[Therapeutics strategies for the management of urinary tract infection in children]. / Stratégies thérapeutiques dans les infections urinaires du nourrisson et de l'enfant.

Urinary tract infections is one of the most common bacterial infections in pediatrics The increasing involvement of multiresistant bacteria including E. coli producing extended spectrum ß-lactamase (ESBL) makes its management difficult. The purpose of this article is to evaluate the state of the art and to propose ways of thinking about the management of E. coli urinary tract infection in children. The current percentage (less than 10%) of E. coli strains resistant to third generation cephalosporins and the relative efficiency of the latter, should not led to an immediate change of our protocols. Nevertheless, we should verify as soon as possible susceptibility of E. coli responsible for urinary tract infections and consider other therapeutic options for initial therapy and adaptation after obtaining antibiogram. The use of an aminoglycosid as initial treatment seems very interesting. Aminoglycosides have a very good distribution in the renal parenchyma and are still working on the majority of ESBL-producing bacteria. A rapid oral relay after 48 to 72 hours may be proposed according to the results of the susceptibility with either cotrimoxazole, cefixime, ciprofloxacin or an association cefixime-amoxicilline/clavulanate. The treatment of cystitis due to ESBL E. coli is much less problematic given the good urinary beta-lactam antibiotics diffusion. If clinical improvement occurs, even if antibiogram shows that the strain is resistant to the antibiotic prescribed, it is usually unnecessary to change treatment.

A new highly discriminatory multiplex capillary-based MLVA assay as a tool for the epidemiological survey of Pseudomonas aeruginosa in cystic fibrosis patients.

Multiple locus variable number of tandem repeats (VNTR) analysis (MLVA) has been shown to provide a high level of information for epidemiological investigations and the follow-up of Pseudomonas aeruginosa chronic infection. In the present study, an automatized MLVA assay has been developed for the analysis of 16 VNTRs in two multiplex polymerase chain reactions (PCRs), followed by capillary electrophoresis. The result in the form of a code is directly usable for clustering analyses. This MLVA-16(Orsay) scheme was applied to the genotyping of 83 isolates from eight cystic fibrosis patients, demonstrating that the same genotype persisted during eight years of chronic infection in the majority of cases. Comparison with pulsed-field gel electrophoresis (PFGE) analysis showed that both methods were congruent, MLVA providing, in some cases, additional informativity. The evolution of strains during long-term infection was revealed by the presence of VNTR variants.

[Study of nasopharyngeal colonization by Streptococcus pneumoniae and its antibiotics resistance in healthy children less than 2 years of age in the Marrakech region (Morocco)]. / Étude du portage rhinopharyngé de Streptococcus pneumoniae et de sa sensibilité aux antibiotiques chez les enfants en bonne santé âgés de moins de 2 ans dans la région de Marrakech (Maroc).

UNLABELLED: The healthy carrier of Streptococcus pneumoniae (S. pneumoniae) has been studied very little at the national level. With the emergence of antibiotic-resistant strains worldwide, and the emergence of new serotypes, an epidemiological survey is needed before the vaccine can be introduced in Morocco. OBJECTIVES: This study's objective was to determine the prevalence and risk factors of pneumococcal nasopharyngeal carriage in children less than 2 years of age in the Marrakech region and to assess the antibiotic susceptibility of the isolates and the serotypes present prior to the introduction of the conjugate pneumococcal vaccine. PATIENTS AND METHODS: From 2008 to 2009, 660 nasopharyngeal samples were collected on children under 2 years of age during scheduled visits to dispensaries for routine immunization in the Marrakech region. RESULTS: S. pneumoniae carriage was found in 45.8% of children. Of the 660 samples, 302 strains were isolated. The percentage of pneumococcal strains with reduced susceptibility to penicillin (PRSP) was 34.7%. Among these strains, 87.1% showed low-level resistance and 12.9% high-level resistance. Resistance to amoxicillin was found in 3.3% of the strains and no strains were resistant to cefotaxime. Several risk factors for pneumococcal carriage were identified, the main ones being breastfeeding less than 2 months, the presence of more than one sibling, passive smoking, and low socioeconomic level. The most frequent serotypes were 19F, 6, 14, 23, 18, and 9. The study of the vaccine serotype distribution showed that the theoretical vaccine coverage of the 7 valent vaccines was at 57% for all the isolates. CONCLUSION: These data show the frequency and the risk factors on nasopharyngeal carriage, and report the status of penicillin resistance of strains carrying children less than 2 years of age in the Marrakech region. The fluctuation of circulating serotypes at the national level underscores the importance of epidemiological surveillance carried out before the introduction of the heptavalent vaccine in Morocco.

