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Background: Despite the rising demand for home-based health care services in Canada and the increasing medical complexity of elderly patients, there is limited literature exploring the role of home care pharmacists and the clinical activities they perform. Objectives: The primary objective was to describe the types and frequencies of clinical activities (both interventions and recommendations) performed by home care pharmacists upon initial consultation. The secondary objective was to determine which patient characteristics resulted in the highest number of clinical activities. Methods: This study was a retrospective review of adult patients who had an initial in-person or telemedicine consultation with home care pharmacists from June 2018 to May 2019 in the Edmonton Zone of Alberta Health Services. Results: Of the 355 patients whose records were screened, 318 (89.6%) were included in the analysis. Of these, 191 (60.1%) were female, and the median age was 79 years (interquartile range [IQR] 68–86 years). The median numbers of medical conditions and medications were 6 and 10, respectively. Of the total of 1172 clinical activities, there was a median of 3 (IQR 2–5) per patient, irrespective of the patient’s medical conditions, including those with the most common conditions. The most common activities were patient counselling (n = 160, 13.7%), collaboration with another health care professional (n = 157, 13.4%), and deprescribing (n = 140, 11.9%). Across all activities, pharmacists performed a total of 562 interventions and made 610 recommendations. Each additional year of age and each additional medication on a patient’s medication list resulted in an increase in the number of clinical activities (by 0.01 for each additional year of age [p = 0.003] and by 0.03 for each additional medication [p < 0.001]). Conclusions: Home care pharmacists in the Edmonton Zone performed a wide range of clinical activities, particularly for older patients and those with more medications. Further research is required to evaluate the outcomes of pharmacist consultations. RÉSUMÉ Contexte : Malgré l’augmentation de la demande de services de soins de santé à domicile au Canada et la complexité médicale croissante des patients âgés, il existe peu de documentation examinant le rôle des pharmaciens au sein de l’équipe de soins à domicile et leurs activités cliniques. Objectifs : L’objectif primaire consistait à décrire le type et la fréquence des activités cliniques (interventions et recommandations) effectuées par les pharmaciens à domicile lors de la consultation initiale. L’objectif secondaire consistait quant à lui à déterminer les caractéristiques des patients qui ont entraîné le plus grand nombre d’activités cliniques. Méthodes : Cette étude était une revue rétrospective de patients adultes ayant eu une première consultation en personne ou par télémédecine avec des pharmaciens de soins à domicile de juin 2018 à mai 2019 dans la zone d’Edmonton des services de soins de santé de l’Alberta. Résultats : Sur les 355 patients dont les dossiers ont été examinés, 318 (89,6 %) ont été inclus dans l’analyse. Parmi eux, l’âge médian était de 79 ans (écart interquartile [IQR] 68–86) et 191 (60,1 %) étaient des femmes. Le nombre médian de problèmes médicaux et de médicaments était respectivement de 6 et 10. Sur les 1172 activités cliniques au total, le nombre médian était de 3 activités (IQR 2-5) par patient, indépendamment de ses problèmes médicaux, y compris ceux présentant les maladies les plus courantes. Les activités les plus courantes étaient le conseil aux patients (n = 160, 13,7 %), la collaboration avec un autre fournisseur de soins de santé (n = 157, 13,4 %) et la déprescription (n = 140, 11,9 %). Toutes activités confondues, les pharmaciens ont effectué 562 interventions et fait 610 recommandations. Chaque année d’âge supplémentaire et chaque médicament ajouté à la liste des médicaments donnaient lieu à une augmentation du nombre d’activités cliniques (de 0,01 pour chaque année d’âge supplémentaire [p = 0,003] et de 0,03 pour chaque médicament supplémentaire [p < 0,001]). Conclusions : Les pharmaciens de soins à domicile de la zone d’Edmonton effectuaient un large éventail d’activités cliniques, en particulier pour les patients âgés et ceux prenant plus de médicaments. Des recherches supplémentaires sont nécessaires pour évaluer les résultats des consultations des pharmaciens.

