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R J Courcol

Publications and source records attributed to R J Courcol.

At least 19 recordsLinked to original sources
PubMed2005

Bacterial flora of the low male genital tract in patients consulting for infertility.

The physiological aerobic bacterial flora of the low male genital tract was determined. This prospective study was performed on 600 semen specimens collected from 543 asymptomatic males consulting for infertility. Semen cultures were sterile in 28.8%, with a polymicrobial flora and/or absence or low titres of Ureaplasma urealyticum in 49.3%, and with one or two aerobic and facultative bacteria > or =1 x 10(3) CFU ml(-1) and/or U. urealyticum with titres > or =10(4) CCU ml(-1) (colour changing units) in 21.8%. In standard aerobic cultures, Gardnerella vaginalis was the most commonly isolated species (26.1%), followed by coagulase-negative staphylococci (15.7%) and Streptococcus anginosus (14.2%). Ureaplasma urealyticum was absent in 84.5% of semen samples, but when recovered, high (> or =10(4) CCU ml(-1)) and low titres (< or =10(3) CCU ml(-1)) were counted in 7.2% and 8.3% respectively. Of 48 patients, the follow-up of semen cultures showed marked variations in time. This study shows that (i) there was no relationship between the bacterial flora and the leucocytospermia; (ii) low titres of U. urealyticum in semen were not associated with a disturbance of the ecosystem; (iii) the critical threshold for U. urealyticum should be raised to > or =10(4) CFU ml(-1) and (iv) a positive semen culture should be repeated before any treatment.

Escherichia coli↗
PubMed2001

Multicenter evaluation of an automated system using selected bacteria that harbor challenging and clinically relevant mechanisms of resistance to antibiotics.

A multicenter study was carried out to evaluate the performance of a new commercial automated system in comparison with that of the reference agar dilution method. Ten clinical microbiology laboratories tested a collection of 61 strains of gram-negative bacilli (49 Enterobacteriaceae and 12 Pseudomonas aeruginosa), and 6 other laboratories tested a collection of 55 strains of gram-positive cocci (10 enterococci and 45 staphylococci) against 10-20 antimicrobial agents. The strains were selected on the basis that they harbored challenging and characterized mechanisms of resistance. In comparison with the agar reference method, the automated system gave an overall essential agreement (+/-1 dilution) of 94.5%, 93.5%, and 97% for the gram-negative bacilli, enterococci, and staphylococci, respectively. According to the interpretive standards of the National Committee for Clinical Laboratory Standards, the category agreement ranged from 96 to 96.4% for the three sets of organisms. The accuracy of the automated system, as determined by the kappa test, ranged from 0.80 to 0.88, reflecting an almost perfect agreement with the reference technique. Very major, major, and minor errors obtained with the automated system were 0.3%, 2.9%, and 6.6% for gram-negative bacilli, 3.4%, 0%, and 5% for enterococci, and 1%, 1.6%, and 2.7% for staphylococci, respectively. The high rate of very major errors in enterococci was mostly due to a single strain of multidrug-resistant Enterococcus faecium, which was found susceptible to several antibiotics in a majority of participant laboratories. The use of a heavy inoculum and of a broth test medium by the automated system might account for a better expression of certain resistance mechanisms, including beta-lactamases, as compared to the agar dilution reference method. The interlaboratory reproducibility was acceptable, as shown by the narrow dispersion of MICs and by the results of quality control.

Anti-Bacterial Agents↗
PubMed2001

[Bacterial epidemiological study of acute otitis media in children observed at home in the Nord Pas-de-Calais region].

