Impact of rapid diagnostic tests on the management of patients presenting with Enterobacteriaceae bacteremia.

OBJECTIVE: Pathogens are usually identified from blood cultures using a two-step procedure: Gram staining on the day of bacterial growth (D0), followed by identification and susceptibility testing the following day (D1). We aimed to evaluate the use of rapid tests performed on D0 in patients presenting with Enterobacteriaceae bacteremia. PATIENTS AND METHODS: Patients with≥1 positive monomicrobial blood culture with Gram staining suggestive of an Enterobacteriaceae were prospectively included. Two successive strategies were evaluated: i) conventional strategy (CS), ii) combination of a rapid identification test and third-generation cephalosporin susceptibility testing (rapid strategy, e.g. RS). RESULTS: Eighty-three patients were included (CS=42; RS=41). Compared with CS, the median delay of identification was significantly shorter with RS (22 hours [20-27] vs. 47 hours [42-53]; P<0.001). Patients in the RS group more frequently received an effective (82.9% vs. 73.8%, P=0.43) and appropriate (70.7% vs. 54.7%, P=0.17) antibiotic therapy on D1. Moreover, all five RS patients infected with a non-susceptible strain received an effective therapy on D1 versus only three of eight CS patients. CONCLUSIONS: Use of rapid testing was associated with a reduced time to result availability. This strategy should be useful to initiate an early effective and appropriate therapy and to improve the care of patients.

[Are investigations for underlying causes needed for the management of an adult patient with bronchiectasis?]. / La recherche d'une étiologie est-elle nécessaire à la prise en charge d'un adulte ayant une dilatation des bronches ?

Bronchiectasis may result from various causes. Recognition of these underlying causes may lead to specific management. Focal bronchiectasis are related to luminal blockage or extrinsic narrowing. The causative factors of diffuse bronchiectasis may be suggested by the predominant distribution of the disease and associated extrapulmonary manifestations. Primary immunodeficiencies cystic fibrosis, allergic bronchopulmonary aspergillosis, chronic Mycobacterium avium complex infection, and systemic diseases have to be looked for, even in patients with knowledge of a childhood respiratory infection.

[Evaluation of 6 years of group B streptococcus (GBS) screening in near-term pregnant women]. / Bilan bactériologique de six ans de dépistage du streptocoque de groupe B (SGB) au cours du dernier trimestre de la grossesse.

Streptococcus agalactiae (GBS) is a significant cause of morbidity and mortality among newborns. Colonization frequently occurs in pregnant women, nearly all international recommendations suggest that all pregnant women must be screened for vaginal colonization at 34 to 37 weeks of gestation. The microbiological diagnostic modalities used to combat GBS had to be accurate and in short time frame. We reported a 6 years experience of GBS screening, comparing results of culture swab of prenatal vaginal specimens and newborns colonization or infection. The carriage rate of 13 to 14% of GBS in newborn was unchanged during all the study period.

[Is aztreonam could become "a challenger" for treatment of Gram negative infections? May be an answer from microbiological data: in vitro study including 36,485 strains of enterobacteria and Pseudomonas]. / L'Aztréonam est-il "un challenger" possible pour le traitement des infections à Gram négatif? Tentative de réponse à partir des données microbiologiques: étude in vitro concernant 36,485 entérobactéries et Pseudomonas.

During 6 years, 2000 to 2006, we looked for evolution of antimicrobial resistance to beta-lactams of clinical isolates from patients with Gram negative infections. In vitro susceptibilities to piperacillin+tazobactam, ceftazidime, and aztreonam were followed along the period. Enterobacteriaceae of group 1 to 3 represent 24,884 strains and Pseudomonas spp. 11601. The global sensitivity of aztreonam was 85%, 87.1% for ceftazidime and 88.8% for pieracilline-tazobactam. Of course, aztreonam spectrum of activity is dedicated to Gram negative bacteria only but it is known to have a great penetration ratio in tissues and a half-live observed up to 6 times higher than in serum in experimental models. Antimicrobial rotation strategy is recommended in the prudent use of antibiotics. It seems that in our hospital a consistent increase of the use of aztreonam might be possible and proposed without increasing risk for infection control practices according to the microbiological laboratory results.

