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Biomedical subjects

H Richet

Publications and source records attributed to H Richet.

At least 19 recordsLinked to original sources
PubMed2006

Determination of HPV type 16 and 18 viral load in cervical smears of women referred to colposcopy.

It has been recognized that human papillomavirus infection is the major causal factor for high-grade cervical lesions. The aim of the study was to evaluate the relationship between HPV 16 and 18 viral loads and cervical status in different age strata. A duplex real time PCR method was devised to determine HPV 16 and 18 viral load per million of human cells using an in house plasmidic construct as a standard of quantification. The 151 cervical scrapes were collected before colposcopic examination from either abnormal cervico-vaginal smear (group 1, 97 patients) or from post treatment clinical follow-up (group 2, 54 patients). In women aged 30-40, the HPV16 viral loads were significantly higher in high-grade squamous intraepithelial lesion than in low-grade squamous intraepithelial lesion in both groups and HPV18 in group 1. In women aged 20-30 of group 1, high HPV viral load was associated in few cases with high-grade squamous intraepithelial lesion or low-grade squamous intraepithelial lesion, and surprisingly in some patients with normal cervix. HPV 16 and 18 viral loads are related to the severity of cervical lesion, and may be useful in the clinical management of cervical lesions. A specific follow-up may be useful for those with high viral load despite normal cervix.

Adolescent↗
PubMed2006

Role of hospital stay and antibiotic use on Pseudomonas aeruginosa gastrointestinal colonization in hospitalized patients.

The prospective cohort study presented here assessed the risk factors associated with Pseudomonas aeruginosa gastrointestinal colonization (PAGIC) in 933 patients hospitalized in five different wards in a French university hospital. A total of 195 patients were colonized. By logistic regression, hospitalization in an intensive care unit and length of hospital stay were independent risk factors. A significant association was observed between fluoroquinolone use and PAGIC caused by an ofloxacin-resistant strain (p < 0.0001), imipenem use and PAGIC caused by an imipenem-resistant strain (p < 0.0002) and ceftazidime use and PAGIC caused by a ceftazidime-resistant strain (p < 0.02). The ecological impact of antibiotic use is of great clinical relevance and clinicians should consider antimicrobial resistance in order to limit the development and dissemination of resistant microorganisms.

Aged↗
PubMed2006

Assessment of ica operon carriage and biofilm production in Staphylococcus epidermidis isolates causing bacteraemia in bone marrow transplant recipients.

The clinical significance of coagulase-negative staphylococci isolated from blood culture is typically assessed on the basis of a combination of clinical and microbiological criteria. However, these criteria are difficult to apply to haematology patients who are highly immunosuppressed and from whom blood cultures are obtained most frequently through a central venous catheter. This study analysed 112 episodes of Staphylococcus epidermidis bacteraemia that occurred in 79 bone marrow transplant recipients. In 73 (65%) episodes, only one blood culture set was positive for S. epidermidis, while 39 (35%) episodes grew S. epidermidis from multiple blood cultures. Nine patients had two or more episodes of bacteraemia with the same strain, as determined by pulsed-field gel electrophoresis (PFGE). The PFGE method also showed that 34 (31%) isolates belonged to seven clusters, indicating the persistence of certain clones in the environment. Of the 109 isolates analysed, 59 (54%) produced biofilm and 91 (83.5%) carried the ica operon. Isolates that produced biofilm were observed to colonise central venous catheters faster than non-biofilm-producing isolates (18 vs. 37 days; p 0.03). No clinical features were associated with carriage of the ica operon, but the ica operon was carried more frequently by the isolates that formed clusters.

Adhesins, Bacterial↗
PubMed2006

Risk-factors for gastrointestinal colonisation with resistant Enterobacteriaceae among hospitalised patients: a prospective study.

