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Y Carmeli

Publications and source records attributed to Y Carmeli.

At least 19 recordsLinked to original sources
PubMed2006

Influx of extended-spectrum beta-lactamase-producing enterobacteriaceae into the hospital.

BACKGROUND: The prevalence of infections caused by extended-spectrum beta -lactamase (ESBL)-producing Enterobacteriaceae is increasing worldwide. The influx of these bacteria into hospitals has major implications for infection-control and empirical treatment strategies. METHODS: Isolates from 2 patient cohorts--patients with gram-negative bacteremia within 2 days after admission and patients screened for fecal colonization at admission--were assessed for ESBL production. ESBL phenotype was confirmed according to Clinical and Laboratory Standards Institute guidelines. Predictors of ESBL phenotype were examined by univariate and multivariate analyses. RESULTS: Of 80 Enterobacteriaceae isolates from blood samples obtained at admission to the hospital, 13.7% produced ESBL. Thirty-eight patients with ESBL-positive isolates and 72 with ESBL-negative isolates were included in a case-control study. Predictors of ESBL production were male sex and nursing home residence (area under receiver operator characteristic curve, 0.7). Of 241 persons screened at admission, 26 (10.8%) had fecal carriage of ESBL-producing Enterobacteriaceae. Predictors of fecal carriage were poor functional status, antibiotic use, chronic renal insufficiency, liver disease, and use of histamine2 blockers (area under receiver operator characteristic curve, 0.8). Four (15.4%) of the 26 individuals with fecal carriage had subsequent bacteremia with ceftazidime-resistant Enterobacteriaceae, compared with 1 (0.5%) noncarrier (odds ratio, 38.9; P<.001). Of 80 ESBL-producing Enterobacteriaceae isolates obtained at admission, 65 were health care associated, and 15 were community acquired. The 15 community-acquired ESBL-producing Enterobacteriaceae belonged to diverse clones. The most prevalent ESBL gene among these isolates was CTX-M-2 (found in 53.3% of the isolates). CONCLUSIONS: We report high rates of bacteremia and colonization with ESBL-producing Enterobacteriaceae at admission to our institution, which may undermine infection-control measures and complicate the selection of empirical treatment.

Aged↗
PubMed2006

Prevalence and genetic relatedness of community-acquired methicillin-resistant Staphylococcus aureus in Israel.

The aims of the study presented here were to determine the prevalence of Staphylococcus aureus carriage and, specifically, community-acquired methicillin-resistant S. aureus (CA-MRSA) carriage in children and their parents in Israel and to determine the genetic relatedness of these isolates. S. aureus was isolated from 580 of 3,373 (17.2%) individuals screened. The predominant type identified by pulsed-field gel electrophoresis was strain ST45-MSSA (25%). Five MRSA isolates were detected, and two of these were classified as CA-MRSA, based on the following criteria: no previous contact with a healthcare facility, absence of a multidrug-resistant (MDR) phenotype, and presence of SCCmec type IV. Isolates were negative for pvl and were classified as ST-45-MRSA. Although CA-MRSA is still rare in Israel, the genetic relatedness of the strains found in this study to a successful MSSA clone warrants close follow up.

Adolescent↗
PubMed2005

Unexpected hospital-acquired bacteraemia in patients at low risk of bloodstream infection: the role of a heparin drip.

Following a cluster of cases of unexpected hospital-acquired bacteraemia suspected to be related to an intravenous (iv) heparin drip, all cases of hospital-acquired primary bloodstream infection (BSI) in patients at low risk of bacteraemia were analysed over a four-year period. Ninety-six bacteraemic patients (6%) from 1618 episodes of hospital-acquired bacteraemia had a peripheral iv line as the only risk factor. These patients were divided into two groups: 60 patients with phlebitis and 36 without local signs of inflammation. Baseline features of the two groups were comparable, but in univariate and multivariate analysis, a significant association was found between iv heparin use, predominance of Gram-negative organisms (especially Klebsiella, Serratia and Enterobacter species), and absence of phlebitis. In spite of clear statistical association, however, the means by which the heparin solution became contaminated with Gram-negative organisms remained unknown. Following implementation of infection control methods concerning heparin handling, no more cases occurred. Unexpected hospital-acquired Gram-negative bacteraemia in patients with peripheral iv lines should prompt investigation of potential infusate-related infection, especially in patients without phlebitis and those receiving iv heparin.

Aged↗
PubMed2005

Acinetobacter baumannii: emergence and spread in Israeli hospitals 1997-2002.