[Is there a change in ecology of Candida species incriminated in fungemia? A 7 years study at Foch Hospital]. / Y a-t-il un changement perceptible dans l'écologie des Candida species responsables de fungémie? Observation de 2000 à 2006 à l'hôpital Foch.

Some Candidemia studies have documented changes in epidemiology of Candida species and some species were reported as emerging species. We conducted a study over a 6 years period and until 2005 we do not noticed any change in epidemiology of Candida even if Candida albicans still the most common species followed by Candida glabrata. No increase of candidemia was observed from 2000 to 2005 and we observed a decrease during the year 2006, this fact have to be confirm and may be related to other data: reinforcement of hygienic measures in our hospital, changes in treatment or preemptive treatment of yeasts and fungi with new azoles or candines molecules. On another side, patients from intensive care units and patients suffering of cancer were, as expected, the most represented population in our study.

[Uncomplicated urinary tract infections, what about fosfomycin and nitrofurantoin in 2006?]. / Quelle sensibilité aux antibiotiques pour les bactéries responsables d'infections urinaires ? Que penser de fosfomycine et nitrofuranes ?

Since 2000 to 2005 we assessed the prevalence of antimicrobial resistance among uropathogens causing acute uncomplicated urinary tract infections (UTI). A total of 19 618 bacteria were studied, fosfomycin, fluoroquinolones, nitrofurantoin were in vitro the most potent drugs with more than 80% of susceptibility. If we compare year 2000 to 2005 we observed a significant decrease of susceptibility for fluoroquinolones. For the same point of comparison, fosfomycin and nitrofurantoin showed a favourable evolution. Rationale and prudent use of antibiotics must now moved us to prescribe parsimoniously fluoroquinolones especially for some indications such as uncomplicated UTI though there are some others "old antibiotics" with a role may be underestimated for this specific indication.

Surveillance of methicillin-resistant Staphylococcus aureus (MRSA) and Enterobacteriaceae producing extended-spectrum beta-lactamase (ESBLE) in Northern France: a five-year multicentre incidence study.

In order to measure the incidence of methicillin-resistant Staphylococcus aureus (MRSA) and of Enterobacteriaceae producing extended-spectrum beta-lactamase (ESBLE), and to evaluate the impact of the national guidelines for multidrug-resistant bacteria (MDRB) prevention in hospitals of Northern France, a multicentre study was conducted for three months every year starting in 1996, in volunteer hospital laboratories. All clinical specimens positive for MRSA and ESBLE were prospectively surveyed. During the five-year surveillance period, the overall proportion of MRSA was 38.4% in the 28,534 strains of S. aureus, and that of ESBLE was 11.4% in the 6121 strains of Klebsiella pneumoniae and 47.7% in the 2353 strains of Enterobacter aerogenes. The overall incidence rates of clinical specimens positive for MRSA, ESBL-K. pneumoniae and E. aerogenes were 0.84. 0.05 and 0.12/1000 hospital-days (HD), respectively. In the 23 hospitals that participated in the survey every year, the proportion and incidence of ESBLE decreased. Hence, despite recommendations as for isolation precautions, MRSA remains poorly controlled and requires more effective measures.

Soluble and cell-associated forms of the adhesion molecule LFA-3 (CD58) are differentially regulated by inflammatory cytokines.

The adhesion molecule lymphocyte function-associated antigen 3 (LFA-3) (CD58) is an important regulator of immune cell function which occurs as both surface-associated and 'soluble' forms. This study has investigated the inter-relationship and the effects of cytokines on the expression of LFA-3 isoforms. The surface antigen was found to be relatively unaffected by cytokines, but the release of soluble LFA-3 (sLFA-3) was highly responsive to interleukin 1beta (IL-1beta), interferon gamma (IFN-gamma) and tumour necrosis factor alpha (TNF-alpha). This modulation was cell-specific, particularly with regard to IFN-gamma, which up-regulated sLFA-3 release by A431 cells but down-regulated the release of the soluble form from HEp2 and HepG2 cells. We further demonstrated that LFA-3 is also present in a cytoplasmic 'pool' in each of the cells and, moreover, that cleavage of LFA-3 from the cell surface by phospholipase C resulted in an increase in the levels of the intracellular LFA-3 and replacement of the membrane-associated antigen. These observations suggest that the expression of the surface, soluble and intracellular forms of LFA-3 may be linked by regulatory mechanisms which are likely to exert an important influence on inflammatory interactions.