To report the clinical effectiveness and the safety of cryoablation in first or second-line therapy in symptomatic soft tissues vascular malformation, a mini-invasive therapeutic alternative to sclerotherapy or surgery.This retrospective and monocentric study included patients with symptomatic low-flow vascular malformation. The interventions were carried out under computed tomography (CT) scan, Cone-beam CT (CBCT) and/or USA guidance. Clinical response was evaluated by collecting the Numerical Rating Scale (NRS) for symptoms before and after the ablation. Safety was assessed based on criteria proposed by the Cardiovascular and Interventional Radiological Society of Europe. Imaging response was evaluated with post-ablation Magnetic Resonance Imaging.Twenty-one patients were included. Cryoablation was the first operative treatment for 12 patients (12/21, 57%). The remaining patients had already undergone surgery (2/21, 9%) or one or more sclerotherapy procedures (7/21, 33%).Symptoms assessed by Numerical Rating Scale dropped from a median of 7 [IQR 6-8] before the procedure to a median of 1 [IQR 0-2] after cryoablation (p 0.001). Half of the patients declared a full effectiveness of cryoablation on their symptoms (11/21). No major complications and four minor adverse events (two skin lesions, two patients with neuropathic pain) were reported (19%). Lesional volume significantly decreased after cryoablation (median from 3.7 cmCryoablation seems to be a safe and effective first- or second-line therapy for soft tissue vascular malformations.

Research investigating the potential of standards for the build, operation, and maintenance phases of small water and wastewater systems in the Canadian North was conducted to identify opportunities for standards to help ensure safe, accessible, and high-quality drinking water and sanitation for all northerners. This involved a review of literature, a survey of northern water system users and practitioners, and key informant interviews. The study highlights a general trend of low adaptation to local conditions for standardization documents on many technical topics in northern Canada. A number of major themes and corresponding recommendations are subsequently drawn with respect to potential for standardization efforts. Of these, training and certification/classification were identified as a key area that has many gaps, challenges, and potential opportunities with respect to the use of standardized procedures for small-scale water and wastewater systems. Subsequently, this is also identified as the area where standardization efforts may have the broadest social benefit, urgency, as well as potential feasibility.

We have used a soybean (Glycine max L. Merr . ) hydroponic system to s tudy host control of modulat ion by fas t -growing Rhizobium fredi i and s low-growing Bradyrhizobium japonicum. Nodules were not formed on soybean cul t ivars grown hydroponical ly that produced ineffect ive nodules when grown in vermicul i te . Nodules were formed on compatible cul t ivars by mutant s t ra ins that f ixed l i t t le or no ni t rogen. Introduct ion Hydroponic growth systems have been used to s tudy host control of nodulat ion in the soybean (Glycine max L. Merr i l l ) -Bradyrhizobium ni t rogen-f ixing symbiosis . Rals ton and Imsande (1983) developed a method for growing individual plants in l i ter f lasks of nutr ient solut ion. A s ingle inoculat ion of plants a t four weeks af ter germinat ion al lowed the synchronous development of approximately 1000 nodules per plant . They used this method to s tudy ni t ra te inhibi t ion of nodulat ion. Concentrat ions greater than or equal to 2 .0 mM n i t ra te res t r ic ted nodule development but not ni t rogen f ixat ion in nodules formed. Exposure to high levels of n i t ra te up to 8 days af ter inoculat ion blocked nodule formation. This observat ion indicated that soybean plants act ively regulated nodulat ion in this hydroponic growth system. In other words, s ignals in the environment a l tered nodule formation on plant roots . Singleton (1983) created a hydroponic growth system that placed spl i t roots from a s ingle plant in two different solut ions. Although the pr imary role of this system was to

