PubMed Health⌕ Search

Biomedical subjects

M C Ploy

Publications and source records attributed to M C Ploy.

At least 19 recordsLinked to original sources

Use of antibiotics in hospitals in south-western France.

Data on the use of antibiotics were collected by means of a questionnaire from 49 hospitals in south-western France. Use was expressed as a usage density rate: number of defined daily doses (DDDs) per 1000 patient-days. The average use of antibiotics amounted to 402 DDDs per 1000 patient-days and varied between 60 and 734. In acute-care wards, the amount of antibiotic use increased with the size of the hospital: 461 DDDs per 1000 patient-days for group A (<100 beds), 510 DDDs per 1000 patient-days for group B (more than 100 and less then 300 beds) and 676 DDDs per 1000 patient-days for group C (>300 beds). The rate of use differed among different types of hospital areas and varied from 58 for psychiatry departments to more than 1273 DDDs per 1000 patient-days for the infectious diseases departments. Broad-spectrum penicillins were the most frequently prescribed antibiotics. Fluoroquinolone and third-generation cephalosporin use were relatively uniform in the three size categories. This study shows that it is possible for a hospital to benchmark its consumption with other hospitals that are similar in size. In this way, surveillance of antibiotic use can aid hospitals in targeting infection control efforts.

Anti-Infective Agents↗

[Methi-resistant Staphylococcus aureus in dermatological practice: origin, risk factors and outcome].

BACKGROUND: Increased frequency of methiresistant Staphylococcus aureus (MRSA) in inpatients is a day to day problem. OBJECTIVE: To determine the origin of MRSA, the causes for contamination, and potential complications in a department of Dermatology. PATIENTS AND METHODS: A retrospective study of patients hospitalized in a dermatology department with cutaneous MRSA during 1997-1998. We considered age, type and duration of dermatitis, geographic origin of patients on admission, previous hospitalizations, time between arrival in the ward and positive MRSA, and complications requiring systemic antibiotics. RESULTS: Out of 4579 of our patients, 53 (0.011 p. 100) had positive MRSA. They were on average 70.86 years-old (26 to 97). The most common underlying dermatitis was leg ulcers (30) and foot sores (4). Dermatitis had lasted for more than 1 month in 48 patients. Most of the patients (40) had their MRSA on admission to our ward. Twenty six patients admitted from home had MRSA; only 9 had never been in an hospital. Six patients had diabetes mellitus. Thirty two patients healed with local treatment for their dermatitis. Thirteen patients have had some complications (erysipela 1, osteoarthritis 3, septicemia 2, febrile syndrome 9). DISCUSSION: Most patients with MRSA had leg ulcers or foot sores, confirming liability of chronic wounds to MRSA colonizing. Thirty one out of 40 patients with MRSA at arrival had been previously hospitalized. Hospitalization increases the risk of MRSA contamination. Treatment of MRSA is essentially that of the underlying dermatitis. However, it is still necessary to monitor the lesion for complications.

Adult↗

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↗

[Erysipelas: microbiological and pathogenic data].

Streptococcus pyogenes is considered as the primary cause of erysipelas and the virulence factors of this species are reviewed. The role of Staphylococcus aureus alone or associated with Streptococcus pyogenes remains unclear. Other etiologies are infrequent. Several techniques were used to detect bacteria (direct examination, culture, antigen or genome assay) in local samples (needle aspiration, swab.), in others sites (throat, blood cultures), or specific antibodies. The performance of the various diagnosis methods is evaluated. Despite the combination of 2 or more methods, the etiology remains unknown in almost 20 p. 100 of the cases.

Erysipelas↗

Molecular characterization of integrons in Acinetobacter baumannii: description of a hybrid class 2 integron.

Twenty Acinetobacter baumannii strains resistant to various antibiotics were analyzed for integron content and sequences of the amplification products. Sixteen clinical isolates had a class 1 integron, 2 contained an additional class 1 or class 2 integron, but no class 3 integron was detected. Thirteen strains had integrons with a single cassette: aac(3)-Ia (9 strains), ant(2")-Ia (2 strains), or aac(6')-Ib (2 strains); 1 had aac(6')-Ib and oxa20 cassettes and an unknown gene; and 1 had an integron containing ant(2")-Ia and an oxa3 cassette truncated by IS6100. The remaining strains harbored class 1 integrons with gene cassettes previously found in Enterobacteriaceae. One integron had a hybrid structure composed of intI2 and the 3' conserved segment of class 1 integrons. These data indicate that integrons play a major role in multidrug resistance in Acinetobacter.

Acinetobacter↗

Prevalence of vancomycin-resistant enterococci in fecal samples from hospitalized patients and nonhospitalized controls in a cattle-rearing area of France.