Regulation of LFA-3 (CD58) by dexamethasone and retinoic acids in vitro.

INTRODUCTION: The oral form of lichen planus (OLP) is a chronic inflammatory disease characterized by the accumulation of T cells below the basal layer of the buccal mucosa. We have previously shown that the adhesion molecule lymphocyte function-associated antigen-3 (LFA-3; CD58) is up-regulated in lesional tissue and may play an important part in the molecular pathology of this disease. OLP is often treated with glucocorticoids, and glucocorticoid-resistant cases with retinoid drugs. However, it is not yet known whether the pharmacological action of these drugs is mediated directly or indirectly via LFA-3. METHODS: In the present experiments we have used the technique of flow cytometry (FCM) to accurately measure the effects of the glucocorticoid dexamethasone (DEX), all-trans retinoic acid (ATRA) and 13-cis retinoic acid (13RA) on LFA-3 expression by three main cell types found in OLP lesions--an oral epithelial cell line (KB cells), a T lymphocyte cell line (Jurkat cells) and an antigen presenting myelomonocytic cell line (U937 cells). The relative levels of the specific receptors for the drugs were also determined in these cell lines using FCM. RESULTS: ATRA and 13RA were found to have a more pronounced inhibitory effect on LFA-3 expression than did DEX, the U937 cells being the most sensitive and the KB cells the least affected. The KB cells also expressed the lowest relative levels of drug receptors. DISCUSSION: The results showed that the three drugs differentially down-regulated LFA-3 expression by each of the cell lines. Moreover, the relative inhibitory effects of the drugs appeared to be related to the relative expression of the specific drug receptors by each of the cells. Our findings suggest that the down-regulation of LFA-3 in vitro might explain at least partly the efficacy of glucocorticoids and retinoids in the treatment of inflammatory diseases in vivo.

[Microbiological diagnosis of bacteremia from a catheter: a simple method? Results of a retrospective study]. / Diagnostic microbiologique de bactériémie liée à une chambre implantable: une méthode simple? Résultats d'une étude rétrospective.

Diagnosing catheter-related bloodstream infections is important but not always easy and a failure to make the diagnosis may have serious consequences. A high rate of unnecessary catheter removal is noted. We retrospectively compared the clinical and usual methods of microbiological diagnoses of catheter-related sepsis to the speed of detection of the catheter versus peripheral blood cultures using the Bact-Alert system. We analyzed 50 files of patients with central indwelling devices: 16 single lumen catheters and 34 implanted ports. Twenty-one catheters were classified as infected, and we observed an earlier positivity of catheter versus peripheral blood in all cases, but significant for 19 patients. According to standard diagnosis methods, 29 catheters were estimated non-infected, a more rapid detection of peripheral culture was reported for 17 specimens and, for another eight patients, the time of detection was equal to blood culture drawn from the catheter. In this group, four discrepancies were recorded with a differential time in favor of sepsis related to catheters ranging from 0.5 to 2 hours. Because of its simplicity and low cost, we believed that this method could be the first step of a diagnosis of catheter-related sepsis and could, therefore, avoid unjustified removal, in particular for the implanted ports for which the diagnostic methods are less codified than for catheters. A prospective study is ongoing; the design of the study focuses only on implanted ports.

[Nitrofurans: a modern treatment for uncomplicated urinary infections?]. / Les nitrofuranes: un traitement moderne des infections urinaires non compliquées?

