Biomedical subjects
Publications and source records attributed to H Monteil.
We collected 3,397 consecutive isolates of coagulase-positive staphylococci from various specimens of hospitalized patients. All were retrospectively classified as Staphylococcus aureus, except two which were identified as S. intermedius: one isolated from the nasal flora of a healthy carrier and the other isolated from pleural fluid, probably as a sample contaminant.
The aim of the study was the influence of transport conditions of antrum biopsies on the diagnostis of Helicobacter pylori infection by mean of bacteriological methods. We compare bacteriological to anatomopathological methods of Helicobacter pylori infection during two periods which differed by the transport conditions for antrum biopsies. During the first period (P1), 57 specimens were carried to the laboratory at room temperature and physiological serum immersion was inconstant. During the second period (P2), 56 specimens were all correctly immerged into 5 ml of physiological serum, in a 15 mm diameter tube which was vertically maintained in ice. Anatomopathological methods were considered as the reference method for the diagnostic of Helicobacter pylori infection. The sensibility of bacteriological culture was increased from 59% (P1) to 84% (P2) (p < 0.05) when specificity was unchanged. Furthermore sensibility of bacteriological direct examination was increased from 41% (P1) to 61% (P2). Complete biopsy immersion and ice transport of samples appear as necessary conditions for the optimal diagnostic of Helicobacter infections by mean of bacteriological methods.
Three female Yucatan micropigs were included and received a single dose of amikacin (15 mg/kg) by short infusion (30 min) combined either with a single dose of cefepime or cefpirome (30 mg/kg/12 h) or meropenem (7 mg/kg/8 h). The beta-lactams were administered either by intravenous intermittent injection or by continuous infusion. The mean elimination half-life and clearance value of amikacin were 1.88 h and 2.15 ml/min.kg-1 respectively. These pharmacokinetic parameters were similar to those obtained in man (t1/2 = 2,42 h et Cl = 1,61 ml/min kg-1). Furthermore, they were not affected by coadministration of cefepime, cefpirome and to meropenem. While resistant to cefepime, cefpirome and amikacin, Klebsiella pneumoniae producing ESBL was susceptible to combination of these cephalosporins with amikacin in an in vitro/ex vivo micropig model. For the six dosage regimens used in this study, the killing activities were similar and resulted in at least 4 log decrease at 6 h after drug exposure. For antimicrobial combination consisting of bolus dosing of amikacin plus continuous infusion of cefepime or cefpirome, the 12 h serum bactericidal titers (SBTs) were 1:8 for cefepime and 1:2 for cefpirome dosage regimen. When each drug administered intermittently, the 12 h SBTs were 1:4 for cefepime and 1:2 for cefpirome. The 8 h SBTs for dosing schedule containing meropenem combined with amikacin were 1:4 and 1:16 after 30 min short infusion and continuous infusion respectively. In conclusion, our study showed that the micropig model is a reliable model for pharmacokinetic investigation of amikacin. It was concluded that beta-lactam antibiotics tested with amikacin may be coadministered by using the standard recommended dosing regimen of amikacin. Continuous infusion of beta-lactams combined with once dosing of amikacin seems to be as or more effective than intermittent injection of each drug.
The aim of this study was to evaluate the susceptibility of 300 Pseudomonas aeruginosa strains to 6 beta-lactams and to 2 aminoglycosides and to compare this susceptibility according to the serotype, the sample nature, the unit activity and the geographic situation of the hospital. The susceptibility level was ascertained using the disk method. Serotyping of the strains was also performed. Susceptibility level was 67% for ticarcillin, 82% for piperacillin-tazobactam combination, 85% for ceftazidim, 81% for cefepim, 74% for aztreonam, 83% for imipenem, 73% for tobramycin and 86% for amikacin. Non-serotypable strains represented 20.6%. The most common serotypes were O6 (19%) and O11 (13%). Discrepancies between cefepime and ceftazidime were found in 15 strains after MIC determination, 6 of them were O12 strains. It appears that strain susceptibility was function of the serotype distribution. Cefepime exhibited outstanding activity against P. aeruginosa, similar to ceftazidim activity.
BACKGROUND: A strong association has been observed between furuncles and Panton-Valentine leukocidin-producing Staphylococcus aureus. CASE REPORTS: Within one year, we cared for three men at the Cayenne hospital who had Staphylococcus aureus septicemia with severe pleuropulmonary involvement originating from furuncular lesions. The Staphylococcus aureus strains isolated from the skin lesions and from blood cultures produced Panton-Valentine leukocidin. CONCLUSION: These cases demonstrate the gravity of S. aureus septicemia in young patients with furunculosis. These cases are the first reported with severe S. aureus infections associated with Panton-Valentine leukocidin producing strains.
