PubMed Health⌕ Search

Biomedical subjects

P Geslin

Publications and source records attributed to P Geslin.

At least 73 records · Page 4Linked to original sources
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↗
PubMed1996

Epidemiological features of and risk factors for infection by Streptococcus pneumoniae strains with diminished susceptibility to penicillin: findings of a French survey.

A nationwide retrospective study was performed in France to describe the susceptibility of Streptococcus pneumoniae strains to penicillin G and to identify risk factors for infection with nonsusceptible strains. From January 1991 to May 1992, 10,350 S. pneumoniae strains were recorded. The overall rate of penicillin-nonsusceptible pneumococcal (PNSP) strains was 11%; specific prevalence rates, according to the sources of the isolates, were as follows: blood, 6%; cerebrospinal fluid, 10%; lower respiratory tract, 10%; and middle ear, 18%. Large variations in regional distribution were observed. In 85% of cases, PNSP strains belonged to serogroup 23, 19, 6, 14, or 9, by order of decreasing frequency. A logistic regression model identified the following factors as being associated with PNSP infections: age of < 15 years (OR = 2.01), isolation of the organisms from the upper respiratory tract (OR = 2.36) or from sinus and middle ear (OR = 1.63), HIV infection (OR = 2.01), beta-lactam antimicrobial therapy in the previous 6 months (OR = 1.99), and nosocomial acquisition (OR = 2.12). The attributable risk of beta-lactam antimicrobial therapy in the previous 6 months was 19%, showing that suppression of this factor alone could not eradicate PNSP infections.

Adolescent↗
PubMed1996

Mechanisms of the spread of penicillin resistance in Streptococcus pneumoniae strains causing meningitis in children in France.

The molecular epidemiology of penicillin-resistant Streptococcus pneumoniae strains causing meningitis in children was studied in France. Typing procedures included analysis of total DNA polymorphism by random amplification of polymorphic DNA, restriction fragment length polymorphism (RFLP) analysis of the ribosomal RNA gene regions, and pulsed-field gel electrophoresis. Penicillin-binding protein (PBP) genes pbp2b and pbp2x were studied by RFLP analysis and DNA sequencing in selected cases. Statistical analysis of the data by factorial analysis of correspondence established that the emergence of penicillin-resistant pneumococci in this pathology is the result of the spread of two highly resistant closely related clusters and a cluster of serotype 23 strains with an intermediate level of resistance, the spread of genes confering high resistance to penicillin between the two highly resistant clusters, and complex genetic events involving the pbp genes in a heterogeneous population of strains leading to an intermediate level of resistance.

Base Sequence↗
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

6-day amoxicillin versus 10-day penicillin V for group A beta-haemolytic streptococcal acute tonsillitis in adults: a French multicentre, open-label, randomized study. The French Study Group Clamorange.

We compared the efficacy and safety of amoxicillin 1 g b.i.d. for 6 days and penicillin V 1 MU t.i.d. for 10 days in the treatment of group A beta-haemolytic streptococcal (GABHS) tonsillitis in adults. 342 patients with acute tonsillitis and a positive test for streptococcal antigen were included in a multicentre, randomized, open-label study; 338 patients were evaluable in an intention-to-treat analysis, and 234 with a positive throat swab culture in a per-protocol analysis. In the per-protocol analysis, the GABHS eradication rate at the end of treatment was comparable in the two groups: 92% (115/125) on amoxicillin and 92.7% (101/109) on penicillin (p = 0.95), as were the clinical success rates of 96% and 95.4%, respectively (p = 0.92). At the follow-up visit (day 28-32), 90.8% of patients treated with amoxicillin and 92.6% of those treated with penicillin V were free of GABHS (p = 0.85). Sore throat disappeared significantly faster on day 2 (p = 0.039) in the amoxicillin group. The intention-to-treat analysis gave similar clinical results. Tolerability was good in both groups. The efficacy and safety of amoxicillin 1 g b.i.d. for 6 days were not statistically different from those of penicillin V 1 MU t.i.d. for 10 days in the treatment of streptococcal tonsillitis in adults.