From January 1995 to December 1998, 2,912 strains of enteric bacilli were isolated from the urinary tract. Increasing antibiotic resistance in Enterobacteriaceae as a cause of urinary tract infection (UTI) led us to reevaluate first- and second-line therapies. We studied antimicrobial susceptibilities of these strains to norfloxacin (NOR), nalidixic acid (NAL), trimethoprim sulfamethoxazole (TS) and nitrofurantoin (FT) using the disk diffusion method. These results show no significant superiority of the activity of nitrofurantoin against Enterobacteriaceae compared with the other antibiotics with sustained concentration in urine. However, if we consider only multiresistant Enterobacteriaceae (cefotaxime resistant), this molecule appears to be very active. These results show a significant superiority of nitrofurantoin in vitro against these multiresistant Enterobacteriaceae. Thus, this molecule could once again become a good choice for the treatment of uncomplicated UTI.

Study by (23)Na-NMR, (1)H-NMR, and ultraviolet spectroscopy of the thermal stability of an 11-basepair oligonucleotide.

23Na-NMR, (1)H-NMR, and ultraviolet (UV) spectroscopy have been used to study the thermal stability of the double helix structure of an 11-basepair oligonucleotide. The denaturation curves obtained by (23)Na-NMR and UV are analyzed using a two-state model. The melting temperature and DeltaH(0) obtained are identical within experimental error, suggesting that modifications in the ionic atmosphere, probed by (23)Na-NMR, and the modifications in the basepair stacking, probed by UV, occur at the same temperature. Additional dynamical information on the denaturation process has been obtained by (1)H-NMR: slow exchange is observed between the thymine methyl resonances, and the disappearance of imino protons shows that a single basepair opening does not contribute significantly to proton exchange.

LFA-3 (CD58) mediates T-lymphocyte adhesion in chronic inflammatory infiltrates.

Previous studies have suggested that LFA-3 has an important role in a number of chronic inflammatory pathologies, although an active role for LFA-3 within in vivo inflammatory reactions has not previously been directly observed in humans. To assess the importance of LFA-3 in this process, this study used an adaptation of the Stamper-Woodruff lymphocyte adhesion assay to measure the binding of exogenous activated lymphocytes to the T-cell-dominated chronic inflammatory infiltrate of oral lichen planus. Antibody blockade experiments showed that anti-LFA-3 monoclonal antibody reduced lymphocyte adhesion by approximately 29%, while anti-ICAM-1 produced a reduction of 26%. These results thus suggest that both LFA-3 and ICAM-1 are likely to mediate cell-cell interactions within lesional tissues in vivo. Moreover, these findings are also the first to directly demonstrate that LFA-3-mediated adhesion, like that of ICAM-1, is functionally important in the molecular pathology of inflammatory mucosal disease.

Emergence of multidrug-resistant Enterobacter cloacae: nosocomial outbreak or change of microbial ecology?

Frequent selection of mutants resistant to extended and broad spectrum cephalosporins in Enterobacter cloacae is observed in hospital. As we noticed an unusual number of isolates of these strains and to answer the question arose whether these Enterobacter had a common source, we retrospectivally studied 56 strains collected in 11 wards of the hospital. Using PFGE with Spe 1 restriction analysis we identified a prevalent clone (11 patients) dispatched in 8 wards. We also obviously proved cross-contamination patients to patients with other clones. PFGE allow us to point out that clonal Enterobacter cloacae has taken place in our hospital, even if there is no real outbreak. A reinforcement of basic hygienic measures and a control of antibiotics prescription seemed very important to jugulate the sudden increase of multiresistant Enterobacter cloacae prevalence.

[Utilization of Bichrolatex albicans test for the rapid identification of Candida albicans in blood culture bottles in fungemia: preliminary results from a multicenter study]. / Utilisation du réactif Bichrolatex albicans pour l'identification rapide de Candida albicans dans les flacons d'hémoculture au cours des fongémies: résultats préliminaires d'une étude multicentrique.

In patients with fungemia, reliable and rapid identification of the causative organism has a large impact on treatment decisions. The Bichrolatex albicans test (Fumouze, Levallois-Perret, France) allows rapid identification of Candida albicans in colonies. Its usefulness for identifying C. albicans in liquid blood culture media was evaluated using a previously published protocol. Ninety-seven blood culture bottles from 86 fungemia episodes in 13 study centers were studied. C. albicans contributed 52% of the fungemia episodes, whereas C. glabata and C. tropicalis contributed 15% and 11.5%, respectively. The 48 bottles containing a yeast other than C. albicans were all negative by the Bichrolatex albicans test. Of the remaining 48 bottles, which were positive for C. albicans, 33 produced marked to moderate agglutination and 15 were negative. In one case of mixed fungemia (C. albicans plus C. glabata), weak agglutination was seen. Sensitivity of the test was 69%, negative predictive value was 76%, specificity was 100%, and positive predictive value was 100%. Because of its limited sensitivity, the Bichrolatex albicans test cannot be recommended as a confirmation test for C. albicans fungemia. In contrast, the specificity and positive predictive value of the test are excellent.

