[Urogenital infections linked to Chlamydia and mycoplasmas].

Chlamydia trachomatis is responsible for urogenital infections, often minimally symptomatic, revealed by their complications. Mycoplasmas, mainly Ureaplasma urealyticum and Mycoplasma hominis, are normal commensal organisms of the genital tract, which sometimes makes it difficult to determine their pathogenicity. However, they are responsible for urogenital infections, and U.

Mycoplasmas and arthritides.

Rheumatoid arthritis and other autoimmune diseases might be triggered by infectious agents. We have reviewed the evidence suggesting that mycoplasmas may play a role in the genesis of arthritis. Mycoplasmas are a common cause of spontaneous arthritis in many animal species.

Characterization of Mycoplasma hominis mutations involved in resistance to fluoroquinolones.

Fluoroquinolone-resistant mutants of Mycoplasma hominis were selected in vitro from the PG21 susceptible reference strain either by multistep selection on increasing concentrations of various fluoroquinolones or by one-step selection on agar medium with ofloxacin. The quinolone resistance-determining regions (QRDR) of the structural genes encoding the A and b subunits of DNA gyrase were amplified by PCR, and the nucleotide sequences of eight multistep-selected resistant strains were compared to those of susceptible strain PG21. Four high-level resistant mutants that were selected on norfloxacin or ofloxacin contained a C-to-T transition in the gyrA QRDR, leading to substitution of Ser-83 by Leu in the GyrA protein.

Study of the haemolytic process and receptors of thermostable direct haemolysin from Vibrio parahaemolyticus.

The haemolytic action of 125I-labelled thermostable direct haemolysin from Vibrio parahaemolyticus was studied on human and equine erythrocytes. In the first step, the haemolysin bound to the membranes of both erythrocyte species. This binding seemed temperature-independent.

Mycoplasma fermentans, but not M penetrans, detected by PCR assays in synovium from patients with rheumatoid arthritis and other rheumatic disorders.

Aim/background: Mycoplasmas, especially Mycoplasma fermentans, were suggested more than 20 years ago as a possible cause of rheumatoid arthritis but this hypothesis was never substantiated. In view of the superior sensitivity of the polymerase chain reaction (PCR) assay over culture, the aim was to use this method to seek M fermentans and M penetrans in synovial samples from patients with various arthritides.

Methods: Synovial fluid samples (n = 154) and synovial biopsy specimens (n = 20) from 133 patients with various rheumatic disorders were stored at -80 degrees C for between one and 40 months.

Epidemiological study of an outbreak due to multidrug-resistant Enterobacter aerogenes in a medical intensive care unit.

In 1993, 63 isolates of Enterobacter aerogenes were collected from 41 patients in a medical intensive care unit (ICU). During the same period, only 46 isolates from 32 patients were collected in the rest of the hospital. All isolates were analyzed by antibiotic resistance phenotype, and 77 representative isolates were differentiated by plasmid restriction analysis, ribotyping, and arbitrarily primed (AP)-PCR.

[Molecular typing by pulsed field gel electrophoresis of Stenotrophomonas maltophilia isolated in a department of hematology].

Stenotrophomonas maltophilia is an important nosocomial pathogen. The increased isolates of S. maltophilia among hematology unit patients led to an epidemiological survey.

[In vitro activity of a new quinolone, NM 394, against Chlamydia trachomatis].

A study of antimicrobial susceptibility of Chlamydia trachomatis was performed with a new quinolone, NM 394 (Laboratoire Dr. Bouchara). Ten C.

Epidemiological study of an outbreak of infection with Staphylococcus aureus resistant to lincosamides and streptogramin A in a French hospital.

A significant increase in the incidence of isolates of methicillin-resistant Staphylococcus aureus (MRSA), that were also resistant to lincosamides and streptogramin A (LSA-MRSA), was observed in a French university hospital. Twenty-seven isolates from the outbreak were characterised, including 17 isolates from a plastic surgery ward and six control strains of MRSA. The strains were examined by antibiotyping and biotyping, and by three molecular methods: plasmid analysis, ribotyping and insertion sequence (IS) typing with IS256 sequence as a probe.

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.

Arbitrarily-primed PCR confirms the differentiation of strains of Ureaplasma urealyticum into two biovars.

Fourteen serotypes are currently recognized in the Ureaplasma urealyticum species. These serotypes have been divided into two genomic clusters or biovars by a large number of typing methods. The parvo-biovar includes strains of serotypes 1, 3, 6 and 14 and the T960-biovar, strains belonging to the ten other serotypes.

Detection of Chlamydia trachomatis by ligase chain reaction compared with polymerase chain reaction and cell culture in urogenital specimens.

Objective: The aim of this study was to evaluate the newly developed ligase chain reaction (LCR) assay for the detection of Chlamydia trachomatis in urogenital specimens using cell culture and Amplicor PCR for comparison.

Subjects: Two hundred and eighty patients attending hospital or urban STD clinics (high-risk population, 62 men and 84 women) and obstetric/gynaecology clinics (low-risk population, 134 women) in Bordeaux, France.