This study assessed the incidence of gastrointestinal colonisation by resistant Enterobacteriaceae among hospitalised patients, and identified risk-factors for ceftazidime and ofloxacin resistance. A prospective cohort study was performed in five wards in a French teaching hospital during a 2-year period. Patients hospitalised for > 48 h were enrolled between 17 April 2000 and 30 April 2002. A rectal swab was taken at admission, then once-weekly and/or on the day of discharge. In total, 933 patients were investigated and 585 amoxycillin-resistant isolates were obtained. Resistance rates for ceftazidime and ofloxacin were 9.4% and 4.8%, respectively. Multivariate analysis indicated that previous hospitalisation (p < 0.004) and exposure to amoxycillin-clavulanate (p < 0.003) and ceftriaxone (p < 0.002) were associated significantly with ceftazidime resistance. Hospitalisation in the urology ward (p < 0.02) and previous exposure to fluoroquinolones (p < 0.01) were the two independent risk-factors associated with ofloxacin resistance. The results of the study confirmed that antibiotic use selected resistant Enterobacteriaceae from the gut flora. Resistance was observed mostly in patients with previous antibiotic exposure and previous hospitalisation in wards with a high antibiotic selection pressure.

Adolescent↗
PubMed2005

The training curriculum in hospital infection control.

Standardised training curricula for infection control nurses (ICNs) and recognition of the specialty exist in many European countries, but infection control physician (ICP) is not a specialty recognised by the UEMS. To gather information on curricula for ICPs, members of the ESCMID Study Group on Nosocomial Infections received a questionnaire. There is discussion about which 'professions' should be included in an infection control team. Within the 12 countries included, the average full-time equivalents (FTEs) for ICPs and ICNs per 1000 beds were 1.2 and 3.4, respectively. In addition to ICNs and ICPs, an infection control team should also include a data manager, an epidemiologist, secretarial/administrative support, and possibly, surveillance technicians. Overall, the composition of an ideal infection control team was estimated to be 9.3 FTE per 1000 beds. The background of ICPs can be clinical microbiology or infectious diseases. Among the participants, it was predominantly clinical microbiology. The ideal training curriculum for the ICP should include 6 years of postgraduate training. Of these, at least 2 years should be 'clinical training' (e.g., internal medicine) to acquire experience in the management of high-risk patients. Furthermore, training with regard to infection control and hospital epidemiology should be offered as a 'common trunk' for those being trained in clinical microbiology or infectious diseases. Important issues that remain are: implementation/standardisation of training curricula for doctors, recognition of ICP as a separate specialty or sub-specialty of clinical microbiology and/or infectious diseases, validation of on-the-job training facilities in terms of the number of doctors and nurses who can give training and the category of patients/problems present, and mandatory postgraduate education/continuing medical education specific for infection control for doctors and nurses in the field.

Cross Infection↗
PubMed2005

Contribution of systematic serological testing in diagnosis of infective endocarditis.

Despite progress with diagnostic criteria, the type and timing of laboratory tests used to diagnose infective endocarditis (IE) have not been standardized. This is especially true with serological testing. Patients with suspected IE were evaluated by a standard diagnostic protocol. This protocol mandated an evaluation of the patients according to the modified Duke criteria and used a battery of laboratory investigations, including three sets of blood cultures and systematic serological testing for Coxiella burnetii, Bartonella spp., Aspergillus spp., Legionella pneumophila, and rheumatoid factor. In addition, cardiac valvular materials obtained at surgery were subjected to a comprehensive diagnostic evaluation, including PCR aimed at documenting the presence of fastidious organisms. The study included 1,998 suspected cases of IE seen over a 9-year period from April 1994 to December 2004 in Marseilles, France. They were evaluated prospectively. A total of 427 (21.4%) patients were diagnosed as having definite endocarditis. Possible endocarditis was diagnosed in 261 (13%) cases. The etiologic diagnosis was established in 397 (93%) cases by blood cultures, serological tests, and examination of the materials obtained from cardiac valves, respectively, in 348 (81.5%), 34 (8%), and 15 (3.5%) definite cases of IE. Concomitant infection with streptococci and C. burnetii was seen in two cases. The results of serological and rheumatoid factor evaluation reclassified 38 (8.9%) possible cases of IE as definite cases. Systematic serological testing improved the performance of the modified Duke criteria and was instrumental in establishing the etiologic diagnosis in 8% (34/427) cases of IE.

