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Biomedical subjects

R Quentin

Publications and source records attributed to R Quentin.

At least 19 recordsLinked to original sources
PubMed2000

Capnocytophaga ochracea: characterization of a plasmid-encoded extended-spectrum TEM-17 beta-lactamase in the phylum Flavobacter-bacteroides.

A plasmid-encoded extended-spectrum TEM beta-lactamase with a pI of 5.5 was detected in a Capnocytophaga ochracea clinical isolate. The bla gene was associated with a strong TEM-2 promoter and was derived from bla(TEM-1a) with a single-amino-acid substitution: Glu(104)-->Lys, previously assigned to TEM-17, which is thus the first TEM beta-lactamase to be reported in the phylum Flavobacter-Bacteroides.

Amino Acid Substitution↗
PubMed1999

Nucleotide sequences of genes coding for fimbrial proteins in a cryptic genospecies of Haemophilus spp. isolated from neonatal and genital tract infections.

Nineteen isolates belonging to a cryptic genospecies of Haemophilus (referred to here as genital strains) isolated from genital tract infections (6 strains) and from neonatal infections (13 strains) were studied for fimbrial genes. Sixteen strains exhibit peritrichous fimbriae observed by electron microscopy. By PCR with primers corresponding to the extreme ends of the Haemophilus influenzae type b (Hib) hifA and hifD genes and Southern blotting, a hifA-like gene (named ghfA) and a hifD-like gene (named ghfD) were identified in 6 of the 19 strains. Five of these six strains were from the genital tracts of adults, and one was from a neonate. For each gene, the nucleotide sequence was identical for the six strains. A hifE-like gene (named ghfE) was amplified from only one of the 19 genital strains of Haemophilus, but the ghfE probe gave a signal in Southern hybridization with the five other strains positive for ghfA and ghfD. Therefore, these strains may carry a ghfE-like gene. The Hib fimbrial gene cluster is located between the purE and pepN genes as previously described. For the 13 genital Haemophilus strains that lack fimbrial genes, this region corresponds to a noncoding sequence. Another major fimbrial gene designated the fimbrin gene was previously identified in a nontypeable H. influenzae strain. A fimbrin-like gene was identified for all of our 19 genital strains. This gene is similar to the ompP5 gene of many Haemophilus strains. Therefore, other, unidentified genes may explain the piliation observed in electron microscopy on genital Haemophilus strains which do not possess LKP-like fimbrial genes. Fimbrial genes were significantly associated with strains isolated from the genital tract. They may confer on the strain the ability to survive in the genital tract.

Adhesins, Bacterial↗
PubMed1999

Genetic features of Streptococcus agalactiae strains causing severe neonatal infections, as revealed by pulsed-field gel electrophoresis and hylB gene analysis.

A collection of 114 independent Streptococcus agalactiae strains, including 54 strains isolated from the cerebrospinal fluid (CSF) samples of neonates and 60 strains from asymptomatic patients, was characterized by pulsed-field gel electrophoresis (PFGE) of DNA restricted with SmaI and by PCR analysis of the hylB gene. All strains were previously studied by multilocus enzyme electrophoresis (MLEE) (R. Quentin, H. Huet, F.-S. Wang, P. Geslin, A. Goudeau, and R. K. Selander, J. Clin. Microbiol. 33:2576-2581, 1995). Among these 114 strains, there were 92 PFGE patterns. Eleven genetic groups (A to K) were identified with 38% divergence. A more homogeneous group (PFGE group A) was defined, consisting of 73% of the strains previously identified as belonging to a particular MLEE phylogenetic group. A 162-kb fragment was identified as a marker of strains that invaded the central nervous system of neonates. It was detected in 69% of the PFGE patterns obtained with CSF isolates and in only 1.8% of the PFGE patterns obtained with carrier strains. The hylB gene encoding hyaluronate lyase was amplified for all strains in our collection. Ten of 15 isolates belonging to an MLEE subgroup, previously described as being likely to cause invasive infection, had an insertion in the hylB gene (IS1548).

Chromosome Mapping↗
PubMed1999

[The Pneumococcus Observatory of the Central Region, from June 1, 1997 to May 31, 1998].

