Investigation of platelet measurands in dogs with hematologic neoplasia.

INTRODUCTION: Thrombocytopenia has been associated with some neoplastic processes, including hematologic neoplasia. There is no information regarding specific changes in platelet measurands in dogs with hematologic neoplasia compared with healthy dogs. The objectives of our study were to establish RIs, evaluate platelet measurands in dogs with hematologic neoplasia, and compare these measurands in patients with hematologic malignancies with or without thrombocytopenia. METHODS: This was a retrospective study. Platelet measurands were determined using the ADVIA 120 Hematology analyzer when a CBC was performed and included the platelet count, MPV, platelet distribution width (PDW), plateletcrit (PCT), mean platelet component (MPC), platelet component distribution width (PCDW), mean platelet mass (MPM), platelet mass distribution width (PMDW), and number of large platelets. Reference intervals were determined retrospectively using data from 129 healthy dogs. Patients with hematologic neoplasia (n = 50) were identified through retrospective evaluation of medical records from the Auburn University Veterinary Teaching Hospital and separated into thrombocytopenic (n = 20) and nonthrombocytopenic groups (n = 30). RESULTS: Platelet count and PCT were significantly higher in older healthy dogs compared with younger dogs. Significant differences were identified when comparing healthy dogs with those with hematologic neoplasia without thrombocytopenia for PDW, PCDW, PMDW, and the number of large platelets, indicating the presence of more heterogeneous platelets. Thrombocytopenic dogs with hematologic neoplasia had significantly decreased MPCs and increased MPVs, MPMs, and PCDWs compared with nonthrombocytopenic dogs with neoplasia. CONCLUSIONS: Dogs with hematologic neoplasia had more heterogeneous platelets, whereas thrombocytopenic patients with neoplasia had more activated platelets.

Mitochondrial copper and phosphate transporter specificity was defined early in the evolution of eukaryotes.

The mitochondrial carrier family protein SLC25A3 transports both copper and phosphate in mammals, yet in Saccharomyces cerevisiae the transport of these substrates is partitioned across two paralogs: PIC2 and MIR1. To understand the ancestral state of copper and phosphate transport in mitochondria, we explored the evolutionary relationships of PIC2 and MIR1 orthologs across the eukaryotic tree of life. Phylogenetic analyses revealed that PIC2-like and MIR1-like orthologs are present in all major eukaryotic supergroups, indicating an ancient gene duplication created these paralogs. To link this phylogenetic signal to protein function, we used structural modeling and site-directed mutagenesis to identify residues involved in copper and phosphate transport. Based on these analyses, we generated an L175A variant of mouse SLC25A3 that retains the ability to transport copper but not phosphate. This work highlights the utility of using an evolutionary framework to uncover amino acids involved in substrate recognition by mitochondrial carrier family proteins.

Identification of Staphylococci by Polymerase Chain Reaction Directly from a Positive Blood Culture and Effect on Patient Care.

BACKGROUND: As one of the most common bloodstream infections worldwide, Staphylococcus aureus bacteremia places a major burden on health care. Implementation of a rapid, genetic-based diagnostic test may have important implications in the clinical management of patients with S. aureus bacteremia. OBJECTIVES: The primary objective was to assess concordance between testing based on polymerase chain reaction (PCR) and the current gold standard, culture and sensitivity testing; the secondary objective was to assess the impact of this technology on patient care. METHODS: A pre-post intervention retrospective chart review was used to document the hospital course of patients with a diagnosis of S. aureus bacteremia before and after implementation of the PCR-based diagnostic system. Laboratory results from all patient samples subjected to PCR-based analysis following implementation of this system were compared with culture and sensitivity data for the same samples to determine accuracy of the new system. In addition, time to optimal therapy for each patient was calculated as the interval between the initiation of empiric and terminal therapies. The appropriateness of antimicrobial treatment was characterized as guideline-concordant, nonconcordant with the guidelines, or nonconcordant yet still clinically appropriate. RESULTS: In total, 98 and 99 patients met the inclusion criteria before and after implementation of the PCR-based diagnostic system, respectively. PCR-based results displayed 99.8% concordance (440/441 total samples) with results from culture and sensitivity testing. The time to optimal therapy was significantly shorter after implementation, by a mean of 22.8 h (p < 0.001). Overall, 97% of empiric and 99% of terminal antimicrobial regimens were either guideline-concordant or clinically appropriate for treatment of S. aureus bacteremia; 3% of empiric and 1% of terminal antimicrobial regimens were nonconcordant with clinical guidelines without any explanation based on other clinical considerations. CONCLUSIONS: The study findings support the utility of using a direct-from-positive-blood-culture PCR-based diagnostic tool as the primary method of identifying S. aureus bacteremia in patients, as well as the acceptance of and acting upon the new assay's results by our local clinicians. PCR-based assays can help reduce the time to optimal terminal therapy for patients with bacteremia.