BACKGROUND: The aim of this work is the study of the bacteriologic epidemiology of acute otitis media in infants observed at home in Nord Pas-de-Calais area, and the analysis of bacteria associated to recurrent otitis and clinical failure. OBSERVATIONS: A total of 295 specimens of ear pus specimens were collected from children (mean age: 18 months; average: one month-12 years). Pneumococcus strains were isolated from 52% of samples and 80% of these showed resistance to penicillin. H. influenzae was found in 35% of specimens and the half produced a beta lactamase. Pneumococcus is the predominant pathogen isolated in prolonged otitis media, while H. influenzae is preferentially found during recurrent otitis media. The main bacteriologic cause of failure traitement was penicillin-intermediate or -resistant pneumococci. The therapy administered 48 to 72 hours before collection of ear pus sample in therapeutic failure was ineffective (oral cephalosporins or macrolides), or administered to low dosage (50 mg/kg/j). CONCLUSION: Our results demonstrate, in opposition to other studies, Streptococcus pneumoniae as the most frequent pathogen in acute otitis media. They also show the excellent correlation between antibiotic therapy and clinical failures.

Bacterial Infections↗
PubMed2000

Peritonitis due to Staphylococcus sciuri in a patient on continuous ambulatory peritoneal dialysis.

Among the coagulase-negative staphylococci, Staphylococcus sciuri has rarely been described as the aetiology of continuous ambulatory peritoneal dialysis (CAPD) peritonitis. It has been reported in 1 case of endocarditis and has been isolated from peritoneal dialysis fluid in 2 patients. The case reported here describes CAPD peritonitis due to S. sciuri shortly after a previous episode due to S. aureus, showing the necessity to identify coagulase-negative staphylococci to find new species that cause CAPD peritonitis.

Adult↗
PubMed2000

Molecular identification of Pasteurella dagmatis peritonitis in a patient undergoing peritoneal dialysis.

Pasteurella dagmatis was identified as the etiologic agent of peritonitis in a continuous ambulatory peritoneal dialysis patient by utilizing a molecular kit in our hospital's clinical laboratory. This method would appear a useful approach to identify a species of Pasteurella not included in the existing database of commercial identification kits when discrepancies exist between phenotypic tests.

Adult↗
PubMed1999

Characterization of the Acinetobacter baumannii Fur regulator: cloning and sequencing of the fur homolog gene.

Growth kinetics, siderophore activity and iron-regulated bacterial proteins of Acinetobacter baumannii BM2580 were studied in iron-restricted and iron-supplemented chemically defined media. Iron-regulated outer membrane proteins of 75 kDa and 80 kDa were expressed under iron-restricted conditions. Cloning and sequencing of the complete iron-uptake regulatory (fur) gene from A. baumannii BM2580 is reported for the first time. This gene is preceded by a single autoregulated promoter whose -10 region overlaps the Fur binding site. The open reading frame identified encodes a polypeptide consisting of 145 amino acids. The fur gene is followed by a divergent open reading frame coding for the C-terminus of a putative PilU protein. Sequence analysis indicates that the Fur protein of A. baumannii was 63% identical to the Escherichia coli Fur protein.

Acinetobacter↗
PubMed1999

Evaluation of an automated system for identification of Enterobacteriaceae and nonfermenting bacilli.

The performance of the Vitek 2 (bioMérieux, France), a new fully automated system allowing rapid identification of microorganisms and susceptibility testing, and the Vitek 2 ID-GNB card (bioMérieux) was evaluated using 502 clinical isolates and stock collection strains of gram-negative rods belonging to 70 taxa. The number of isolates correctly identified to species and genus levels was 430 (85.7%) and 485 (96.6%), respectively. Clinical isolates of both Enterobacteriaceae and non-Enterobacteriaceae were better identified at the species level (95.3% and 74%, respectively) than stock collection strains (86.4% and 52.2%, respectively). The Vitek 2 ID-GNB card provides after 3 h a highly acceptable level of accuracy for identification of Enterobacteriaceae and non-Enterobacteriaceae, including most atypical strains encountered in clinical situations.

Automation↗
PubMed1999

[Determination of the nosocomial origin of vancomycin-resistance strains of Enterococcus isolated from stool of patients in a hematology department].