Acute Disease↗
PubMed1996

[Molecular epidemiology of pneumococci with decreased susceptibility to penicillin isolated in a Parisian pediatric hospital].

Pneumococci with decreased susceptibility or resistant to penicillin (PRP) have been isolated with an increasing frequency in France. Among PRP, isolates of serotypes 23F and 9V were the most frequently recovered in our children's hospital. Penicillin-resistance is due to the appearance of altered penicillin binding proteins (PBPs) with reduced affinity for beta-lactam antibiotics. 3 PBPs have been well studied, 2b, 2x and 1a, and the sequences of their genes have been determined. Our molecular epidemiological study of 14 PRP 9V and 26 PRP 23F isolated mainly from otitis in 1993-94, consisted of determining chromosomic restriction patterns (Apa I) by pulsed-field gel electrophoresis, and restriction patterns (Hinf I) of PBP genes pbp 2b, pbp 2x and pbp 1a after PCR. All the PRP 9V exhibited the same pulsotype and identical patterns for each of the genes pbp 2b, pbp 2x and pbp 1a, suggesting a clonal origin. The origins of PRP 23F were more heterogenous: 5 clones could be defined, with one predominant clone composed of 20 isolates. Most of the PRP 23F shared identical profiles for the genes pbp 2b, pbp 2x and pbp 1a with the PRP 9V, suggesting a horizontal transfer of DNA. Molecular markers, which provide more informations than serotyping, were useful to clarify the complex epidemiology of PRP.

Child↗
PubMed1996

Pulsed field gel electrophoresis in Streptococcus pneumoniae isolated in France and Portugal.

During a multicenter surveillance study on Streptococcus pneumoniae resistant to antibiotics in Portugal we have analyzed, within the predominant serotypes of penicillin G resistant strains, the chromosomal DNA restriction profiles by pulsed field gel electrophoresis. The aim of this work was to compare the PFGE restriction profiles of penicillin resistant pneumococci isolated in France with those of Portuguese strains within each serotype. We have studied fifteen penicillin resistant strains isolated in different geographical regions of France, and representing equally the three predominant resistant serotypes 23F, 9V and 14. In general we observed an important homogeneity of profiles within each serotype, in the two countries. In serotype 23F, the five French strains studied show subtypes of a pattern called A, also detected in the majority of 23F Portuguese strains; similarly 4 of the 5 serotype 9V strains belong to subtypes of the pattern G, also common within 9V Portuguese strains; 4 of the 5 strains of serotype 14 show a subtype of profile H, found often in Portuguese strains. The observed homogeneity of chromosomal DNA restriction profiles within each serotype in the two countries, confirms the importance of geographic spread of pneumococcal resistant clones, previously described.

DNA, Bacterial↗
PubMed1996

[Is the presence of right ventricular high intensity signals sufficient for the diagnosis of right ventricular dysplasia?].

The aim of this study was to assess "morphological" MRI data (spin-echo) compared with cine-MRI in 10 patients with documented right ventricular dysplasia and 10 normal controls. Data was acquired with a 0.5 Tesla superconductor magnet associating sequences of spin-echo and gradient echo (cine-MRI). An abnormal high intensity signal was observed in spin-echo in 9 out of the 10 patients. They were present on the anterior and sub-tricuspid walls of the right ventricle (8/10) and in the pulmonary infundibulum (8/10). A dyskinetic zone corresponding to the abnormal signals was detected in 8 patients. In the control group, only one subject had an abnormal high intensity signal and no dyskinesis could be detected. The association of high intensity signals and dyskinesis would seem to be very specific of right ventricular dysplasia. On the other hand, a high intensity signal alone may be observed in apparently normal subjects and would seem to be less specific.

Aged↗
PubMed1995

Radionuclide angiography and magnetic resonance imaging: complementary non-invasive methods in the diagnosis of constrictive pericarditis.

