Effectiveness of gloves in the prevention of hand carriage of vancomycin-resistant enterococcus species by health care workers after patient care.

Gloving reduces acquisition of vancomycin-resistant Enterococcus species (VRE) on the hands, and it should be considered for routine inpatient care, even for contact with the intact skin of patients who may be colonized with VRE. However, gloving does not completely prevent contamination of the hands, and hand washing is necessary after glove removal.

Randomized, blinded, placebo-controlled trial of tissue factor pathway inhibitor in porcine septic shock.

This study tested the hypothesis that tissue factor pathway inhibitor (TFPI) would improve mortality and morbidity evoked by peritonitis-induced bacteremia in pigs. Secondarily, it sought to determine if TFPI treatment would attenuate cardiodynamic abnormalities produced by this septic model. 32 pigs were chronically instrumented with intracardiac transducers to measure left ventricular pressure and diameter, pulmonary and aortic pressures, and cardiac output. At least 5 days after surgery to implant transducers, basal cardiovascular readings and blood samples were obtained. Using a randomized, blinded study design, either purified, reconstituted TFPI (1 mg/kg bolus, 10 mg/kg/min for 48 h), placebo (arginine buffer), or saline was administered to pigs immediately after Escherichia coli 0111.B4 (3.0-11 x 10(9) colony-forming U/kg)-laden fibrin clots were implanted intraperitoneally, producing peritonitis and bacteremia. Pigs did not receive antibiotics or supportive therapy. No significant differences in primary or secondary endpoints were noted between the arginine and saline groups, so these data were combined into a control group (N = 20). 5 of 12 TFPI pigs survived (42%), while 5 of 20 control pigs survived (25%); this difference was not significant (p = .714, Fisher's exact test). TFPI treatment augmented cardiac output in surviving pigs, but did not affect any other cardiovascular performance variable (heart rate, % diameter shortening, or systemic and pulmonary vascular resistance). In controls, peritonitis induced rapid increase in plasma tumor necrosis factor-alpha (428 +/- 771 to 5,933 +/- 559 pg/mL at 2 h) and interleukin-8 (180 +/- 153 to 1,393 +/- 145 pg/mL at 2 h). TFPI treatment significantly attenuated cytokine responses to sepsis, reducing peak tumor necrosis factor-alpha to 2,103 +/- 813 pg/mL and reducing peak interleukin-8 levels to 534 +/- 211 pg/mL at 2 h (p < .05, Tukey test, two-way ANOVA). In conclusion, TFPI treatment attenuated important mediator components of the inflammatory response but did not provide significant survival benefit.

Skin colonization with vancomycin-resistant enterococci among hospitalized patients with bacteremia.

To assess the prevalence of skin and rectal colonization by vancomycin-resistant enterococci (VRE) in hospitalized bacteremic patients and to determine the relation between colonization and bacteremia, we compared 14 case patients who had bacteremia due to VRE with 30 control patients who had bacteremia due to other pathogens. Rectal colonization and skin (inguinal area and/or antecubital fossa) colonization with VRE were common among both case patients (100% had rectal colonization, and 86% had skin colonization) and control patients (37% had rectal colonization and 23% had skin colonization). Among patients with rectal colonization, skin colonization was more common when diarrhea or fecal incontinence was present. The bloodstream cleared without appropriate antimicrobial therapy in nine of the 14 patients with bacteremia due to VRE. The high prevalence of skin colonization with VRE may increase the risk of catheter-related sepsis, cross-infection, or blood culture contamination (which may explain the frequent spontaneous resolution of bacteremia due to VRE).

A porcine model of peritonitis and bacteremia simulates human septic shock.