Patient safety is the foundation of high-quality health care, as recognized both nationally and worldwide. Patient blood specimen identification is critical in ensuring the delivery of safe and appropriate care. The practice of nephrology nursing involves frequent patient blood specimen withdrawals to treat and monitor kidney disease. A critical review of the literature reveals that incorrect patient identification is one of the major causes of blood specimen labelling errors. Misidentified samples create a serious risk to patient safety leading to multiple specimen withdrawals, delay in diagnosis, misdiagnosis, incorrect treatment, transfusion reactions, increased length of stay and other negative patient outcomes. Barcode technology has been identified as a preferred method for positive patient identification leading to a definitive decrease in blood specimen labelling errors by as much as 83% (Askeland, et al., 2008). The use of a root cause analysis followed by an action plan is one approach to decreasing the occurrence of blood specimen labelling errors. This article will present a review of the evidence-based literature surrounding blood specimen labelling errors, followed by author recommendations for completing a root cause analysis and action plan. A failure modes and effects analysis (FMEA) will be presented as one method to determine root cause, followed by the Ottawa Model of Research Use (OMRU) as a framework for implementation of strategies to reduce blood specimen labelling errors.

Soaring healthcare costs, increasing rates of chronic illness, and an aging population have left Canada struggling to meet the growing demands for quality health care. Hospitals battle to cope with altering patient demand, higher costs, provincially imposed global budgets, fast developing technology, rigid rules, new drugs, and social inequalities that lead to poor health. Canadian population health trends have played an important role in examining innovation opportunities that can dictate terms for the effective re-design of Canada's health system. Independent (home) dialysis is associated with cost savings and improved quality of life in comparison with hospital-based hemodialysis treatment. Despite this, independent dialysis has failed to increase at the same rate as hospital-based treatment for chronic kidney disease. One probable reason is the lack of healthcare providers to truly understand the patient experience of living with chronic kidney disease. Qualitative data have shown that patients living with chronic kidney disease desire independence and minimal impact to their quality of life. Parse's Humanbecoming theory has been widely accepted in nursing practice as a theoretical base in which to gain an understanding of the lived experience. The values and assumptions of the Humanbecoming theory are also congruent with patient-centered care practice and transferable to all areas of healthcare practice and disciplines.

Polycyclic aromatic hydrocarbons (PAH's) are ubiquitous, recalcitrant, and potentially carcinogenic pollutants. Plants and their associated rhizosphere microbes can promote PAH dissipation, offering an economic and ecologically attractive remediation technique. This study focused on the effects of different types of vegetation on PAH removal and on th einteraction between the plants and their associated microorganisms. Aged PAH-polluted soil with a total PAH level of 753 mg kg -1 soil dry weight was planted with 18 plant species representing eight families. The levels of 17 soil PAHs were monitored over 14 mo. The size of soil microbial populations of PAH degraders was also monitored. Planting significantly enhanced the dissipation rates of all PAHs within the first 7 mo, but this effect was not significant after 14 mo. Although the extent of removal of lower-molecular-weight PAHs was similar for planted and unplanted control soils after 14 mo, the total mass of five- and six-ring PAHs removed was significantly greater in planted soils at the 7- and 14-mo sampling points. Poaceae (grasses) were the most effective of the families tested, and perennial ryegrass was the most effective species; after 14 mo, soils planted with: perennial ryegrass contained 30% of the initial total PAH concentration (compared with 51% of the initial concentrations in implanted control soil). Although the presence of some plant species led to higher populations of PAH degraders, there was no correlation across plant species between PAH dissipation and the size of the PAH-degrading population. Research is needed to understand differences among plant families for stimulating PAH dissipation.