Constrictive pericarditis presents with a suggestive clinical picture, and its diagnosis is based on a haemodynamic pattern revealing impaired ventricular filling. In this study of 15 patients with pure isolated constrictive pericarditis, we attempted to evaluate the diagnostic value of two non-invasive methods not usually employed in this indication: radionuclide angiography (RNA) and magnetic resonance imaging (MRI). Whilst RNA permits analysis of the functional pattern of the global and segmental left ventricular filling impairment, MRI allows measurement of the thickness of the pericardium. RNA revealed increased early diastolic filling as evidenced by a shorter one-third filling time (TF1/3; P<0.0001 with respect to a normal population), a higher peak filling rate (PFR; P<0.01) and its early occurrence (P<0.001), increased one-third and mid diastolic filling fractions (P<0.01), and the ratio of the PFR over the peak ejection rate (P<0.01). During late diastole, the atrial filling fraction decreased (NS). The patients with constrictive pericarditis also showed a decrease in the physiological filling asynchrony, as assessed by segmental evaluations. Seven patients underwent MRI. The pericardium was thickened in all the patients, varying from 6 to 14 mm (normal: 2.5+/-0.7 mm), without any systolo-diastolic variation. Pericardial thickening appeared as a dark low-intensity signal band, demonstrating the fibrocalcific nature of the pericardial contents. Sagittal and coronal cross-sections were particularly well-suited to show the non-uniformity of the pericardial thickening. These results indicate that RNA and MRI are complementary non-invasive methods, and can provide the functional and anatomical information required for the diagnosis of constrictive pericarditis.

Adult↗
PubMed1995

Acute otitis media in children: a study of nasopharyngeal carriage of potential pathogens and therapeutic efficacy of cefixime and amoxicillin-clavulanate.

We conducted a large, multicenter, randomized, open-label study throughout France comparing the efficacy and safety of cefixime suspension (8 mg/kg/day, b.i.d., for 10 days) versus amoxicillin-clavulanate suspension (80 mg/kg/day, t.i.d., for 10 days) in 510 children (ages 6 to 36 months) with acute otitis media. The most frequent microorganisms colonizing the nasopharynx at the start of treatment were Streptococcus pneumoniae (51.5%), Haemophilus influenzae (45%) and Moraxella catarrhalis (30.2%). Rates of beta-lactamase positivity were 32.1% and 95.3% for H. influenzae and M. catarrhalis, respectively. Decreased susceptibility of S. pneumoniae to penicillin was found in 39.7% of isolates. Clinical efficacy was 87.8% (223/254) for cefixime and 87.0% (215/247) for amoxicillin-clavulanate. At the 5-week follow-up visit, relapse had occurred in 15.7% (31/197) of cefixime-treated patients and in 15.6% (32/205) of those treated with amoxicillin-clavulanate. We conclude that these two regimens are equally effective in acute otitis media in children.

Acute Disease↗
PubMed1995

Penicillin-resistant Streptococcus pneumoniae in Germany: genetic relationship to clones from other European countries.

Penicillin-resistant Streptococcus pneumoniae strains isolated in different parts of Germany between 1982 and 1992 were compared with penicillin-resistant isolates, mainly of serogroups 6, 9, 14, 19 and 23, from other European countries. The main clones were recognised by their serotypes, antibiotic resistance patterns and penicillin-binding protein properties, and this typing was confirmed by multi-locus enzyme electrophoresis for a sample of 43 selected isolates. Eleven of the 14 resistant German isolates could be assigned to five genotypes isolated also in other countries. These included representatives of two distinct serotype 23F lineages predominant in Spain and France; a cluster of three serotype 6B isolates identical to clones in Spain, France, Finland and Hungary; and a serotype 9V clone of a type prevalent in Spain and now also in France. Serotype 19A clones of the type found in Hungary were not collected in Germany. The data suggest that two 23F lineages, represented by seven isolates from different locations, have become disseminated in Germany. Several resistant types found in the former West Germany resembled those found elsewhere in Western Europe whereas those from East Germany were distinct or, in one case, resembled a clone from Hungary. These data may reflect pre-unification travel patterns.

