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B de Barbeyrac

Publications and source records attributed to B de Barbeyrac.

At least 19 recordsLinked to original sources
PubMed2006

Detection of Chlamydia trachomatis DNA using MagNA Pure DNA extraction and Cobas Amplicor CT/NG amplification.

The automated MagNA Pure DNA extraction method for Chlamydia trachomatis was compared with the manual Cobas Amplicor protocol using 100 microL of input sample volume from 964 specimens. Agreement between protocols was 96.1%. The automated extraction method had a sensitivity of 99% and a specificity of 100%. Amplification inhibition observed after manual preparation of samples (3.8%) was not apparent following automated extraction. Using 200 microL of sample in the automated extraction process lowered the detection limit without raising the inhibition rate. Furthermore, the automated extraction method halved the hands-on time required for the procedure.

Automation↗
PubMed2006

Rectal lymphogranuloma venereum surveillance in France 2004-2005.

Lymphogranuloma venereum (LGV) is a sexually transmitted infection (STI) caused by Chlamydia trachomatis strains belonging to the L1, L2 or L3 genotype. An alert about an outbreak of LGV among MSM in the Netherlands was published in January 2004. The first cases of rectal LGV in France were retrospectively diagnosed in March 2004 and sentinel surveillance for LGV was implemented in April 2004. Most of the participating centres were located in the cities of Paris and Bordeaux. Only confirmed rectal LGV cases were included in the surveillance. Rectal specimens from men that were found to be positive for C trachomatis by PCR were sent to the National Reference Centre for Chlamydia infection for genotyping. Simple epidemiological data provided by clinicians and genotyping results were sent to the Institut de Veille Sanitaire (InVS) where data were anonymously recorded. A total of 328 C. trachomatis rectal strains isolated in men were genotyped by the end of December 2005. Of these, 244 (74%) were LGV strains belonging to the L2 genotype. No L1 or L3 C. trachomatis genotype was found. Diagnosis was made retrospectively for 46 cases. The median age of patients with LGV was 39 years. HIV status was known for 96 patients: 82/96 (85%) were HIV-infected. Most LGV cases were diagnosed in the Paris area (92%). Among the remaining 26% C. trachomatis strains, genotypes Da and G were the most frequent. As with syphilis in recent years, the emergence of LGV in Europe is mainly affecting HIV-infected MSM. The screening and treatment of STIs should be included in the clinical follow-up of all HIV-infected MSM.

Adult↗
PubMed2005

[Epidemiology of sexually transmitted infections in France].

BACKGROUND: Sexually transmitted infections (STI) in France are reported on a voluntary basis through several sentinel surveillance systems. METHODS: To monitor STI, sentinel laboratory- or clinician-based surveillance systems were set up by the Institut de Veille Sanitaire: gonorrhea surveillance (Renago) in 1986, Chlamydia infections surveillance (Renachla) in 1989, and more recently, syphilis surveillance in 2000 and rectal lymphogranuloma venereum (LGV) in 2004. RESULTS: From 2000 to 2003, 1,089 syphilis infections were reported. Most of the cases were diagnosed in men having sex with men (MSM) and were mainly reported by STI clinics located in the Paris area. From 1997 to 2000, an increase of gonorrhea was observed each year. After two years of stable trend, the prevalence of gonorrhea increased again in 2003. From 2002 to 2004, 123 LGV cases were diagnosed in France and were observed only in MSM. Since 2001, Chlamydia infections have steadily increased, particularly in women. COMMENTS: Because STI surveillance is based on a voluntary basis, the number of reported cases is probably lower than the number of STI diagnosed in France. However, the data provided by the different surveillance systems reveals that STI have been increasing in France since 1997. Moreover, the resurgence of syphilis in 2000 and the emergence of rectal LGV in 2004 indicate that these STI occur mainly in MSM. Trends on incidence and patients characteristics observed in France are similar to those of several Europeans countries. European Public Health interventions are becoming necessary to prevent and control STI.

Chlamydia Infections↗
PubMed2005

[Chlamydial pathogenesis: diagnostic and therapeutic consequences].