Microbial growth on pollutant mixtures is an important aspect of bioremediation and wastewater treatment. However, efforts to develop mathematical models for mixed substrate kinetics have been limited. Nearly all models group either the microbial population (as "biomass") or the chemical species (e.g., as biological oxygen demand). When individual chemical species are considered, most models assume either no interaction or that the nature of the interaction is competition for the same rate-limiting enzyme. And when individual microbial species are considered, simple competition for the growth substrate is the only interaction included. Here, we present results using Pseudomonas putida F1 and Burkholderia sp. strain JS150 growing individually and together on benzene, toluene, phenol, and their mixtures and compare mathematical models to describe these results. We demonstrate that the simple models do not accurately predict the outcome of these biodegradation experiments, and we describe the development of a new model for substrate mixtures, the sum kinetics with interaction parameters (SKIP) model. In mixed-culture experiments, the interactions between species were substrate dependent and could not be predicted by simple competition models. Together, this set of experimental and modeling results presents our current state of work in this area and identifies challenges for future modeling efforts.

Human polyclonal antibodies (hPABs) are useful therapeutics, but because they are available only from human donors, their supply and application is limited. To address this need, we prepared a human artificial chromosome (HAC) vector containing the entire unrearranged sequences of the human immunoglobulin (hIg) heavy-chain (H) and lambda (lambda) light-chain loci. The HAC vector was introduced into bovine primary fetal fibroblasts using a microcell-mediated chromosome transfer (MMCT) approach. Primary selection was carried out, and the cells were used to produce cloned bovine fetuses. Secondary selection was done on the regenerated fetal cell lines, which were then used to produce four healthy transchromosomic (Tc) calves. The HAC was retained at a high rate (78-100% of cells) in calves and the hIg loci underwent rearrangement and expressed diversified transcripts. Human immunoglobulin proteins were detected in the blood of newborn calves. The production of Tc calves is an important step in the development of a system for producing therapeutic hPABs.

Interspecies interactions and changes in the rate and extent of biodegradation in mixed culture-mixed substrate studies were investigated. A binary mixed culture of Pseudomonas putida F1 and Burkholderia sp. JS150 degraded toluene, phenol, and their mixture. Both toluene and phenol can serve as sole sources of carbon and energy for both P. putida F1 and strain JS150. To investigate the population dynamics of this system, a fluorescent in-situ hybridization method was chosen because of its ability to produce quantitative data, its low standard error, and the ease of use of this method. When the binary mixed culture was grown on toluene or phenol alone, significant interactions between the species were observed. These interactions could not be explained by a pure-and-simple competition model and were substrate dependent. Strain JS150 growth was slightly inhibited when grown with P. putida F1 on phenol, and P. putida F1 grew more rapidly than expected. Conversely, when the two species were grown together on toluene alone, P. putida F1 was inhibited while strain JS150 was unaffected. During growth of the mixed culture on a combination of toluene and phenol, the interactions were similar to that observed during growth on phenol alone; P. putida F1 growth was enhanced while strain JS150 was unaffected. Because of the observed interspecies interactions, monoculture kinetic parameters were not sufficient to describe the mixed culture kinetics in any experiment. This is one of the first reports of microbial population dynamics in which molecular microbial ecology and mathematical modeling have been combined. The use of the 16S-rRNA-based method allowed for observation and understanding of interspecies interactions that were not observable with standard culture-based methods. These results suggest the need for more investigations that account for both substrate and microbial interactions when predicting the fate of organic pollutants in real systems.

Background: This project designed and tested an economical apparatus to safely expose guinea pigs to biohazardous aerosol. The goals were to design a system that can be easily decontaminated, fits in a biosafety cabinet, and affordable. Methods: It is composed of three main chambers housed in an outer box that fits within a conventionally sized biosafety cabinet. The animal chamber contains a removable housing unit for either four or eight guinea pigs. The aerosol chamber is separate to minimize contamination. The nebulizer chamber is also sealed to reduce risks from leakages. This apparatus is easily decontaminated by immersion in disinfectant. Results and Conclusions: This system has been tested for safety, ergonomics, efficiency of rodent exposure to bacteria, airflow, access points, seal mechanisms, and size. This system is effective, consistent, safe and cost efficient.

