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1.
The ability of seventy clinical laboratories in nine European countries to detect glycopeptide resistance in Gram-positive bacteria was investigated. Results of routine tests were compared with those on the same strains by a reference method in national co-ordinating laboratories. In addition, control strains were tested by some of the participants. Errors in reporting susceptibility of Staphylococcus aureus to teicoplanin and vancomycin and coagulase-negative staphylococci to vancomycin were < 1%. With coagulase-negative staphylococci however, 44 (3.4%) teicoplanin susceptible isolates were reported intermediate and six (0.4%) resistant; 18 (58.1%) of 31 teicoplanin intermediate isolates were reported susceptible and five (16.1%) resistant; and six of nine teicoplanin resistant isolates were reported susceptible and two intermediate. All seven isolates of enterococci intermediate to vancomycin were reported susceptible. Distribution of a known vancomycin intermediate strain of E. gallinarum indicated problems with vancomycin susceptibility testing (44.4% reported susceptible, 32.7% intermediate, 32.1% resistant) and identification (only 34.1% correct) of this organism. Two of 28 teicoplanin resistant enterococci and three of 30 vancomycin resistant isolates were reported susceptible. Among other organisms, one resistant Lactobacillus sp. was reported susceptible to teicoplanin and vancomycin. In reporting teicoplanin susceptible organisms, there were fewer errors with comparative/Stokes methods than with most other methods and more errors with the ATB and Sceptor methods than most other methods. None of the methods used were reliable for testing teicoplanin intermediate and resistant coagulase-negative staphylococci or low-level vancomycin resistant enterococci. Alternative methods, such as breakpoint screening, should be considered for detecting glycopeptide resistance.  相似文献   

2.
Vancomycin-resistant enterococci (VRE) are a major problem in numerous institutions in the United States. Most VRE are resistant to all available antimicrobial agents, resulting in serious therapeutic dilemmas. The resistance genes are transmitted on transposons, so the potential for dissemination to other species is significant. Risk factors associated with VRE infection and colonization are vancomycin and cephalosporin use, but numerous patient-related factors also contribute. Although resistant strains appear to arise from the patient's endogenous flora, VRE may be spread through direct contact with contaminated environmental surfaces and hands of caregivers. Published guidelines for preventing such spread suggest implementing infection-control practices and vancomycin restrictions. The ideal drug regimen for the treatment of VRE is unknown. Various drug combinations have been studied in the laboratory, but patient treatment data are scarce. There is an urgent need for new antimicrobial agents.  相似文献   

3.
Enterococci are normal intestinal flora in humans. Among enterococci, Enterococcus faecalis and Enterococcus faecium are frequently isolated and can become nosocomial pathogens in hospitals, especially in intensive care units and oncology wards. Recently, vancomycin-resistant enterococci (VRE) such as E. faecalis and E. faecium have caused a serious problem of hospital-acquired infections in Europe and the USA. VRE also has another aspect as a cause of community-acquired infections. Especially, avoparcin which had been used to enhance growth of food animals is documented as associated with the spread of VRE in European countries. In Japan, there have only been a few of reports about VRE so far. However, there evidence that VRE might become prevalent in many hospitals in Japan. In fact, we have already isolated another highly vancomycin-resistant E. faecium (VCM:MIC > 128 micrograms/ml) from a hospitalized diabetic patient. We should pay a careful attention to VRE and perform the following control measures: 1)re-education and re-training about hospital infection control procedures, 2) prudent use of vancomycin in clinical settings, 3)accurate report of VRE in clinical laboratories, and 4) good communications and collaborations among physicians, nurses and other health care personnel and laboratory technicians. We should learn more from countries in which VRE are already prevalent, and pursue further investigations, to prevent the spread of VRE in Japan.  相似文献   