Cardiovascular responses to systemic bacteremia were evaluated in a pre-instrumented, conscious pigs. Basal observations were obtained 5-7 days after instrumentation. On the next day, Escherichia coli 0111.B4 (1.1 to 33 x 10(9) CFU/kg)-laden fibrin clots were implanted intraperitoneally. Nonsurvivors (9/18) demonstrated rapid cardiovascular decompensation. Survivors (9/18) demonstrated significant cardiovascular injury, which was reversed by 5-7 days postimplant. Cardiac inotropicity was significantly reduced in this period, but recovered by day 7. Circulating myocardial depressant substance activity (assayed by serum-induced depression of beating neonatal rat myocytes) was present on days 1-4 of bacteremia and recovered to basal values on day 6. No clinical or cardiovascular changes were seen in pigs implanted with sterile clots (n = 4). These data demonstrate that implantation of bacteria-laden fibrin clots in pigs induces cardiovascular alterations that mimic responses seen in human sepsis.

Epidemiology of colonisation of patients and environment with vancomycin-resistant enterococci.

BACKGROUND: Vancomycin-resistant enterococci (VRE) have emerged as nosocomial pathogens during the past 5 years, but little is known about the epidemiology of VRE. We investigated colonisation of patients and environmental contamination with VRE in an endemic setting to assess the importance of different sources of colonisation. METHODS: Between April 12, and May 29, 1995, cultures from body sites (rectum, groin, arm, oropharynx, trachea, and stomach) and from environmental surfaces (bedrails, drawsheet, blood-pressure cuff, urine containers, and enteral feed) were obtained daily from all newly admitted ventilated patients in our medical intensive-care unit (MICU). Rectal cultures were obtained from all non-ventilated patients in the MICU. Strain types of VRE were determined by pulsed-field gel electrophoresis. FINDINGS: There were 97 admissions of 92 patients, of whom 38 required mechanical ventilation. Colonisation with VRE on admission was more common in ventilated than in non-ventilated patients (nine [24%] vs three [6%], p < 0.05). Of the nine ventilated patients colonised with VRE on admission, one acquired a new strain of VRE in the MICU. Of the 29 ventilated patients who were not colonised with VRE on admission, 12 (41%) acquired VRE in the MICU. The median time to acquisition of VRE was 5 days (interquartile range 3-8). Of the 13 ventilated patients who acquired VRE, 11 (85%) were colonised with VRE by cross-colonisation. VRE were isolated from 157 (12%) of 1294 environmental cultures. The rooms of 13 patients were contaminated with VRE, but only three (23%) of these patients subsequently acquired colonisation with VRE. Pulsed-field gel electrophoresis of 262 isolates showed 20 unique strain types of VRE. INTERPRETATION: Frequent colonisation with VRE on MICU admission and subsequent cross-colonisation are important factors in the endemic spread of VRE. Persistent VRE colonisation in the gastrointestinal tract and on the skin, the presence of multiple-strain types of VRE, and environmental contamination may all contribute to the spread of VRE.

Rapid preparation of bacterial DNA for pulsed-field gel electrophoresis.

A disadvantage of genotyping bacterial strains by pulsed-field gel electrophoresis is that the procedure requires up to 6 days to complete. We modified a standard pulsed-field gel electrophoresis method (B.E. Murray, K.V. Singh, J.D. Health, B.R. Sharma, and G.M. Weinstock, J.Clin. Microbiol. 28:2059-2063, 1990) so that it could be completed in less than 3 days. We successfully applied this method to the analysis of a variety of gram-positive and gram-negative bacteria.

A comparison of the effect of universal use of gloves and gowns with that of glove use alone on acquisition of vancomycin-resistant enterococci in a medical intensive care unit.