Vancomycin-resistant enterococci (VRE) have emerged as nosocomial pathogens over the last decade, but little is known about their epidemiology. We report on the prevalence of VRE fecal colonization on the basis of a prospective study among patients hospitalized in a hematology intensive care unit and among nonhospitalized subjects living in the local community. A total of 243 rectal swabs from hematology patients and 169 stool samples from the control group were inoculated onto bile-esculin agar plates with and without 6 mg of vancomycin per liter and into an enrichment bile-esculin broth supplemented with 4 mg of vancomycin per liter. A total of 37% of the hospitalized patients and 11.8% of the subjects from the community were found to be VRE carriers. A total of 65 VRE strains were isolated: 12 (18.5%) E. faecium, 46 (70.7%) E. gallinarum, and 7 (10.8%) E. casseliflavus strains. No E. faecalis strains were detected. All the E. faecium strains were of the vanA genotype. Molecular typing by pulsed-field gel electrophoresis revealed a different pattern for each vanA VRE strain that originated from an individual subject. To our knowledge, this is the first study to be carried out in a cattle-rearing region of France. It reports a higher VRE prevalence than that reported in previous European or U.S. studies. A partial explanation is the use of an enrichment broth step which enabled detection of strains which would otherwise have been missed, but the fact that subjects and patients were recruited from a predominantly agricultural area where vancomycin-related antibiotics have recently been used in animal husbandry could also contribute to the high levels of VRE in patients and subjects alike.

Adolescent↗

Integrons: an antibiotic resistance gene capture and expression system.

Bacteria can transfer genetic information to provide themselves with protection against most antibiotics. The acquisition of resistance gene arrays involves genetic mobile elements like plasmids and transposons. Another class of genetic structures, termed integrons, have been described and contain one or more gene cassettes located at a specific site. Integrons are defined by an intl gene encoding an integrase, a recombination site attl and a strong promoter. At least six classes of integrons have been determined according to their intl gene. Classes 1, 2 and 3 are the most studied and are largely implicated in the dissemination of antibiotic resistance. A gene cassette includes an open reading frame and, at the 3'-end, a recombination site attC. Integration or excision of cassettes occur by a site-specific recombination mechanism catalyzed by the integrase. However, insertion can occur, albeit rarely, at non-specific sites leading to a stable situation for the cassette. Cassettes are transcribed from the common promoter located in the 5'-conserved segment and expression of distal genes is reduced by the presence of upstream cassettes. Most gene cassettes encode antibiotic resistant determinants but antiseptic resistant genes have also been described. Integrons seem to have a major role in the spread of multidrug resistance in gram-negative bacteria but integrons in gram-positive bacteria were described recently. Moreover, the finding of super-integrons with gene-cassettes coding for other determinants (biochemical functions, virulence factors) in Vibrio isolates dating from 1888 suggests the likely implication of this multicomponent cassette-integron system in bacterial genome evolution before the antibiotic era and to a greater extent than initially believed.

Animals↗

In-vitro antibacterial activity of levofloxacin against hospital isolates: a multicentre study.

The objective of this study was to evaluate the activity of the fluoroquinolone, levofloxacin, against hospital isolates of bacteria. MICs of levofloxacin were determined for 2154 strains by agar dilution. Breakpoints for susceptibility testing were calculated using the agar diffusion technique with 5 micrograms discs. The activity of levofloxacin against nalidixic acid- and pefloxacin-susceptible Enterobacteriaceae (n = 668) was higher (MIC50/90 0.06-0.12 mg/L) than previously reported for ofloxacin. As seen with other fluoroquinolones, this activity was reduced against nalidixic acid-resistant and pefloxacin-intermediate and -resistant strains (MIC 1-8 mg/L). MICs for Pseudomonas aeruginosa (n = 104) were between 0.12 and 128 mg/L. Levofloxacin had good activity against nalidixic acid- and pefloxacin-susceptible Acinetobacter baumannii (n = 12; MIC 0.06-0.25 mg/L), but the activity was reduced against nalidixic acid- and pefloxacin-resistant strains (n = 80; MIC 1-32 mg/L). Haemophilus influenzae (n = 70), Haemophilus parainfluenzae (n = 47) and Moraxella catarrhalis (n = 64) were inhibited by low concentrations of levofloxacin (MICs 0.016-0.03 mg/L, 0.03-0.12 mg/L) and 0.03-0.12 mg/L, respectively). Clostridium perfringens (n = 23; MIC 0.25-1 mg/L) was more susceptible than Bacteroides fragilis (n = 60; MIC 0.5-4 mg/L). Levofloxacin showed superior activity compared with ofloxacin against methicillin-susceptible staphylococci (n = 107; MIC 0.03-0.5 mg/L); the resistant strains (MICs 2-32 mg/L) were usually also resistant to methicillin. Levofloxacin was less effective against enterococci (n = 105; MIC 1-32 mg/L), but streptococci (n = 192) and pneumococci (n = 129), including 58 penicillin-non-susceptible strains, were inhibited by low concentrations (MICs 0.5-2 mg/L). According to the regression curve, zone diameters were usually 20-22 mm, 17-19 mm and 15-16 mm for MICs of 1, 2 and 4 mg/L, respectively. In conclusion, this study, performed on a large number of strains, confirms the superior anti-bacterial activity of levofloxacin compared with ofloxacin, especially against pathogens isolated from respiratory tract infections.