4.
In order to determine whether hospital-based clinical laboratories conducting active surveillance for vancomycin-resistant enterococci in three San Francisco Bay area counties (San Francisco, Alameda, and Contra Costa counties) were accurately reporting vancomycin resistance, five vancomycin-resistant enterococcal strains and one vancomycin-susceptible beta-lactamase-producing enterococcus were sent to 31 of 32 (97%) laboratories conducting surveillance. Each strain was tested by the laboratory's routine antimicrobial susceptibility testing method. An Enterococcus faecium strain with high-level resistance to vancomycin (MIC, 512 microg/ml) was correctly reported as resistant by 100% of laboratories; an E. faecium strain with moderate-level resistance (MIC, 64 microg/ml) was correctly reported as resistant by 91% of laboratories; two Enterococcus faecalis strains with low-level resistance (MICs, 32 microg/ml) were correctly reported as resistant by 97 and 56% of laboratories, respectively. An Enterococcus gallinarum strain with intrinsic low-level resistance (MIC, 8 microg/ml) was correctly reported as intermediate by 50% of laboratories. A beta-lactamase-producing E. faecalis isolate was correctly identified as susceptible to vancomycin by 100% of laboratories and as resistant to penicillin and ampicillin by 68 and 44% of laboratories, respectively; all 23 (74%) laboratories that tested for beta-lactamase recognized that it was a beta-lactamase producer. This survey indicated that for clinically significant enterococcal isolates, laboratories in the San Francisco Bay area have problems in detecting low- to moderate-level but not high-level vancomycin resistance. Increasing accuracy of detection and prompt reporting of these isolates and investigation of cases are the next steps in the battle for control of the spread of vancomycin resistance.  相似文献   

5.
The comparative in vitro activities of two new oxazolidinone antimicrobial agents, U-100592 and U-100766, against 180 isolates of enterococci representing several resistance profiles were examined by using an agar dilution technique. The two oxazolidinones inhibited all isolates, including strains resistant to vancomycin, ampicillin, and minocycline, at concentrations between 1 and 4 micrograms/ml.  相似文献   

6.
OBJECTIVE: To document the risk of the development of vancomycin-resistant bacteria in a population of seriously burned patients during a 10-year period of common vancomycin hydrochloride use. DESIGN: Retrospective study. SETTING: The US Army Institute of Surgical Research, Burn Center, Fort Sam Houston, Tex. POPULATION AND METHODS: Microbiology, infection, and antibiotic use records collected during the hospitalization of 2266 consecutively admitted seriously burned patients were reviewed. Vancomycin was the primary therapeutic agent used for gram-positive infections and was also used as a perioperative prophylactic antibiotic during burn wound excision. This policy was established prior to this review because of a high incidence of methicillin-resistant Staphylococcus aureus colonization and an anecdotal association of increased beta-lactam resistance in endemic gram-negative pathogens associated with the use of penicillinase-resistant penicillins and cephalosporins. MAIN OUTCOME MEASURES: Isolation of vancomycin-resistant enterococci (VRE) or other gram-positive organisms resistant to vancomycin. RESULTS: Examinations of 15 125 gram-positive isolates, including 957 enterococci, for in vitro sensitivity to vancomycin yielded 3 VRE isolates in 3 patients. Vancomycin was used prior to VRE isolation in one of these patients. Resistance was found in 3 other organisms (2 Corynebacterium species, 1 Lactobacillus species). Vancomycin was used prior to these isolations in 2 of 3 patients. None of the vancomycin-resistant organisms was associated with infection and all 6 patients survived. Vancomycin-resistant enterococci or other vancomycin-resistant gram-positive organisms were not found in 663 patients treated with vancomycin for documented gram-positive infections or in 1027 patients where perioperative vancomycin was used. CONCLUSION: Use of vancomycin as the primary therapeutic agent in seriously burned patients was not associated with increased risk of VRE isolation or VRE infection.  相似文献   

7.
Susceptibility patterns of methicillin-resistant Staphylococcus aureus (MRSA) and Enterococcus faecium obtained from various hospitals of the Tohoku district were documented. MICs of 6 antimicrobial agents against a total of 480 strains (380 strains were MRSA and 100 were E. faecium) were estimated. All MRSAs were susceptible to vancomycin, teicoplanin and quinupristin/dalfopristin, but all of them were resistant to ampicillin and benzylpenicillin. None of the E. faecium strains were found to be resistant to vancomycin, teicoplanin and quinupristin/dalfopristin. Excluding these, almost all strains of E. faecium were resistant to the remaining drugs. These data suggest that despite the emergence of vancomycin resistance to E. faecium in Europe and in the United States, vancomycin, teicoplanin and quinupristin/dalfopristin will nevertheless provide effective bactericidal activity in the Tohoku area of Japan.  相似文献   

