[Early neonatal bacterial infections: could superficial bacteriologic samples at birth be limited?]. / Infections bactériennes néonatales précoces en maternité: peut-on limiter les prélèvements bactériologiques périphériques en salle de naissance ?

INTRODUCTION: Without promptly started antibiotic therapy, early neonatal bacterial infections incur a significant mortality. Superficial bacteriologic samples at birth have in France a real place for the diagnosis and the decision to treat a neonate. OBJECTIVES: In order to limit their indication and their choice, the aim of this article was to describe the proportion of neonates with samples and to determine the diagnostic value of the gastric aspirate, the ear swab and the placental sample. METHODS: Neonates born in the CHRU of Lille in 2005 and staying in the maternity ward were prospectively included. Criteria for samples, type of samples and diagnosis taken were noted. Sensibility, specificity, positive and negative predictive values and likelihood ratios for a positive test and a negative test were calculated. RESULTS AND CONCLUSION: This study included 3918 neonates; 1.7% (65 children) were infected according to our criteria; 42.3% received bacteriologic samples. In accordance with the Anaes guidelines (2002), if mothers were Group B Streptococci positive and received intrapartum antibiotics (up to 2 injections) or did not have any screening test without any other indication of samples, the neonate did not have to receive bacteriologic samples. The gastric aspirate was the best exam thanks to the excellent negative predictive value of its direct examination: 99.4% (IC 95%: 98.8-99.7), its high likelihood ratio for a positive test: 10.04 (IC 95%: 8.29-12.15) and its low likelihood ratio for a negative test: 0.16 (IC 95%: 0.09-0.29); this sample could restrict the antibiotics' ratio given to the neonate. Placental sample could be taken only in certain indications.

[Kinetics of Pseudomonas aeruginosa virulence gene expression during chronic lung infection in the murine model]. / Cinétique d'expression des gènes de virulence de Pseudomonas aeruginosa au cours d'une infection pulmonaire chronique dans le modèle murin.

UNLABELLED: Pseudomonas aeruginosa is a Gram-negative bacillus frequently encountered in human diseases. P. aeruginosa produces a large number of secreted and cell associated virulence factors. Their production is coordinated by various systems of gene regulation. The correlation and sequential intervention of regulation systems during a pulmonary infection have not been determined yet. OBJECTIVE: The aim of this study was to analyze the expression of three P. aeruginosa virulence genes (exoS, lasI, and algD) during the first seven days of chronic lung infection. To do so, mice were infected intratracheally with agarose beads containing P. aeruginosa. RESULTS: The results were a progressive decrease of exoS transcription and an increase of algD, and lasI transcription during infection. This dynamic evolution was consistent with the clinical observation, which demonstrated a progressive loss of type III secretion system function and an increase in the mucoid phenotype development in P. aeruginosa strains from cystic fibrosis patients. CONCLUSION: The development of a P. aeruginosa pulmonary chronic infection associates a decrease of gene expression related to a type III secretion system and an increase of alginate production.

[Self-collected vaginal swabs to diagnosis bacterial vaginosis during pregnancy: A pilot study]. / Autoprélèvement vaginal à la recherche d'une vaginose bactérienne pendant la grossesse: étude pilote.

OBJECTIVE: To study the feasibility of a screening for bacterial vaginosis by a self-collected vaginal swab during pregnancy. To measure bacterial vaginosis prevalence in a non-representative sample of women. PATIENTS AND METHODS: A self-collected swab was suggested to 398 women who consulted between 15 and 33 weeks of gestation in three different centres. Gram stain evaluation using Nugent criteria was used for the diagnosis of bacterial vaginosis. RESULTS: Three hundred and forty-one women agreed to take part in the study (86%). The quality of the swabs was satisfactory in 93% of the cases. Concerning the 15 non-interpretable slides, the cellular and bacterial density was too poor, owing to a poor quality or a low vaginal flora. Thirty-one women (9%) had a bacterial vaginosis--Nugent score included between 7 and 10--and this frequency did not vary according to the centre. Thirty-five women (10%) had an intermediate flora--score between 4 and 6--and this result varied from 2 to 12% depending on the centre, but the difference was not significant. DISCUSSION AND CONCLUSION: Self-collected swabs to detect bacterial vaginosis are well accepted by most of pregnant women, and the quality of the swabs seems to be satisfactory. In case vaginal flora is intermediate--between 4 and 6--the interpretation of the slides could be difficult.