The incidence of multi-drug-resistant Acinetobacter baumannii bloodstream infections (BSIs) increased two- to four-fold in three Israeli hospitals between 1997 and 2002, accounting for 3.5-18% of all hospital-acquired BSIs. This was associated with increasing carbapenem resistance reaching 35-54%, and by a dramatic increase in carbapenem consumption. In-hospital fatality rates ranged between 47% and 58% and were significantly higher than those seen with other nosocomial Gram-negative pathogens. A. baumannii was not restricted to intensive care units, but had spread to all hospital wards. Multi-drug-resistant A. baumannii has the potential to reach endemicity in hospitals and warrants more vigorous and innovative efforts to limit its spread.

Acinetobacter Infections↗
PubMed2005

Erroneous reporting of coagulase-negative Staphylococci as Kocuria spp. by the Vitek 2 system.

Misidentification of coagulase-negative staphylococci (CoNS) may delay appropriate treatment. We investigated 20 clinical isolates identified as Kocuria spp. by the Vitek 2 system. All were identified as CoNS by 16S rRNA gene sequencing (18 Staphylococcus epidermidis, 1 Staphylococcus haemolyticus). Four Kocuria isolates were shown to be identical to CoNS from the same patient by pulsed-field gel electrophoresis. Isolates identified by Vitek 2 as Kocuria most likely represent misidentified CoNS, and if clinically indicated, should be investigated further by genomic methods.

Bacteriological Techniques↗
PubMed2004

Protocol for the accelerated detection of extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella pneumoniae strains from blood cultures.

The study presented here was performed to evaluate an accelerated protocol for the early detection of organisms producing extended-spectrum beta-lactamase (ESBL). The procedure involved testing isolates directly from positive blood-culture bottles, and a total of 40 clinical isolates (10 ESBL-producing and 10 non-ESBL-producing isolates of both Escherichia coli and Klebsiella pneumoniae) were used. The isolates were inoculated into blood cultures bottles and, upon growth signal, fluid from the bottle was cultured directly onto plates with combination discs containing cefotaxime or ceftazidime with and without clavulanate. Results were compared with those of standard methods for the detection of ESBL. High concordance between the two methods was found, and the direct test showed high sensitivity (95%) and specificity (100%). Use of this accelerated protocol may speed detection of the ESBL phenotype and thereby facilitate the early administration of appropriate antimicrobial therapy.

Bacteriological Techniques↗
PubMed2001

Parallel analysis of individual and aggregated data on antibiotic exposure and resistance in gram-negative bacilli.

To evaluate the potential bias of analyzing aggregated data, we separately examined antibiotic exposure and resistance data for 35,423 patients admitted to a university hospital in Utah, from both an individual-patient perspective and group-level perspective. From 1994 through 1998, use of defined daily doses (per 1000 patient-days) of fluoroquinolones, third-generation cephalosporins, ampicillin-sulbactam, and imipenem increased by 82%, 38%, and 99%, and decreased by 38%, respectively, whereas group-level resistance rates of Enterobacteriaceae or Pseudomonas species changed only minimally. However, in individual-patient-level analyses performed by multivariable proportional hazards regression, exposure to a fluoroquinolone, third-generation cephalosporin, ampicillin-sulbactam, or imipenem was a strong risk factor for resistance to fluoroquinolones (adjusted hazard ratio [AHR], 4.0; P<.001), third-generation cephalosporins (AHR, 3.5; P<.001), ampicillin-sulbactam (AHR, 2.3; P=.008), or imipenem (AHR, 5.7; P<.001), respectively. Thus, group-level and individual-patient-level analyses of antibiotic-use-versus-susceptibility relations yielded divergent results. Multicenter studies should include individual-patient-level data to elucidate more fully the relation between antibiotic exposure and resistance.

Ampicillin↗
PubMed2001

Methodological principles of case-control studies that analyzed risk factors for antibiotic resistance: a systematic review.

Case-control studies that analyze the risk factors for antibiotic-resistant organisms have varied epidemiological methodologies, which may lead to biased estimates of antibiotic risk factors. A systematic review of case-control studies that analyzed risk factors for antibiotic-resistant organisms addressed 3 methodological principles: method of control group selection, adjustment for time at risk, and adjustment for comorbid illness. A total of 406 abstracts were reviewed. Thirty-seven studies met the inclusion and exclusion criteria and were reviewed and evaluated for the 3 methodological principles. Thirteen (35%) of 37 studies chose the preferred control group. Eleven adjusted for time at risk. Twenty-seven adjusted for comorbid illness. Future studies need to consider more closely the optimization of control group selection, adjusting for confounding caused by time at risk, and adjusting for confounding caused by comorbid illness.