Use of the generalised linear model with Poisson distribution to compare caries indices.

In dental epidemiological studies, an analysis of variance assuming a normal distribution is commonly used to compare caries indices, which are often not normally distributed. As these indices represent discontinuous data, it would be preferable to use the negative binomial or the Poisson distribution. In this study, in order to compare the DMFS indices of adults working in the confectionery manufacturing industry in France, the results of the generalised linear model obtained using the normal and the Poisson distribution with identity or log built-in link function were compared. The negative binomial distribution was not used because it is very often unavailable in the most used statistical software. Analysis of the caries indices showed that the use of the normal distribution could lead to an incorrect interpretation of the data. Therefore it is concluded that the generalised linear model with Poisson distribution and over dispersion is to be preferred when comparing caries levels.

[Resistance to penicillin G and Streptococcus pneumoniae infection at the Hôpital Foch, Paris, France, in 1995]. / Résistance à la pénicilline G et infection à Streptococcus pneumoniae, en 1995 à l'Hôpital Foch, Paris, France.

UNLABELLED: Decreased susceptibility to penicillin G of pneumococcal strains is continuously increasing in France. OBJECTIVE: We assessed effect of resistance to penicillin on therapeutic management and mortality in adults with pneumococcal pneumonia in our hospital. METHODS: This one-year retrospective study (1995) included patients with proven pneumococcal infection (positive blood culture, pleural fluid, or specimens from the lower respiratory tract). Strains of Streptococcus pneumoniae were screened for susceptibility to antimicrobial agents. Resistance to penicillin G was defined as a minimal inhibitory concentration > or = 0.12 microgram/ml. Age immune and nosocomial status, first and second line antibiotherapy and death were compared according to the strains susceptibility to penicillin G. A p value below 0.05 was statistically significant. RESULTS: In 15 cases a pneumococcal strain susceptible to penicillin G was isolated while 23 patients were infected with a strain with a decreased susceptibility to penicillin G. Age was significantly higher in the latest group (61.6 versus 54.7 years) while no difference was noted between the 2 groups according to immune and nosocomial status, therapeutic management and death. DISCUSSION: Resistance to penicillin did neither appear to increase mortality nor to influence therapeutic management in patients with pneumococcal infection.

[Systematic detection of toxigenic strains of Clostridium difficile--is it useful?]. / La détection systématique des souches toxinogénes de Clostridium difficile est-elle utile?

The incidence of Clostridium difficile (Cd) infection is rising and Cd in fact is now endemic in many hospitals. During the past 4 years we analyzed our data concerning diarrhea caused by Cd in our 700 beds hospital. A positive case was defined as a Cd cytotoxine positive with or without positive culture for Cd. In the present study 120 episodes of Cd associated diarrhea occurred in 102 patients. 1101 stools were cultured from 921 patients. Since 1995 we choose to systematically evaluate Cd in diarrheal stools from hospitalized patients. 120 stool were positives (102 patients), we observed a significant difference between the 2 study periods: Cd was recovered from 16.9% of stool specimen during 1993-1994 and from 9.6% since 1995. This study clearly confirm the common role of Cd in our hospitalized patients as in all positive case, Cd was the only enteropathogen isolated. We suggest the systematic investigation of Cd in hospitalized patients.

Growth inhibition of human in vitro and mouse in vitro and in vivo mammary tumor models by retinoids in comparison with tamoxifen and the RU-486 anti-progestagen.