Bacterial Proteins↗
PubMed1995

Relatedness of penicillin-resistant Streptococcus pneumoniae serogroup 9 strains from France and Spain.

Pulsed-field gel electrophoresis of the genomic DNA of penicillin-resistant strains of Streptococcus pneumoniae was carried out. Eleven clinical strains of serogroup 9 from different French towns and Paris hospitals were tested. The restriction enzymes Apal and Smal were used to digest intact chromosomes, and the fragments were resolved by field-inversion gel electrophoresis (FIGE). Five strains were similar using Apal and Smal. Four others were closely related when using Apal, and five others were closely related when using Smal. These results suggest that 10 of these strains are genetically related and have a clonal origin. The profile of the eleventh strain was completely different. Thus, in a given serotype the spreading of penicillin resistance can result from both clonal and independent events. Five strains had similar FIGE profiles to strains first isolated in Spain, suggesting that a resistant strain had spread from Spain to France.

DNA, Bacterial↗
PubMed1995

Killing activity of cefpirome against penicillin-resistant Streptococcus pneumoniae isolates from patients with meningitis in a pharmacodynamic model simulating the cerebrospinal fluid concentration profile.

An in vitro pharmacodynamic model was used to determine the killing kinetics of cefpirome against 20 Streptococcus pneumoniae strains (penicillin G MICs, > 0.125 to 2 micrograms/ml) isolated from patients with meningitis. The concentration of cefpirome was adjusted dynamically to simulate the median concentration profile obtained in the cerebrospinal fluid of adults after the infusion of a single dose of 2 g. The cefpirome MIC at which 90% of isolates are inhibited was 0.5 microgram/ml. Bactericidal activity was observed at 6 h, with mean killing of 3.51 +/- 0.34 log10 CFU/ml for all strains for which the cefpirome MIC was < 0.5 microgram/ml. In contrast, for strains for which the cefpirome MIC was > or = 0.5 microgram/ml, killing was significantly less (P < 0.05), with a mean reduction of only 2.86 +/- 0.57 log10 CFU/ml.

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↗
PubMed1994

[Bacterial epidemiology of pharyngitis in pediatric private practice].

OBJECTIVES: While viruses are usually the causal agents of common sore throat in children, bacterial infections cannot be distinguished solely on the basis of clinical presentation. Thus most physicians in France prefer to prescribe antibiotics in order to prevent rheumatismal complications of group A streptococcal infections. We updated current epidemiological data on bacterial pharyngitis in paediatric out-patient clinics. METHODS: A prospective study was conducted from March 1 to June 1, 1992 by 9 physicians. Throat swabs were obtained from 102 controls and from 307 patients with acute pharyngitis. Samples were transferred to the same bacteriology laboratory for examination. RESULTS: The mean age of the children was 6.1 years for patients and 7.2 years for controls. Throat swabs were inoculated for culture within a mean delay of 22.6 hours. Cultures were performed on Columbia blood medium with nalidixic acid and colistin then incubated in CO2 enriched atmosphere and on trypticase blood soy medium + 3.5% NaCl. Group A streptococcal strains were identified by search for beta-haemolysis and latex characterisation of group A polyosides. Group A streptococcal strains were found in 8.8% of the controls and 36.8% of the patients. Groups B, C or G streptococci were found in 10.8 et 11.4% of the controls and patients respectively (NS). Arcanobacterium haemolyticum was never isolated. Clinical association of sore throat, erythematous pharyngitis, fever > 38 degrees C and cervical lymph nodes was found in only 33.63% of the sore throat cases with group A streptococcal infection and in 7.73% of those without group A streptococcal infection (p < 0.0001, sensitivity 33%, specificity 92%). CONCLUSION: These results emphasize the necessity either to treat all pharyngitis or to do throat swabs or rapid group A streptococcal tests for diagnosis.

Age Factors↗