Comparison of routine glove use and contact-isolation precautions to prevent transmission of multidrug-resistant bacteria in a long-term care facility.

OBJECTIVES: To compare routine glove use by healthcare workers for all residents, without use of contact-isolation precautions, with contact-isolation precautions for the care of residents who had vancomycin-resistant enterococci or methicillin-resistant Staphylococcus aureus isolated from a clinical culture. DESIGN: Random allocation of two similar sections of the skilled-care unit to one of the infection-control strategies during an 18-month study period. SETTING: Skilled-care unit of a 667-bed acute- and long-term care facility. PARTICIPANTS: All residents present or admitted to the skilled-care unit from June 1, 1998, through December 7, 1999. MEASUREMENTS: Resident acquisition of four antimicrobial-resistant organisms (methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, or extended-spectrum beta-lactamase-producing Klebsiella pneumoniae or Escherichia coli). All isolates were strain typed. The facility level costs associated with each strategy were estimated. RESULTS: Resident acquisition of antimicrobial-resistant organisms was no different in the glove-use and isolation-precautions sections (31 episodes (1.5 per 1,000 resident-days) vs 38 episodes (1.6 per 1,000 resident-days)). Acquisition of either of two prevalent K. pneumoniae strains was more likely (P=.06) in residents in the isolation-precautions section. The estimated costs of contact-isolation precautions were 40% greater than those of routine glove use. CONCLUSION: There was a similar frequency of transmission of antimicrobial-resistant bacteria in the two study sections; there was evidence for resident-to-resident K. pneumoniae transmission in the isolation-precautions section. Routine glove use for healthcare workers, which decreases resident social isolation and healthcare facility costs, may be preferable in many long-term care facilities.

Multiparameter analysis of human oocytes at metaphase II stage after IVF failure in non-male infertility.

BACKGROUND: Using fluorescence imaging, an a posteriori multiparametric analysis was performed of human oocytes which failed to give pronucleated zygotes after IVF in cases of very low rates of fertilization or complete fertilization failure. METHODS: The analysis included: (i) the state of the maternal and paternal chromatin; (ii) quality of the metaphase II oocytes; and (iii) cortical granule (CG) distribution. RESULTS: Most oocytes were arrested in metaphase II, but they were abnormal in 50% of cases. The incidence of spindle and chromosome aberrations was strongly influenced by maternal age (69% for 40- to 45-year-old women versus 35% for 26- to 33-year-olds), and sperm chromatin was always condensed in immature oocytes, and fully decondensed only in normal metaphase II. The migration of CGs appeared to be associated with achievement of nuclear maturation at the time of puncture. CONCLUSIONS: These factors, when analysed on a complete set of oocytes from the same patient, provided information about potential causes of IVF failure, and also represented part of an 'oocyte quality evaluation' to select the assisted fertilization technique most suitable for each patient. For example, when the majority of oocytes were judged non-fertilizable at a first attempt, no pregnancy was registered at any subsequent attempt.

Impact of ring wearing on hand contamination and comparison of hand hygiene agents in a hospital.

We determined risk factors for hand contamination and compared the efficacy of 3 randomly allocated hand hygiene agents in a group of surgical intensive care unit nurses. We cultured samples of one of the subjects' hands before and samples of the other hand after hand hygiene was performed. Ring wearing was associated with 10-fold higher median skin organism counts; contamination with Staphylococcus aureus, gram-negative bacilli, or Candida species; and a stepwise increased risk of contamination with any transient organism as the number of rings worn increased (odds ratio [OR] for 1 ring worn, 2.6; OR for >1 ring worn, 4.6). Compared with use of plain soap and water, hand contamination with any transient organism was significantly less likely after use of an alcohol-based hand rub (OR, 0.3; 95% confidence interval [CI], 0.1-0.8) but not after use of a medicated hand wipe (OR, 0.9; 95% CI, 0.5-1.6). Ring wearing increased the frequency of hand contamination with potential nosocomial pathogens. Use of an alcohol-based hand rub resulted in significantly less frequent hand contamination.

Chromatin configuration and transcriptional control in human and mouse oocytes.