714 pneumococcus were listed from 14 laboratories between the 1 June 1997 and the 31 May 1998. Data capture was done on Epi info software and concerned age, file number, consultation/hospitalization, sample type, susceptibility to oxacilline (5 micrograms), the results of the E-test for penicillin G, amoxicillin, cefotaxime and the results of the routine disk diffusion susceptibility method. Strains with reduced susceptibility to penicillin G (PRSP) were collected by the coordinating center to perform MICs by the reference method of agar dilution and serotyping. Over 714 strains, 45.7% of the samples originated from lungs, followed by 22% for blood samples, 14% for ear pus and 2.3% for CSF. 34% of the patients were female. 36.7% were children under 16 (57.8% PRSP) and 63.3% were adults (41% PRSP). 338 strains (47.3%) were determined as PRSP and 293 of them were studied by the coordinating center. 81 of the 293 PRSP (27.7%) were resistant et 212 (72.3%) were intermediate to penicillin G. 81% of the PRSP studied had a CMI value for penicillin G within +/- 1 log2 dilution. 20 strains of PRSP were resistant for amoxicillin (6.8% of the PRSP) and two (0.7% of the PRSP) for cefotaxime. 289 serotyping were done, most met serotypes were 23 (25%), 14 (23%). The least met was 15 (2.4%). These results let assess the epidemiology of pneumococcus in our region.

Adult↗
PubMed1997

Use of a DNA typing method to investigate a fatal perinatal infection due to Staphylococcus aureus.

The aim of this study was to determine, by random amplified polymorphic DNA analysis, the origin of a fatal Staphylococcus aureus perinatal infection which occurred after multiple cervical examinations before induction of labor for patient convenience. This DNA typing method was able to demonstrate that this infection originated from S. aureus genital carriage and urinary tract infection of the mother, and was not acquired in the hospital. This observation argues for the systematic screening of genital flora for highly virulent strains before induction of labor for non medical reasons. In addition, the DNA typing method used demonstrates that one neonate was subsequently infected by the strain responsible for the chorioamnionitis. This shows that molecular typing methods can help determine hospital staff responsibility.

Adult↗
PubMed1997

Endocervical infection in a pregnant woman caused by Neisseria meningitidis: evidence of associated oropharyngeal colonization of the male partner.

A case of premature birth associated with an endocervical infection caused by Neisseria meningitidis is reported. Treatment of the mother with amoxycillin eradicated the bacteria from the endocervix and avoided newborn colonization or infection. Epidemiological investigation identified meningococcal oropharyngeal colonization of the male partner. The two strains were of the same antigenic formula B:4:P1.14 and exhibited identical rDNA restriction fragment patterns and outer membrane protein profiles. This phenotypic and genomic identity of strains is the first clear evidence for cross-colonization between sexual partners.

Adult↗
PubMed1997

Characterization of Streptococcus agalactiae strains by randomly amplified polymorphic DNA analysis.

A collection of 54 unrelated Streptococcus agalactiae strains isolated from cerebrospinal fluid samples from neonates and 60 unrelated strains isolated from carriers that had been previously studied by multilocus enzyme electrophoresis (R. Quentin, H. Huet, F.-S. Wang, P. Geslin, A. Goudeau, and R. K. Selander, J. Clin. Microbiol. 33:2576-2581, 1995) were characterized by randomly amplified polymorphic DNA (RAPD) assay. Four primers, 5'AGGGGGTTCC3', 5'AACGCGCAAC3', 5'GCATCAATCT3', and 5'AGTCGGGTGG3', named OPS16, AP42, A4, and OPS11, respectively, were selected from 29 primers tested. This investigation identified 71 RAPD types. The three families of strains defined by multilocus enzyme electrophoresis analysis, which contain most of the cerebrospinal fluid isolates, were also identified by clustering analysis of RAPD data. Each of these three groups exhibits specific RAPD patterns or fragments. The discriminatory power of the RAPD typing method was also evaluated. The simplest typing scheme was obtained by the combination of RAPD typing done with primers AP42 and OPS11 and serotyping (index of discrimination, 0.97).

Bacterial Proteins↗
PubMed1997

[Pristinamycin versus oxacillin in the treatment of superficial pyoderma. A multicenter randomized study in 293 outpatients].