Energetic cost of physical activity in cystic fibrosis children during Pseudomonas aeruginosa pulmonary exacerbation.

Chronic pulmonary infection by Pseudomonas aeruginosa is observed in 50% of patients with cystic fibrosis and requires the use of recurrent intravenous therapy. A decrease of resting energy expenditure (REE) and an increase of physical activity (PA) after intravenous anti-P. aeruginosa therapy (IVAT) is observed while total energy expenditure (TEE) does not change. A decrease in the energetic cost of physical activity (ECPA) could be hypothesized but has never been studied. Our aim was to assess the evolution of ECPA after home IVAT in both standardized condition at hospital and in free-living condition twice before and after IVAT. Sixteen CF patients (nine boys, seven girls) chronically colonized by P. aeruginosa with a mean age of 12.1+/-2.3 years (range 7.1-14.6) were studied before and after IVAT. Each patient passed throughout a visit in hospital: weight, height and fat-free mass were measured. Then, energy expenditure (EE) measured by indirect calorimetry and heart rate (HR) were simultaneously recorded at different levels of PA: REE, and at different intensity of physical activities on a cycloergometer using an incremental increase of the power brake force. Physical activity energy expenditure (PAEE) was computed in laboratory condition using PAEE=EE-BEE (basal energy expenditure). Linear regression between PAEE and power brake force was fitted for each patient before and after IVAT. ECPA in standardized conditions was compared at different range of power brake force using area under the curve (AUC). After coming back at home, 24 h TEE using the heart rate monitoring technique and PA by triaxial accelerometry were simultaneously measured in free-living condition for 24 h during a school day. ECPA in free-living conditions was compared by the ratio PAEE:PA where PAEE=DEE-REE (DEE=daily energy expenditure). After IVAT, median AUC between 60 and 90 W in standardized condition decreased significantly by -15.4% (median 14.9, range 8.8-30.3 vs. median 12.6, range 8.5-17.6; P<0.05, Wilcoxon rank test) while the decrease for lower range of power work load did not reach significance. Spearman correlation was significant between variations of forced expiratory volume in 1 s and variation of AUC at 30-60 W before and after IVAT in standardized condition. In free-living conditions, ratio PAEE/PA did not vary significantly (median 3.4, range 1.6-6.4 vs. median 2.8, range 1.4-4.8; NS). Our data demonstrate a decrease of ECPA after IVAT in standardized conditions for moderate level of PA (60-90 W), but not in free-living conditions. The decrease of ECPA was probably due to a decrease in the energetic cost of breathing after IVAT, that is particularly relevant to promote PA in CF patients.

Natural outcome of Helicobacter pylori infection in asymptomatic children: a two-year follow-up study.