Antibodies, Bacterial↗
PubMed2004

[Methicillin-resistant Staphylococcus aureus nosocomial infections in ICU: risk factors, morbidity and cost].

OBJECTIVE: Methicillin resistance and infections caused by methicillin-resistant Staphylococcus aureus represent a growing problem and a challenge for health-care institutions. We evaluated risk factors, morbidity and cost of infections caused by methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) Staphylococcus aureus. DESIGN: We performed an un-matched case-control study in an 20-bed medical intensive care unit from 1994-2001 at Nantes teaching hospital, France. All patients with pneumonia, bacteraemia and urinary MRSA (cases) or MSSA (controls) nosocomial infections were included in the study. RESULTS: Twenty four patients with MRSA infection were compared to 64 patients with MSSA infections. Patients with MRSA infection were older (56 vs. 45 years, P < 0.01), had longer length of stay (47 vs. 35 days, P < 0.05) and were infected later (22 vs. 10 days, P < 0.00001) than patients with MSSA infection. No difference was observed between the two groups according to the Omega index, acute simplify index and mortality. MRSA infections involved extra cost due to antimicrobial treatment (184 vs. 72 Euros, P < 0.005) and length of stay (37,278 vs. 27,755 Euros, P < 0.05). CONCLUSION: Patient infected by MRSA seems to be different from patient infected by MSSA but without consequence on Omega index and mortality. But methicillin-resistance involves extra cost due to antimicrobial treatment and length of stay.

Costs and Cost Analysis↗
PubMed2002

Candidemia in French hospitals: incidence rates and characteristics.

OBJECTIVE: To determine the incidence of candidemia in French hospitals. MATERIALS AND METHODS: A representative sample of 25 French hospitals [nine teaching hospitals (TH), ten general hospitals (GH) and six cancer referral centers (CRC)] was randomly selected. The incidence rates of candidemia per number of admissions and per patient-days of hospitalization were determined and extrapolated to the national level. RESULTS: From January 1, 1995 to December 31, 1995, the overall incidence rate per 1000 admissions was 0.29, ranging from 0.71/1000 in CRC, to 0.17/1000 in GH. The overall incidence for 1000 patient-days was 0.035 and the highest incidence was also observed in CRC (0.116/1000), followed by TH (0.052/1000). Candida albicans (53%) was the most common species isolated, a central venous catheter (26%) was the most common portal of entry and 50% of the candidaemic patients had a neoplasm. CONCLUSION: This study should enable us to optimize surveillance, prevention and treatment of these potentially life-threatening infections.

Candida↗
PubMed2001

Longitudinal study of bacterial, viral, and fungal infections in adult recipients of bone marrow transplants.

The epidemiology of infections was studied in a retrospective cohort of 446 recipients of bone marrow transplants (BMTs; 92 of which were allogeneic and 354 of which were autologous) during 1993--1996. Infections that were microbiologically documented in 274 recipients included bacteremia, urinary tract infections, cytomegalovirus viremia, fungemia, invasive aspergillosis, and catheter-related infections. During the period of neutropenia, no differences were found between recipients of allogeneic BMTs and recipients of autologous BMTs with regard to the incidence and the nature of infection. After patients underwent engraftment, bacteremia, cytomegalovirus viremia, and invasive aspergillosis were significantly more common in recipients of allogeneic BMTs than in recipients of autologous BMTs. Deaths caused by infection were uncommon and were mainly the result of invasive aspergillosis. Therefore, empirical antimicrobial therapy should be the same for recipients of both allogeneic and autologous BMTs during the period of neutropenia; after engraftment, more attention should be paid to the risk of infection in allogeneic BMT recipients, particularly with regard to detection and prevention of invasive aspergillosis.

Adolescent↗
PubMed2001

Surveillance and control of methicillin-resistant Staphylococcus aureus infections in French hospitals.