BACKGROUND: Although Clostridium difficile is the main agent responsible for nosocomial diarrhea in adults, its prevalence in stool cultures sent to hospital microbiology laboratories is not clearly established. OBJECTIVES: To determine the prevalence of C difficile in inpatient stools sent to hospital microbiology laboratories and to assess the relationship between serotypes and toxigenicity of the strains isolated and the clinical data. METHODS: From January 18, 1993, to July 31, 1993, the presence of C difficile was systematically investigated in a case-control study on 3921 stool samples sent for stool culture to 11 French hospital microbiology laboratories. The prevalence of C difficile in this population (cases) was compared with that of a group of 229 random hospital controls matched for age, department, and length of stay (controls). Stool culture from controls was requested by the laboratory although not prescribed by the clinical staff. Serotype and toxigenesis of the strains isolated were compared. RESULTS: The overall prevalence of C difficile in the cases was twice the prevalence in the controls (9.7% vs 4.8%; P < .001) and was approximately 4 times as high in diarrheal stools (ie, soft or liquid) as in normally formed stools from controls (11.5% vs 3.3%; P < .001). The strains isolated from diarrheal stools were more frequently toxigenic than those isolated from normally formed stools. Serogroup D was never toxigenic, and its proportion was statistically greater in the controls than in the cases (45% vs 18%; chi 2 = 5.2; P < .05). Conversely, serogroup C was isolated only from the cases. Clostridium difficile was mainly found in older patients ( > 65 years), suffering from a severe disabling disease, who had been treated with antibiotics and hospitalized for more than 1 week in long-stay wards or in intensive care. CONCLUSIONS: This multicenter period prevalence study clearly supports the hypothesis of a common role of C difficile in infectious diarrhea in hospitalized patients. Disease associated with C difficile should therefore be systematically evaluated in diarrheal stools from inpatients.
OBJECTIVE: To compare the detection rates of chromosomal flagellin gene from Borrelia burgdorferi in synovial tissue (ST) and synovial fluid (SF) using polymerase chain reaction (PCR) techniques. METHODS: B burgdorferi DNA was sought in SF and ST from 12 consecutive patients with Lyme arthritis and from 29 patients with noninfectious diseases (controls). RESULTS: No DNA amplification was observed in samples obtained from the 29 control patients, whereas B burgdorferi DNA was detected in all ST and/or SF samples from the 12 patients with Lyme arthritis. Results from 1 ST sample were not interpretable because of PCR inhibitors. Among the 11 remaining patients, 10 had positive ST samples, whereas only 4 had positive SF samples (P < 0.05). CONCLUSION: These data suggest that detection of chromosomal B burgdorferi DNA may be more efficient in ST than SF.
A new, well-documented case of Mycobacterium shimoidei infection is reported. This bacterium was isolated from a patient with preexisting pulmonary lesions who developed a tuberculosis-like cavity in the lung. Isolation of fewer than ten strains, not epidemiologically related, has been reported worldwide; all originated from human pulmonary samples. Identification of the strain described here was first accomplished by 16S rDNA direct sequencing after in vitro amplification. This method allows rapid identification of unusual bacteria. The identification was confirmed by specific phenotypical tests and by chromatographic methods.
Over a 14-month period, 415 clinical isolates of coryneform gram-positive rods were recovered from various sources and identified to the species level according to recent identification schemes. Corynebacterium urealyticum, Corynebacterium striatum, Corynebacterium amycolatum, and Corynebacterium jeikeium predominated, accounting for 63% of all isolates. Corynebacterium accolens, Corynebacterium striatum, Corynebacterium argentoratense, Corynebacterium propinquum and Corynebacterium pseudodiphtheriticum were mostly recovered from the respiratory tract, whereas Corynebacterium afermentans, CDC group G, and Corynebacterium jeikeium were mainly isolated from blood. None of the isolates was identified as Corynebacterium diphtheriae or Corynebacterium xerosis. Ampicillin resistance was detected in Corynebacterium jeikeium (96%) and Corynebacterium urealyticum (99%) and varied among Corynebacterium amycolatum (56%) and CDC group G (26%). These data emphasize the need for an accurate identification of coryneform organisms at the species level and for antimicrobial susceptibility testing of these organisms.