BACKGROUND AND OBJECTIVES: It is known that Helicobacter pylori can be acquired in early childhood. There is not enough data to know whether or not infected children should be treated. A better knowledge of the natural outcome and implications of H pylori infection may provide evidence that eradication therapy is beneficial in childhood. This prospective study looks at clinical symptoms, endoscopic, microbial, and histologic changes during a 2-year period in infected asymptomatic children. It is hoped that some prognostic indicators will be found that select out the children that later need therapy. PATIENTS AND METHODS: During epidemiologic study of the prevalence of H pylori infection, 18 children aged 7 +/- 4 years (mean +/- 1 SD) were discovered to have H pylori infection and enrolled in the 2-year follow-up study. These patients had received no eradication therapy because they were asymptomatic. The follow-up for each patient consisted of an initial assessment, a clinical examination every 6 months, and an endoscopic reevaluation at the end of the first and second years. Gastric mucosal samples were analyzed for bacteriologic and histologic changes. Various factors were initially recorded: individual factors included sex, age, and housing conditions; microbial factors included bacterial load and the presence of the CagA gene. Inflammatory changes were also noted, such as the presence of active gastritis and nodular formation, and these were correlated with the histology which was described using the Sydney classification. Typing polymerase chain reaction-restriction fragment length polymorphism was performed to check the persistence of the same strain of H pylori in each patient. RESULTS: All of the children were still infected after 2 years with the same strain as in the initial assessment with the exception of 1 child whose infection cleared spontaneously. The density of antral and fundal mucosal colonization with H pylori also remained stable. There were progressive inflammatory changes in this cohort, particularly between the first and second year (histologic score, 3.5 +/- 1.3 vs 5 +/- 1). Active antral gastritis occurred in 3 out of 14 and 1 out of 8 children during the first and second year, respectively. Gastritis became active in the fundus in 2 out of 14 and 2 out of 8 children during the same period. Increases in the histologic score were found particularly in male children, and children colonized by cagA- strains of H pylori during the follow-up. The frequency of nodular gastritis significantly rose from 11% (2 out of 18 children) to 64% (9 out of 14 children) after 1 year, and to 80% (8 out of 10 children) after 2 years. CONCLUSION: These findings demonstrate a deterioration in the histologic features of the gastric mucosa of infected children despite stable H pylori colonization and the absence of symptoms.

Comparison of iron uptake in different Helicobacter species.

Comparison of iron uptake of four Helicobacter species (Helicobacter pylori, Helicobacter felis, Helicobacter acinonyx, and Helicobacter mustelae), associated with various degrees of gastritis in their respective host, with five other species which colonize the intestinal tract of various animals (Helicobacter fennelliae, Helicobacter cinaedi, Helicobacter muridarum, Helicobacter bilis, and Helicobacter hepaticus), demonstrated that the iron acquisition system differed according to the ecological niche of the organism. Gastric Helicobacter, except for H. pylori, which used iron from human lactoferrin, were nonsiderophore-producing organisms and were only able to obtain iron from heme and hemoglobin. Nongastric Helicobacter produced siderophores and were able to use for growth a wide range of iron sources (bovine and human lactoferrin and transferrin, heme, hemoglobin).

Validation of diffusion methods for macrolide susceptibility testing of Helicobacter pylori.

Helicobacter pylori resistance to macrolides is increasing, and the need for susceptibility testing has become crucial. The only standardized method is agar dilution, which is not adapted to clinical practice. The present work aimed: (1) to optimize the technical conditions and to assess the reproducibility of the E-test and disk diffusion method for macrolides susceptibility testing of H. pylori, and (2) to assess the performances of these two phenotypic methods in detecting strains harboring a resistance mechanism to macrolides. We used 191 isolates collected in nine centers of France and Belgium. Phenotypic tests were performed on Mueller-Hinton agar supplemented with 10% horse blood, inoculated with a 2-day-old H. pylori suspension (10(8) CFU/ml), and incubated for 72 hr at 37 degrees C under microaerophilic conditions. The reproducibility studied on two randomly selected strains was better for disk diffusion than for the E-test for both clarithromycin and erythromycin. For a subset of 10 strains, the MICs of erythromycin and clarithromycin did not differ from more than one two-fold dilution when determined by E-test or agar dilution method. The breakpoints were for MICs: 1 mg/L for both clarithromycin and erythromycin and for inhibition diameters, 22 mm for clarithromycin and 17 mm for erythromycin. There was a 100% concordance between susceptibility to erythromycin and clarithromycin. However, the susceptible and resistant populations were better separated by testing erythromycin. Of 34 resistant strains, two lacked the A2142G and A2143G point mutations in 23S rRNA by PCR-RFLP. None of 15 tested sensitive strains were positive for one of these two point mutations. For clinical practice, we recommend to assess macrolide susceptibility of H. pylori by using one of these two phenotypic methods under the described technical conditions.