8.
HR Devlin 《Canadian Metallurgical Quarterly》1998,44(8):32-40; discussion 34-8; quiz 41-2
Staphylococcus aureus and Enterococci have gained prominence as the causes of wound infections during this decade. Methicillin-resistant Staphylococcus aureus (MRSA) became commonplace in the United States during the 1980s. In Canada, infections with MRSA have been increasing in frequency since 1995. MRSA develops resistance by producing an altered penicillin-binding protein, PBP 2a, coded for by the mecA gene. Vancomycin is the usual drug of choice. Recently, strains with intermediate resistance to vancomycin (VISA) have been isolated from patients in Japan and the United States. Interim guidelines for their control have been developed by the Centers for Disease Control. Enterococci have developed a resistance to a variety of antimicrobials during the past three decades, including beta-lactams and aminoglycosides. Recently, strains resistant to vancomycin (VRE) have been found in the United States and Canada. They are particularly difficult to treat, although some success has been achieved with experimental drugs. These microorganisms have the ability to escape control by antimicrobials almost as soon as they are developed. Thus, we must practice good infection control and reserve antimicrobials only for clear cases of infection if we are to prevent or delay the emergence of resistance.  相似文献   

9.
Prostatitis due to vancomycin-resistant enterococci has not been previously described. Reported here is a case of chronic prostatitis due to Enterococcus faecium, resistant to vancomycin, ampicillin, ciprofloxacin and doxycycline, in a 42-year-old liver transplant recipient. Treatment with a combination of rifampin and nitrofurantoin for 6 weeks resulted in long-lasting cure. Other antimicrobial agents active in vitro against vancomycin-resistant enterococci, such as quinupristin/ dalfopristin and chloramphenicol, are unlikely to achieve sufficient prostatic tissue levels to be successfully utilized for treatment of this condition.  相似文献   

10.
A significant number of open and comparative studies have now addressed the use of teicoplanin in the treatment of documented or presumed infection in patients with haematological and non-haematological malignancy. Available evidence suggests that teicoplanin is an effective agent against such infections, with an excellent safety profile. The use of teicoplanin and vancomycin may be justified as part of the initial management of clinically infected right atrial catheters in patients with malignancy. The first-line use of glycopeptides may also be appropriate in units where streptococcal and methicillin resistant staphylococcal infections are prevalent. However, such a policy should be reviewed regularly. Except in the above situations, a delay in the introduction of either teicoplanin or vancomycin in cancer patients does not appear to produce any excess mortality, but there may be some additional morbidity in terms of fever and malaise. The introduction of glycopeptides as second-line agents is indicated for sensitive, microbiologically documented infections and for patients who have not responded to empirical, first-line therapy. Non-inpatient treatment with teicoplanin is an area of ongoing interest and may be justified on both humanitarian and pharmacoeconomic grounds. The use of glycopeptides in the prophylactic setting remains controversial and should be avoided while the emergence of resistance, particularly in enterococci, should be monitored closely.  相似文献   

11.
Since 1995, KePRO has worked with the peer review organization for 13 other states/commonwealths and the District of Columbia, as well as the Boston Regional Office of the Health Care Financing Administration, in the implementation of the largest study ever conducted involving Vancomycin-resistant enterococci (VRE). Fifteen Pennsylvania hospitals volunteered to participate in the study, designed to identify and assess the appropriateness of vancomycin use, contributing 19 percent of the total records used in the baseline study. This article, the first of two, describes VRE and its increasing prevalence. In the second installment, we will describe patterns of vancomycin use identified in KePRO's study of participating Pennsylvania hospitals, as well as the steps these hospitals are taking to control antibiotic use. Since all data gathered by KePRO are protected by federal confidentiality guidelines, the facilities that graciously agreed to pioneer KePRO's vancomycin utilization project will not be identified or identifiable.  相似文献   