Chlamydiae are among the most common of the human pathogens. Clinical persistence is a key concept in chlamydial pathogenesis. The damaging disease sequelae such as sterility caused by Chlamydia trachomatis and coronary artery disease associated with Chlamydia pneumoniae, are caused by inflammation-based pathology. Although chlamydiacidal antibiotics may kill the bacteria, chlamydial antigens may persist for prolonged period and there is evidence that these non-cultivable forms may lead to continued inflammation. The problem is the difficulty inherent in proving the presence of chronic chlamydial infection. Only nucleic acid amplification test can diagnose these large atypical forms. Clinical treatment failures have been reported and the persistence of the microorganisms raises the question about optimal therapy.

Anti-Bacterial Agents↗
PubMed2002

Culture-negative endocarditis due to Chlamydia pneumoniae.

We report on the case of a 54-year-old woman diagnosed as having culture-negative endocarditis (clinical and histopathologic evidence compatible with a recent episode of endocarditis). The responsibility of Chlamydia pneumoniae in this episode of endocarditis was suggested by a serological study and was then confirmed by the positive results of PCR and in situ hybridization tests with aortic and mitral valves tissues. To our knowledge, this is the first case of endocarditis due to C. pneumoniae confirmed by molecular biology-based techniques.

Blood↗
PubMed2001

Direct genotyping and nucleotide sequence analysis of VS1 and VS2 of the Omp1 gene of Chlamydia trachomatis from Moroccan trachomatous specimens.

To determine the range of ocular strains of Chlamydia trachomatis circulating in southern Morocco, where trachoma is endemic, and to compare the value of the molecular methods for genotyping C. trachomatis, ocular specimens were subjected to a direct Omp1 PCR-restriction fragment length polymorphism (RFLP)-based analysis and direct sequencing. PCR-RFLP analysis shows that the Ba genotype represents the most frequent one (63%), followed by genotype A (45%), whereas no B or C genotypes were identified among the 53 out of 108 specimens that were strongly positive in the Omp1 CT1-CT5 PCR. Our results further show that the notion of interfamily and intrafamily transmission is very likely. To confirm the genotype identity of C. trachomatis as determined by PCR-RFLP, 16 selected specimens were sequenced across variable sequence 1 (VS1) and 2 (VS2). No discrepancies were found between PCR-RFLP typing and the genotype identity confirmed by nucleotide sequencing of the PCR product. Our results clearly indicate that both molecular methods of typing chlamydiae (i.e., PCR-RFLP and sequencing) are important and have specific applications for clinical epidemiological purposes. This is the case for individuals infected with more than one clonal population of C. trachomatis. The unambiguous nucleotide sequencing therefore defines an important epidemiologic descriptor for the infected patient whether the source is from a clonal population of organisms or whether it represents a more dynamic process of strain dominance or genetic change. Furthermore, Omp1 genotyping affords the necessary approach to epidemiologic investigations in areas of the world endemic for trachoma, where only one or two serovars are known to predominate.

Bacterial Outer Membrane Proteins↗
PubMed2001

Determinants of transfusion-associated bacterial contamination: results of the French BACTHEM Case-Control Study.

BACKGROUND: Transfusion-associated bacterial contamination (TABC), probably the most frequent transfusion-transmitted infection, may induce serious adverse events. Systematic information and documentation on determinants are lacking. STUDY DESIGN AND METHODS: The BACTHEM Study is a French matched case-control study assessing TABC determinants. Included were cases of TABC reported in France in a 2-year period, as determined from uniform definitions. Information on recipient-, blood component-, and donor-related potential determinants was collected on site. ORs were estimated by conditional logistic regression. RESULTS: Of the 158 cases of suspected TABC reported, 41 that involved transfusion with 25 RBCs and 16 platelet concentrates were included. Gram-negative rods accounted for nearly half of the bacteria species involved and for all six deaths. In comparison with the risk of TABC for patients receiving RBCs for anemia, the risk was higher for patients receiving RBCs for pancytopenia (OR, 7.3; 95% CI, 1.3-41.0) and for those receiving platelets for thrombocytopenia (OR, 5.3; 95% CI, 1.2-24.1). Other potential determinants were platelet transfusion for pancytopenia (OR, 4.5; 95% CI, 0.5-40.0), immunosuppressive treatment (OR, 2.8; 95% CI, 0.7-10.6), shelf-life of more than 1 day for platelets or 8 days for RBCs (OR, 2.6; 95% CI, 0.7-9.6), and more than 20 previous donations by donors (OR, 1.9; 95% CI, 0.7-5.3). CONCLUSION: This first comparative study revealed TABC determinants that suggest approaches for prevention.