Patients severely neutropenic, when hospitalized, occasionally receive selective digestive decontamination, and the risk of vancomycin-resistant strain selection is a drawback since glycopeptide resistance is often associated with betalactam and aminoglycosid resistance. Bacterial translocation can lead to multiresistant bacterial sepsis. Eighteen Enterococcus faecium strains were collected from patients hospitalized in the leukemia unit of the Universitary Hospital of Lille (CHRU, Pr Bauters) between October 1992 and July 1997 and were studied. Nosocomial acquisition or endogenous origin were investigated to choose well-adapted prevention. All the vancomycin-resistant strains were shown by Polymerase Chain Reaction having the van A gene. The clonality of these strains was investigated by Pulsed-Field-Gel-Electrophoresis after Sma I restriction. Pulsotype analysis showed variable homology (52%-100%). Our results do not show evidence of patient-to-patient E. faecium transmission and suggest vancomycin-resistant strains were independently selected by antibiotic therapy from individual fecal flora. Except when epidemic events or happen, this strain isolation is more related to antibiotic prescription than misuse of isolation techniques.

Adult↗
PubMed1999

[Contribution of direct bacteriologic examinations to the diagnosis of early materno-fetal bacterial infection: the Lille experience].

A prospective study was conducted in 3056 live-born infants delivered at the Jeanneade-Flandre maternity hospital of the Lille Teaching Hospital between January and August 1997. Clinical, laboratory test, and microbiological test findings were compared. A cohort of 1003 infants who remained in the maternity ward but were considered at increased risk of maternofetal infection (MFI) based on history and/or obstetrical criteria and/or neonatal criteria underwent routine collection of specimens including gastric fluid, auricular and anal swabs, amniotic fluid, and placental fragments. Microscopic examination of gastric fluid smears, the first result available to the clinician, was found to have 27.5% sensitivity (983 samples). Positive predictive value (PPV) was only 17.8% because of a high rate of colonization (16.8%), defined as absence of clinical symptoms and three peripheral specimens positive for the same organism. However, negative predictive value (NPV) was as high as 99.8% as a result of high sensitivity (97.8%) in the infected neonates. The gastric fluid smear was positive in 30% and 35% of neonates born to mothers with hyperpyrexia during early and late labor, respectively, and in 42% of neonates born to mothers with a history of group B streptococcus carriage during the pregnancy. Forty-two per cent of neonates with a history of fetal tachycardia had a positive gastric fluid smear. Diagnostic criteria for infection were three peripheral specimens positive for the same organism, C-reactive protein elevation, and/or one or more clinical signs suggestive of infection, and/or a positive central specimen (blood, CSF). The infection rate in infants who remained in the maternity ward was 1.6%. The most common causative organisms were group B streptococci. These findings illustrate the useful contribution of gastric fluid smears to the early diagnosis of MFI and confirm the predominant role of group B streptococci.

Bacterial Infections↗
PubMed1998

Effects of host iron transport compounds on growth kinetics and outer-membrane protein expression of Bilophila wadsworthia.

Since the environmental iron concentration has emerged as an important attribute in the expression of bacterial virulence, the purpose of this study was to determine the effects of transferrin, lactoferrin, heme compounds, and inorganic iron sources (ferric and ferrous sulfate) on the growth of Bilophila wadsworthia and to study its outer membrane composition when grown under these different simulated in vivo conditions. Lactoferrin, transferrin, hemin and hemoglobin supported full growth of the bacteria in media lacking other iron sources. Bilophila wadsworthia was also capable of growing in the presence of ferrous and ferric sulfate. Profiles obtained by SDS-PAGE showed two iron-regulated outer membrane proteins (IROMPs) of 190 kDa and 88 kDa. The 190 kDa was susceptible to proteinase K cleavage in whole cells, indicating its exposure at the cell surface. These two major IROMPs were expressed in iron-restricted media supplemented with iron-bound organic sources and repressed by the addition of inorganic iron sources.