We studied five strains of a new Nocardia taxon recently identified among Nocardia brasiliensis strains associated with invasive diseases (R. J. Wallace, Jr., B. A. Brown, Z. Blacklock, R. Ulrich, K. Jost, J. M. Brown, M. M. McNeil, G. Onyi, V. A. Steingrube, and J. Gibson, J. Clin. Microbiol. 33:1528-1533, 1995) to determine their taxonomic status. Several characteristics of these organisms, including the presence of chemotype IV cell walls, nocardomycolic acids, a predominant menaquinone similar to that of Nocardia asteroides ATCC 19247T (T = type strain), and G+C contents ranging from 67 to 68 mol%, are characteristics of the genus Nocardia. Phylogenies based on small-subunit ribosomal DNA sequences clearly confirmed that all five strains belong to the genus Nocardia and occur on a single branch that is clearly distinct from N. brasiliensis. This branch forms a clade with Nocardia vaccinii, Nocardia nova, Nocardia otitidiscaviarum, and Nocardia seriolae. The five new strains exhibited high levels of DNA relatedness with each other, as determined by DNA-DNA hybridization experiments (S1 nuclease procedure), but not with N. brasiliensis strains or with strains of the four phylogenetically related Nocardia species mentioned above. The five new strains differ from N. brasiliensis in the following characteristics: mycolic acid pattern, decomposition of adenine, nitrate reduction, and antimicrobial agent susceptibilities. Therefore, we propose that these strains belong to a new species, Nocardia pseudobrasiliensis. The type strain is strain ATCC 51512, which was isolated from a leg abscess on a patient suffering from ulcerative colitis.
In ileal loop assay, ELISA and anion-exchange column chromatography, Clostridium sordellii strain 6018 was shown to produce a cytotoxin, but no detectable enterotoxin. DNA sequence and polymerase chain reaction analyses indicated that the lack of enterotoxin activity is not due to a lack of gene transcription, but to lack of a major portion of the enterotoxin gene. This is the first characterisation of such a strain.
The objective of this study was to examine the effects of rifampin on itraconazole pharmacokinetics, at steady state, in three Yucatan miniature pigs. Daily for 3 weeks, the pigs received 200 mg of itraconazole orally at the beginning of each meal, and for the following 2 weeks they received itraconazole orally combined with intravenous administration of rifampin at 10 mg/kg/day. Coadministration of rifampin resulted in an 18-fold decrease in the maximum concentration of itraconazole in serum, from 113.0 (standard deviation [SD] 17.2) to 6.2 (SD, 3.9) ng/ml and a 22-fold decrease in the area under the concentration-time curve, from 1,652.7 (SD, 297.7) to 75.6 (SD, 30.0) ng.h/ml. The active metabolite of itraconazole, hydroxyitraconazole, was undetectable. This study demonstrates that rifampin affects itraconazole kinetics considerably at steady state in this miniature-pig model, probably by inducing hepatic metabolism of itraconazole.
Serum samples from 35 cat scratch disease (CSD) patients, 180 control patients (123 without lymph node enlargement and 57 with lymph node enlargement not evoking CSD), and 102 nonpatient subjects (35 with cat contact and 67 without cat contact) were tested by semiquantitative indirect immunofluorescence assay for the presence of antibodies directed to Afipia felis (ATCC 53690T) or Bartonella henselae (ATCC 49882T). The CSD group had statistically higher antibody titers against B. henselae than the control groups (P < 10(-5)), whereas no difference in A. felis antibody titers was evidenced among all groups tested. Among the 317 serum samples studied, the three with high A. felis antibody titers ( > or = 64) also had high antibody titers against other alpha-2 proteobacteria. The value of the indirect immunofluorescence assay with B. henselae antigen for the diagnosis of CSD was as follows: for a cutoff of 32, sensitivity was 0.80, specificity was 0.85, and the likelihood ratio was 5.1; for a cutoff of 64, the likelihood ratio was 12.1. In summary, in France, CSD is associated with high antibody titers against B. henselae, as previously described in the United States. However, the causes for B. henselae seronegativity in CSD patients and those for high antibody titers outside the typical nosological frame of CSD still have to be identified.
We report a case of bacteremia due to a strain identified as Gordona sputi in a patient with metastatic melanoma. The origin of infection remains unknown, but extensive cutaneous lesions due to interleukin-2 treatment may have been the portal of entry. The isolate was related to G. sputi on the basis of its biochemical and genomic properties but exhibited some differences from the type strain.