Case-Control Studies↗
PubMed2001

Antibiotic prophylaxis and the risk of Clostridium difficile-associated diarrhoea.

To test the hypothesis that extended antibiotic prophylaxis increases the risk of Clostridium difficile -associated diarrhoea (CDAD), we conducted a retrospective cohort study of 2641 patients under-going cardiovascular surgery. Main outcome measures were the duration of prophylaxis (< 48 h vs. > 48 h) and the occurrence of CDAD. CDAD occurred in 31 patients (1.2%), who were significantly older (70 +/- 9 y vs. 66 +/- 10 y; P = 0.03), received more therapeutic antibiotics (2.2 +/- 1.9 vs. 0.4 +/- 0.9; P = 0.001) and had a longer postoperative hospital stay (26 +/- 19 d vs. 9 +/- 8 d; P < 0.001) than non-cases. After adjusting for confounding, we did not observe an association between prolonged prophylaxis and CDAD [adjusted odds ratio (AOR), 0.8; CI, 0.4-1.8]. In contrast, three independent predictors were identified: increasing length of hospital stay (AOR per one-day-increment, 1.03; CI, 1.01-1.05), and treatment with third generation cephalosporins (AOR, 5.9; CI, 2.2-16.0) or beta-lactam-beta-lactamase inhibitor combinations (AOR, 4.6; CI, 1.7-12.3). Our results did not confirm that extended prophylaxis after clean surgery increases the risk of CDAD, which remains an uncommon postoperative complication, associated even with short antibiotic exposure.

Age Distribution↗
PubMed2001

Clinical isolation and resistance patterns of and superinfection with 10 nosocomial pathogens after treatment with ceftriaxone versus ampicillin-sulbactam.

Isolation of pathogens from clinical cultures and their resistance patterns may be altered by antecedent antibiotic treatment. The objective of this study was to assess the influence of treatment with ceftriaxone versus that with ampicillin-sulbactam on recovery and superinfections with 10 nosocomial pathogens. The study was designed as a historical cohort study, using a propensity score to adjust for confounding by indication and multivariate survival analyses to adjust for other confounding. Two thousand four hundred forty-five patients were treated with ampicillin-sulbactam, and 1, 308 were treated with ceftriaxone. The study analyzed two outcomes: (i) recovery of pathogens from clinical cultures and (ii) microbiologically documented infections. Data were obtained from administrative, pharmacy, clinical, and laboratory databases and by chart extraction. Following treatment, new isolation of at least 1 of the 10 target pathogens occurred for 244 patients. After adjustment, more infections occurred in the ampicillin-sulbactam group (hazard ratio [HR], 1.55; P = 0.009). This was observed with all gram-negative rods combined (HR, 3.6; P < 0.001) and with each genus of the family Enterobacteriaceae. No differences in isolation of gram-positive bacteria were evident (P = 0.33). Microbiologically documented superinfections occurred in 172 patients and were less frequent in the ceftriaxone group (3.8% versus 5%; HR, 1.6; P = 0. 015). All the Escherichia coli and Klebsiella spp. isolates were susceptible to ceftriaxone, but half were resistant to ampicillin-sulbactam. The prevalence of oxacillin resistance among Staphylococcus aureus isolates was higher in the ceftriaxone group (63% versus 31%; odds ratio, 3.8; P = 0.08). Differences in the rates of superinfections and the likely causative organisms following treatment with ceftriaxone or ampicillin-sulbactam were evident. This may guide clinicians in empirical choices of antibiotics to treat superinfection.

Aged↗
PubMed2001

Risk factors for emergence of resistance to broad-spectrum cephalosporins among Enterobacter spp.

Among 477 patients with susceptible Enterobacter spp., 49 subsequently harbored third-generation cephalosporin-resistant Enterobacter spp. Broad-spectrum cephalosporins were independent risk factors for resistance (relative risk [OR] = 2.3, P = 0.01); quinolone therapy was protective (OR = 0.4, P = 0.03). There were trends toward decreased risk for resistance among patients receiving broad-spectrum cephalosporins and either aminoglycosides or imipenem. Of the patients receiving broad-spectrum cephalosporins, 19% developed resistance.

Bacteremia↗
PubMed2000

Prolonged antibiotic prophylaxis after cardiovascular surgery and its effect on surgical site infections and antimicrobial resistance.