12.
The question of why vancomycin-resistant enterococci (VRE) became epidemic in the United States can be answered on at least three basic levels: (1) molecular and genetic, (2) factors affecting host-microbe interactions, and (3) epidemiological. This article will address the epidemiological issues and seek to defend the assertion that, once VRE had evolved, its spread throughout hospitals in the United States was all but assured. Nosocomial VRE outbreaks were reported first in the mid- and late-1980s. Since that time, scientific reports of VRE have increased over 20-fold. Among hospitals participating in the National Nosocomial Infection Surveillance System from 1989 to 1997, the percentage of enterococci reported as resistant to vancomycin increased from 0.4% to 23.2% in intensive-care settings and from 0.3% to 15.4% in non-intensive-care settings. Factors leading to the spread of VRE in US hospitals include (1) antimicrobial pressure, (2) sub-optimal clinical laboratory recognition and reporting, (3) unrecognized "silent" carriage and prolonged fecal carriage, (4) environmental contamination and survival, (5) intrahospital and interhospital transfer of colonized patients, (6) introduction of unrecognized carriers from community settings such as nursing homes, and (7) inadequate compliance with hand washing and barrier precautions. Guidelines developed by the Centers for Disease Control and Prevention's Hospital Infection Control Practices Advisory Committee address each of these factors. The impact of these guidelines on the spread of VRE within individual institutions has been variable, and the overall impact of the guidelines nationally is unknown.  相似文献   

13.
The incidence of vancomycin resistance among enterococci, and Enterococcus faecium in particular, has increased sharply in the last few years. This shift toward infection with resistant Gram-positive organisms is thought to be the consequence of certain features specific to the intensive care setting: a high concentration of severely compromised patients; continued use of indwelling devices and invasive procedures; and widespread, empiric use of antimicrobial agents directed against Gram-negative bacilli. Measures that can be taken to prevent the development of bacterial resistance in the ICU include strict adherence to infection control policies and asepsis, and rational use of antibiotics. Current antimicrobial regimens for serious enterococcal infections consist of a combination of ampicillin, penicillin G, or vancomycin plus streptomycin or gentamicin. High levels of resistances among some enterococcal isolates, however, may render these strategies ineffective. A new agent, quinupristin/dalfopristin (RP 59500), has demonstrated encouraging in vitro activity against vancomycin-resistant E. faecium. Initial clinical reports, though limited, are similarly promising. Although phase III clinical trials with RP 59500 are not completed, the agent is available through an emergency-use program for patients with severe Gram-positive infections who cannot tolerate or do not respond to all other clinically appropriate antibiotics.  相似文献   

14.
The glycopeptide antibacterial drugs, vancomycin and teicoplanin, are widely used in hospitals for therapy of severe or multiresistant infection that has a positive results on Gram's stain test. Although vancomycin resistance is common in some hospital-acquired Enterococcus sp and resistance to teicoplanin occurs among Staphylococci sp glycopeptides remain the cornerstone of therapy for infection due to methicillin-resistant Staphylococcus aureus (MRSA), coagulase-negative Staphylococcus organisms, and infection related to implanted devices. Therapeutic drug monitoring (TDM) of these agents remains controversial, but advances in our understanding of their pharmacodynamics and further clinical studies are helping clarify the situation. In the future, a more rational approach to monitoring will probably result in less intensive monitoring of vancomycin but more intensive monitoring of teicoplanin.  相似文献   