Adult↗
PubMed2000

Detection of Chlamydia trachomatis in symptomatic and asymptomatic populations with urogenital specimens by AMP CT (Gen-probe incorporated) compared to others commercially available amplification assays.

The present study was designed to evaluate the sensitivity and specificity of AMP CT (Gen-Probe Incorporated, San Diego, CA, USA) on urogenital specimens taken from symptomatic patients and on first void urine (FVU) specimens from asymptomatic patients. In symptomatic patients, 618 specimens from 140 men (140 urethral swabs and 140 FVU) and 202 women (202 endocervical swabs and 136 FVU) were tested by using cell culture, AMP CT and Amplicor Chlamydia trachomatis MWP (microwell plate) (Roche Diagnostics, Somerville, NJ, USA) on genital samples, and AMP CT and Amplicor on FVU. A clinical specimen was considered to be truly positive if either the cell culture was positive and/or both AMP CT and Amplicor were positive. In the asymptomatic population, a total of 300 FVU (136 women and 164 men) were tested by four amplification methods, AMP CT, LCx (Abbott, Abbott Park, IL, USA), Amplicor MWP, and Cobas Amplicor. A subject was considered to be infected when two or more amplification methods were positive. In the symptomatic population (prevalence 13%), concordant results were observed in 320/342 cases (93.5%). After analysis of discordant results, the sensitivity of AMP CT, Amplicor, and culture was 100%, 95.5%, 68.8%, respectively, and the specificity was 98.3%, 99.3%, 100% respectively. The number of false negative results by AMP CT in urine, probably due to labile inhibitors, was 3/276 (1%). In the asymptomatic population, the results were concordant in 298/300 (99.3%), seven positive and 291 negative. Two results were considered false positives, one by Cobas Amplicor, one by AMP CT. Compared to other amplification methods, AMP CT is at least as sensitive for the identification of chlamydial infection in symptomatic and asymptomatic men and women on genital or urine specimens.

Adult↗
PubMed2000

Molecular typing of Mycoplasma pneumoniae strains by PCR-based methods and pulsed-field gel electrophoresis. Application to French and Danish isolates.

Restriction fragment length polymorphism (RFLP) analysis of the amplified P1 gene was used to type 153 strains of Mycoplasma pneumoniae isolated in France between 1977 and 1994, and in Denmark between 1962 and 1994, and an additional group of 28 strains isolated from Belgium and Germany between 1990 and 1993. Random amplified polymorphic DNA (RAPD) analysis was tested on French, Belgian and German strains. Both methods separated the strains into two groups corresponding to the two reference strains M129 (group I) and FH (group II), and gave concordant results. When 75 selected strains of different geographical origin were analysed by pulsed-field gel electrophoresis (PFGE), strains of group II fell into two closely related subgroups, subgroup IIa corresponding to the reference strain FH, and subgroup IIb. Most of the strains isolated in Denmark in the period 1962-86 belonged to group I. Almost all strains isolated in France and Denmark between 1987 and 1988 were from group II, the two subgroups being present. In 1991-3, almost all strains from France as well as Denmark, Germany and Belgium belonged to group I.

Bacterial Typing Techniques↗
PubMed1999

Agrobacterium radiobacter as a cause of pseudobacteremia.

Agrobacterium radiobacter was isolated from 15 blood cultures collected from 15 newborns. Contamination of blood cultures was suspected because, in most cases, the babies' illnesses seemed incompatible with infection. A radiobacter was isolated from citrated tubes used for clotting-factor studies. Review of venipuncture technique revealed that occasionally the coagulation study tubes were being inoculated before the blood-culture bottles. This investigation demonstrated how an environmental source coupled with faulty technique caused a cluster of false-positive blood cultures.