[Extended-spectrum beta-lactamase producing-enterobacteriaceae]. / Entérobactéries productrices de bêta-lactamases à spectre étendu.

Extended-spectrum beta-lactamase (ESBLs) are defined as ß-lactamase capable of hydrolyzine oximino-cephalosporins and aztreonam and are encoded by mobile genes. The most frequently encountered ESBLs belong to the CTX-M, SHV, and TEM families. ESBLs were found first in Klebsiella pneumonia and then predominantly in E. coli. The incidence of patients with ESBLs E. coli increase since 2000 in Robert Debré Hospital. They were responsible of cystitis or pyelopnephritis and rarely of materno-foetal infections or neonatal meningitis. These strains were susceptible to colimycin, carbapenems and fosfomycin.

[Use of 16S rRNA gene sequencing for identification of "Pseudomonas-like" isolates from sputum of patients with cystic fibrosis]. / Mucoviscidose: identification des bacilles isolés d'infections bronchiques par séquençage du gène de l'ARN ribosomal 16S.

Since nonfermenting, Gram negative bacilli recovered from patients with cystic fibrosis could be misidentified with phenotypic procedures, we used partial 16S ribosomal RNA gene (16S gene) sequencing to identify these "Pseudomonas-like" isolates. 473 isolates were recovered from 66 patients in 2003. Sequencing was used to identify 29 (from 24 patients) of the 473 isolates, showing unclear results with routine tests. PCR with specific primers was carried out to amplify a 995 bp fragment, which was then sequenced. The sequences were analyzed with GenBank database for species assignment. Phenotypic and genotypic results were concordant for 20/29 isolates (10 Pseudomonas aeruginosa, 5 Burkholderia cepacia, 3 Stenotrophomonas maltophilia, 2 Achromobacter xylosoxidans). However, 3 of the 5 B. cepacia isolates were then identified as Burkholderia multivorans with a PCR-RFLP procedure. Phenotypic misidentification was observed for 9/29 isolates: 4 A. xylosoxidans, 1 P. aeruginosa, 1 Bordetella petrii, 1 Bordetella bronchiseptica, 1 Ralstonia respiraculi and 1 Ralstonia mannitolilytica. Partial 16S gene sequencing improved the identification of "Pseudomonas-like" isolates from cystic fibrosis patients, but the accuracy to distinguish between genomovars of the B. cepacia complex was inadequate.

[Ureaplasma urealyticum and Mycoplasma hominis infections in newborns: personal data and review of the literature]. / Ureaplasma urealyticum, Mycoplasma hominis et pathologies néonatales: Données personnelles et revue de la littérature.

Ureaplasma urealyticum and Mycoplasma hominis colonized 20-40% of newborns and are more frequent in premature. They are responsible for localized infections such as pleural effusion, pneumopathy, adenopathy, abscess or systemic sepsis. An important hyperleukocytosis is often associated with pulmonary infections. Their responsibility, as pathogen agents, is questionable in some non bacterial meningitis. There is large controversy for their role as cofactor, in chronic lung disease (bronchopulmonary dysplasia) and periventricular leukomalacia, because of a too low number of newborns in prospective trials. Genital mycoplamas are resistant to beta lactamines. Macrolides have a good sensitivity, particularly josamycine, but Mycoplasma hominis is resistant to erythromycin. For systemic sepsis, fluoroquinolones such as ciprofloxacine have less deleterious effects than IV erythromycin.

[Current Streptococcus pyogenes sensitivity responsible for acute tonsillopharyngitis in France]. / Sensibilité actuelle en France de Streptococcus pyogenes responsable d'angine aiguë.