15.
In 1994, Microbiology Laboratories of ten Portuguese hospitals analysed isolated microorganisms found in blood and urine samples and studied antimicrobial susceptibilities of the most frequent bacterial pathogens. From 63780 blood samples, the most frequent were Staphylococcus spp. and from 69189 urine samples significant numbers of Escherichia coli, Enterococcus spp., Pseudomonas aeruginosa and Candida spp. were isolated. Escherichia coli strains (c.7000) revealed a low percentage of resistance to antibiotics with the exceptions of ampicillin (48%) and co-trimoxazol (25%). Klebsiella pneumoniae isolates (c.2000) revealed important resistance to ampicillin (98%), cephalotin (31%), co-trimoxazol (38%) and gentamicin (28%), while values for 3rd generation cephalosporins varied among hospitals, with several strains showing phenotype of extended-spectrum beta-lactamase. A great variation in resistance values of P. aeruginosa (c.4000) was found in relation to the antibiotics as well as to the hospitals. Resistance to methicillin in S. aureus (c.6000) was high, reaching an average of 47%, and it was even higher with S. epidermidis (c.3000) and S. haemolyticus (c.650). Only vancomycin was always active against these strains. In E. faecalis (c.2500) resistance was of 2% to ampicillin, 35% to gentamicin, 45% to streptomycin and 1% to vancomycin. E. faecium isolates (c.300) showed the most worrying results with 70% resistance to ampicillin, 42% to gentamicin, 59% to streptomycin and 9% (30 strains isolated in 5 hospitals) to vancomycin. Vancomycin resistant strains were also resistant to all other antibiotics.  相似文献   

16.
A total of 200 medical center laboratories in the USA and Canada contributed results of testing quinupristin-dalfopristin, a streptogramin combination (formerly RP 59500 or Synercid), against 28,029 Gram-positive cocci. Standardized tests [disk diffusion, broth microdilution, Etest (AB BIODISK, Solna, Sweden)] were utilized and validated by concurrent quality control tests. Remarkable agreement was obtained between test method results for characterizing the collection by the important emerging resistances: 1) oxacillin resistance among Staphylococcus aureus (41.0 to 43.7%); 2) vancomycin resistance among Enterococcus faecium (50.0 to 52.0%); and 3) the penicillin nonsusceptible rate for pneumococci (31.1% overall, with 10.6% at MICs of > or = 2 micrograms/mL). The quinupristin-dalfopristin MIC90 for oxacillin-susceptible and -resistant S. aureus was 0.5 microgram/mL and 1 microgram/mL, respectively. The quinupristin-dalfopristin MIC90 for vancomycin-resistant E. faecium was 1 microgram/mL, and only 0.2% of isolates were resistant. Other Enterococcus species were generally not susceptible to the streptogramin combination but were usually inhibited by ampicillin (86 to 97% susceptible; MIC50, 1.0 microgram/mL) or vancomycin (86 to 95%; MIC50, 1.0 microgram/mL). Among all tested enterococci, the rate of vancomycin resistance was 16.2%. The quinupristin-dalfopristin MIC90 (0.75 microgram/mL) for 4,626 tested Streptococcus pneumoniae strains was not influenced by the penicillin or macrolide susceptibility patterns. When five regions in the USA and Canada were analyzed for significant streptogramin and other antimicrobial spectrum differences, only the Farwest region had lower numbers of streptogramin-susceptible E. faecium. Canadian strains were generally more susceptible to all drugs except chloramphenicol and doxycycline when tested against E. faecalis (73% and 89% susceptible, respectively). The U.S. Southeast region had S. pneumoniae strains less susceptible to macrolides (73%) but had more susceptibility among E. faecium isolates tested against vancomycin and ampicillin. The Northeast region of the USA had the greatest rate of vancomycin resistance among enterococci. Strains retested by the monitor because of quinupristin-dalfopristin resistance (MICs, > or = 4 micrograms/mL) were generally not confirmed (2.2% validation), and only 0.2% of E. faecium isolates were identified as truly resistant. The most common errors were: 1) species misidentification (28.0%); 2) incorrect susceptibility results (65.6%); and 3) mixed cultures (4.3%) tested by participants. Overall, quinupristin-dalfopristin was consistently active (> or = 90% susceptible) against major Gram-positive pathogens in North America, regardless of resistance patterns to other drug classes and geographic location of their isolation.  相似文献   

17.
The motile enterococci with the vanC gene have intrinsic low-level resistance to vancomycin, but have not been implicated in a nosocomial outbreak. We determined the colonization rate of motile enterococci in hospitalized and nonhospitalized patients. Perianal or stool specimens were cultured in Enterococcosel broth supplemented with 6 micrograms of vancomycin per mL. Rapid motility and pigment tests were performed on all enterococci isolated. A total of 82 motile and/or pigmented enterococci were isolated from 679 patients for a colonization rate of 12.1%. There were 43 Enterococcus gallinarum, 32 Enterococcus casseliflavus, 4 Enterococcus flavescens, and 3 Enterococcus mundtii identified. The E. gallinarum vancomycin MIC90 was 32 micrograms/mL and the E. casseliflavus vancomycin MIC90 was 8 micrograms/mL.  相似文献   

