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Biomedical subjects

M L Joly-Guillou

Publications and source records attributed to M L Joly-Guillou.

At least 19 recordsLinked to original sources
PubMed2005

Influence of fluoride, hydrogen peroxide and lactic acid on the corrosion resistance of commercially pure titanium.

Titanium is widely used in dental implantology and orthopaedics due to its excellent corrosion resistance and mechanical properties. However, it has been reported that Ti is sensitive to F(-), H(2)O(2) and lactic acid. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to investigate the corrosion resistance of CP-Ti disks after 9 days immersion in different test solutions, based on artificial saliva containing F(-) (0.5% and 2.5%), H(2)O(2) (0.1% and 10%) and/or lactic acid. Because activated macrophages and bacteria can also release locally some of these oxidative compounds, we investigated the role of these cells when plated onto titanium disks. The surface roughness (R(a)) was highly increased when titanium disks were immersed in artificial saliva containing F(-), H(2)O(2) and lactic acid. After 21 days of cell culture, R(a) was significantly increased on disks incubated with activated-J774.2 cells or Streptococcus mitis. AFM appeared to be more sensitive than SEM in evaluating the corrosion of the titanium. Chemical species, either environmental or those released by macrophages and bacteria, can provoke a marked attack of the titanium surface.

Animals↗
PubMed2002

[Acinetobacter, a nosocomial pathogen. Contribution of experimental models].

EPIDEMIOLOGY: The increasing importance of Acinetobacter as a nosocomial pathogen responsible for outbreaks in intensive care units has been pointed out for twenty years. Today Acinetobacter infections are essentially pneumonia in patients under mechanical ventilation. EXPERIMENTAL MODELS: Most clinical isolates are resistant to b-lactam antibiotics as well as to other drugs. Animal models represent an essential step between in vivo testing an<d clinical studies, necessary to understand physiopathology, pharmacology and efficacy of therapy. The virulence of clinical isolates of Acinetobacter spp has been studied in a mouse model of systemic infection. Pharmacological studies and efficacy of antibiotics have been studied in a mouse model of Acinetobacter pneumonia. HUMAN THERAPEUTICS: The majority of strains are multi-resistant to antibiotics and the infections they cause are difficult to treat. Isolated or combined Sulbactam has often been used with success.

Acinetobacter↗
PubMed2001

[Treatment of genital infections in gynecology].

Choice of antimicrobial agents and length of therapy of infections of the female genital tract and chemotherapy are presented with particular mention to their side effects. Clinical approach and antibiotic regimens of pelvic inflammatory diseases are discussed.

Anti-Bacterial Agents↗
PubMed2001

An outbreak of imipenem-resistant Acinetobacter baumannii in critically ill surgical patients.

OBJECTIVE: To describe an outbreak of imipenem-resistant Acinetobacter baumannii (IR-Ab) and the measures for its control, and to investigate risk factors for IR-Ab acquisition. DESIGN: An observational and a case-control study. SETTING: A surgical intensive care unit (ICU) in a university tertiary care hospital. METHODS: After admission to the ICU of an IR-Ab-positive patient, patients were prospectively screened for IR-Ab carriage upon admission and then once a week. Environmental cleaning and barrier safety measures were used for IR-Ab carriers. A case-control study was performed to identify factors associated with IR-Ab acquisition. Cases were patients who acquired IR-Ab. Controls were patients who were hospitalized in the ICU at the same time as cases and were exposed to IR-Ab for a similar duration as cases. The following variables were investigated as potential risk factors: baseline characteristics, scores for severity of illness and therapeutic intervention, presence and duration of invasive procedures, and antimicrobial administration. RESULTS: Beginning in May 1996, the outbreak involved 17 patients over 9 months, of whom 12 acquired IR-Ab (cases), 4 had IR-Ab isolates on admission to the ICU, and 1 could not be classified. Genotypic analysis identified two different IR-Ab isolates, responsible for three clusters. Ten of the 12 nosocomial cases developed infection. Control measures included reinforcement of barrier safety measures, limitation of the number of admissions, and thorough environmental cleaning. No new case was identified after January 1997. Eleven of the 12 cases could be compared to 19 controls. After adjustment for severity of illness, a high individual therapeutic intervention score appeared to be a risk factor for IR-Ab acquisition. CONCLUSION: The outbreak ended after strict application of control measures. Our results suggest that high work load contributes to IR-Ab acquisition.