Bacteremia↗
PubMed1999

Mutations in the gyrA, parC, and parE genes associated with fluoroquinolone resistance in clinical isolates of Mycoplasma hominis.

Five clinical isolates of Mycoplasma hominis from three different patients were examined for resistance to fluoroquinolones; some of these isolates were probably identical. All five isolates harbored amino acid substitutions in the quinolone resistance-determining regions of both DNA gyrase (GyrA) and topoisomerase IV (ParC or ParE). Furthermore, the novobiocin MIC for three isolates showed a significant increase. This is the first characterization of fluoroquinolone-resistant clinical mycoplasma isolates from humans.

Anti-Infective Agents↗
PubMed1998

Antibiotic susceptibility testing for Chlamydia trachomatis using flow cytometry.

The aim of this study was to compare the effectiveness of two methods of antibiotic susceptibility testing performed on Chlamydia trachomatis-infected cells: a flow cytometric detection method and the standard method, which consists of a microscopic reading of minimal inhibitory concentration (MIC). The L2 reference strain and 13 clinical strains isolated from six patients presenting recurrent infections were tested. McCoy cells infected with an inoculum of 10(5) inclusion forming units (IFU)/ml were incubated with serial dilutions of doxycycline, ofloxacin, and erythromycin. Mean fluorescence intensity (MFI) of cells was determined by flow cytometry after staining of chlamydial inclusions with an anti-Chlamydia fluorescent monoclonal antibody. The end-point values determined by flow cytometry and microscopic reading were equivalent but presented the same imprecision. Calculation of the inhibitory concentration 50 (IC50) by flow cytometry, defined as the antibiotic concentration required to reduce the drug-free control MFI by 50%, allowed a more objective and precise evaluation of antibiotic activity than MIC. Moreover, IC50 values were reproducible, independent of the antibiotic dilution series tested, and could be used to compare the in vitro efficiency of various drugs on C. trachomatis. No resistant strain was found among the 13 clinical isolates of C. trachomatis tested.

Anti-Bacterial Agents↗
PubMed1998

Propionibacterium acnes isolated from synovial tissue and fluid in a patient with oligoarthritis associated with acne and pustulosis.

This report describes the case of a patient with a 14-month course of severe oligoarthritis associated with acne. Pure cultures of Propionibacterium acnes were isolated from synovial tissue and synovial fluid specimens collected from the same joint after a 4-month interval. After 2 months of treatment with roxithromycin 300 mg/day, rifampicin 1,200 mg/day, and a nonsteroidal antiinflammatory drug (NSAID), followed by 4 months of treatment with azithromycin 1 gm/week and an NSAID, the synovitis persisted. Cultures of skin lesions and synovial fluid at this time were negative. Although P acnes has previously been isolated from bone specimens obtained from patients with osteitis associated with acne, this is the first report of the isolation of this microorganism from the synovial tissue of a patient with arthritis associated with acne. Our findings raise the question of the role of P acnes in the pathogenesis of arthritis associated with acne.

Acne Vulgaris↗
PubMed1998

Sequencing of gyrase and topoisomerase IV quinolone-resistance-determining regions of Chlamydia trachomatis and characterization of quinolone-resistant mutants obtained In vitro.

The L2 reference strain of Chlamydia trachomatis was exposed to subinhibitory concentrations of ofloxacin (0.5 microg/ml) and sparfloxacin (0.015 microg/ml) to select fluoroquinolone-resistant mutants. In this study, two resistant strains were isolated after four rounds of selection. The C. trachomatis mutants presented with high-level resistance to various fluoroquinolones, particularly to sparfloxacin, for which a 1,000-fold increase in the MICs for the mutant strains compared to the MIC for the susceptible strain was found. The MICs of unrelated antibiotics (doxycycline and erythromycin) for the mutant strains were identical to those for the reference strain. The gyrase (gyrA, gyrB) and topoisomerase IV (parC, parE) genes of the susceptible and resistant strains of C. trachomatis were partially sequenced. A point mutation was found in the gyrA quinolone-resistance-determining region (QRDR) of both resistant strains, leading to a Ser83-->Ile substitution (Escherichia coli numbering) in the corresponding protein. The gyrB, parC, and parE QRDRs of the resistant strains were identical to those of the reference strain. These results suggest that in C. trachomatis, DNA gyrase is the primary target of ofloxacin and sparfloxacin.