OBJECTIVE: To assess the way French hospitals conduct surveillance for, and control infections caused by, methicillin-resistant Staphylococcus aureus (MRSA), and to evaluate the incidence of these infections. DESIGN: Retrospective analysis of sample surveillance data. SETTING: Representative sample of French hospitals. PARTICIPANTS: Representative sample of 38 French public hospitals. METHODS: Hospitals were selected randomly in 1996, taking into account their location and number of beds. Administrative data, surveillance denominators used, antimicrobial resistance rates, and infection control practices were analyzed for the period 1990 to 1995. The same 38 centers were contacted 3 years later, in 1998, to reassess their surveillance and control activities. RESULTS: French hospitals were slow to implement MRSA surveillance programs; only 5% had such programs in 1990, when the median incidence per admission (0.37%) and per patient-days (0.04%) of MRSA infections was already high. Despite the implementation of surveillance programs in 66% of French hospitals in 1995 and 87% in 1998, the MRSA infection rates remained stable from 1990 to 1995 and increased from 1995 to 1998. The proportion of French hospitals having a policy for the transfer of MRSA-infected patients to other hospitals increased from 47% in 1995 to 61% in 1998, whereas screening for MRSA colonization (42%-53%) and isolation for colonized or infected patients (87%-89%) remained stable. CONCLUSIONS: This first national survey showed that French hospitals probably were not optimally prepared to control and prevent MRSA infections, since they were slow to respond to the growing problem.

Cross Infection↗
PubMed2000

Impact of fluoroquinolone administration on the emergence of fluoroquinolone-resistant gram-negative bacilli from gastrointestinal flora.

We assessed the risk factors for acquisition of fluoroquinolone-resistant, gram-negative organisms in the gastrointestinal tract of hospitalized patients. We analyzed stool samples from 204 patients and recovered fluoroquinolone-resistant, gram-negative organisms from 63. Receipt of fluoroquinolone during the month preceding admission was the only risk factor identified, whereas female sex, duration of hospitalization, exposure to indwelling devices, admission from another hospital, and history of infection were risk factors for fecal colonization after day 4.

Acinetobacter↗
PubMed2000

Analysis of the effects of -42 and -32 ampC promoter mutations in clinical isolates of Escherichia coli hyperproducing ampC.

Escherichia coli usually produces only very small amounts of a constitutive AmpC beta-lactamase, but clinical strains overproducing this enzyme have been isolated. Three different ampC promoters of E. coli clinical strains were cloned upstream of the chloramphenicol acetyltransferase (CAT) gene in the pKK232-8 reporter plasmid and their relative strengths were compared by two different methods. The strength of the promoters from AmpC hyperproducers was 70- to 120-fold higher than those from a low-level AmpC producer. One of the strong promoters, which differs from strain K12 at bases -88, -82, -42, -18, -1 and +58, was mutated to abolish the -42 mutation. This change resulted in a 43-fold decrease in CAT concentration. In another promoter, with eight different mutations at positions -88, -82, -32, -18, -1, +5, +24 and +58, the -32T-->A transversion, which created perfect homology with the -35 consensus sequence, was reverted; this led to a 13-fold decrease in CAT concentration. The -42 and -32 mutations play an important role in E. coli resistance to beta-lactams by increasing ampC transcription.

Bacterial Proteins↗
PubMed1999

Mutations in the ampC promoter of Escherichia coli isolates resistant to oxyiminocephalosporins without extended spectrum beta-lactamase production.

Escherichia coli strains showing an increased resistance to oxyiminocephalosporins without an extended spectrum beta-lactamase production have been screened for mutations in their ampC beta-lactamase gene promoter. Mutations were found by direct sequencing of seven promoters at positions -42, -32 (box -35), -18, -1, +5, +24 (attenuator), +31 (attenuator) and +58. By using rapid and simple methods, three of these mutations (-42, -32 and +24), which could enhance transcription, were searched in 37 resistant and 25 sensitive isolates. The -42 mutation was present in 33 of the 37 promoters from the resistant isolates. The -32 and +24 mutations were present only in three and two promoters, respectively, and they were combined in the most resistant strain of the study. The +24 mutation was detected in another strain associated with a 1-bp insertion between the -35 and -10 conserved sequences. None of these mutations was detected in the ampC beta-lactamase from the sensitive isolates.

Anti-Bacterial Agents↗