Retinoids constitute a very promising class of agents for the chemoprevention or treatment of breast cancer. These retinoids exert their biological activity through two distinct classes of retinoic acid (RA) receptors (R), the RAR isotypes (alpha, beta, and gamma) and the three RXR isotypes (alpha, beta, and gamma) and their numerous isoforms which bind as RXR/RAR heterodimers to the polymorphic cis-acting response elements of RA target genes. With respect to these numerous receptor sub-types, the retinoid-induced effects at the biological level include marked modifications with respect to both cell proliferation and cell death (apoptosis), and also in the induction of differentiation processes. The present study aims to characterize the effect which four retinoids (TTNPB, 9-cis-RA, LGD 1069, 4-HPR) with distinct RAR/RXR binding properties induced on various in vitro and in vivo mouse and human breast cancer models. The experiments with the retinoids were carried out in comparison with the anti-estrogen tamoxifen and the anti-progestagen RU-486 compounds. The results show that the 6 compounds under study were markedly more efficient in terms of growth inhibition in the human T-47D cell line when maintained under anchorage-independent culture conditions than when maintained under anchorage-dependent ones. While RU-486 exhibited a weak statistically significant (p < 0.05) influence on the growth of the T-47D stem cells, tamoxifen had a marked inhibitory influence on the growth of these cells. Of the four retinoids, 4-HPR was the least effective since the lowest doses tested (1 and 0.1 nM) exhibited no statistically (p > 0.05) significant influence on the growth of the stem cells. The most efficient retinoid was TTNPB. It was only at the highest dose (10 microM) that tamoxifen and RU-486 showed a weak inhibitory influence on the growth of the T-47D non-stem cells while all 4 retinoids exerted a significant inhibitory influence on the growth of these non-stem cells, with 4-HPR being the most efficient (P < 0.001) at the highest dose, but ineffective (P > 0.05) at the lowest. Tamoxifen and TTNPB were tested in vivo on hormone-sensitive (HS) and hormone-insensitive (HI) strains of the MXT murine mammary carcinoma. While TTNPB appeared to be equally efficient in terms of growth inhibition in both MXT-HS and MXT-HI models, tamoxifen had only a marginal inhibitory influence on the growth of the MXT-HI strain but did inhibit growth in the case of the MXT-HS one. TTNPB was markedly more efficient than tamoxifen in terms of both inhibiting the cell proliferation level (measured by means of computer-assisted microscopy applied to Feulgen-stained nuclei, a method which enables the percentage of cells in the S phase of the cell cycle to be determined) and triggering cell death (measured by means of the determination of the transglutaminase activity) in both the MXT-HI and MXT-HS models. The very significant TTNPB-induced inhibition of the macroscopic MXT-HS growth rate relates to the triggering of cell death (apoptosis) rather than to an inhibition of cell proliferation. All these results clearly indicate that retinoids are very efficient agents against breast cancer, at least as efficient as tamoxifen.

Caries prevalence and salt fluoridation among 9-year-old schoolchildren in Strasbourg, France.

The 9-year-old group (236 children) of an epidemiological study carried out in 1991 in Strasbourg on children aged 6 to 15 years was selected with the aim of determining if the caries prevalence reduction observed could be related to the use of salt fluoridation (FS) introduced in France in 1987. From these 236 children, 143 answered a questionnaire which showed that 36 of them were fluoridated salt users and 107 were not. The dft index was significantly lower in the FS consumers which showed 35.5% dft reduction compared to the non-FS-consuming children. When using the Generalized Linear Model, this reduction was significant (P = 0.03). Although lower in the FS group, the DMFT and DMFS indices showed no statistical significant difference. It appeared that 72.2% of the users took simultaneously fluoride tablets but no dental fluorosis was observed. The use of fluoride tablets had a significant effect on the DMFS (P = 10(-2)). The children who consumed FS used more frequently fluoridated mouthrinses (P = 10(-3)) and had more frequent professional application of fluoridated gel and varnishes than non-consumers (P = 0.02). The DMFS index increased with the number of meals (P = 10(-6)), which was the most significant variable entered into the Generalized Linear Model. The children who brushed their teeth once a day had a DMFS value 2.6 times higher than those who brushed regularly three times a day (P = 10(-3)). The DMFS value was 4.4 times higher among the children who brushed their teeth irregularly when compared with those who brushed three times a day (P = 10(-2)).