BACKGROUND: Superficial pyoderma occurs frequently. Generally, the benign infection is caused by Staphylococcus aureus and/or a group A streptococci. The subject is controversial, but treatment usually is based on narrow-spectrum antibiotics active against both germs. PATIENTS AND METHODS: A multicentric, randomized, double-blind, double-placebo study was conducted to compare pristinamycin (1 g b.i.d.) with a reference antibiotic, oxacillin (1 g b.i.d.) for 10 days. Inclusion criteria were: both sexes, age 15-80 years, clinical diagnosis of superficial pyoderma (impetigo, wound infection within the last 15 days, furunculosis, carbuncle, perionyxis), informed consent. The general practitioner investigators (n = 52) were assisted by 9 dermatologist-coordinators. Clinical diagnosis was validated by a committee of experts at the end of the study after analyzes of the photos and bacteriological results obtained on samples taken at the practitioner's office on visit 1 (D0), visit 3 (D14 +/- 3) and visit 4 (D25 +/- 3). Successful treatment was defined by clinical, bacteriological and photographic efficacy at visit 3 (equivalence analysis: one-way 95 p. 100 confidence interval). RESULTS: There were 293 included patients given pristinamycin (n = 151) or oxacillin (n = 142). Mean age of analyzed patients was 40 +/- 17 years. Diagnosis was confirmed in 255 patients in accordance with the protocol: furunculosis or carbuncle (n = 100), recently superinfected wound (n = 97), impetigo (n = 41), acute perionyxis (n = 17). Thirty-five patients (12 p. 100) were considered to have been wrongly included. The germs most often isolated were: Staphylococcus aureus (n = 126), group A streptococci (n = 13), group B streptococci (n = 5) and P. multocida (n = 3). At visit 3, the two treatments were found to be equivalent with a success rate of 86.7 p. 100 for pristinamycin and 89.8 p. 100 for oxacillin (CI [*9.97]). Tolerance was statistically comparable between the two treatments (27 to 32 percent minor side effects). DISCUSSION: This study is the first performed in outpatients attended by general practitioners with diagnostic confirmation on both bacteriological and photographic evidence of superficial pyoderma. The results obtained demonstrate the good reliability of such studies although 12 p. 100 of the patients were wrongly included, a factor which should be taken into account for future studies. The efficacy and tolerance of pristinamycin were statistically equivalent to those of oxacillin for all the patients with superficial pyoderma. Nevertheless, the subgroup of patients with folliculitis gave rather heterogeneous bacteriology and therapeutic results.

Adolescent↗
PubMed1996

Genetic diversity of rRNA operons of unrelated Streptococcus agalactiae strains isolated from cerebrospinal fluid of neonates suffering from meningitis.

The genetic diversity of a collection of 54 unrelated Streptococcus agalactiae strains isolated from the cerebrospinal fluid of neonates and of 60 unrelated carrier strains was evaluated by investigating the restriction fragment length polymorphism of the rRNA gene region. Three restriction enzymes were selected for use: PstI, HindIII, and CfoI. Clustering analysis revealed two phylogenetic groups of strains with 40% divergence. Group I contained two clusters, A and B, and group II contained three clusters, C, D, and E. Strains of serotype Ia were mostly distributed in cluster A, and strains of serotype Ib were mostly distributed in cluster E. Serotype III isolates did not cluster. Nevertheless, 37 of 39 isolates belonging to cluster B were serotype III. With HindIII, two rRNA gene banding patterns characterized 38 of the 39 strains of cluster B, which represents a high-virulence group. In addition, two rRNA gene banding patterns with each enzyme and/or a pair of CfoI fragments of 905 and 990 bp identified 81% of the invasive strains. On account of the genetic homogeneity of the cerebrospinal fluid strains, ribotyping is a powerful typing method for investigation of nosocomial or epidemic invasive infections only when all three enzymes are used or when PstI and HindIII or PstI and CfoI are combined with serotyping (index of discrimination, > 0.95).

Bacterial Typing Techniques↗
PubMed1996

Genetic identification of cryptic genospecies of Haemophilus causing urogenital and neonatal infections by PCR using specific primers targeting genes coding for 16S rRNA.

Previous genetic analysis of Haemophilus influenzae strains isolated from genital and neonatal infections identified a group of biotype IV that constitutes a cryptic genospecies only distantly related to H. influenzae and H. Haemolyticus. Small-subunit rRNA genes of two representative strains of this genital Haemophilus genospecies (strains 16N and 2406) were sequenced. The analysis indicated that these strains form a monophyletic unit with H. haemolyticus and H. influenzae biogroups Influenzae and Aegyptius and are more closely related to H. haemolyticus than to H. influenzae biogroups Influenzae and Aegyptius. 16S rRNA gene sequences were used to formulate primers for PCR-based identification of cryptic genital Haemophilus organisms. A 242-bp fragment was amplified from strains belonging to the genital Haemophilus genospecies but not from strains of 12 other Haemophilus species, including strains of H. influenzae biotype IV sensu stricto.

Base Sequence↗
PubMed1996

Development of listeriosis during vancomycin therapy in a neutropenic patient.

Vancomycin and aminoglycosides are widely used for fever in neutropenic patients. This combination of antibiotics has also been proposed for the treatment of Listeria monocytogenes bacteremia. We report a case of fatal listeriosis in a 33-year-old man during acute lymphoblastic leukemia induction therapy in a total protective environment despite him having been on vancomycin for 8 days for treatment of staphylococcus bacteremia. Vancomycin and aminoglycoside cannot be proposed for the treatment of L. monocytogenes bacteria in neutropenic patients. Neutropenia might be a risk factor for listeriosis in cancer patients.

