Shiga toxin-producing Escherichia coli (STEC) infections are the product of the interaction between bacteria, phages, animals, humans, and the environment. In the late 1980s, Alberta had one of the highest incidences of STEC infections in North America. Herein, we revisit and contextualize the epidemiology of STEC O157 human infections in Alberta for the period 2009–2016. STEC O157 infections were concentrated in large urban centers, but also in rural areas with high cattle density. Hospitalization was often required when the Shiga toxin genotype stx2a stx2c was involved, however, only those aged 60 years or older and infection during spring months (April to June) independently predicted that need. Since the late 1980s, the rate of STEC O157-associated hemolytic uremic syndrome (HUS) in Alberta has remained unchanged at 5.1%, despite a marked drop in the overall incidence of the infection. While Shiga toxin genotypes stx1a stx2c and stx2a stx2c seemed associated with HUS, only those aged under 10 years and infection during spring months were independently predictive of that complication. The complexity of the current epidemiology of STEC O157 in Alberta highlights the need for a One Health approach for further progress to be made in mitigating STEC morbidity.

ABSTRACT:Background:Flow cytometry of the cerebrospinal fluid (CSF) is used in isolation or as an adjunct to cytology to increase the sensitivity of detecting central nervous system (CNS) lymphoma. We aimed to evaluate the sensitivity of CSF flow cytometry as a diagnostic screening tool for primary CNS lymphoma in patients presenting with undifferentiated neurologic symptoms.Methods:We retrospectively reviewed all CSF samples received by the Calgary Laboratory Services Flow Cytometry Laboratory from 2012 to 2015. Clinical data, laboratory investigations, radiologic imaging studies, and pathological data were analyzed. Clinical review extended to 2 years post-CSF flow cytometric testing.Results:Only 43/763 (5.6%) samples of CSF flow cytometry in 28/573 (4.9%) patients were found to be positive for a hematological malignancy in patients with undifferentiated neurologic symptoms. The overall sensitivity of the test was 13.8% with 25 patients with negative CSF flow cytometry later having a positive biopsy for CNS lymphoma. CSF flow cytometry was negative in all cases when at the time of CSF examination the patient did not have a previous hematological malignancy or findings of abnormal enhancement on MRI (n = 249).Conclusion:CSF flow cytometry has low utility in screening for primary CNS lymphoma in the absence of a previous history of hematologic malignancy or findings of abnormal enhancement on MRI.

The oribatid mite genus Protoribates Berlese (Haplozetidae) is reviewed for North America and the genus diagnosis is revised to account for the North American species, Protoribates robustior (Jacot, 1937) is redescribed and newly reported from western North America and a new species from Alberta is described. Protoribates haughlandae sp. n. is bisexual, heterotridactylous, and lives primarily in the peat soils of fens and bogs. Protoribates robustior is all-female, monodactylous, and occurs primarily in dry forests or in dry, treeless sites dominated by grasses, sedges, and shrubs. Both species feed on fungal hyphae and spores, but P. haughlandae also is an opportunistic predator and/or necrophage of small arthropods and P. robustior gut contents often include material that resembles plant cell walls. Examination of type specimens confirms that Protoribates prionotus (Woolley, 1968) is a junior synonym of the widespread Protoribates lophotrichus (Berlese, 1904). A key to differentiate Lagenobates from Protoribates and to identify the 7 species of the latter that are known or reported from North America is provided.

Flow cytometry of the cerebrospinal fluid (CSF) is used in isolation or as an adjunct to cytology to increase the sensitivity of detecting primary central nervous system (CNS) lymphoma. We aim to evaluate the sensitivity of CSF flow cytometry as a diagnostic tool for primary CNS lymphoma in patients presenting with undifferentiated neurologic symptoms. We retrospectively reviewed all CSF samples received by the Calgary Laboratory Services Flow Cytometry Laboratory from 2012- 2015. Clinical data, laboratory investigations, radiologic imaging studies, and pathological data were analyzed. Clinical review extended to 2 years post CSF flow cytometric testing. The number of samples of CSF flow cytometry that were positive for a hematological malignancy was 43/763 (5.6%). The overall sensitivity of the test was 69.4%. A positive result was more likely to occur in patients with a prior history of a hematological malignancy or abnormal enhancement on MRI (p<0.0001). CSF flow cytometry was negative in all patients who did not have a previous hematological malignancy or abnormal enhancement on MRI (n = 247). CSF flow cytometry has a limited role in screening for primary CNS lymphoma, unless a strictly endorsed testing algorithm is applied. It is, however, an invaluable tool in evaluating CNS involvement in patients with a previous diagnosis of hematolymphoid malignancy or abnormal enhancement on MRI.LEARNING OBJECTIVESThis presentation will enable the learner to:Discuss the costs and benefits of using CSF flow cytometry to diagnose CNS lymphoma 1.Identify appropriate clinical indications for using CSF flow cytometry as a first-line test2.Apply a testing algorithm to increase the diagnostic yield of CSF flow cytometry

Background: Glioblastoma (GBM) is the most common primary malignant brain tumour. Despite aggressive therapy, median survival is only 14 months. Death typically results from treatment failure and local recurrence. The GBM microenvironment is highly hypoxic, which correlates with treatment resistance. Cytoplasmic RNA stress granules (SGs) form in response to hypoxic stress and act as sights of mRNA triage, allowing preferential translation of prosurvival mRNA during stress. We hypothesize that SGs may play a role in hypoxia-induced resistance to therapy, and may be targetable by chemotherapeutics to improve outcomes. Methods: We screened 1280 approved compounds to identify drugs that inhibited formation or dissolution of SGs in U251 glioma cells. Raloxifene inhibited SG dissolution in a dose dependent manner. We treated cells with raloxifene and incubated them in hypoxia, and then measured rates of cell death using cell counting and Presto blue. Results: Cell death rates were synergistically higher in cells treated with the combination of raloxifene and hypoxia compared to either treatment alone. Conclusions: Raloxifene inhibits the dissolution of SGs in glioma cells, and combination treatment results in synergistic tumour cell death. Taken together, this provides evidence that inhibition of SG dissolution may be a viable target for future GBM chemotherapeutics. P.043Volumetric analysis of low-grade glioma growth in seriallyimaged patientsBackground: Diffuse low-grade gliomas (LGGs) are infiltrative, slow-growing primary brain tumors that remain relatively asymptomatic for long periods of time before progressing to aggressive high-grade gliomas. Methods: We retrospectively identified LGG patients that were stably managed by observation with numerous (≥ 8) serial magnetic resonance imaging (MRI) studies. Tumour volumes were measured by manual segmentation on imaging to study the growth of the lesion. Patient demographic information, tumour characteristics, and histological data were collected from electronic medical records. Results: Of 74 LGG patients, 10 (13.5%) patients were included in the study. The number of MRIs acquired ranged from 8 to 18 (median, 11) over a median of 79.7 months (range, 39.8-113.8 months). Tumor diameter increased at a median rate of 2.17 mm/year in a linear trajectory. Cox regression analysis revealed that initial tumour volume predicted time to clinical intervention, and Mann-Whitney U test found that patients diagnosed prior to age 50 had significantly slower-growing tumors. Clinical intervention was more likely for tumours larger than 73.8 mL. Conclusions: We retrospectively analyzed the natural history of LGGs in patients with numerous serial MRIs managed at a single institution.Comparisons to the literature suggest that this is a subset of particularly slow-growing and low-risk tumours. P.044Salvage therapy in recurrent pediatric medulloblastoma: A single centre experience Background: Children diagnosed with medulloblastoma (MB) that are refractory to upfront therapy or experience ...