Search PubMed⌕ Search

Biomedical subjects

A Buu-Hoï

Publications and source records attributed to A Buu-Hoï.

At least 19 recordsLinked to original sources

Colonization and infection of pulmonary artery catheter in cardiac surgery patients: epidemiology and multivariate analysis of risk factors.

OBJECTIVE: To assess the incidence and etiology of colonization and infection of pulmonary artery catheters inserted in cardiac surgery patients. To determine the influence of some variables on the risk of developing pulmonary artery catheter colonization and infection. DESIGN: Prospective observational study of pulmonary artery catheters inserted into the internal jugular vein that were in place for >48 hrs over a 13-month period. Data collected included age, gender, nature of the cardiac surgery intervention, duration of extracorporeal circulation, date of insertion and removal, subsequent infection, and curative antimicrobial therapy. End points were pulmonary artery catheter colonization with >or=10(3) colonies on quantitative cultures and pulmonary artery catheter-related bacteremia. Risk factors for colonization were determined by multiple logistic regression. SETTING: A 17-bed cardiac surgery intensive care unit in a 480-bed teaching hospital in Paris. PATIENTS: Patients undergoing cardiac surgery procedures between May 1, 1997, and May 31, 1998. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Of 164 pulmonary artery catheters inserted in 157 patients, 19 (11.6%) and 1 (0.6%) were associated with colonization (mean duration of catheterization, 7.5 +/- 2.8 days) and bacteremia, respectively. These data represent an incidence of 17.7 and 0.93 episodes per 1000 catheterization-days, respectively. Pulmonary artery catheter colonization was caused by Gram-positive cocci in 48% (67% were coagulase-negative staphylococci), Gram-negative rods in 48%, and Candida albicans in 4%. From multivariate analysis, >4 days of catheterization was the single variable associated with a significantly increased risk of pulmonary artery catheter colonization (odds ratio, 9.81; 95% confidence interval, 1.24-77.5, p = .03). CONCLUSIONS: Our data show that the risk of pulmonary artery catheter-related colonization and bacteremia is quite low despite the use of a high-risk insertion site. In cardiac surgery patient populations, a trial evaluating the impact of a systematic pulmonary artery catheter removal after 4 days is warranted.

Bacteremia↗

Methicillin-resistant Staphylococcus aureus. Nosocomial acquisition and carrier state in a wound care center.

OBJECTIVE: To assess methicillin-resistant Staphylococcus aureus (MRSA) nosocomial acquisition and carrier state in a wound care center. DESIGN AND SETTING: The results of an intervention to control MRSA were compared with those of historical controls at the wound care center of university-based Hôpital Broussais, Paris, France. PATIENTS: Patients admitted for specific care of chronic ulcers and surgical wounds. MAIN OUTCOME MEASURES: Incidence rates of MRSA carriers and acquisition in wounds. RESULTS: Of 88 patients admitted during a 3-month preintervention period in 1993, 18 (21%) were MRSA carriers. Of 334 patients admitted in 1994 and 395 in 1996, 65 (19.5%) and 81 (20.5%) were MRSA carriers, respectively (P=.80). In 1993, 6 (9%) of 70 patients without MRSA acquired MRSA wound infections; the corresponding numbers were 6 (2.2%) of 269 in 1994 and 3 (0.9%) of 314 in 1996. Despite that the number of MRSA carriers remained stable at admission to the wound care center, the rate of MRSA infections in wounds per 100 noncarriers decreased significantly between the preintervention period and subsequent years: 1994 (P=.02) and 1996 (P=.002). CONCLUSIONS: Although our results are limited by the use of historical controls, they showed that simple infection control measures, such as the use of soap and water and barrier precautions associated with staff education, seemed to significantly reduce MRSA infection rates in patients with chronic skin breaks.

Aged↗

Outbreak of methicillin-resistant Staphylococcus aureus with reduced susceptibility to glycopeptides in a Parisian hospital.

