia felis antigens.

Serum samples from 35 cat scratch disease (CSD) patients, 180 control patients (123 without lymph node enlargement and 57 with lymph node enlargement not evoking CSD), and 102 nonpatient subjects (35 with cat contact and 67 without cat contact) were tested by semiquantitative indirect immunofluorescence assay for the presence of antibodies directed to Afipia felis (ATCC 53690T) or Bartonella henselae (ATCC 49882T). The CSD group had statistically higher antibody titers against B. henselae than the control groups (P < 10(-5)), whereas no difference in A. felis antibody titers was evidenced among all groups tested. Among the 317 serum samples studied, the three with high A. felis antibody titers ( > or = 64) also had high antibody titers against other alpha-2 proteobacteria. The value of the indirect immunofluorescence assay with B. henselae antigen for the diagnosis of CSD was as follows: for a cutoff of 32, sensitivity was 0.80, specificity was 0.85, and the likelihood ratio was 5.1; for a cutoff of 64, the likelihood ratio was 12.1. In summary, in France, CSD is associated with high antibody titers against B. henselae, as previously described in the United States. However, the causes for B. henselae seronegativity in CSD patients and those for high antibody titers outside the typical nosological frame of CSD still have to be identified.

Adult↗
PubMed1995

Diagnosis of Lyme disease. Current difficulties and prospects.

Articular manifestations of Lyme disease may be less common in Europe than in the United States, perhaps because European strains of Borrelia burgdorferi are characterized by greater genetic diversity and different organotropisms as compared with American strains. The diagnosis rests on clinical symptoms. A history of erythema migrans is pathognomonic. Isolated articular manifestations with no history of erythema migrans raise difficult diagnostic problems. Monoarthritis and asymmetric oligoarthritis is the most characteristic pattern; enthesitis can occur, a clinical feature shared with spondylarthropathy. Serologic tests (indirect immunofluorescence, Western blotting) have not been standardized and should be used only to confirm the diagnosis in patients with suggestive clinical manifestations. The interpretation of serologic test results is made difficult by the high seroprevalence rates seen among the general population in endemic areas, where subclinical Borrelia burgdorferi infection probably occurs. Detection of Borrelia burgdorferi DNA using polymerase chain reaction amplification is a potent tool both for diagnosis and for gaining insight into the pathophysiology of Lyme disease. However, difficulties subsist (risk of contamination of the specimens, inhibitory effects). Continued work is needed to determine which targets (chromosomal DNA, plasmidic DNA) and specimens (joint fluid and/or synovial membrane) provide optimal results.

Blotting, Western↗
PubMed1995

Effects of bacterial naso-oropharyngeal colonisation on acute graft-versus-host disease in patients undergoing allogeneic bone marrow transplantation.

The efficacy of gastrointestinal decontamination in reducing the incidence of severe bacterial or fungal infections and of moderate to severe acute graft-versus-host disease (GVHD) has been suggested. We report here a retrospective study of 71 patients grafted consecutively in our institution with bone marrow from HLA genotypically identical siblings. Complete decontamination (plastic isolator or laminar airflow room, sterile nursing and oral antimicrobial drugs) was carried out in all patients. Sixty eight patients were evaluable. Only six patients had aerobic Gram negative rods or anaerobic bacteria in their faeces and 44 of 68 (65%) had yeasts in their faeces. Most patients had oropharyngeal and/or nasal colonisation with bacteria (Gram positive cocci: 39 patients (57%); Gram negative rods: 13 patients (19%)) or yeasts (29 patients (43%)). Thirty nine patients (57%) experienced severe grade > or = II acute GVHD (grade II-IV). A significant relation was found between bacterial oropharyngeal or nasal colonisation and GVHD (P < 0.01) but not between gastrointestinal microflora and GVHD, whatever microorganisms were considered (bacteria, yeasts).

Acute Disease↗
PubMed1995

[Value of molecular biology methods for diagnosis in bacteriology].

Progress in molecular biology has led to the development of new tools for bacteriological diagnosis. Sporadic genes coding for virulence factors can be detected with highly specific genetic probes applied to cultured bacteria. Such genetic probes can also be used to specifically identified cultured bacteria whose general taxonomic classification is known. Another advantage of molecular genetics is the possibility that the cell culture step may not be needed, bacteria being identified directly in the sample specimen. Such techniques are particularly interesting to identify bacteria which are difficult to culture (for example: Borrelia burgdorferi, Chlamydia trachomatis) or which grow slowly (mycobacteria). The bacterial DNA must be isolated and amplified with an enzyme reaction. This is a critical step in the method: several positive and negative controls are required. When performed under optimal conditions, amplification techniques are excellent methods which can offer results similar to culture methods in culturable bacteria. Finally, molecular biology can be used to identify previously cultured bacteria for which there is no taxonomic orientation. Here the ribosome 165 DNA must be amplified and sequenced. The sequence is then compared with a data bank allowing classification. One could image future techniques applied to certain pathology samples for the detection and identification of bacteria without need for a culture step. However, direct microscope examination and bacterial culture remain the basic methods for bacteriologic diagnosis, the advantages and disadvantages of molecular biology leading to its use a complementary method for improving the quality of the diagnosis.