CONTEXTE: La bactériémie à Staphylococcus aureus (BAC-SA), qui est l'une des infections du sang les plus répandues dans le monde, fait peser une lourde charge sur les soins de santé. La mise en place d'un test diagnostique génétique rapide pourrait avoir des retombées importantes sur la gestion clinique des patients présentant une BAC-SA. OBJECTIFS: L'objectif principal consistait à évaluer la concordance entre les tests basés sur la réaction en chaîne par polymérase (PCR) et le test de sensibilité et de culture, qui est la référence absolue actuelle; l'objectif secondaire consistait à évaluer l'impact de cette technologie sur les soins des patients. MÉTHODES: Un examen rétrospectif des dossiers pré-et post-intervention a servi à décrire le séjour à l'hôpital des patients ayant reçu un diagnostic de BAC-SA avant et après la mise en place du système de diagnostic de la PCR. Les résultats de laboratoire de tous les échantillons des patients soumis à une analyse de la PCR à la suite de la mise en place de ce système ont été comparés avec les données relatives à la culture et à la sensibilité de ces mêmes échantillons afin de déterminer la précision du nouveau système. De plus, l'évaluation du délai d'atteinte du traitement optimal de chaque patient repose sur le calcul de l'intervalle entre le début des thérapies empiriques et terminales. La pertinence du traitement antimicrobien était caractérisée comme suit : concordance avec les lignes directrices, non-concordance avec les lignes directrices ou non-concordance mais encore approprié d'un point de vue clinique. RÉSULTATS: Au total, 98 et 99 patients ont satisfait au critère d'inclusion respectivement avant et après la mise en place du système de diagnostic de la PCR. Les résultats basés sur la PCR affichaient une concordance de 99,8 % (440/441 échantillons au total) avec les résultats des tests de sensibilité et de culture. La diminution du délai d'atteinte du traitement optimal était importante après la mise en place du système, puisqu'elle atteignait en moyenne 22,8 h (p < 0,001). De manière générale, 97 % des régimes antimicrobiens empiriques et 99 % des régimes antimicrobiens terminaux concordaient avec les lignes directrices ou étaient cliniquement appropriés pour le traitement de la BAC-SA; 3 % des régimes antimicrobiens empiriques et 1 % des régimes antimicrobiens terminaux n'étaient pas conformes aux lignes directrices cliniques sans qu'aucune explication basée sur d'autres considérations cliniques n'ait été donnée. CONCLUSIONS: Les résultats de l'étude confirment la nécessité d'utiliser un outil diagnostique basé sur la PCR directement de l'hémoculture positive en guise de méthode principale pour déterminer la présence de BAC-SA chez les patients ainsi que l'acceptation et l'utilisation des nouveaux résultats du test par nos cliniciens locaux. Les tests basés sur la PCR peuvent aider à réduire le délai d'attente du traitement optimal pour les patients atteints de BAC-SA.

The viral prescription pad - a mixed methods study to determine the need for and utility of an educational tool for antimicrobial stewardship in primary health care.