BACKGROUND: Despite evidence supporting short antibiotic prophylaxis (ABP), it is still common practice to continue ABP for more than 48 hours after coronary artery bypass graft (CABG) surgery. METHODS AND RESULTS: To compare the effect of short (<48 hours) versus prolonged (>48 hours) ABP on surgical site infections (SSIs) and acquired antimicrobial resistance, we conducted an observational 4-year cohort study at a tertiary-care center. An experienced infection control nurse performed prospective surveillance of 2641 patients undergoing CABG surgery. The main exposure was the duration of ABP, and main outcomes were the adjusted rate of SSI and the isolation of cephalosporin-resistant enterobacteriaceae and vancomycin-resistant enterococci (acquired antibiotic resistance). Adjustment for confounding was performed by multivariable modeling. A total of 231 SSIs (8.7%) occurred after a median of 16 days, including 93 chest-wound infections (3.5%) and 13 deep-organ-space infections (0. 5%). After 1502 procedures using short ABP, 131 SSIs were recorded, compared with 100 SSIs after 1139 operations with prolonged ABP (crude OR, 1.0; CI, 0.8 to 1.3). After adjustment for possible confounding, prolonged ABP was not associated with a decreased risk of SSI (adjusted OR, 1.2; CI, 0.8 to 1.6) and was correlated with an increased risk of acquired antibiotic resistance (adjusted OR, 1.6; CI, 1.1 to 2.6). CONCLUSIONS: Our findings confirm that continuing ABP beyond 48 hours after CABG surgery is still widespread; however, this practice is ineffective in reducing SSI, increases antimicrobial resistance, and should therefore be avoided.

Adult↗
PubMed2000

A survey on handwashing practices and opinions of healthcare workers.

Studies have consistently demonstrated rates of handwashing compliance are less than 50%. The objective of this study was to gain the following information about handwashing: self-reported compliance; attitudes towards handwashing in different patient settings; and attitudes towards interventions aimed at increasing compliance. A 74-question survey was administered to healthcare workers in two tertiary care hospitals. One hundred and ninety nine healthcare workers completed the survey and 89% reported that handwashing is an important means of preventing infection. Sixty-four percent believed that they washed their hands as often as their peers and 2% believed that they washed less often than their peers. Patients with diarrhoea, AIDS or patients on antibiotics led to increased handwashing. Relative to potential interventions, 76% reported that rewards for handwashing would have no effect, 73% reported that punishment would have no effect and 80% reported that easy access to sinks and availability of washing facilities would lead to increased compliance. This survey suggests that healthcare workers understand the importance of handwashing, but tend to overestimate their own compliance. Healthcare workers are not in favour of interventions involving rewards and punishments, but are more attracted to interventions that make handwashing easier.

Attitude of Health Personnel↗
PubMed2000

Clinical implications of stenotrophomonas maltophilia resistant to trimethoprim-sulfamethoxazole: a study of 69 patients at 2 university hospitals.

We conducted a retrospective case study at 2 tertiary care centers to determine the clinical implications of trimethoprim-sulfamethoxazole resistant Stenotrophomonas maltophilia (TSRSM). Of 69 reviewed cases (mean age, 57 y; male gender, 70%), 40 (58%) were classified as infections associated with TSRSM (respiratory tract, 14; soft tissue, 11; bloodstream, 8; other sites, 7). Severe underlying comorbidities (86%) and previous antibiotic exposure (99%) were common. Cefotetan (susceptibility, 55%), chloramphenicol (49%) and ticarcillin-clavulanate (45%) showed the highest in vitro activity against TSRSM, but were seldom used for therapy (7%). Among the 40 infected cases, 8 developed sepsis disorders and 8 died. Only 1 death could be directly attributed to autopsy-proven TSRSM infection (pneumonia). McCabe score (p = 0.03) and organ dysfunction (p = 0.006) were associated with an increased risk of death in infected patients; exposure to appropriate therapy tended to be protective against death (p = 0.08). 22 infected patients were treated medically; an additional procedure was necessary to clear the infection in 18 cases (surgery, 13; catheter removal, 5). Isolation precautions were rarely exercised, even in the presence of panresistant isolates. In summary, TSRSM-related infections occurred in severely ill patients with extensive exposure to the health-care system, and often required invasive procedures for cure. Infections were directly associated with severe morbidity, and tended to have an indirect rather than a direct impact on mortality.

Anti-Bacterial Agents↗