The benefits of clinical nursing experience in nursing education cannot be overemphasized. Literature has shown that proficient clinical nursing education enhances nursing practice through the development of professional growth with opportunities for the application of theoretical knowledge. Clinical preceptorship has been shown to be an effective method in the development of professional nurses through clinical education. The role of a clinical nursing preceptor is complex and not necessarily applicable to all nurses. Understanding the clinical environment, comprehending individual learning styles, and dealing effectively with conflict are skills that an effective preceptor needs to acquire before participating in the role. This article describes the origin of the preceptor role in clinical nursing education and discusses how the role can be enhanced through a proficient and well-planned preceptorship education program.

Grieving a loss is a devastating universal human experience that affects our emotional, physical and spiritual well being. End stage renal disease is a lifelong illness creating a serious and complex impact on individually defined quality of life. Losses such as that of independence, employment, self-esteem and physical functioning can leave individuals in a state of ongoing grief. Parse's humanbecoming theory provides nephrology nurses with a framework for practice that is based in a human science philosophy. The purpose of this paper is to explore the phenomenon of loss and grieving in the population with end stage renal disease, and how Parse's humanbecoming theory can have a positive impact on the lives of both nephrology nurses and the patients for whom they care.

We have used a new technique to identify discrete genetic markers in aphids, a family in which biochemical and morphological genetic polymorphisms are rare. The new technique uses the polymerase chain reaction (PCR) to amplify random regions of aphid genomes (random amplified polymorphic DNA) and has been termed RAPD-PCR. We demonstrate the use of the technique in revealing genetic variation in four aphid species, the greenbug (Schizaphis graminum (Rondani)), the Russian wheat aphid (Diuraphis noxia (Mordvilko)), the pea aphid (Acyrthosiphon pisum (Harris)), and the brown ambrosia aphid (Uroleucon ambrosiae (Thomas)). In contrast with allozyme surveys, RAPD-PCR revealed large amounts of genetic variation among individuals in each of these species. Variation was detected among biotypes, populations, colour morphs and even individuals on a single plant. We also explored the utility of RAPD-PCR in the detection and identification within aphid bodies of two endoparasitic wasps, Diaeretiella rapae (McIntosh) and Lysiphlebus testaceipes (Cresson). The use of RAPD-PCR in species diagnostics, parasitoid detection, and population studies is discussed.

Virtually all new tuberculosis vaccine candidates are tested in animals using the laboratory strains H37Rv or Erdman. However, naturally occurring M. tuberculosis infections are caused by strains that are widely different in phenotype and genotype. Very little is known about the characteristics of these clinical isolates in terms of basic biology, virulence and in vivo pathogenicity. In this study, we have used a standardized aerosol infection of guinea pigs to compare in vivo differences between clinical strains of M. tuberculosis. Strains consisted of both drug sensitive and multi-drug resistant (MDR) strains of Beijing and non-Beijing varieties. Collectively, these clinical isolates tested in the guinea pig model exhibited a wide range of virulence. Infection with certain isolates caused severe and rapidly progressive pulmonary and extra-pulmonary lesion necrosis, some of which progressed to atypical cavitary lesions in draining mediastinal and tracheobronchial lymph nodes. The two MDR-TB strains used in this study exhibited low level virulence as determined by bacterial growth, lesion scores and survival. Since infections with clinical M. tuberculosis isolates produce such varied disease, it is unknown whether new tuberculosis vaccines being developed will provide the same level of protection as seen when tested using laboratory challenge strains. The use of appropriate animal models allows for this important question to be addressed.