Acinetobacter↗
PubMed2001

Accuracy of delayed cultures of plugged telescoping catheter samples for diagnosing bacterial pneumonia.

OBJECTIVE: It is not always feasible to culture immediately bacteriologic samples of protected pulmonary specimens on a 24-hr basis before starting antibiotic treatment. We have evaluated the effect of delaying the culture of immediate plugged telescoping catheter (PTC) samples performed before starting antibiotherapy. DESIGN: Prospective paired comparisons study. SETTING: Intensive care unit in a university hospital. PATIENTS: Ninety-nine PTCs were performed on 68 intensive care unit patients suspected of nosocomial or community- acquired bacterial pneumonia. INTERVENTION: PTC samples were divided into two aliquots: one for immediate (H0) analysis and one for storage at 4 degrees C (H24) for 24 hrs before being cultured. MEASUREMENTS AND MAIN RESULTS: The results from these delayed cultures (H24) were compared with those from immediate ones (H0). All negative H0 samples (n = 59) were also negative at H24. Forty PTCs yielded one or more microorganisms, with a total of 69 microorganisms in one or both samples. H0 and H24 cultures were concordant in 119 of 128 (97.9%) cases (kappa coefficient value 0.79) with a threshold of 103 colony-forming units (cfu)/mL. Agreement between paired cultures was very good. The bias calculated as the mean difference between paired culture results was 0.128 +/- 1.024 (Deltalog). Concordance using the 103 cfu/mL threshold (102/107 cases, kappa coefficient value 0.82) and agreement were enhanced (0.067 +/- 0.645) when possible contaminants were excluded (n = 21). CONCLUSIONS: Storing PTC specimens for 24 hrs at 4 degrees C is an acceptable alternative when culturing cannot be performed immediately. This allows starting antibiotic treatment without any delay.

Adult↗
PubMed2000

Microbiological evaluation of central venous catheter administration hubs.

We compared, in three intensive care units, colonization of hubs with hub protection boxes or hubs with needleless closed connectors; 137 central venous catheters and 451 hubs were randomized in two groups with similar characteristics. Catheter and hub colonization were not different between the two groups. Among 30 colonized catheters, the same isolate was found in only two hubs; hub contamination rarely is responsible for catheter colonization in short-term catheters. Further studies are required to evaluate the benefit of protected hubs compared with unprotected hubs.

Bacteremia↗
PubMed2000

Nosocomial bacteremia in HIV patients: the role of peripheral venous catheters.

A retrospective case-control study compared 40 human immunodeficiency virus (HV)-infected patients with 43 nosocomial bacteremias (NB) to 77 HIV-infected patients without NB. Presence of a peripheral venous catheter (PVC) was associated with occurrence of NB and was significantly more frequent in NB without an identified source. PVCs probably are an underestimated source of NB in HIV-infected patients.

Adult↗
PubMed2000

In vivo activity of levofloxacin alone or in combination with imipenem or amikacin in a mouse model of Acinetobacter baumannii pneumonia.

We evaluated the in vivo activity of levofloxacin alone or in combination with imipenem or amikacin in a mouse model of Acinetobacter baumannii pneumonia using a susceptible strain and one with low-level resistance (MIC/MBC of levofloxacin: 0.06/0.06 and 4/4 mg/L, respectively). As demonstrated previously with other pathogens, the AUC/MIC ratio predicted the efficacy of fluoroquinolones against A. baumannii. This parameter correlated with bactericidal effect and survival. Combination therapy did not enhance the efficacy of levofloxacin.

Acinetobacter Infections↗
PubMed2000

Nucleotide sequence of the bla(RTG-2) (CARB-5) gene and phylogeny of a new group of carbenicillinases.

We determined the nucleotide sequence of the bla gene for the Acinetobacter calcoaceticus beta-lactamase previously described as CARB-5. Alignment of the deduced amino acid sequence with those of known beta-lactamases revealed that CARB-5 possesses an RTG triad in box VII, as described for the Proteus mirabilis GN79 enzyme, instead of the RSG consensus characteristic of the other carbenicillinases. Phylogenetic studies showed that these RTG enzymes constitute a new, separate group, possibly ancestors of the carbenicillinase family.