Bacteriological Techniques↗
PubMed1992

Synthetic DNA probes for detection of genes for enterotoxins A, B, C, D, E and for TSST-1 in staphylococcal strains.

A dot blot hybridization technique with oligonucleotide probes was developed for the specific detection of the TSST-1 gene and the staphylococcal enterotoxin (SE) genes A, B, C, D and E. For each toxin gene a probe sequence was chosen from the previously determined sequence. A total of 145 staphylococcal strains (133 Staphylococcus aureus and 12 coagulase-negative staphylococci (CNS) were studied by this genotypic method and by two phenotypic assays (gel immunodiffusion and ELISA). An excellent correlation (96%) was observed between the genotypic and phenotypic assays. DNA from two CNS strains hybridized with a probe without detection of the corresponding toxin (SEB for one strain and SEC for the other strain). One Staph. aureus strain was shown to be an SEC producer, but was not detected by the corresponding probe. Gene probe and immunological assays seem to be complementary methods for studies of staphylococcal strains producing (or potentially producing) TSST-1 or enterotoxins.

Bacterial Toxins↗
PubMed1992

Detection of Legionella spp. in bronchoalveolar lavage fluids by DNA amplification.

By using Taq polymerase, DNA amplification of a specific fragment of the macrophage infectivity potentiator (mip) gene from Legionella pneumophila was used to detect Legionella spp. in bronchoalveolar lavage (BAL) fluid specimens. We were able to detect DNAs from all 30 L. pneumophila strains tested (serogroups 1 to 14), L. micdadei, and L. bozemanii serogroup 1. DNA from bacteria of other species tested and DNA from human leukocytes were not amplified by this procedure. After optimization of the conditions for DNA extraction from BAL fluid, a 2-ml sample of BAL fluid seeded with 25 CFU/ml tested positive after DNA amplification. A total of 68 frozen BAL fluid specimens sent to the laboratory because of suspected legionellosis were tested in a retrospective study. The eight culture-positive samples were all positive after specific DNA amplification. Among 60 culture-negative samples, 7 were positive after amplification. Of these seven samples, four were from patients who had presented a typical clinical history of legionellosis; the samples had antibody titer increases of 2 dilutions. For the three remaining samples, serological diagnosis of legionellosis in the patients from whom the samples were obtained could not be documented, and although the causative agent of these pulmonary infections was not determined, the clinical features of the patients were in accordance with legionellosis.

Bacteriological Techniques↗
PubMed1992

DNA fingerprinting by pulsed-field gel electrophoresis is more effective than ribotyping in distinguishing among methicillin-resistant Staphylococcus aureus isolates.

Pulsed-field gel electrophoresis (PFGE) after SmaI restriction of DNA from 239 methicillin-resistant Staphylococcus aureus isolates (from 142 patients) produced 26 different fingerprints. The deduced chromosome sizes ranged from 2,200 to 3,100 kb (+/- 100 kb). A total of 81 isolates taken from 65 patients were then typed by PFGE and ribotyping with ClaI, EcoRI, and HindIII. Ribotypes were less discriminating than PFGE. Ribotyping did not discriminate isolates from a given PFGE fingerprint into different subsets. PFGE may be a more effective epidemiological tool than ribotyping for the typing of methicillin-resistant S. aureus strains.

Bacterial Typing Techniques↗
PubMed1991

Specific detection of the toxic shock syndrome toxin-1 gene using the polymerase chain reaction.

A rapid and specific assay for toxic shock syndrome toxin-1 gene (tst gene) detection in Staphylococcus aureus was developed using the polymerase chain reaction. A two-primer set and an oligonucleotide detection probe were synthesized. After 40 cycles of amplification, detection of a 160-bp amplified DNA fragment was carried out by agarose gel electrophoresis and Southern blot hybridization. This assay was sensitive since it was able to detect 1-10 bacteria. It was also specific since no amplification was documented with DNAs from enterotoxigenic S. aureus or Gram-negative bacteria devoid of the tst gene.

Bacterial Toxins↗