Adult↗
PubMed1995

Characterization of Streptococcus agalactiae strains by multilocus enzyme genotype and serotype: identification of multiple virulent clone families that cause invasive neonatal disease.

The chromosomal genotypes of 277 isolates of 16 serotypes of Streptococcus agalactiae were characterized by analysis of electrophoretically demonstrable allele profiles at 12 metabolic enzyme loci. The collection comprised the type strain and 276 strains recovered from French symptomatic and asymptomatic subjects. Sixty-one distinctive electrophoretic types (ETs), representing multilocus clonal genotypes, were identified. Cluster analysis of the ETs revealed two primary phylogenetic divisions separated by a genetic distance of 0.62, Division I contained 67 isolates which could be assigned to 13 ETs. Twenty-seven of these isolates were from samples of cerebrospinal fluid (CSF) from neonatal meningitis patients. Two ETs, separated by a genetic distance of 0.217, contained 26 of these 27 isolates. Division II contained 210 isolates, of which 27 were isolated from CSF. This division was more polymorphic and included 48 ETs. Spanning a genetic distance of 0.3, three clusters and one ET were identified within this group. Twenty-four of 27 strains isolated from CSF belonged to one cluster, and 19 of them belonged to two adjacent ETs with a genetic distance of 0.083. Fifty-five of the 68 serotype Ia strains and 24 of the 26 serotype Ib strains were each confined to one of the evolutionary lineages, and 85 of the 86 strains which carried protein antigen c belonged to phylogenetic division II. Most of the type III organisms were assigned to two clone families. The characteristics of this French population argue for the existence of particular groups of strains responsible for neonatal meningitis and demonstrate that serotyping can supply information about the genetic distribution of strains.

Alleles↗
PubMed1995

Genetic diversity of Pseudomonas aeruginosa strains isolated from patients with cystic fibrosis revealed by restriction fragment length polymorphism of the rRNA gene region.

The restriction fragment length polymorphism patterns of rDNAs from Pseudomonas aeruginosa strains isolated from the respiratory tracts of patients suffering from cystic fibrosis were obtained to evaluate the genetic polymorphism of this population of strains. Eighty-seven P. aeruginosa strains isolated from 87 patients from diverse areas of France and the ATCC 10145 strain were examined. Four restriction enzymes were used: BamHI, ClaI, EcoRI, and PstI. Forty-nine strains (56%) were in the three most frequent ribotypes (ribotypes R1 to R3). In addition, hierarchical clustering analysis of the data showed that 71 of the 88 strains (81%) clustered at a distance of less than one-third of the greatest distance observed in the total population. This indicates that clinical isolates implicated in the pathology of cystic fibrosis present a low degree of heterogeneity of rRNA operons, in contrast to the heterogeneity of strains of P. aeruginosa isolated from patients with various other pathologies. This relative homogeneity of rRNA genes was observed independently of the clinical status of the patient and the colony morphology.

Adolescent↗
PubMed1993

Use of nonradioactive DNA probes to identify a Campylobacter jejuni strain causing abortion.

A case of human abortion due to a Campylobacter infection is reported. Cultures revealed two morphologically different isolates with large and small colonies respectively. Using conventional methods of identification, the large colonies were identified as Campylobacter jejuni and the small colonies as Campylobacter coli. Dot blot hybridization and determination of rDNA restriction fragment patterns revealed that both colony types were the same strain of Campylobacter jejuni. This observation illustrates the need to use methods other than phenotypic methods when identifying strains of Campylobacter.

Abortion, Spontaneous↗
PubMed1993

Evaluation of a rapid latex test for direct detection of Streptococcus agalactiae in various obstetrical and gynaecological disorders.

Cervical samples collected during speculum examination in 413 women were tested for the presence of Streptococcus agalactiae by Gram staining, a new latex agglutination test and standard cultures. The results of each method are reported in correlation with the clinical circumstances of isolation. Gram stain and the latex agglutination test had a sensitivity of 30% and 78%, and a specificity of 89% and 98% respectively compared with culture. The sensitivity of the latex agglutination test was higher in cases of premature rupture of membranes (90%), presumed chorioamnionitis (86%), presumed post-partum endometritis (86%) and presumed salpingitis (87%). This latex agglutination test appears to be useful for identifying patients who are heavily colonized with Streptococcus agalactiae and are at a high risk of infection.

Evaluation Studies as Topic↗