Epidemiological relationships were investigated between 40 methicillin-resistant Staphylococcus aureus (MRSA) strains with decreased glycopeptide susceptibility isolated from November 1998 to March 1999 from 39 patients (17 infected and 22 colonized patients) in nine wards of the Broussais Hospital, Paris, France. Reduced glycopeptide susceptibility was readily detected on brain heart infusion (BHI) agar containing 6 microg of teicoplanin per ml and on gradient plates, but not by the standard disk diffusion method. The MICs of vancomycin and teicoplanin, determined on BHI agar, were 4 and 8 to 32 microg/ml, respectively (standard antibiotic dilution), and 4 to 8 and 8 to 32 microg/ml, respectively (E-test). All strains were resistant to macrolides, aminoglycosides, tetracycline, rifampin, sulfonamides, and pefloxacin, showed reduced susceptibility to fusidic acid and fosfomycin, and were susceptible to trimethoprim and chloramphenicol. Pulsed-field gel electrophoresis and lysotyping revealed that a multidrug-resistant MRSA clone with decreased susceptibility to glycopeptides has been discretely endemic since at least 1996 in our institution, where it was responsible for an outbreak in November and December 1998.

Anti-Bacterial Agents↗

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↗

High-level chromosomal gentamicin resistance in Streptococcus agalactiae (group B).

This is the first report of high-level gentamicin resistance in a group B streptococcus. Strain B128 of serotype II was isolated from an infected leg wound in 1987. B128 was resistant to high levels of gentamicin as well as of all other available aminoglycosides and was also resistant to tetracyclines. No bactericidal synergism was found between ampicillin or vancomycin and any of these aminoglycosides. Gentamicin, kanamycin, streptomycin, and tetracycline resistance determinants transferred by conjugation into a plasmid-free group B streptococcus recipient at a frequency of 10(-8) to 10(-9) transconjugants per donor cell. No transconjugants were detected when streptococci of groups A, C, and G, Streptococcus sanguis, or Enterococcus faecalis was used as a recipient. No plasmids were detected in B128 or in any of the four transconjugants tested. By DNA-DNA hybridization, homology was detected between gene aac6/aph2, of E. faecalis origin, and a 2.4-kilobase HindIII chromosomal fragment of B128; homology to the genes aph3 and aadE, of E. faecalis origin, was found with HindIII chromosomal fragments of the same size (3.0 kilobases). Strains like B128, which potentially can be responsible for severe neonatal infections, are of great clinical concern, since there are to date no antibiotic combinations exhibiting bactericidal synergism against them.

Blotting, Southern↗

Genetic basis of antibiotic resistance in Aerococcus viridans.

Resistance to at least one of the following antibiotics was found in eight wild-type strains of Aerococcus viridans: erythromycin (six strains), tetracycline and minocycline (five strains), chloramphenicol (one strain), and high levels of streptomycin (one strain). None of the strains transferred any of their antibiotic resistance markers into streptococcal, enterococcal, or A. viridans recipients by conjugation. By DNA-DNA hybridization experiments, the ermB gene of transposon Tn917, of Enterococcus faecalis origin, was detected in five of the six strains resistant to erythromycin and was localized for one strain on the chromosome and for four strains on nonconjugative small (4.7- to 4.9-kilobase) plasmids. The tetM gene of the conjugative transposon Tn916, of E. faecalis origin, was localized on the chromosome of four of the five strains resistant to tetracycline and minocycline; in three of these strains a structure similar to that of Tn916 was found. Homology to the tetO gene of pUA466, of Campylobacter jejuni origin, was detected on the chromosome of the fifth strain. No sequence homology was detected in any strain with probes corresponding to the tetL gene of group B Streptococcus origin, to the ermA gene of the transposon Tn554 of Staphylococcus aureus origin, or to the cat genes of either pC194 or pC221 of S. aureus origin.

Anti-Bacterial Agents↗

Vancomycin-resistant streptococci or Leuconostoc sp.