Amino Acid Sequence↗
PubMed1998

Genotypic characterization of seven strains of Mycoplasma fermentans isolated from synovial fluids of patients with arthritis.

We performed a genotypic characterization of seven strains of Mycoplasma fermentans which have been isolated from the synovial fluid of patients with rheumatoid arthritis (n = 2), spondyloarthropathy (n = 1), and unclassified arthritis (n = 4). We compared them to three reference strains (strains PG18 and K7 and incognitus strain) and to a clinical isolate from the urethra of a patient with nongonococcal urethritis. The characterization methods included electrophoresis of native DNA, arbitrarily primed PCR, and restriction fragment length polymorphism analysis following conventional and pulsed-field gel electrophoresis. Southern blot analysis with a probe internal to an insertion sequence was performed with the restriction products produced by the last two techniques. No extrachromosomal DNA sequences were detected. The M. fermentans strains identified by these methods did not present a unique profile, but they could be separated into two main categories: four articular isolates were genetically related to PG18 and the three other isolates, the urethral isolate, and the incognitus strain were related to K7. We also looked for the presence of the bacteriophage MAV1 (associated with the arthritogenic property of Mycoplasma arthritidis in rodents) in the M. fermentans strains. MAV1 DNA was not detected in either the clinical isolates or the reference strains of M. fermentans.

Adult↗
PubMed1997

New developments in diagnostic and treatment of mycoplasma infections in humans.

Several methods can be used for the diagnosis of mycoplasmal human infections. Culture is not satisfactory for fastidious species, while serological procedures allow only a retrospective diagnosis. Recently, rapid methods have become available. Antigenic detection proposed for Mycoplasma pneumoniae lacks sensitivity. Hybridization based techniques include DNA probes and mainly DNA amplification. The main usefulness of the polymerase chain reaction (PCR) is the detection of fastidious organisms such as M. pneumoniae, M. genitalium, M. fermentans, M. penetrans, but PCR can also be used for characterization of the strains for epidemiological purposes, or for detection of antimicrobial resistance genes. The major advantage of PCR for detection is its very high sensitivity. However, until now, the major drawback of this technique has been the lack of commercial kits. When available, they should provide better standardization of the technique and, if available at a reasonable cost, become the major technique for the diagnosis of mycoplasma infections. The antibiotics used for the treatment of mycoplasmal infections belong to tetracyclines, macrolides-lincosamides and fluoroquinolones. These products are highly active in vitro against mycoplasmas. However, some of them have a differential activity according to the species, and acquired resistance has been reported, mainly in genital mycoplasmas. Most of mycoplasmal infections are cured by adapted antibiotics, but they may be difficult to cure in immunosuppressed patients.

Anti-Bacterial Agents↗
PubMed1996

A Tn1545-like transposon carries the tet(M) gene in tetracycline resistant strains of Bacteroides ureolyticus as well as Ureaplasma urealyticum but not Neisseria gonorrhoeae.

The presence of the tet(M) determinant and conjugative transposons related to Tn1545 in urogenital pathogens, Bacteroides ureolyticus (10 strains), Neisseria gonorrhoeae (37 strains) and Ureaplasma urealyticum (81 strains), was studied by PCR analysis and hybridization assay. All tetracycline-resistant strains that hybridized with a probe specific for tet(M) gave the expected fragment when their DNA's were subject to PCR. The tet(M) gene and int-Tn, the gene encoding the protein required for the movement of Tn1545-like transposons, were always found together in tetracycline resistant strains of B. ureolyticus and U. urealyticum. In contrast, int-Tn was not detected in tet(M)-mediated tetracycline-resistant N. gonorrhoeae strains. These data suggest carriage of tet(M) by a Tn1545-like transposon in some tetracycline-resistant B. ureolyticus.

Bacteroides↗