Regulation of the transcription of genes encoding different virulence factors in Helicobacter pylori by free iron.

Since free iron possesses a poor solubility under physiologic conditions and thus becomes a limiting nutrient for growth, a shift from high- to low-iron environmental conditions is an important signal for bacteria to coordinate the regulation of gene expression. Here, we studied and compared the level of transcripts corresponding to the vacA (cytotoxin), ureA (urease), cagA (cytotoxin-associated antigen) and fur (ferric uptake regulator) genes of Helicobacter pylori, grown under iron-sufficient and iron-restricted conditions. A significant increase in the accumulation of vacA and fur transcripts was observed under iron-restricted conditions. This up-regulation by low levels of iron seems to be not directly regulated by Fur, and certainly requires other regulatory factors. No statistical difference was defined in the accumulation of cagA and ureA.

Local antibiotic lock for the treatment of infections related to central catheters in parenteral nutrition in children.

BACKGROUND: Central venous catheter-related (CVC) infections represent the most common complication of parenteral nutrition. These infections are usually treated by means of long-term systemic antibiotic treatment. The objective of this study was to determine the efficacy of combining a local antibiotic lock with a short systemic double antibiotic to treat CVC-related staphylococci infections. METHODS: Any child with coagulase-negative staphylococci or Staphylococcus aureus septicemia, confirmed by a positive blood culture, was included in the study. A double antibiotic systemic treatment composed of amikacin and teicoplanin was started and continued for 5 days. The antibiotic treatment was combined from the first day (D0) with a local teicoplanin lock, which was left for 12 hours a day in the catheter for 15 days. Parenteral nutrition was continued on a nocturnal cyclic mode during antibiotic treatment. The efficacy of the treatment was evaluated by clinical (body temperature), biologic [C-reactive protein levels (CRP)], and bacteriologic (blood culture) measures. RESULTS: Twenty CVC-related infection episodes in 13 patients were analyzed for the study. In the initial biologic test, CRP varied from 2 to 130 mg/L (mean 43 mg/L). After 3 days of treatment, CRP varied from 2 to 61 mg/L (mean 12 mg/L). The median time until normalization of temperature and CRP levels after the beginning of antibiotic treatment was 3.2 days (range 1 to 14 days) and 6.2 days (range 2 to 19 days), respectively. All blood cultures were negative for infection 48 hours after stopping the treatment. Only 1 therapeutic failure was observed during the treatment. The patient had persistent signs of clinical septicemia that required removal of the CVC. Two catheter-related infection recurrences were observed in the month after termination of the local antibiotic lock, which also required removal of the CVC. The central venous catheter was maintained in the other cases. CONCLUSIONS: Teicoplanin antibiotic locks, combined with a short conventional systemic antibiotic treatment and continuation of cyclic parenteral nutrition, seem effective and well-tolerated treatments for CVC infections.

Antimicrobial activity of cefotiam combinations against Enterobacteriaceae moderately susceptible or resistant to this new cephalosporin.

The interaction of cefotiam with each of the four aminoglycosides gentamicin, tobramycin, netilmicin and amikacin were studied by the broth microdilution method ("checkerboard" technique) against 36 strains of Enterobacteriaceae chosen for their moderate susceptibility (MIC: 4-32 mg/l) or resistance (MIC: 64-512 mg/l) to cefotiam. A high rate of synergistic combinations was found with all the aminoglycosides: 81% with gentamicin, 76% with amikacin, 67% with tobramycin and netilmicin. The therapeutic value of these interactions appeared excellent.

In vitro activity of pefloxacin.

A broth dilution method was used to measure the minimal inhibitory concentrations of pefloxacin, a new quinolone derivative. Because this new agent could be used in systemic infections, mezlocillin, cefotaxime, ceftazidime and amikacin were used as comparative agents. Pefloxacin was found to be more active than mezlocillin and as active as or more active than cefotaxime, ceftazidime and amikacin. With the exception of Serratia marcescens, only 7% of Enterobacteriaceae strains were resistant to pefloxacin with a MIC greater than 8 micrograms/ml. Pefloxacin was also found to be the best agent against the non-fermenters Staphylococcus aureus and St. epidermidis. Resistance to ampicillin, carbenicillin and gentamicin did not affect the effectiveness of pefloxacin. However, pefloxacin appeared more susceptible to nalidixic acid resistance, with MICs four to sixfold higher.