Nosocomial infections encountered in intensive care units are frequently due to Gram negative bacilli among which Stenotrophomonas maltophilia, Acinetobacter sp., and Enterobacter sp. The aim of the present study was to evaluate the in vitro bactericidal activity of the new broad spectrum cephalosporins cefepime (FEP) and cefpirome (CPO) alone or in combination with amikacin (AKN), gentamicin (GTN) or ciprofloxacin (CIP) against Acinetobacter baumannii, Stenotrophomonas maltophilia and Enterobacter cloacae producing a derepressed cephalosporinase. This study was performed by using the time-kill curve method on 24 h with a starting inoculum of 10(6) - 10(7) cfu/ml. The combination of FEP (4 mg/l) with AKN (4 mg/l) against A. baumanii only results in about 1 log decrease at 24 h, but when FEP is combined at 8 mg/l, the decrease reaches 4 log in 24 h. The combination of FEP (16 and 32 mg/l) clavulanic acid (4 mg/l) resulted in 3 log decrease at 24 h. When combined with CIP 2 mg/l, FEP (16 and 32 mg) resulted in 5 and 6 log decrease in 24 h respectively. There were no survival bacteria at 6 h when FEP (32 mg/l) was combined with clavulanic acid (4 mg/l) and GTN (8 mg/l) at 6 h. Used alone FEP (1 mg/l) or CPO (1 mg/l) against E. cloacae, a 3 log decrease occurs at 6 h followed by a regrowth at 24 h. Combined with AKN (2 mg/l), FEP (1 mg/l) results in a 6 log decrease at 24 h, when CPO at 2 mg/l is needed for an equivalent result. These data show synergistic bactericidal activity of both new extended cephalosporins combined with AKN, GTN or CIP at concentrations achievable in biological fluid with adaptative dosage regimen.
The miniature pig exhibits physiological and anatomical similarities to man. In addition, its reduced size and its docility make it appropriate for laboratory use. Curiously, this model remains seldom used in experimental pharmacokinetics. We present here in a chronic model of catheterized micropig allowing long term investigations of antiinfective agents. We work with Yucatan adult female micropigs weighing between 20 and 40kg. A catheter (60 cm x 2 mm) is placed in the external jugular vein under general anaesthesia and exits in the midline dorsal neck. The catheter is flushed every two days with heparinized saline to retain its potency. At the time of kinetic studies, the antiinfective agent is injected in an ear vein. Blood samples are obtained using the jugular catheter. The mean time of viability of the device is 13 weeks (SD: 10 weeks). Thrombosis was the main cause of arrest of the model. In conclusion, this chronic model of catheterized micropig is suitable for long term pharmacokinetic and pharmacodynamic investigations of antiinfective agents.
The objective of this study was to examine the effects of rifampin on itraconazole pharmacokinetics, at steady state, in three Yucatan miniature pigs. The pits received daily during three weeks oral itraconazole at a dosage of 200 mg at the beginning of the meal, then during the next two weeks oral itraconazole combined with an intravenous administration of rifampin at a dosage of 10 mg/kg/day. The coadministration of rifampin resulted in a 18 fold decrease of the Cmax of itraconazole [from 113.0 (SD: 17.2) to 6.2 ng/ml (SD: 3.9)], and in a 22 fold decrease of the AUC [from 1652.7 (SD: 297.7) to 75.6 ng.h/ml (SD: 30.01)]. The active metabolite of itraconazole, hydroxyitraconazole, was undetectable. This study demonstrates that rifampin considerably affects itraconazole kinetics at steady-state in this model of micropig, probably by inducing the hepatic metabolism of itraconazole.
Staphylococcal synergohymenotropic (SHT) toxins damage membranes of host defence cells and erythrocytes by the synergy of two secreted and non-associated proteins: class S and class F components. Whereas Panton-Valentine leucocidin (PVL), gamma-hemolysin and Luk-M from Staphylococcus aureus are members of this toxin family, a new bi-component toxin (LukS-I + LukF-I) from Staphylococcus intermedius, a pathogen for small animals, was characterised and sequenced. It is encoded as a luk-I operon by two cotranscribed genes, like PVL, LukS-I + LukF-I shares a strong leukotoxicity of various PMNs, but only slight haemolytic properties on rabbit erythrocytes. When intradermally injected into rabbit skin, a 100 ng dose caused acute inflammatory reaction leading to tissue necrosis. The new SHT seemed to be largely distributed among various Staphylococcus intermedius strains.