Amino Acid Sequence↗
PubMed2000

Control of staphylococcal adhesion to polymethylmethacrylate and enhancement of susceptibility to antibiotics by poloxamer 407.

We studied the antiadhesive effect of Poloxamer 407 (P407), together with modifications in the antimicrobial susceptibility of residual adherent staphylococci. Bacterial adherence was markedly inhibited (77% to more than 99.9%) whether polymethylmethacrylate was exposed to P407 before or during the adherence assay. Furthermore, residual adherent staphylococci appeared to be more susceptible to antibiotic activity, suggesting that combination of P407 with antibiotics could be a promising approach to the prevention of infection of foreign material.

Anti-Bacterial Agents↗
PubMed1999

[Some aspects of virulence].

GLYCOPEPTIDE INTERACTION AND THE STAPHYLOCOCCI WALL: Glycopeptides induce modifications in the cell wall of staphylococci. This modification has been observed in VISA strains and could involve bacterial adherence to materials. QUORUM SENSING: Bacterial virulence in Gram-negative germs is closely related to quorum sensing, a system regulated by bacterial inoculum. The use of strains deficient in different steps of quorum sensing in a experimental rat model has been useful in better understanding the pathophysiological effects linked to this system of virulence.

Animals↗
PubMed1999

[Nosocomial infections].

GLYCOPEPTIDE RESISTANCE: Resistance to glycopeptides raises many therapeutic problems when it occurs in strains such as enterococci or staphylococci causing clinical infections. Two observations described here exemplify the emergence of such resistance in a metacillin-resistant Staphylococcus aureus (MRSA) strain during vancomycin treatment and in a Clostridium difficile strain. NASAL MRSA IN HOSPITAL PERSONNEL: Nasal cavities of hospital personnel is a not well recognized reservoir of MRSA. A survey conducted in a Parisian hospital evidenced problems of personnel-patient transmission. MRSA were found in 6% of the hospital personnel samples.

Anti-Bacterial Agents↗
PubMed1999

[Focus on Acinetobacter baumannii].

RESISTANCE: Acinetobacter baumannii carbapeneme-resistance is a serious problem due to the difficulty encountered in treating patients infected with this type of multiresistant bacteria. Several teams have detailed the resistance mechanisms and the way this type of strain spreads around the world. Different factors (plasmid transmission, strain variability) suggest that this type of resistance can diffuse and tends to increase with time. A NEW STRAIN: An outbreak of 15 colonizations with Acinetobacter baumannii, a BLSE producing a type PER-1 enzyme, was described in a neurosurgery intensive care unit in Great Britain. This type of strain has been exception to data and this outbreak emphasizes the problems encountered in controlling the epidemic.

Acinetobacter↗
PubMed1999

Control of a prolonged outbreak of extended-spectrum beta-lactamase-producing enterobacteriaceae in a university hospital.

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBLPE) were isolated from clinical specimens from 130 to 140 patients/year in 1989-1991 in our hospital. In February 1992, a control program was initiated: screening tests in 3 intensive care units (ICUs) and contact-isolation precautions in all units. The septic surgical unit served as an isolation ward for surgical patients from whom ESBLPE was isolated. In 1992, the incidence of ESBLPE acquisition failed to decrease, and most acquisitions occurred in 3 ICUs. Critical evaluation of implementation of isolation procedures in these ICUs prompted corrective measures for barrier precautions. The incidence of acquired cases subsequently decreased, and a second evaluation determined that these measures had been correctly applied. The incidence of acquired cases in the septic surgical unit was lower than those in the other units. Decreases were also found in the incidence of acquisition of other hand-transmitted multidrug-resistant organisms. Barrier precautions, screening tests for ICU patients, and grouping of cohorts after ICU discharge are effective in controlling the spread of multidrug-resistant microorganisms by cross-contamination. The outbreak was effectively controlled without restricting antimicrobial use.

Anti-Bacterial Agents↗
PubMed1999

In vivo efficacies of combinations of beta-lactams, beta-lactamase inhibitors, and rifampin against Acinetobacter baumannii in a mouse pneumonia model.