In vitro maturation of human oocytes at the germinal vesicle (GV) stage could offer an alternative in several cases of female infertility. It however rests on a better knowledge of the quality of human oocyte. Using fluorescence imaging of DNA and of the transcription sites, combined with electron microscopy, we show that human oocytes follow size-dependent changes in chromatin configuration, transcription sites distribution and nuclear ultrastructure that follow those observed in mouse GV oocytes. We thus analyzed in mouse GV oocytes the phosphorylation dependence of the transcriptional activity. We show by Western blot that, while active GV oocytes have approximately the same proportion of hypo- and hyperphosphorylated forms of the RNA polymerase II (RNAP II), the hyperphosphorylated form is almost absent from inactive oocytes. We also show that (1) RNAP II-dependent transcription is much less sensitive to various kinase inhibitors in mouse oocytes than in somatic cells or mouse one-cell embryos, although the phosphorylation equilibrium of RNAP II was largely shifted towards the hypo-phosphorylated form upon treatment with these inhibitors (2) RNAP I is completely insensitive to kinase inhibitors in GV oocytes.

Difference in the incidence of Clostridium difficile among patients infected with human immunodeficiency virus admitted to a public hospital and a private hospital.

OBJECTIVE: To compare the occurrence of Clostridium difficile among inpatients infected with human immunodeficiency virus (HIV) in two different hospitals. DESIGN: Prospective, observational study. SETTING: Specialized HIV inpatient units. PATIENTS: HIV-infected inpatients at Cook County Hospital (CCH) and Rush Presbyterian St. Luke's Medical Center (RPSLMC). INTERVENTIONS: A clinical and epidemiologic assessment of patient risk factors for C. difficile was performed. C. difficile isolates found on stool, rectal, and environmental cultures were typed by pulsed-field gel electrophoresis. RESULTS: Twenty-seven percent of patients admitted to CCH versus 4% of patients admitted to RPSLMC had positive cultures for C. difficile (P = .001). At CCH, 14.7% of environmental cultures were positive versus 2.9% at RPSLMC (P = .002). Risk factors for C. difficile acquisition included hospitalization at CCH, more severe HIV, use of acyclovir and H2-blockers, and longer hospital stay. Patients admitted to CCH were taking more antibiotics, had longer hospital stays, and more frequently had a history of C. difficile infection. During the study, two strains (CD1A and CD4) extensively contaminated the CCH environment. However, only CD1A caused an outbreak. CONCLUSIONS: The C. difficile acquisition rate at CCH was sevenfold higher than that at RPSLMC, and CCH had a more contaminated environment. Differences in patient acquisition rates likely reflect a greater prevalence of traditional C. difficile risk factors and a concurrent outbreak at CCH. Although two strains heavily contaminated the environment at CCH, only one caused an outbreak, suggesting that factors other than the environment are important in initiating C. difficile outbreaks.

Possible overestimation of penicillin resistant Streptococcus pneumoniae colonization rates due to misidentification of oropharyngeal streptococci.

Standard identification of Streptococcus pneumoniae by optochin and bile solubility testing can lead to ambiguous results for certain isolates. Newer bacteriologic identification techniques (e.g., DNA probes) now exist. In a prospective point prevalence study of oropharyngeal S. pneumoniae carriage rates among outpatients, we compared standard organism identification techniques to DNA probe testing. By standard identification criteria, 35 (4%) of 872 isolates were characterized as presumptive S. pneumoniae. Thirty of 35 presumptive isolates were recoverable for DNA probing; 9 (30%) presumptive isolates were confirmed using a DNA probe. The antimicrobial susceptibility pattern of these DNA probe positive isolates closely paralleled that of clinical blood isolates of S. pneumoniae obtained during the study period. The 21 (70%) DNA probe negative isolates, which may represent phylogenetically related species (such as S. mitis or S. oralis), had significantly reduced antimicrobial susceptibility patterns when compared with the DNA probe positive isolates. In colonization studies, if classic criteria (optochin disc zone and bile solubility) are the sole means of identification, S. pneumoniae penicillin resistance rates may be over-reported.