Acinetobacter↗

Characterization of the chromosomal aac(6')-Iz gene of Stenotrophomonas maltophilia.

The aac(6')-Iz gene of Stenotrophomonas maltophilia BM2690 encoding an aminoglycoside 6'-N-acetyltransferase was characterized. The gene was identified as a coding sequence of 462 bp corresponding to a protein with a calculated mass of 16,506 Da, a value in good agreement with that of ca. 16,000 found by in vitro coupled transcription-translation. Analysis of the deduced amino acid sequence indicated that the protein was a member of the major subfamily of aminoglycoside 6'-N-acetyltransferases. The enzyme conferred resistance to amikacin but not to gentamicin, indicating that it was an AAC(6') of type I. The open reading frame upstream from the aac(6')-Iz gene was homologous to the fprA gene of Myxococcus xanthus (61% identity), which encodes a putative pyridoxine (pyridoxamine) 5'-phosphate oxidase. Pulsed-field gel electrophoresis of total DNA from BM2690 and S. maltophilia ATTC 13637 digested with XbaI, DraI, and SpeI followed by hybridization with rRNA and aac(6')-Iz-specific probes indicated that the gene was located in the chromosome. The aac(6')-Iz gene was detected by DNA-DNA hybridization in all 80 strains of S. maltophilia tested. The MICs of gentamicin against these strains of S. maltophilia were lower than those of amikacin, netilmicin, and tobramycin, indicating that production of AAC(6')-Iz contributes to aminoglycoside resistance in S. maltophilia.

Acetyltransferases↗

[Lactobacillus acidophilus endocarditis].

BACKGROUND: Lactobacillus is a commensal germ found in the buccal cavity, the digestive tract and the vagina. Usually non-pathogenic except in case of dental caries, it can occasionally be the causal agent in severe endocarditis. CASE REPORT: A 70-year-old woman developed endocarditis on an aortic valve bioprosthesis. Lactobacillus acidophilus was isolated from blood cultures of the valve after surgery. COMMENTS: Forty-four cases of Lactobacillus endocarditis have been reported in the literature to date. Mortality is high (26%). The main difficulty in treatment is germ tolerance to penicillin and aminosides found in all cases. Cure requires high dose parenteral antibiotics and surgery in many cases (26%).

Aged↗

Characterization of In40 of Enterobacter aerogenes BM2688, a class 1 integron with two new gene cassettes, cmlA2 and qacF.

Enterobacter aerogenes BM2688, which is resistant to multiple antibiotics, and its aminoglycoside-susceptible derivative BM2688-1 were isolated from the same clinical sample. Strain BM2688 harbored plasmid pIP833, which carries a class 1 integron, In40, containing (in addition to qacEDelta1 and sul1, which are characteristic of class 1 integrons) four gene cassettes: aac(6')-Ib, qacF, cmlA2, and oxa-9. The cmlA2 gene had 83.7% identity with the previously described nonenzymatic chloramphenicol resistance cmlA1 gene. The qacF gene conferred resistance to quaternary ammonium compounds and displayed a high degree of similarity with qacE (67.8% identity) which, however, has been found as part of a cassette with a very different 59-base element. The oxa-9 gene was not expressed due to a lack of promoter sequences. Study of the antibiotic-susceptible derivative BM2688-1 indicated that a 3,148-bp deletion between the 3' end of the aac(6')-Ib gene and the 3' conserved segment of In40 was responsible for the loss of resistance. The occurrence of this DNA rearrangement, which did not involve homologous sequences, suggests that the In40 integrase could promote recombination at secondary sites.

Amino Acid Sequence↗

[Emergence of Enterobacter aerogenes strains producing derepressed cephalosporinase at CHU in Limoges: molecular epidemiology by the RAPD technique].

From the beginning of the year 1996, an increase of multiresistant Enterobacter aerogenes isolates was observed. These strains overproduced their chromosomally cephalosporinase. From February to September 1996, we studied the genotypic diversity of multiresistant E. aerogenes isolates. Fifty-seven strains were analysed with the RAPD technique. These strains were isolated from 38 patients in 25 different units. These isolates were collected from urines (37), respiratory tracts (14) and wounds (6). We have observed two distinct profiles. The predominant profile (A) was recovered from 55 strains (36 patients) and the second profile (B) from 2 strains (2 patients). The clonal relatedness of strains isolated (profile A) showed an epidemic spread in our hospital. The RAPD technique is easy to perform and gives results in less than 48 h with a good discriminatory power.

Cephalosporinase↗