18.
We compared the abilities of Enterococcus faecium strains (three vancomycin-resistant enterococci [VRE] and five vancomycin-susceptible enterococci [VSE]) and Enterococcus faecalis strains (one VRE and 10 VSE) to survive under dry conditions. Bacterial suspensions of the strains were inoculated onto polyvinyl chloride and stored under defined conditions for up to 16 weeks. All strains survived for at least 1 week, and two strains survived for 4 months. A statistical model was used to distribute the 19 resulting survival curves between two types of survival curves. The type of survival curve was not associated with the species (E. faecalis versus E. faecium), the source of isolation (patient versus environment), or the susceptibility to vancomycin (VRE versus VSE). Resistance to dry conditions may promote the transmissibility of a strain, but VRE have no advantages over VSE with respect to their ability to survive under dry conditions.  相似文献   

19.
The success of managing the infectious complications of acute leukemia has permitted oncologists to develop new approaches to induction and high-dose therapy. The single most important risk factor for infection is the duration of absolute neutropenia. Historically, most attention was directed towards gram negative aerobes, especially Pseudomonas aeruginosa, but in recent years gram positive bacteria, generally considered to be less virulent, have become the most frequent isolates in most centers. A recent disturbing trend is the isolation of vancomycin-resistant enterococci. A recent controversy has been whether to use empirical vancomycin; the Centers for Disease Control has issued a formal recommendation discouraging empirical vancomycin in the febrile neutropenic patient. Empirical monotherapy has replaced combination therapy in many institutions except where there has been an increase in resistant isolates. In patients who remain profoundly neutropenic, fungal infections represent a serious source of secondary infection, especially species of Candida and Aspergillus. Recently lipid-based formulations of amphotericin B have offered reduced nephrotoxicity. Less toxic antifungals, the azoles, which include fluconazole and itraconazole, offer an attractive alternative to amphotericin B. New patterns of invasive mycoses have emerged, as for example hepatosplenic candidiasis, presenting new problems in diagnosis and therapy. The successful management of virus infections with herpes simplex, cytomegalovirus, varicella zoster, and Epstein Barr virus is based on early recognition and careful attention to prevention.  相似文献   

20.
Gram-negative rods (GNR) carrying the transferable carbapenem resistance gene blaIMP, including Pseudomonas aeruginosa and Serratia marcescens, have been isolated from more than 20 hospitals in Japan. Although the emergence of such multiple-drug-resistant bacteria is of utmost clinical concern, little information in regard to the distribution of blaIMP-positive GNR in hospitals and the clinical characteristics of infected patients is available. To address this, a system for the rapid detection of the blaIMP gene with a simple DNA preparation and by enzymatic detection of PCR products was developed. A total of 933 ceftazidime-resistant strains of GNR isolated between 1991 and 1996 at Nagasaki University Hospital, Nagasaki, Japan, were screened for the blaIMP gene; 80 isolates were positive, including 53 P. aeruginosa isolates, 13 other glucose-nonfermenting bacteria, 13 S. marcescens isolates, and 1 Citrobacter freundii isolate. Most of the patients from whom blaIMP-positive organisms were isolated had malignant diseases (53. 8%). The organisms caused urinary tract infections, pneumonia, or other infections in 46.3% of the patients, while they were just colonizing the other patients evaluated. It was possible that blaIMP-positive P. aeruginosa strains contributed to the death of four patients, while the other infections caused by GNR carrying blaIMP were not lethal. DNA fingerprinting analysis by pulsed-field gel electrophoresis suggested the cross transmission of strains within the hospital. The isolates were ceftazidime resistant and were frequently resistant to other antibiotics. Although no particular means of pathogenesis of blaIMP-positive GNR is evident at present, the rapid detection of such strains is necessary to help with infection control practices for the prevention of their dissemination and the transmission of the resistance gene to other pathogenic bacteria.  相似文献   

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