Phytoremediation offers an ecologically and economically attractive remediation technique for soils contaminated with polycyclic aromatic hydrocarbons (PAHs). In addition to the choice of plant species, agronomic practices may affect the efficiency of PAH phytoremediation. Inorganic nutrient amendments may stimulate plant and microbial growth, and clipping aboveground biomass might stimulate root turnover, which has been associated with increases in soil microbial populations. To assess the influence of fertilization and clipping on PAH dissipation in a nutrient-poor, aged PAH-contaminated soil, a 14-mo phytoremediation study was conducted using perennial ryegrass (Lolium perenne) as a model species. Six soil treatments were performed in replicate: implanted; unplanted and fertilized; planted; planted and fertilized; planted and clipped; and planted, clipped, and fertilized. Plant growth, soil PAH concentrations, and the concentrations of total and PAH-degrading microorganisms were measured after 7 and 14 mo. Overall, planting (with nearly 80% reduction in total PAHs) and planting + clipping (76% reduction in total PAHs) were the most effective treatments for increased PAH dissipation after 14 mo. Fertilization greatly stimulated plant and total microbial growth, but negatively affected PAH dissipation (29% reduction in total PAHs). Furthermore, unplanted and fertilized soils revealed a similar negative impact (25% reduction) on PAH dissipation after 14 mo. Clipping did not directly affect PAH dissipation, but when combined with fertilization (61% reduction in total PAHs), appeared to mitigate the negative impact of fertilization on PAH dissipation. Therefore, fertilization and clipping may be included in phytoremediation design strategies, as their combined effect stimulates plant growth while not affecting PAH dissipation.

The Electronic Warfare Engagement Simulation Facility (EWESF) is a research facility used at the Defence Research Establishment Ottawa (DREO) to assess the performance of electronic warfare systems. The facility is designed to evaluate the effectiveness of radar jamming hardware and jamming techniques using a hardware-in-the-loop configuration. Actual radar jamming equipment is interfaced to the facility and is stimulated by radar signals from a victim radar. The jammer response to the threat radar signal is radiated into the EWESF anechoic chamber to degrade the performance of the radar. The radar performance can be monitored and the jamming techniques can be modified until a technique design is obtained which maximizes the radar degradation. This paper describes the basic design and operation of the EWESF. >

Genetic counseling and testing for mutations in XXX (BRCA)1/2 genes that increase breast cancer susceptibility potentially offer a number of benefits (e.g., more informed decision making regarding breast cancer prevention options) but also raise potential problems (e.g., issues of discrimination). However, the literature suggests that African-American women underuse genetics-related services. Therefore, the primary aim of the current study was to investigate predictors of the use of genetic counseling and testing for breast cancer susceptibility in this population. Participants were 76 African-Americans at increased risk for breast cancer attributable to their family history of the disease. Participants were recruited from an urban cancer screening clinic and completed measures assessing sociodemographic information, breast cancer knowledge, breast cancer-specific emotional distress, and perceived benefits of and barriers to BRCA testing. Free BRCA counseling and testing were offered to all interested participants, and measures were completed before counseling sessions. On the basis of their subsequent acceptance or refusal of these services, participants were described as having either: (a) declined BRCA-related genetic counseling (GC-); (b) participated in genetic counseling but refused genetic testing (GC+GT-); or (c) participated in both genetic counseling and testing (GC+GT+). Results revealed that participants who declined counseling had significantly less knowledge of breast cancer genetics than those who accepted both counseling and testing. No differences emerged among the three groups in terms of perceived benefits of testing. However, participants declining counseling demonstrated significantly higher perceived barrier scores compared with those accepting counseling and testing. Specifically, those who did not participate in counseling reported greater anticipation of negative emotional responses to testing and more concern about stigmatization, whereas those who underwent both counseling and testing had significantly lower family-related guilt. Finally, cancer-specific distress was positively associated with participation in counseling, regardless of participation in testing. The current findings underscore the need for refinement of outreach and intervention efforts that both increase awareness of BRCA counseling and testing among African-American women and provide information to those considering these options.