Journal Article↗
PubMed1997

Pharmacokinetics and bronchial diffusion of single daily dose amikacin in cystic fibrosis patients.

A single daily dose of amikacin 35 mg/kg by i.v. infusion over 30 min in 18 cystic fibrosis patients achieved mean serum peak and trough concentrations of 121.4 mg/L (+/- 37.3) and 0.88 mg/L (+/- 0.62), respectively. Pharmacokinetic parameters and bronchial diffusion of amikacin showed marked inter-patient variability. The highest concentrations in sputum were obtained at 2 h (10.95 +/- 7.55 mg/L) and decreased slowly to reach a mean concentration of 2.14 mg/L (range 0.2-3.8 mg/L) just before the following infusion. An increase in the body clearance of amikacin and a decrease in the volume of distribution according to age were observed.

Adolescent↗
PubMed1997

Siderophore production by Staphylococcus aureus and identification of iron-regulated proteins.

Siderophore activity of Staphylococcus aureus was detected in an iron-restricted chemically defined medium. The molecular mass of this siderophore, called aureochelin, was 577 Da. Surface-associated proteins of 120, 88, 57, 35, and 33 kDa were mainly expressed under iron restriction conditions. Results showed a relationship between siderophore production and the existence of the 120- and 88-kDa proteins. Western blotting of surface-associated proteins revealed that these proteins were recognized both by patients sera and polyclonal rabbit serum.

Bacterial Proteins↗
PubMed1997

Effect of vancomycin and teicoplanin alone or in combination with fusidic acid or amikacin against methicillin-resistant staphylococci.

The action of two glycopeptides (vancomycin and teicoplanin) alone or in combination with amikacin or fusidic acid has been studied against 10 non-repetitive strains of methicillin-resistant Staphylococcus. The plotted killing curves show that the combination of vancomycin or teicoplanin plus fusidic acid always exhibited an antagonist effect at 24 h for the 10 strains. The combination vancomycin or teicoplanin plus amikacin shows the same effect at 24 h as vancomycin or teicoplanin alone. Thus, the combination glycopeptide plus amikacin does not alter the activity of the glycopeptide but does increase the spectrum of activity of the combination versus Gram-negative nosocomial bacteria (Pseudomonas aeruginosa, Acinetobacter sp). The vancomycin or teicoplanin plus fusidic acid combination may be responsible for bacteriological failure against methicillin-resistant Staphylococcus.

Amikacin↗
PubMed1997

The binding of surface proteins from Staphylococcus aureus to human bronchial mucins.

Colonization by Staphylococcus aureus is frequently observed in obstructive lung diseases, particularly in cystic fibrosis. It has been shown that the bacteria bind to mucins, the main constituent of bronchial secretions. The binding mechanism, however, remains unclear. We have investigated the interactions of two strains of S. aureus, one mucoid and one nonmucoid, with human bronchial mucins. Using a solution phase assay, the binding capacity of the two strains to radiolabelled bronchial mucins was assessed. The bacterial constituents were released by lysostaphin lysis and the surface components of the nonmucoid strain were extracted with the use of a detergent (3-([3-cholamidopropyl] dimethylammonio)-1-propane sulphonate (CHAPS)). All were analysed for mucin-binding using an overlay assay. The amount of mucins bound to the nonmucoid strain was threefold greater than that of the mucoid strain. In the lysostaphin extract from the mucoid strain, only a 57 kDa protein faintly bound 125I-labelled mucins, whereas three mucin-binding proteins (52, 57 and 71 kDa) were identified from the nonmucoid strain. Two surface proteins, one major at 60 kDa and one minor at 71 kDa, bound radiolabelled bronchial mucins and their binding was almost completely inhibited by ovine submaxillary mucin. These results indicate: 1) differences in the mucin-binding capacity from one strain of S. aureus to another; and 2) the presence of external and internal adhesins binding to human respiratory mucins in the nonmucoid strain.