Methods: Specimens from men were tested with LCR on urethral swabs and urine, with Amplicor or urine, with cell culture on urethral swabs.

Epidemiologic and molecular investigations of genital mycoplasmas from women and neonates at delivery.

The rates of colonization by Ureaplasma urealyticum and Mycoplasma hominis were evaluated in 208 women at delivery and in their neonates. Mycoplasmas were isolated from the cervicovaginal specimens of 100 mothers (48.1%) and from the gastric secretions of 40 neonates (19.

[Molecular typing by pulsed field gel electrophoresis of Pseudomonas (Burkholderia) cepacia isolated from a nosocomial infection].

Because of the emergence of Pseudomonas (Burkholderia) cepacia, isolated among patients from an intensive care unit of the Hôpital Pellegrin (Bordeaux), strains were studied in the aim to determine the source and the mode of transmission of the bacteria. The study was performed on 44 isolates of P. cepacia from 21 patients (23 strains) or from the environment (16 isolates from ventilators and five from the distilled water used for these ventilators).

Improved microplate immunoenzymatic assay of PCR products for rapid detection of Mycoplasma pneumoniae.

We developed a microtitre hybridization assay for the detection of polymerase chain reaction (PCR) amplified sequences. For this, cloned Mycoplasma pneumoniae DNA containing a sequence complementary to the PCR products is first covalently bound to microtitre wells. These coated microplates can be stored for several months.

Genetic variability among Chlamydia trachomatis reference and clinical strains analyzed by pulsed-field gel electrophoresis.

Pulsed-field gel electrophoresis (PFGE) was applied to Chlamydia trachomatis reference strains representing each of the 18 serovars and to 29 clinical isolates from genital specimens collected in Bordeaux, France, or Malmö, Sweden. Comparison of the fingerprint patterns of the reference strains revealed a high level of polymorphism of the total DNA when SmaI was used (14 profiles), whereas the other enzymes, Sse8387I and ApaI, showed fewer differences. Some serovars, considered to be closely related on the basis of their antigenic determinants located on the major outer membrane protein (MOMP), such as D and Da or I and Ia, were shown to be different after PFGE of their genomic DNAs.

Evaluation of the Amplicor Chlamydia trachomatis test versus culture in genital samples in various prevalence populations.

Objective: To evaluate a newly developed polymerase chain reaction (PCR) assay, Amplicor C trachomatis for the detection of C trachomatis in genital samples using cell culture for comparison.

Subjects: 501 patients (431 women and 70 men) attending an STD clinic in Hôpital Pellegrin (high-risk population) and gynaecological clinics (low-risk population) in Bordeaux, France.

Methods: The genital samples (cervical and urethral) were tested for the presence of C trachomatis using the Amplicor test and using standard cell culture identified by the immunofluorescence test using a monoclonal antibody to C trachomatis.

[In situ hybridization of cells infected by Chlamydia trachomatis].

Hybridization in situ of chlamydia trachomatis allows identification of the bacteria. Moreover exact chlamydia trachomatis localization at tissue level can be demonstrated. It seems to us very important to know for instance in conjunctiva were chlamydia trachomatis are located.

Detection of Mycoplasma pneumoniae and Mycoplasma genitalium in clinical samples by polymerase chain reaction.

Respiratory tract specimens, 75 bronchoalveolar lavage (BAL) samples and 19 throat swabs from 75 hospitalized adult patients (of whom 55 were seropositive for human immunodeficiency virus) with pulmonary infiltrates, were examined for Mycoplasma pneumoniae and Mycoplasma genitalium by culture and polymerase chain reaction (PCR). Urogenital specimens (103 from 48 male patients with nongonococcal urethritis and 55 female patients with genital infections) were examined for M. genitalium by the same techniques.

Potential improvements in therapeutic options for mycoplasmal respiratory infections.

Macrolides and tetracyclines are the most active antibiotics against mycoplasmas in vitro. In particular, erythromycin has been widely used for the treatment of infections caused by Mycoplasma pneumoniae. However, improvements in therapy are needed to accommodate specific characteristics of the microorganism or unusual manifestations of the illness it causes.

Evaluation of molecular typing for epidemiological study of Chlamydia trachomatis genital infections.

Molecular typing and serotyping were compared for 150 Chlamydia trachomatis strains isolated from genital sources, belonging to 10 different serovars. Because of the general agreement of the two methods, molecular omp1 genotyping was applied to the epidemiological study of C. trachomatis isolates from genital infections in Bordeaux (France), during a 29-month period.

Detection of mollicute contamination in cell cultures by 16S rDNA amplification.

A polymerase chain reaction (PCR) system was developed for the detection of mollicutes as contaminants of cell cultures. By using three oligonucleotides chosen in the 16S rDNA sequences, two sets of primers able to promote amplification of all Mycoplasma and Ureaplasma (molli1-molli2a) or all Acholeplasma (molli1-molli2b) species examined were determined. This PCR system, first applied to experimentally infected Vero cell lines, was then evaluated for the detection of mollicutes in 86 cell culture samples, comparatively to DNA staining, culture and ELISA.