OBJECTIVE: To determine the efficacy of the use of gloves and gowns compared with that of the use of gloves alone for the prevention of nosocomial transmission of vancomycin-resistant enterococci. DESIGN: Epidemiologic study and controlled, nonrandomized clinical trial. SETTING: University-affiliated, 900-bed, urban teaching hospital in which vancomycin-resistant enterococci are endemic. PATIENTS: 181 consecutive patients admitted to the medical intensive care unit for 48 hours or more. INTERVENTION: It was determined that all hospital employees would always use gloves and gowns when attending 8 particular beds in the medical intensive care unit and would always use gloves alone when attending 8 others. Compliance with precautions was monitored weekly. Rectal surveillance cultures were taken from patients daily. Cultures of environmental surfaces, such as those of bed rails, bedside tables, and other frequently touched objects in patient rooms and common areas, were taken monthly. Pulsed-field gel electrophoresis was used for molecular epidemiologic typing of vancomycin-resistant enterococci. MEASUREMENTS: The number of patients becoming colonized by vancomycin-resistant enterococci; the number of days to acquisition of vancomycin-resistant enterococci; and other measurements, including nosocomial infections, length of hospital stay, and mortality rates. RESULTS: The 93 patients in glove-and-gown rooms and the 88 patients in glove-only rooms had similar demographic and clinical characteristics. Fifteen (16.1%) patients in the glove-and-gown group and 13 (14.8%) in the glove-only group had vancomycin-resistant enterococci on admission to the medical intensive care unit. Twenty-four (25.8%) patients in the glove-and-gown group and 21 (23.9%) in the glove-only group acquired vancomycin-resistant enterococci in the medical intensive care unit. The mean times to colonization among the patients who became colonized were 8.0 days in the glove-and-gown group and 7.1 days in the glove-only group. None of these comparisons were statistically significant. Risk factors for acquisition of vancomycin-resistant enterococci induced length of stay in the medical intensive care unit, use of enteral feeding, and use of sucralfate. Compliance with precautions was 79% in glove-and-gown rooms and 62% in glove-only rooms (P < 0.001). Only 25 of 397 (6.3%) environmental cultures were positive for vancomycin-resistant enterococci. Nineteen types of vancomycin-resistant enterococci were documented by pulsed-field gel electrophoresis during the study period. CONCLUSIONS: Universal use of gloves and gowns was no better than universal use of gloves only in preventing rectal colonization by vancomycin-resistant enterococci in a medical intensive care unit of a hospital in which vancomycin-resistant enterococci are endemic. Because the use of gowns and gloves together may be associated with better compliance and may help prevent transmission of other infectious agents, this finding may not be applicable to outbreaks caused by single strains or hospitals in which the prevalence of vancomycin-resistant enterococci is low.

Ceftazidime-resistant Klebsiella pneumoniae and Escherichia coli bloodstream infection: a case-control and molecular epidemiologic investigation.

In a molecular, microbiologic, and case-control study to describe the epidemiology of ceftazidime-resistant Klebsiella pneumoniae and Escherichia coli bloodstream infection, 32 unique isolates were recovered over 31 months from the blood of patients hospitalized in a 900-bed hospital in Chicago. Multivariate analysis revealed cases occurred more frequently in debilitated nursing home patients with central venous catheters than in younger, healthier patients. Mortality rates were similar for cases and controls. Case-patients were less likely to die if they received appropriate antibiotic treatment within 3 days of bacteremia onset (P = .02). Pulsed-field gel electrophoresis analysis indicated a polyclonal outbreak, with strain-specific temporal and geographic clustering. Isoelectric focusing results suggested that a predominant enzyme, TEM-10, was responsible for the ceftazidime resistance. The resistance gene was usually carried on a large conjugative plasmid. The polyclonality of the resistant strains suggests that ceftazidime resistance due to TEM-10 is now endemic in Chicago.

Comparison of the in vitro activity of levofloxacin and other antimicrobial agents against vancomycin-susceptible and vancomycin-resistant Enterococcus species.

The in vitro activities of levofloxacin and other antibiotics against 133 clinical isolates of vancomycin-resistant and vancomycin-susceptible enterococci were evaluated. Only 14 (39%) of the vancomycin-susceptible isolates and 11 (11%) of the vancomycin-resistant isolates were susceptible to levofloxacin. Levofloxacin exhibited a marked inoculum effect for all enterococci tested. These results suggest that levofloxacin may be of limited use in the treatment of serious enterococcal infections.