Binding Sites↗
PubMed1996

Iron depletion and virulence in Staphylococcus aureus.

Staphylococcus aureus is able to grow in the presence of extremely low iron concentrations (0.04 microM). In iron-limiting conditions, this species develops alternative metabolic strategies such as highly efficient iron-uptake mechanisms which are only partially shared with S. epidermidis. Here we summarize the mechanisms induced by iron starvation in S. aureus in order to elucidate the virulence characteristics of this bacterium.

Genes, Bacterial↗
PubMed1996

Choice of a routine method for detecting methicillin-resistance in staphylococci.

Four methods were compared for their abilities to detect methicillin-resistance of Staphylococcus strains using mecA gene PCR analysis in 6 h as the gold standard. 57 Staphylococcus aureus and 100 coagulase negative staphylococci (CNS) were evaluated by the oxacillin disc diffusion method (Kirby-Bauer), the automated API (ATB-plus) system (bioMérieux, La Balme les Grottes, France) in 24 h, the rapid BBL Crystal MRSA ID system (Becton Dickinson, Cockeysville, Md.), the oxillin MICs using the NCCLS agar dilution method in 24 h, and the mecA gene PCR analysis. For S. aureus, the correlation was excellent between the BBL Crystal MRSA ID system and mecA gene PCR analysis (positive predictive value = 100%; negative predictive value = 97%) and oxacillin MIC (positive predictive value = 96%; negative predictive value = 96%). The correlation between BBL Crystal MRSA ID and mecA gene PCR was not reliable for CNS (negative predictive value = 68%). For CNS, the slower routine susceptibility methods to identify intrinsic methicillin-resistance were better: API ATB Staph has a positive predictive value = 94% and a negative predictive value = 82%, and the disc diffusion test has a positive predictive value = 95% and a negative predictive value = 74%. However, BBL Crystal MRSA ID was as reliable as some of the other methods tested for CNS after 6 h incubation when the inoculum was increased: positive predictive value = 94% and a negative predictive value = 77%. These results emphasize that genotypic detection of methicillin-resistance will undoubtedly become important to detect rapidly methicillin-resistance, especially for CNS.

Bacterial Proteins↗
PubMed1996

In vitro bactericidal effect of a beta-lactam+aminoglycoside combination against multiresistant Pseudomonas aeruginosa and Acinetobacter baumannii.

Pseudomonas aeruginosa and Acinetobacter baumannii are frequently isolated in hospital outbreaks of nosocomial infections. In our hospital, among 1018 strains isolated one year in an intensive care unit, 84 strains (8.3%) of P. aeruginosa and 155 strains (15.2%) of A. baumannii were considered responsible for infections. The major problem related to these bacteria is their multiresistant characteristic which confers great difficulty in treating infections. We carried out a 24 h time-kill study to assess the bactericidal effect of three beta-lactams [imipenem (IPM), ticarcillin+clavulanic acid (TCC), piperacillin+tazobactam (PTB)] in combination with each other and with sulbactam (SUL) and amikacin (AKN) against 8 P. aeruginosa strains and 8 A. baumannii strains. The initial inoculum was 10(6) cfu/ml. Antibiotics were tested at clinically achievable concentrations: TCC (112 mg/l), PTB (100 mg/l), IPM (25 mg/l) and AKN (15 mg/l). The results showed: IMP + TCC + AKN = PTB + SUL + AKN = PTB + TCC + AKN > > IMP + SUL + AKN against P. aeruginosa; and PTB + SUL + AKN = PTB + TCC + AKN > IMP + SUL + AKN or IMP + TCC + AKN against A. baumannii. When infection due to these multiresistant strains was suspected, PTB + AKN combined with either TCC or SUL was bactericidal against both strains. These combinations appeared to be an alternative therapy in the treatment of undocumented nosocomial infections in intensive care units. These in vitro results are being evaluated in patients and seem to give good results for the moment.

Acinetobacter↗