An intensive linkage map of the yellow fever mosquito, Aedes aegypti, was constructed using single-strand conformation polymorphism (SSCP) analysis of cDNA markers to identify single nucleotide polymorphisms (SNPs). A total of 94 A. aegypti cDNAs were downloaded from GenBank and primers were designed to amplify fragments

▪ Abstract Modern population genetics underwent a major paradigm shift during the last decade of the 20th century with the discovery that thousands of genes of known function and position in a genome can be analyzed simultaneously in a single individual. The impact of this technology on insect population genetics is potentially profound. Sampling distributions of genetic statistics can now be derived from many individual loci or among many segregating sites within a gene. Inferences regarding random mating, gene flow, effective population sizes, disequilibrium, and relatedness among populations can now be based on patterns of variation at many loci. More importantly, genome-wide sampling enables population geneticists to distinguish effects that act on the whole genome from those that act on individual loci or nucleotides. We introduce the term “population genomics” to describe the process of simultaneous sampling of numerous variable loci within a genome and the inference of locus-specific effects from the sample distributions. The four critical assumptions implicit in the population genomics approach are explained in detail. Studies adopting this paradigm are reviewed, and the steps necessary to complete a population genomics study are outlined.

Interspecies interactions and changes in the rate and extent of biodegradation in mixed culture-mixed substrate studies were investigated. A binary mixed culture of Pseudomonas putida F1 and Burkholderia sp. JS150 degraded toluene, phenol, and their mixture. Both toluene and phenol can serve as sole sources of carbon and energy for both P. putida F1 and strain JS150. To investigate the population dynamics of this system, a fluorescent in-situ hybridization method was chosen because of its ability to produce quantitative data, its low standard error, and the ease of use of this method. When the binary mixed culture was grown on toluene or phenol alone, significant interactions between the species were observed. These interactions could not be explained by a pure-and-simple competition model and were substrate dependent. Strain JS150 growth was slightly inhibited when grown with P. putida F1 on phenol, and P. putida F1 grew more rapidly than expected. Conversely, when the two species were grown together on toluene alone, P. putida F1 was inhibited while strain JS150 was unaffected. During growth of the mixed culture on a combination of toluene and phenol, the interactions were similar to that observed during growth on phenol alone; P. putida F1 growth was enhanced while strain JS150 was unaffected. Because of the observed interspecies interactions, monoculture kinetic parameters were not sufficient to describe the mixed culture kinetics in any experiment. This is one of the first reports of microbial population dynamics in which molecular microbial ecology and mathematical modeling have been combined. The use of the 16S-rRNA-based method allowed for observation and understanding of interspecies interactions that were not observable with standard culture-based methods. These results suggest the need for more investigations that account for both substrate and microbial interactions when predicting the fate of organic pollutants in real systems.

To evaluate 2 polymerase chain reaction (PCR)-based methods for differentiating cytotoxic and noncytotoxic Pasteurella trehalosi from Rocky Mountain bighorn sheep (Ovis canadensis canadensis).23 isolates of P. trehalosi from bighorn sheep in Colorado, including 18 from free-ranging herds and 5 from a captive herd.Using a sequence of the leukotoxin gene region of P. haemolytica serotype 1, 7 PCR primers were designed. A PCR amplification was performed on a sample of bacterial cell suspensions from pure cultures of P. trehalosi with known in vitro cytotoxic effects. The 2 most promising primer pairs were used in a study of 23 P. trehalosi isolates. Results were analyzed for association with cytotoxicity and 3 distinct ribotypes (Eco, Aco, and Bco).Significant associations were observed between in vitro cytotoxicity and PCR results for coding region, between ribotype Eco classification and PCR results for coding region, and between ribotype Eco classification and PCR results for promoter region. There was a negative association between ribotype Aco classification and PCR results for coding and promoter regions.The PCR for the leukotoxin A coding region may be useful in differentiating cytotoxic from noncytotoxic P. trehalosi isolates recovered from bighorn sheep. It may be useful for studying epidemiologic features of pasteurellosis in bighorn sheep and for designing vaccines to protect wild sheep against pneumonia caused by P. trehalosi and P. haemolytica.