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J L Mainardi

Publications and source records attributed to J L Mainardi.

At least 37 records · Page 2Linked to original sources
PubMed2000

[Staphylococcus epidermidis infective endocarditis after mitral surgery, successfully treated with aspirin and antibiotics: a case report].

We report a case of infectious endocarditis from Staphylococcus epidermidis that occurred early after mitral valve repair (one month), suggested by fever of 38.5 degrees C and valvular vegetations of less than 10 mm on the mitral valve. In the absence of standard recommendations (medical or surgical) in treating patients with infectious endocarditis occurring after mitral valve repair, and in the absence of complications, a medical regimen was chosen associating aspirin (anti-aggregant dosages) with antibiotics. The benefit of aspirin in endocarditis has been demonstrated in experimental studies with regards to valvular vegetations and embolic risk but remains to be studied in human clinical trials. With the association of aspirin (100 mg/d) and triple antibiotic therapy (rifampicin 1200 mg/d, vancomycin 2 g/d, gentamycin 180 mg/d), the clinical status improved with complete regression of vegetations in less than 24 days and the absence of recurrence at one-year follow-up.

Adult↗
PubMed1999

Bacterial contamination of hospital physicians' stethoscopes.

Because stethoscopes might be potential vectors of nosocomial infections, this study, conducted in a 450-bed general hospital, was devised to evaluate the bacterial contamination of stethoscopes; bacterial survival on stethoscope membranes; the kinetics of the bacterial load on stethoscope membranes during clinical use; and the efficacy of 70% alcohol or liquid soap for membrane disinfection. Among the 355 stethoscopes tested, 234 carried > or =2 different bacterial species; 31 carried potentially pathogenic bacteria. Although some bacteria deposited onto membranes could survive 6 to 18 hours, none survived after disinfection.

Bacteria↗
PubMed1999

[Stenotrophomonas maltophilia endocarditis following mitral valve prosthesis implantation. Report of a case].

The authors report the first case of early postoperative endocarditis after mitral valvuloplasty due to Stenotrophomonas Maltophilia, a Gram negative organism, in a 37 year old man with no special risk factors. Pyrexia and mitral valve vegetations were the main features, and, in the absence of complications or of embolism, the patient was treated initially with triple antibiotherapy (ceftazidime, amikacine, ciprofloxacine). Relapse two weeks after withdrawal of treatment due to two variants of Stenotrophomas Maltophilia, one of which was resistant to ciprofloxacine, and the presence of a large vegetation, required repeat mitral valvuloplasty and a change in antibiotic therapy (ticarcilline with clavulanic acid, trimethoprim sulphamethoxazole, colistine). This time, the outcome was good. The little known Stenotrophomonas Maltophilia infectious endocarditis is a serious complication and, in the absence of standardised management, the authors suggest that, in view of the multi-resistant character of the organism and in the light of this case, surgery should be considered in association with prolonged antibiotic therapy.

Adult↗
PubMed1998

[The microbiology of infectious endocarditis].

If streptococci and staphylococci remain the main bacteria responsible for infective endocarditis (80%), the emergence of Streptococcus bovis associated with intestinal lesions, the confirmation of the role of Coxiella burnetii, and the discovery of the responsibility of Bartonella sp in case of negative blood culture endocarditis have been the principal microbiological modifications during the last few years. Blood cultures performed under the best technical conditions and the examination and culture of the valve after surgery remain the better means for diagnosing infective endocarditis. In case of negative blood culture (11% of the infective endocarditis), the serologic tests against C. burnetii and Bartonella should decrease the rate of diagnostic uncertainty. The development of bacteriological techniques, particularly molecular methods, should improve the microbiology of infective endocarditis lead to the discovery new aetiological agents.

Bacteremia↗
PubMed1998

Low rate of Clostridium difficile colonization in ambulatory and hospitalized HIV-infected patients in a hospital unit: a prospective survey.