Anti-Helicobacter pylori IgG levels in abattoir workers.

The aim of our study was to detect antibodies against Helicobacter pylori (H. pylori) in abattoir workers whose activity was variable (pig, poultry-carcasses, poultry-intestinal organs treatment). An adsorption of all sera with H. pylori and Campylobacter species known to be ubiquitous and responsible for zoonosis was included in the ELISA reaction to eliminate possible cross-reactions between these species. Statistically higher specific titres of IgG antibodies against H. pylori were observed in men and women who had only worked for 1 or 2 years versus matched controls, indicating a possible transmission of H. pylori from animal to man. The role of poultry or pigs as contaminants alone or in association remains to be determined.

[Rapid diagnosis of purulent meningitis]. / Diagnostic rapide des méningites purulentes.

The cerebrospinal fluid of 589 subjects, 78 of whom were suffering from a purulent meningitis were examined. Comparatively by classical bacteriological techniques (direct examination and culture) and by electro-immunodiffusion, latex agglutination, and Limulus endotoxin assay. Soluble bacterial Haemophilus influenzae type B, Neisseria meningitidis group A, C, and Streptococcus pneumoniae antigens, were tested by electro-immunodiffusion and latex agglutination, and soluble bacterial N. meningitidis group B, Listeria monocytogenes and Streptococcus agalactiae antigens by electro-immunodiffusion. Specific antigens and endotoxin were found in 75.8 per cent of the specimens with a rapid answer (120 min). The three tests revealed also only the diagnosis in 29.1 per cent of cases of pneumococcal meningitis, in 33.3 per cent of meningococcal meningitis and in 47 per cent of Gram-negative bacteria meningitis. Only five cerebrospinal fluid from the 589 specimens tested were given a non-specific reaction. These two advantages--sensitivity and specificity--of these three tests render them techniques of the future in the diagnosis of purulent meningitis.

[Rapid, automatic methods for identifying enterobacteria]. / Méthodes rapides et automatiques d'identification des entérobactéries.

The biochemical testing of Enterobacteriaceae can be rapidly and automatically performed with commercial identification systems. There are three groups of identification systems: the kits, the microtiter plates and laboratory apparatus. The ratios of agreement between these new systems and the conventional tests are equivalent. The two first categories of systems are inexpensive unlike apparatus which must be utilized only in important laboratories.

[Epidemiology of infections associated to "Burkholderia cepacia complex" in the course of cystic fibrosis]. / Epidémiologie des infections provoquées par les bactéries du "complexe Burkholderia cepacia" au course de la mucoviscidose.

Within a few years bacteriological knowledge on Burkholderia cepacia species has progressed considerably. Within bacterial classification (taxonomy), B. cepacia gathers eight species and one species on standby of nomenclature (genomovar VI); the whole of these species constitutes the "B. cepacia complex" or B. cepacia "sensu lato" and the denomination B. cepacia "sensu stricto" is attributed to the genomovar I. These new data call into question the knowledge on the clinic and the epidemiology of B. cepacia "sensu lato" infection in the course of cystic fibrosis. Among these newly described species, B. cenocepacia (formerly genomovar III) and B. multivorans (formerly genomovar II) are the most frequent species and together they represent more than 90% of infections associated to "B. cepacia complex" in the course of cystic fibrosis. B. cenocepacia is often associated to the "cepacia syndrome" which is characterized as a fatal necrotizing pneumonia with bacteremia. The progress of molecular epidemiology allowed the description of bacterial clones of which some are highly transmissible from person-to-person. Their distribution varies according to the species and the geography. The identification of these new species appears particularly difficult and, by the fact, the data on taxonomy and molecular epidemiology can be provided only by highly specialized reference centers.