BACKGROUND: In order to combat rising rates of antimicrobial resistant infections, it is vital that antimicrobial stewardship become embedded in primary health care (PHC). Despite the high use of antimicrobials in PHC settings, there is a lack of data regarding the integration of antimicrobial stewardship programs (ASP) in non-hospital settings. Our research aimed to determine which antimicrobial stewardship interventions are optimal to introduce into PHC clinics beginning to engage with an ASP, as well as how to optimize those interventions. This work became focused specifically around management of viral upper respiratory tract infections (URTIs), as these infections are one of the main sources of inappropriate antibiotic use. METHODS: This mixed methods study of sequential explanatory design was developed through three research projects over 3 years in Regina, Saskatchewan, Canada. First, a survey of PHC providers was performed to determine their perceived needs from a PHC-based ASP. From this work, a "viral prescription pad" was developed to provide a tool to help PHC providers engage in patient education regarding appropriate antimicrobial use, specifically for URTIs. Next, interviews were performed with family physicians to discuss their perceived utility of this tool. Finally, we performed a public survey to determine preferences for the medium by which information is received regarding symptom management for viral URTIs. RESULTS: The majority of PHC providers responding to the initial survey indicated they were improperly equipped with tools to aid in promoting conversations with patients and providing education about the appropriate use of antimicrobials. Following dissemination of the viral prescription pad and semi-structured interviews with family physicians, the viral prescription pad was deemed to be a useful educational tool. However, about half of the physicians interviewed indicated they did not actually provide a viral prescription to patients when providing advice on symptom management for viral URTIs. When asked about their preferences, 76% of respondents to the public survey indicated they would prefer to receive written or a combination of verbal and written information in this circumstance. CONCLUSIONS: PHC providers indicated a need for educational tools to promote conversations with patients and provide education about the appropriate use of antimicrobials. Viral prescription pads were regarded by family physicians and patients as useful tools in facilitating discussion on the appropriate use of antimicrobials. PHC providers should exercise caution in opting out of providing written forms of information, as many respondents to the general public survey indicated their preference in receiving both verbal and written information.

Educational intervention to reduce treatment of asymptomatic bacteriuria in long-term care.

OBJECTIVE: To determine if an educational intervention can decrease the inappropriate antibiotic treatment of long-term care (LTC) residents with asymptomatic bacteriuria (ASB). DESIGN: Prospective chart audit between May and July 2017. SETTING: Seven LTC facilities in Regina, Saskatchewan, Canada. PARTICIPANTS: Chart audits were performed on all LTC residents over 18 years of age with a positive urine culture. Educational sessions and tools were available to all clinical staff at participating LTC facilities. INTERVENTION: Fifteen-minute educational sessions were provided to LTC facility staff outlining the harms of unnecessary antibiotic use, antibiotic resistance and the diagnostic criteria of a urinary tract infection (UTI). Educational sessions were complimented with posters and pocket cards that summarised UTI diagnostic criteria. MAIN OUTCOME MEASURE: The primary outcome measure was the number of residents who received inappropriate antibiotic treatment for ASB. Secondary outcome measures included the appropriateness of urine culture tests, number of tests and cost associated with inappropriate treatments. RESULTS: In the preintervention period, 172 urine culture and sensitivity (UC&S) tests were performed, 62 (36.0%) were positive and 50/62 (80.6%) residents had ASB based on chart review. In the postintervention period, 151 UC&S tests were performed, 50 (33.1%) were positive and 35/50 (70.0%) residents had ASB. There was a statistically significant decrease in the number of residents treated with antibiotics for ASB, from 45/50 (90%) preintervention to 22/35 (62.9%) postintervention (χ2=9.087, p=0.003). CONCLUSIONS: An educational intervention was associated with a statistically significant decrease in inappropriate antibiotic treatment of LTC residents with ASB.

The mammalian phosphate carrier SLC25A3 is a mitochondrial copper transporter required for cytochrome c oxidase biogenesis.

Copper is required for the activity of cytochrome c oxidase (COX), the terminal electron-accepting complex of the mitochondrial respiratory chain. The likely source of copper used for COX biogenesis is a labile pool found in the mitochondrial matrix. In mammals, the proteins that transport copper across the inner mitochondrial membrane remain unknown. We previously reported that the mitochondrial carrier family protein Pic2 in budding yeast is a copper importer. The closest Pic2 ortholog in mammalian cells is the mitochondrial phosphate carrier SLC25A3. Here, to investigate whether SLC25A3 also transports copper, we manipulated its expression in several murine and human cell lines. SLC25A3 knockdown or deletion consistently resulted in an isolated COX deficiency in these cells, and copper addition to the culture medium suppressed these biochemical defects. Consistent with a conserved role for SLC25A3 in copper transport, its heterologous expression in yeast complemented copper-specific defects observed upon deletion of PIC2 Additionally, assays in Lactococcus lactis and in reconstituted liposomes directly demonstrated that SLC25A3 functions as a copper transporter. Taken together, these data indicate that SLC25A3 can transport copper both in vitro and in vivo.