OBJECTIVE: To determine the frequency of Clostridium difficile carriage in HIV-infected in- and out-patients, and to assess the role of this carriage in nosocomial transmission of C. difficile. PATIENTS AND METHODS: Prospective study in a university hospital. Forty-five consecutive HIV-infected out-patients and 120 hospitalized patients (52 HIV and 68 non HIV-infected-patients) were studied. During the period of hospitalization, 44 patients (24 HIV and 20 non-HIV-infected patients) with a negative culture within 48 h of admission were followed weekly for fecal carriage. Clostridium difficile culture and latex agglutination were performed on the fecal samples of each patient. In the case of positive culture and/or latex agglutination, C. difficile toxin assays were performed by microtitre cytotoxicity method. RESULTS: Out-patients: one patient was a carrier and one patient with diarrhoea was infected with a toxigenic strain (2/45, 4.5%, 95% CI = 1-17). Eighty percent of the HIV-infected out-patients had received antimicrobial agents previously. In-patients: in the first 48 h, five asymptomatic patients were carriers (three non-HIV and two HIV-infected patients). Among 20 patients who complained of diarrhoea, one HIV-infected patient had only a positive latex agglutination and one HIV-infected patient was infected with a toxigenic strain. Overall, 7/120 (5.8%, 95% CI = 2-10) patients were infected or colonized with C. difficile. During the hospitalization (743 patient-days), none of the 44 patients acquired C. difficile. CONCLUSION: This study suggests that in this given unit, C. difficile carriage is low, at least with single room accommodation, and in the absence of clusters of cases. This carriage is not different in HIV and non-HIV infected patients despite treatment with multiple antibiotics, and is not different in patients managed in different care environments. The systematic identification of C. difficile carriers for isolation and prophylactic treatment is not useful under these circumstances.

Ambulatory Care↗
PubMed1998

Antibiotic resistance problems in the critical care unit.

The increased resistance of bacteria to antimicrobial agents poses major therapeutic problems for the treatment of patients hospitalized in critical care units. This article discusses the mechanisms of resistance and the basic rationale for the treatment of infected patients. The authors also discuss methods used to control the dissemination of resistant bacteria from patient to patient, the complex problems of colonization, and the strategies used to delay the emergence of resistance to new antibiotics.

Aminoglycosides↗
PubMed1998

Penicillin-binding protein 5 sequence alterations in clinical isolates of Enterococcus faecium with different levels of beta-lactam resistance.

The low-affinity penicillin-binding protein (PBP) 5 is the main beta-lactam target and is responsible for resistance to this class of antibiotics in Enterococcus faecium. The PBP 5 variants of 15 clinical isolates (including 8 resistant to vancomycin) with different levels of beta-lactam resistance were analyzed. Most of the highly beta-lactam-resistant isolates produced small quantities of PBP 5 of low affinity. This was associated with particular amino acid substitutions: an Ala or Ile for Thr-499, a Glu for Val-629, and a Pro for Ser-667. A change of Met-485 to Thr or Ala (adjacent to the conserved SDN box) was observed in isolates with MICs of ampicillin of 64 or 128 microg/mL, respectively. In the 2 most resistant isolates, with MICs of ampicillin of 256 microg/mL, an additional Ser was present just after Ser-466. Thus, particular point mutations in PBP 5 and combinations thereof may lead to high-level beta-lactam resistance in E. faecium.

Amino Acid Sequence↗
PubMed1998

Critical importance of in vivo amoxicillin and cefotaxime concentrations for synergy in treatment of experimental Enterococcus faecalis endocarditis.

The synergy between amoxicillin and cefotaxime against two strains of Enterococcus faecalis (JH2-2 and 6370) in vitro and in rabbit endocarditis was investigated. In vitro synergy was obtained only when amoxicillin concentrations were below the MBC and when cefotaxime concentrations were above 1 microg/ml. No synergy was observed in vivo, because of the short period of time during which these pharmacologic requirements were achieved.

Amoxicillin↗
PubMed1998

[Mechanisms underlying resistance of the bacteria responsible for nosocomial infections].

Resistance of nosocomial bacteria to antimicrobials is due to both natural and acquired factors. Production of inactivating enzymes (beta-lactamases, aminoglycoside detoxifying enzymes) is the most common mechanism in Gram-negative bacteria. The concomitant presence of other mechanisms such as abnormalities in the targets (for fluoroquinolones), permeability, or efflux of antimicrobials, explains why many nosocomial strains are resistant to multiple drugs. In Gram-positive bacteria, the main mechanism involves modifications in the bacterial targets of antimicrobials; for instance, changes in penicillin-binding proteins lead to penicillin resistance in enterococci and to methicillin resistance in staphylococci, whereas changes in peptidoglycans result in glycopeptide resistance in enterococci. As is the case for Gram-negative bacteria, the concomitant presence of other mechanisms is common, and as a result many nosocomial strains are multiresistant.

Acinetobacter↗
PubMed1997

Haemophilus endocarditis: report of 42 cases in adults and review. Haemophilus Endocarditis Study Group.