The effects of various regimens containing combinations of beta-lactams, beta-lactam inhibitor(s), and rifampin were assessed in a recently described mouse model of Acinetobacter baumannii pneumonia (M. L. Joly-Guillou, M. Wolff, J. J. Pocidalo, F. Walker, and C. Carbon, Antimicrob. Agents Chemother. 41:345-351, 1997). Two aspects of the therapeutic response were studied: the kinetics of the bactericidal effect (treatment was initiated 3 h after intratracheal inoculation, and bacterial counts were determined over a 24-h period) and survival (treatment was initiated 8 h after inoculation, and the cumulative mortality rate was assessed on day 5). Two clinical strains were used: a cephalosporinase-producing strain (SAN-94040) and a multiresistant strain (RCH-69). For SAN-94040 and RCH-69, MICs and MBCs (milligrams per liter) were as follows: ticarcillin, 32, 64, 256, and >256, respectively; ticarcillin-clavulanate, 32, 64, and 512, and >512, respectively; imipenem, 0.5, 0.5, 8, and 32, respectively; sulbactam, 0.5, 0.5, 8, and 8, respectively; and rifampin, 8, 8, 4, and 4, respectively. Against SAN-94040, four regimens, i.e., imipenem, sulbactam, imipenem-rifampin, and ticarcillin-clavulanate (at a 25/1 ratio)-sulbactam produced a true bactericidal effect (>/=3-log10 reduction of CFU/g of lung). The best survival rate (i.e., 93%) was obtained with the combination of ticarcillin-clavulanate-sulbactam, and regimens containing rifampin provided a survival rate of >/=65%. Against RCH-69, only regimens containing rifampin and the combination of imipenem-sulbactam had a true bactericidal effect. The best survival rates (>/=80%) were obtained with regimens containing rifampin and sulbactam. These results suggest that nonclassical combinations of beta-lactams, beta-lactamase inhibitors, and rifampin should be considered for the treatment of nosocomial pneumonia due to A. baumannii.

Acinetobacter↗
PubMed1999

Practical recommendations for the drug treatment of bacterial infections of the male genital tract including urethritis, epididymitis and prostatitis.

Bacterial infections of the male genital tract in young men (<35 years old) are primarily caused by sexually transmissible bacteria like Chlamydia trachomatis, Neisseria gonorrhoeae but also Mycoplasma or Haemophilus spp. In men aged over 35 years, Enterobacteriaceae are more frequently involved in urethritis, epididymitis and prostatitis. The traditional treatments suggested like tetracyclines or erythromycin are less effective since bacterial resistance is increasingly frequent, particularly in N. gonorrhoeae. Moreover, patient compliance with these drug treatments are frequently not well observed. New therapies including short term therapy with fluoroquinolones or azalides (e.g. azithromycin) are very effective and easy to use and thus eliminate any problem of compliance. However, we have to be vigilant for the emergence of resistant strains to these agents.

Anti-Bacterial Agents↗
PubMed1998

Ventilator-associated pneumonia caused by potentially drug-resistant bacteria.

To determine risk factors for ventilator-associated pneumonia (VAP) caused by potentially drug-resistant bacteria such as methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii, and/or Stenotrophomonas maltophilia, 135 consecutive episodes of VAP observed in a single ICU over a 25-mo period were prospectively studied. For all patients, VAP was diagnosed based on results of bronchoscopic protected specimen brush (> or = 10(3) cfu/ml) and bronchoalveolar lavage (> or = 10(4) cfu/ml) specimens. Seventy-seven episodes were caused by "potentially resistant" bacteria and 58 episodes were caused by "other" organisms. According to logistic regression analysis, three variables among potential factors remained significant: duration of mechanical ventilation (MV) > or = 7 d (odds ratio [OR] = 6.0), prior antibiotic use (OR = 13.5), and prior use of broad-spectrum drugs (third-generation cephalosporin, fluoroquinolone, and/or imipenem) (OR = 4.1). Distribution of the 245 causative bacteria was analyzed according to four groups defined by prior duration of MV (< 7 or > or = 7 d) and prior use or lack of use (within 15 d) of antibiotics. Although 22 episodes of early-onset VAP in patients receiving no prior antibiotics were caused by antibiotic-susceptible bacteria, 84 episodes of late-onset VAP in patients receiving prior antibiotics were mainly caused by potentially resistant bacteria. Differences in the potential efficacies (ranging from 100% to 11%) against microorganisms of 15 antimicrobial regimens were studied according to classification into these four groups. These findings may provide a more rational basis for selecting the initial therapy of patients suspected of having VAP.

Aged↗