Spread of a single multiresistant methicillin-resistant Staphylococcus aureus clone carrying a variant of staphylococcal cassette chromosome mec type III isolated in a university hospital.

The purpose of the study was the molecular characterization of methicillin-resistant Staphylococcus aureus (MRSA) isolates cultured from patients treated in seven wards of a university hospital in Lublin, Poland, over a 14-month period. Eleven nosocomial MRSA isolates were analyzed. Phenotypic identification of the isolates as MRSA was confirmed by the detection of the nuc and mecA genes using a multiplex PCR assay. The MRSA isolates were further characterized by pulsed-field gel electrophoresis, 16S-23S rRNA spacer length polymorphism analysis, and the simplex and multiplex SCCmec PCR assays. The MRSA isolates were found to be multiresistant: in addition to resistance to beta-lactam agents, they demonstrated resistance to ciprofloxacin, tetracycline, erythromycin, and gentamicin. The MRSA isolates were genetically identical and shared common pulsed-field gel electrophoresis profiles and 16S-23S rRNA spacer length polymorphism profiles. The PCR-based method revealed that the profile of the Lublin clone was identical to that of the Brazilian pandemic MRSA isolates. By SCCmec typing, all MRSA isolates harbored the C variant of the SCCmec type III that differed from the typical SCCmec type III pattern by the lack of locus F (414 bp). The results of this study indicate the spread of a single, multiresistant, MRSA clone in various wards of a university hospital over a 14-month period. The SCCmec structure harbored by the Lublin clone has previously been identified among Polish MRSA isolates representing the HoMRSA-Pol1 clone. The data from this study indicate that the Lublin MRSA clone is most probably genetically related to the HoMRSA-Pol1 clone. Moreover, this latter clone belongs to ST239, the same sequence type as the Hungarian and Brazilian pandemic MRSA isolates.

In vitro protein binding studies with BMS-204352: lack of protein binding displacement interaction in human serum.

BMS-204352, a maxi-K channel opener, is currently under development for the treatment of stroke. Protein binding of BMS-204352 was determined in sera from several species, namely, rat, monkey, dog, and human. Data indicated that the compound was shown to be highly protein bound in serum from all species (ca. 99.6%). In order to test for the potential for drug-drug interactions and competitive displacement of BMS-204352 by diazepam, phenytoin, propranolol, and warfarin, in vitro experiments were performed using spiked human serum and ex vivo human plasma samples. Protein binding was determined using equilibrium dialysis for 4 h at maximal therapeutic concentrations for each drug alone or in appropriate combination in spiked serum samples. Ex vivo samples from a clinical BMS-204352 study (0, 1, and 24 h) were dialyzed separately after addition of diazepam, phenytoin, propranolol, or warfarin. Drug content in biological matrices was measured for radioactivity using liquid scintillation counting. Results indicated that (1) addition of diazepam, phenytoin, propranolol, or warfarin did not alter the free fraction of BMS-204352; (2) BMS-204352 did not displace diazepam, phenytoin, propranolol, or warfarin from their protein binding sites, and (3) comparison of ex vivo plasma samples after BMS-204352 dosing indicated no impact of BMS-204352 and/or its metabolites on the free fraction of diazepam, phenytoin, propranolol, or warfarin. In conclusion, the potential for a drug-drug interaction due to alterations in protein binding with BMS-204352 is unlikely.

Selection and implementation for coagulation instruments/reagents in a multiple hospital/clinic network.

Selection, standardization, and implementation of instrumentation and reagents throughout a health care facility network can often be a difficult process. However, in today's ever-changing health care setting, it is often mandated. The Veteran's Integrated Systems Network 16 (VISN 16) was faced with such a task early in 1999, with the targeted area being its coagulation laboratories. The plan outlined in this paper was drafted to help facilitate the selection, standardization and implementation of coagulation systems for 17 health care facilities that make up the VISN 16 network. The VISN, encompassing 170,000 square miles, has 10 tertiary care hospitals, six of which have close relationships with affiliate universities. There are 299,733 patients enrolled in this health delivery system. The facilities range from large institutions performing both tertiary and outpatient care to small outpatient clinics. Because of the plan's detailed, comprehensive content, which included analyses of a large number of performance parameters as well as cost-efficiency, the selection process was carried out using a checklist that could be helpful to other organizations selecting equipment and reagents for coagulation studies. An implementation process was devised, resulting in coagulation standardization across the Integrated Health Network.

Male pesticide exposure and pregnancy outcome.

Potential health effects of agricultural pesticide use include reproductive outcomes. For the Ontario Farm Family Health Study, the authors sampled Ontario farms from the 1986 Canadian Census of Agriculture, identified farm couples, and obtained questionnaire data concerning farm activities, reproductive health experience, and chemical applications. Male farm activities in the period from 3 months before conception through the month of conception were evaluated in relation to miscarriage, preterm delivery, and small-for-gestational-age births. Among the 1,898 couples with complete data (64% response), 3,984 eligible pregnancies were identified. Miscarriage was not associated with chemical activities overall but was increased in combination with reported use of thiocarbamates, carbaryl, and unclassified pesticides on the farm. Preterm delivery was also not strongly associated with farm chemical activities overall, except for mixing or applying yard herbicides (odds ratio = 2.1, 95% confidence interval 1.0-4.4). Combinations of activities with a variety of chemicals (atrazine, glyphosate, organophosphates, 4-[2,4-dichlorophenoxy] butyric acid, and insecticides) generated odds ratios of two or greater. No associations were found between farm chemicals and small-for-gestational-age births or altered sex ratio. Based on these data, despite limitations in exposure assessment, the authors encourage continued evaluation of male exposures, particularly in relation to miscarriage and preterm delivery.

Evaluation of different mixing study reagents and dilution effect in lupus anticoagulant testing.

Until recently, the laboratory identification of lupus anticoagulants (LA) was not considered important. Often LA were regarded as a nuisance, resulting in factor assays and other coagulation tests with inconclusive results. However, the recognition of important clinical complications associated with the presence of LA has resulted in an emphasis on the detection of this phospholipid-dependent inhibitor. Most studies have evaluated the sensitivity of various screening or confirmatory procedures used in establishing the diagnosis of LA. The authors have focused on the variables involved in the mixing studies used to identify the presence of a circulating inhibitor. To detect the latter, attention to the ratio of patient plasma to normal plasma is important, particularly in the case of a minimally prolonged APTT. Also the source of "normal" plasma must be platelet poor to maximize sensitivity in the case of a weak LA.

Laboratory diagnosis of lupus inhibitors: a comparison of the tissue thromboplastin inhibition procedure with a new platelet neutralization procedure.

The introduction of the activated partial thromboplastin time (APTT) as a screening test has resulted in increased recognition of circulating anticoagulants. The most frequently encountered inhibitor is the lupus-type anticoagulant. However, criteria for differentiation of this inhibitor are not well-established. We evaluated the ability of two procedures, tissue thromboplastin inhibition (TTI) and a new platelet neutralization procedure (PNP), to differentiate between various types of coagulation inhibitors. The TTI, widely used for the diagnosis of lupus anticoagulants, proved to be nonspecific. The PNP specifically separated lupus-type inhibitors from Factor VIII, X, and V inhibitors. The PNP may be a useful test for the diagnosis of lupus anticoagulants.