[Acquisition of secondary resistance after failure of a first treatment of Helicobacter pylori infection in children]. / Acquisition d'une résistance secondaire après échec d'un premier traitement lors de l'infection à Helicobacter pylori chez l'enfant.

AIMS: To assess the frequency of acquisition of secondary Helicobacter pylori resistant-strains after a first course of antimicrobial treatment. PATIENTS AND METHODS: A retrospective study was performed during the 1994-2000 period, in 15 girls and eight boys, mean age 10.9 +/- 4.8 years (1.4-17 years), with Helicobacter pylori gastritis (culture and antimicrobial susceptibility) presenting a failure of first course treatment, with during one week a proton pump inhibitor and amoxicillin together with either clarithromycin (n = 14) or metronidazole (n = 9). Two endoscopies were performed, the first at the time of diagnosis and the second after the failure of bacterial eradication demonstrated by a positive 13C urea breath test six weeks after the end of treatment. Antimicrobial susceptibility of all Helicobacter pylori strains was tested after each endoscopy and before starting a second course of the treatment. RESULTS: Comparison of antimicrobial susceptibility before and after the first course of treatment showed that Helicobacter pylori strains were all sensitive to amoxicillin, clarithromycin-resistant in eight children (34.7%) before treatment vs 12 (52.1%) after treatment, p = 0.42, ns, metronidazole-resistant in 13 (56.5%) vs 12 (52.1%), p = 0.80, ns, and both clarithromycin and metronidazole-resistant in four (17.3%) vs seven (30.4%), p = 0.63, ns. Among the 14 children treated by a triple therapy including clarithromycin, three (21.4%) developed a secondary resistance to clarithromycin and in one metronidazole resistance was no more detected. Among the nine children treated with a triple therapy including metronidazole, none developed a secondary resistance to metronidazole and one developed a secondary resistance to clarithromycin. CONCLUSION: This study shows the absence of amoxicillin-resistant strains, a high initial clarithromycin-resistant strains level (primary resistance), increasing after a first course of treatment, and for metronidazole a high initial level of resistance not influenced by treatment. Secondary clarithromycin-resistance of Helicobacter pylori strains following the first course of treatment could account for failure of bacterial eradication and suggests the importance of antimicrobial susceptibility.

[Pharmacokinetics of cefotaxime in cirrhotic patients with or without ascites]. / Pharmacocinétique du céfotaxime chez les malades cirrhotiques avec ou sans ascite.

Pharmacokinetic values of cefotaxime were measured in 12 cirrhotic male patients (6 without ascites and 6 with ascites) after intravenous injection of a single 2 gram dose of the antibiotic. In patients without ascites elimination of the drug was about the same as in normal subjects or control patients, although clearance was increased. In patients with ascites, the drug elimination half-life was significantly more prolonged (7.5 +/- 3.9 h versus 1.3 +/- 0.4 h, P less than 0.01) and the drug clearance was significantly lower (193.6 +/- 92.4 ml/min versus 475.8 +/- 152.2 ml/min, P less than 0.01) than in the other group. The accumulation of cefotaxime in these patients produced concentration in the ascites fluid that were above the critical therapeutic values for about 20 hours.

[A method of bacterial count by epifluorescence with acridine orange. Application to skin biopsies performed in burnt patients]. / Etude d'une méthode de dénombrement des bactéries par épifluorescence à l'acridine orange. Application aux biopsies de peau effectuées chez les brûlés.

Acridine orange was used for staining and counting micro-organisms obtained from 136 skin biopsies performed in burned patients. The number of organisms per gram of tissue was compared to the number of colony-forming-units (CFU) calculated from cultures of the same biopsies. The staining method was positive in 97 per cent of septic samples, and in 25 per cent of these it proved more sensitive than bacterial cultures, with a 100 to 1000-fold greater number of pathogens detected. Acridine orange also demonstrated bacteria in 69 biopsies which remained sterile after culture. In some cases, the same bacterial species was found in other samples taken a few days later.