OBJECTIVE: Current guidelines recommend that only tonsillopharyngitis due to group A beta-haemolytic streptococcus (GABHS) diagnosed by rapid diagnostic test should be treated with antibiotics. Empirical antibiotic therapy must be based on epidemiological surveillance of resistance of GABHS to antibiotics. The aim of our study was to assess the activity of antimicrobial agents currently recommended for the treatment of GABHS tonsillopharyngitis. Method The activity of penicillin G, amoxicillin, cefaclor, cefpodoxime, cefuroxime, erythromycin, clarithromycin and clindamycin was determined against 93 consecutive GABHS isolates collected in 2002. MIC50 and MIC90 of antibiotics tested were determined by agar dilution method according to CA-SFM guidelines. Macrolide resistance genes (ermA, ermB, mef) were detected by PCR. Genetic diversity of erythromycin-resistant isolates was analysed by pulsotypic method after digestion by SmaI (Finger-printing II, Biorad). RESULTS: The activity of beta-lactam agents tested was similar and no resistant strain was detected (0%). Nevertheless, this study shows an increasing emergence of erythromycin-resistant GABHS strains reaching 14% in 2002 (vs. 6.2% in a previous study carried out in 1996-1999). CONCLUSION: The empirical antibiotic therapy of tonsillopharyngitis must consider, on the one hand, the high risk of GABHS eradication failure associated with in vitro resistance to erythromycin and clarithromycin, and on the other hand, the sustained susceptibility of GABHS to beta-lactam agents. These results reinforce the recommendations to use beta-lactam agents as first line treatment of GABHS tonsillopharyngitis.

[Pathogenic bacteria in cystic fibrosis]. / Bactéries pathogènes dans la mucoviscidose.

Since the CF gene identification in 1989 and despite the improvement of our knowledge in the physiopathology of the disease, bronchopulmonary infection determines the vital prognosis. Following Staphylococcus aureus infection, patients are colonized or colonized by Pseudomonas aeruginosa, greatly involved in the pulmonary deterioration. Other bacteria may be involved Burkholderia cepacia, Stenotrophomonas maltophilia, Alcaligenes sp. Intensive antibiotic treatment of primocolonisation helps to prevent or delay chronic colonisation. Chronic colonization needs a rational long term antibiotic strategy to prevent the occurrence of multiresistant germs; antibiotic cures are performed every 3 or 4 months before pulmonary exacerbation symptoms.

Genotypic characterization of Pseudomonas aeruginosa strains recovered from patients with cystic fibrosis after initial and subsequent colonization.

Chronic infection by Pseudomonas aeruginosa (PA) in patients with cystic fibrosis (CF) is preceded by a period of colonization and acute infection. Early aggressive antibiotic treatment of initial colonisation may prevent or at least delay chronic pulmonary infection. We initiated treatment with a combination of IV beta-lactam tobramycin, followed by nebulized colistin when PA was first isolated from patients with CF. Subsequent serial PA isolates obtained from these colonized CF patients were characterized by means of molecular methods to determine whether they were genetically related to the initial strain. Initial colonization was eradicated in all 19 patients. All patients reacquired PA within 3-25 months during the 3 years of follow-up. Fourteen patients acquired a new PA strain with a distinct genotypic profile, suggesting a new source of contamination. Five patients had two PA isolates with identical genotypes, suggesting either previous undetected respiratory tract colonization or a persistent environmental source of contamination.

Genetic and phenotypic characterization of macrolide resistance in group A streptococci isolated from adults with pharyngo-tonsillitis in France.

Three hundred and three strains of group A streptococci (GAS) isolated from adults with pharyngitis were tested to evaluate their phenotype of resistance to macrolides-lincosamides and to search for macrolide resistance genes. MICs of clarithromycin were determined. The overall rate of resistance to both erythromycin and clarithromycin was 9.6%. Constitutive, inducible and M phenotypes of resistance were detected in 4.3, 2 and 3.3% of strains, respectively. All constitutive phenotypes harboured ermB genes, whereas inducible phenotypes had the ermTR gene and M phenotypes had the mefA gene. In France, the current resistance rate of GAS to erythromycin and clarithromycin remains low.

Mechanisms of macrolide resistance in clinical group B streptococci isolated in France.

Macrolide susceptibility was investigated in clinical group B streptococci obtained from neonates or pregnant women in 2000 in France. Of 490 consecutive isolates, 18% were resistant to erythromycin. The erm(B), erm(A) subclass erm(TR), and mef(A) genes were harbored by 47, 45, and 6% of these strains, respectively. Two isolates did not harbor erm or mef genes.

Mechanisms of macrolide resistance in clinical pneumococcal isolates in France.

The genetic basis of macrolide resistance was investigated in a collection of 48 genotypically unrelated clinical isolates of Streptococcus pneumoniae obtained between 1987 and 1997 in France. All strains were resistant to erythromycin, clindamycin, and streptogramin B, exhibiting a macrolide-lincosamide-streptogramin B resistance phenotype, and harbored the erm(B) gene. None of the strains carried the mef(A) or erm(A) subclass erm(TR) gene.