To define the clinical, microbiological, and therapeutic characteristics of haemophilus endocarditis, we reviewed the charts of 42 adults with haemophilus endocarditis (native valve disease, 37; prosthetic valve disease, five) who were followed up between 1983 and 1995 in France. The mean duration of symptoms before diagnosis was 34 days. The causative Haemophilus species were as follows: H. parainfluenzae (26 adults), H. aphrophilus (9), H. paraphrophilus (4), and H. influenzae (3). According to the Duke criteria, 38 cases of endocarditis were definitive and four were possible. Thirty-nine patients received combination antibacterial therapy and three received therapy with a beta-lactam agent alone (mean duration, 46 days). Arterial embolism occurred in 15 patients. Cardiac surgery was indicated for 18 patients; 16 of these surgeries were performed within 3 months. Two patients died of heart failure. In conclusion, haemophilus endocarditis is rare and is mainly due to H. parainfluenzae. Although surgery is often necessary, haemophilus endocarditis has a favorable prognosis.

Adolescent↗
PubMed1997

Carbapenem resistance in a clinical isolate of Citrobacter freundii.

Carbapenem resistance was studied in two sets of Citrobacter freundii strains: (i) strain CFr950, resistant to imipenem (MIC, 16 microg/ml) and isolated in vivo during imipenem therapy, and strain CFr950-Rev, the spontaneous, imipenem-susceptible revertant of CFr950 selected in vitro, and (ii) strains CFr801 and CFr802, two imipenem-resistant mutants selected in vitro from the susceptible clinical isolate CFr800. In all strains, whether they were imipenem-susceptible or -resistant strains, production of the cephalosporinase was derepressed and their Km values for cephaloridine were in the range of 128 to 199 microM. No carbapenemase activity was detected in vitro. The role of cephalosporinase overproduction in the resistance was demonstrated after introduction of the ampD gene which decreased the level of production of cephalosporinase at least 250-fold and resulted in an 8- to 64-fold decrease in the MICs of the carbapenems. The role of reduced permeability in the resistance was suggested by the absence, in CFr950 and CFr802, of two outer membrane proteins (the 42- and 40-kDa putative porins whose levels were considerably decreased in CFr801) and the reappearance of the 42-kDa protein in imipenem-susceptible strain CFr950-Rev. This role was confirmed after introduction of the ompF gene of Escherichia coli into the CFr strains, which resulted in 8- to 16-fold decreases in the MICs of carbapenems for CFr802 and CFr950. We infer from these results that the association of reduced, porin-mediated permeability with high-level cephalosporinase production, observed previously in other gram-negative bacteria, may also confer carbapenem resistance on C. freundii.

Anti-Bacterial Agents↗
PubMed1995

Bartonella (Rochalimaea) quintana endocarditis in three homeless men.

BACKGROUND: Bartonella (Rochalimaea) quintana is the agent of trench fever and is transmitted by the body louse. We searched for this organism in three alcoholic homeless men with endocarditis. METHODS: Blood samples were cultured on a human endothelial cell line and on blood agar. Bacteria were identified by sequencing the amplified 16S ribosomal RNA gene. The presence of bartonella in tissue was assessed by Gram's staining, immunostaining, and polymerase-chain-reaction amplification. Serologic studies for antibodies to bartonella species were performed by indirect immunofluorescence and Western immunoblotting. RESULTS: B. quintana was isolated from one patient in the blood-agar culture and from the other two patients in the endothelial-cell culture. The organism was also identified by both immunostaining and molecular techniques in the valvular vegetations from the three patients and in a cervical lymph node from one patient. The 16S ribosomal RNA gene sequences of the three isolates were almost identical to that of the prototype strain of B. quintana. High titers of antibodies to B. quintana were detected in all three patients, but so were cross-reacting antibodies to chlamydia species. In all three patients studies were repeatedly negative for antibodies to the human immunodeficiency virus. CONCLUSIONS: B. quintana is a cause of endocarditis in homeless patients and may be serologically misdiagnosed as a chlamydial infection.

Adult↗
PubMed1995

Decreased teicoplanin susceptibility of methicillin-resistant strains of Staphylococcus aureus.

Between February 1992 and February 1993, 12 patients were seen who were infected or colonized with methicillin-resistant strains of Staphylococcus aureus. The strains had decreased susceptibility to teicoplanin (MICs, 8-16 micrograms/mL). Field inversion gel electrophoresis showed the strains belonged to three related clones (A1, A2, and A3). The patients were though to have acquired the strains nosocomially. Consistent with results of laboratory studies of teicoplanin-resistant S. aureus, all but 1 strain expressed a 35-kDa membrane protein, and 9 strains expressed increased levels of penicillin-binding protein 2 complex. Six strains were isolated from patients treated with glycopeptides. These data suggest that nosocomial transmission of S. aureus with decreased teicoplanin susceptibility may occur during glycopeptide use and that such strains develop resistance by a mechanism associated with the appearance of a 35-kDa membrane protein. Surveillance is necessary to monitor for the potential selection of resistant clones that may be capable of dissemination.

Adult↗