Two strains of gram-positive cocci highly resistant to vancomycin (MICs of 512 and 1,024 micrograms/ml) were isolated from blood cultures in two compromised patients. These organisms were identified as Leuconostoc spp. Leuconostoc spp. are gram-positive cocci found in vegetables and dairy products; they had not been isolated previously from clinical specimens. The susceptibility of eight Leuconostoc spp. strains, including the two clinical isolates, to 23 antimicrobial agents was determined.

Adult↗

Bactericidal activity of five combinations of penicillin G with aminoglycosides against Streptococcus faecium.

Combinations of penicillin G and five aminoglycosides were tested against 7 strains of S. faecium. For all the strains that had a low-level of resistance to streptomycin, the combination of penicillin G with streptomycin was synergistic. Penicillin combined with either kanamycin or netilmicin was ineffective against all strains. The combination of penicillin and amikacin was synergistic against only one of the aminoglycoside-susceptible strains and ineffective against all the other strains. Penicillin G with gentamicin was the only combination synergistic against all strains. The clinical implications of these findings for the treatment of bacterial endocarditis caused by S. faecium are discussed.

Aminoglycosides↗

Broad host range of streptococcal macrolide resistance plasmids.

Four macrolide-lincosamide-streptogramin B resistance plasmids transferred into 13 recipients belonging to Streptococcus, Staphylococcus, and Listeria genera. The plasmids were stably maintained in all new hosts except Streptococcus sanguis, Streptococcus pneumoniae, Staphylococcus aureus, and Listeria innocua and were identical to those found in the corresponding donor strains.

Anti-Bacterial Agents↗

Antimicrobial susceptibility of Gemella haemolysans isolated from patients with subacute endocarditis.

Gemella haemolysans, a member of the family Streptococcacae, was isolated from patients with subacute endocarditis. The minimal inhibitory concentrations of 21 antimicrobial agents for five strains of the organism were determined. All strains were highly sensitive to penicillin G and ampicillin. Cefotaxime was the most active cephalosporin tested. All strains were sensitive to vancomycin, chloramphenicol and rifampin. Four strains were sensitive to tetracycline and erythromycin. All strains demonstrated a low level of resistance to aminoglycosides and were highly resistant to sulfonamides and trimethoprim. Killing curves and checker-board titration demonstrated synergism between penicillin G and streptomycin or gentamicin, and also between vancomycin and streptomycin or gentamicin. The results suggest that penicillin G combined with an aminoglycoside can be recommended for the treatment of subacute endocarditis caused by Gemella haemolysans.

Anti-Bacterial Agents↗

High-level aminoglycoside resistance in group A, B, G, D (Streptococcus bovis), and viridans streptococci.

Of 20 clinical isolates of group A, B, G, D (Streptococcus bovis), and viridans streptococci, 5 transferred their antibiotic resistance markers into streptococcal recipients at a low frequency (10(-4) to 10(-8)) in the apparent absence of extrachromosomal elements. All strains carried genetic markers for high-level resistance to streptomycin, kanamycin, neomycin, lividomycin A, and ribostamycin, as well as resistance to macrolides and related drugs, tetracycline, and chloramphenicol.

Aminoglycosides↗

[Antibiotic resistance genetic basis of human origin streptococci (author's transl)].

One hundred strains of group A, B, C, D (S faecalis, S. faecium, S. bovis) F, G, S. pneumoniae and viridans streptococci were studied. All these strains were clinical isolates from infective endocarditis and fron upper respiratory, skin, genital and urinary tract infections. These stains were resistant to one or several antibiotics : tetracycline, macrolide and related drugs, chloramphenicol, aminoglycosides (high-level resistance to streptomycin, kanamycin, gentamicin), and penicillin. Conjugative transfer of antibiotic resistance markers (except penicillin) into streptococcal recipients was obtained at a high frequency (10(-1) to 10(-4)) for 12 strains and at a low frequency (10(-5) to 10(-8)) for 29 strains. R plasmids carrying various groups of resistance markers were isolated with different molecular weights. Enzyme restriction analysis showed the existence of different molecular species of streptococcal plasmids. All attempts to detect extrachromosomal DNA in 17 wild-type strains and in the corresponding transconjugants were unsuccessful.

Anti-Bacterial Agents↗