Effects of oral Saccharomyces boulardii on bacterial overgrowth, translocation, and intestinal adaptation after small-bowel resection in rats.

BACKGROUND: Small-bowel resection in animals results in alterations of the morphology and functional adaptation in the remaining intestine. The aim of our study was to study the effect of Saccharomyces boulardii versus placebo in rats after 50% small-bowel resection. METHODS: Sixty-three rats were assigned to one of three groups: small-bowel resection (n = 31), transected surgery controls (n = 16), or non-surgical controls (n = 16). Of the 31 rats with small-bowel resection, 15 were given S. boulardii (140 mg/dl), and 16 were given placebo. Intestinal markers measured included bacterial overgrowth (BO) on days 4 and 8 and translocation into mesenteric lymph nodes, liver, and spleen. Markers of small-bowel adaptation included histomorphology of the mucosa, protein content, and various brush-border enzymes (sucrase, glucoamylase, n-aminopeptidase). RESULTS: In the jejunal mucosal samples on day 8, S. boulardii-treated rats showed a significant increase in protein content (58.3 +/- 12 mg/10 cm) compared with placebo-treated rats (29.2 +/- 1.8) or non-surgery controls (18.3 +/- 1.2; P < 0.001). S. boulardii-treated rats also had significantly higher levels of all three brush-border enzymes. A significant increase of enzyme-specific activities was observed in the ileum of S. boulardii resected rats compared with the placebo resected group on day 4, and no significant differences were seen in the remnant ileum except an increase in protein content in S. boulardii-treated rats on day 8. Histomorphometric studies showed no differences in ileal villus height or translocation frequencies by day 8 in S. boulardii or placebo resected rats. CONCLUSIONS: These data indicate that, after resection, S. boulardii does not modify bacterial overgrowth or translocation frequency but does significantly enhance the functional adaptation of the remaining intestinal segments.

[Pediatric nosocomial diarrhea]. / Diarrhées nosocomiales en pédiatrie.

Nosocomial diarrhea are an important cause of childhood morbidity and mortality. Rotavirus has been recognized as the most important cause of nosocomial gastroenteritidis particularly in infants during winter months. Nosocomial diarrhea are also, caused by bacterial pathogen like Clostridium difficile, Salmonella, Shigella, Campylobacter. Clostridium difficile toxin assay should be considered for patients who are receiving antibiotics. Modifications of hygiene procedures and preventive measures are necessary in order to reduce nosocomial infection.

Capillary electrophoresis-single-strand conformation polymorphism analysis for rapid identification of Pseudomonas aeruginosa and other gram-negative nonfermenting bacilli recovered from patients with cystic fibrosis.

We used capillary electrophoresis-single-strand conformation polymorphism (CE-SSCP) analysis of PCR-amplified 16S rRNA gene fragments for rapid identification of Pseudomonas aeruginosa and other gram-negative nonfermenting bacilli isolated from patients with cystic fibrosis (CF). Target sequences were amplified by using forward and reverse primers labeled with various fluorescent dyes. The labeled PCR products were denatured by heating and separated by capillary gel electrophoresis with an automated DNA sequencer. Data were analyzed with GeneScan 672 software. This program made it possible to control lane-to-lane variability by standardizing the peak positions relative to internal DNA size markers. Thirty-four reference strains belonging to the genera Pseudomonas, Brevundimonas, Burkholderia, Comamonas, Ralstonia, Stenotrophomonas, and Alcaligenes were tested with primer sets spanning 16S rRNA gene regions with various degrees of polymorphism. The best results were obtained with the primer set P11P-P13P, which spans a moderately polymorphic region (Escherichia coli 16S rRNA positions 1173 to 1389 [M. N. Widjojoatmodjo, A. C. Fluit, and J. Verhoef, J. Clin. Microbiol. 32:3002-3007, 1994]). This primer set differentiated the main CF pathogens from closely related species but did not distinguish P. aeruginosa from Pseudomonas alcaligenes-Pseudomonas pseudoalcaligenes and Alcaligenes xylosoxidans from Alcaligenes denitrificans. Two hundred seven CF clinical isolates (153 of P. aeruginosa, 26 of Stenotrophomonas maltophilia, 15 of Burkholderia spp., and 13 of A. xylosoxidans) were tested with P11P-P13P. The CE-SSCP patterns obtained were identical to those for the corresponding reference strains. Fluorescence-based CE-SSCP analysis is simple to use, gives highly reproducible results, and makes it possible to analyze a large number of strains. This approach is suited for the rapid identification of the main gram-negative nonfermenting bacilli encountered in CF.

Comparative in vitro activities of meropenem, imipenem, temocillin, piperacillin, and ceftazidime in combination with tobramycin, rifampin, or ciprofloxacin against Burkholderia cepacia isolates from patients with cystic fibrosis.

We evaluated the activities of meropenem, imipenem, temocillin, piperacillin, and ceftazidime by determination of the MICs for 66 genotypically characterized Burkholderia cepacia isolates obtained from the sputum of cystic fibrosis patients. In vitro synergy assays, as performed by the time-kill methodology, of two- and three-drug combinations of the beta-lactams with tobramycin, rifampin, and/or ciprofloxacin were also performed with 10 strains susceptible, intermediate, or resistant to fluoroquinolones. On the basis of the MICs, meropenem and temocillin were the most active beta-lactam agents, with MICs at which 90% of isolates are inhibited of 8 and 32 micrograms/ml, respectively. The addition of ciprofloxacin significantly enhanced the killing activities of piperacillin, imipenem, and meropenem against the 10 strains tested (P < 0.05). The best killing activity was obtained with the combination of meropenem and ciprofloxacin, with bactericidal activity of 3.31 +/- 0.36 log10 CFU/ml (P < 0.05). Compared to the activity of the two-drug beta-lactam-ciprofloxacin combination, the addition of rifampin or tobramycin did not significantly increase the killing activity (P > 0.05). The three-drug combinations (with or without ciprofloxacin) significantly enhanced the killing activities of piperacillin, imipenem, and meropenem relative to the activities of the beta-lactams used alone (P < 0.05). The combination beta-lactam-ciprofloxacin-tobramycin was the combination with the most consistently synergistic effect.

[Escherichia coli virulence factors in pediatric urinary tract infections]. / Facteurs de virulence de Escherichia coli dans les infections urinaires de l'enfant.

As many as 90% of all community-acquired urinary tract infections (UTIs) and more than 30% of nosocomially acquired UTIs are caused by E coli. The migration of bacteria into proximal urethra and bladder mucosa requires that the organisms travel "upstream" and resist being carried away by the flow of urine. Colonisation requires binding of specific adhesions of the bacteria to appropriate receptors on the surfaces of the epithelial cells. P fimbrae are found in 80%, 30% and 20% of strains from patients with pyelonephritis, cystitis and asymptomatic bacteriura, respectively. P fimbrae are found in only 30% of strains isolated from patients with pyelonephritis associated with compromising host factors such as vesicoureteral reflux, urinary tract anatomical abnormalities and recent urinary tract instrumentation.

Enteroaggregative, Shiga toxin-producing Escherichia coli O111:H2 associated with an outbreak of hemolytic-uremic syndrome.

Shiga toxin-producing Escherichia coli O111:H2 strains from an outbreak of hemolytic-uremic syndrome showed aggregative adhesion to HEp-2 cells and harbored large plasmids which hybridized with the enteroaggregative E. coli probe PCVD432. These strains present a novel combination of virulence factors and might be as pathogenic to humans as the classic enterohemorrhagic E. coli.

Genotypic analysis of Burkholderia cepacia isolates from 13 French cystic fibrosis centers.

Burkholderia cepacia has been involved in outbreaks of pulmonary infection among patients with cystic fibrosis (CF), and the spread of a highly transmissible clone has been reported throughout the United Kingdom and Canada. These data prompted a DNA-based typing study of the strains recovered in French CF centers. Ninety-five isolates recovered from 71 patients attending 13 CF centers in 9 regions of France were characterized by randomly amplified polymorphic DNA (RAPD) analysis and pulsed-field gel electrophoresis (PFGE). Twenty-one genotypes were identified among the 95 isolates, and the results of RAPD and PFGE were concordant for 89 isolates (94%). Cross-colonization was demonstrated in 7 of the 13 CF centers. The investigation of serial isolates showed that most chronically colonized patients harbored a single B. cepacia strain. A geographically clustered distribution of B. cepacia genotypes was observed, except for one genotype, which was detected in four regions but was proven to be different from the genotype of the British-Canadian highly transmissible strain. The present study confirms the ability of B. cepacia to spread among CF communities in France and the importance of epidemiological surveys in the institution of prevention policies.