Lab Matters Fall 2024 | Page 43

APHL 2024 POSTER ABSTRACTS

IMB clean-up kit has all the reagents and consumables necessary to perform twenty extractions . In the kit procedure , matrix-matched microcystins standard curves of known concentrations ranging from 0.025 to 0.4 ppb in synthetic urine and blood serum are extracted alongside unknown biological samples .

Results obtained during the development and validation of the IMB cleanup kit will be presented , including a novel LC-MS downstream analytical method developed in collaboration with Waters Corporation that optimizes the detection of microcystins following the IMB sample cleanup and GSDH evaluation of the method using a commercially available ELISA kit for Microcystins , as well as a phosphatase enzyme-inhibition assay ( PP2A ).

Presenter : Leah Ruth , Leah . Ruth @ us . goldstandarddiagnostics . com

Measurement of Vitamin E in Animal Tissue by LC-MS / MS with Comparison to LC-PDA

D . Prince , J . Zyskowski , J . Buchweitz , Michigan State University Veterinary Diagnostic Laboratory

Vitamin E ( alpha-tocopherol ) status in liver tissue is a key measure of overall animal health . Deficiency of vitamin E has been tied to the development of neurodegenerative diseases and muscular dystrophy in animals . The current method of analysis used by most clinical veterinary diagnostic laboratories for detecting and quantifying tissue vitamin E is liquid chromatography coupled with photodiode array detection ( LC-PDA ). A drawback to this method is the imprecision of specificity and inability to account for oxidation . Herein , we describe the validation of a liquid chromatography tandem-mass spectrometry ( LC-MS / MS ) method for the detection and quantitation of vitamin E and its quinone oxidation product in liver with comparison to the current LC-PDA method . For the LC-MS / MS method , a deuterated internal standard was added to liver tissue samples prior to homogenizing with polished water . The homogenate was solvent extracted with hexane , evaporated and reconstituted in acetonitrile for injection on the LC-MS / MS . Vitamin E and its quinone were detected and quantified by optimized multiple reaction monitoring ( MRM ) settings . For vitamin E , the LC- MS / MS method was linear from 0.400 ug / g to 72 ug / g tissue with an R = 0.993 . Interday vitamin E standards yielded a % CV of 15 or less for concentrations ranging 4 to 72 ug / g which is well within the clinically relevant range ( 20 – 40 ug / g ) for animal health . The LC-MS / MS method agreed well with LC-PDA ( R = 0.952 ) The mean bias determined by Bland Altman was -1.8 ng / g . Passing-Bablok fit gave a slope of 1.05 and an intercept of -1.55 and an R = 0.91 . In conclusion , the LC-MS / MS method is well-suited for clinical use on liver tissue samples and provides an accurate determination of vitamin E with the added advantage of detecting oxidation products .

Presenter : Delanie Prince , princed7 @ msu . edu

Operationalization of a Novel Indoor Air Surveillance Program in Chicago

H . Hutchison , M . Bertagna , C . Lilly , K . Anderson , A . Kittner , V . McSorley , Chicago Department of Public Health

The indoor air monitoring for pathogens program is a novel public health initiative of the Chicago Department of Public Health , initiated to address the changes in individual COVID-19 testing behavior and decreased availability of lab-confirmed clinical specimens for whole genome sequencing . The program aims to ensue citywide trend analysis ( virus detection across sites and variant circulation ), early detection of novel variants and pathogens and outbreak prevention and response . The 2023 pilot program successfully evaluated air samples with a multiplex panel of respiratory pathogens ( SARS-CoV-2 , RSV , Influenza A / B . Human metapneumovirus , Streptococcus pneumoniae , Adenovirus , Enterovirus ) from office , health care and congregate living facilities . Findings from this program demonstrated successful technical implementation , but a need for dedicated staff for logistical and operational functions to support the partnering facilities .

To better support partnering facilities and expand the program into phase 1 , a dedicated team was assigned to develop and implement an operations plan to support facility engagement and communication . On-site training was provided to all partners to ensure all facilities had the tools necessary to ensure cartridges are exchanged correctly . A REDCap program was created to track all cartridge exchanges . Weekly check-in emails to all sites were established every Monday as a reminder to exchange cartridges and determine if facilities were experiencing issues or required supplies . This allowed for better communication with facilities to ensure optimal function of the program . CDPH provided shipping for the cartridges to the laboratory through a courier service and training on how to access and utilize the shipping website was provided during installation . Providing a simple and prepaid shipping option to sites aided in onboarding new sites and retention . Monthly reports were established to provide partners with trends seen in their specimen data .

Since phase 1 began , seven new facilities have been onboarded . On-site training , retraining , ease of sample shipment and regular check-ins with site staff by CDPH representatives ’ fosters buyin and continued engagement in the air monitoring program . All sites exchange cartridges on Mondays to align with MMWR weeks and other surveillance data . Dedicated staff have led to more timely responses to facility questions and concerns with the implementation of weekly check-in emails . Additionally , onsite training and the option for onsite reeducation enhanced partner participation , retention and performance . Monthly reports of specimen results enhanced partner engagement with data visualization , trends , comparative data to the City of Chicago and other partners .

Our indoor air monitoring for pathogens program demonstrated a successful supplemental surveillance method for respiratory pathogen surveillance using a novel approach for several targets . It has provided CDPH with data regarding viral distribution across the City of Chicago , ensuring equitable representation of communities that may have limited access to testing . However , strong encouragement and operational support of participating facilities is needed to ensure data quality . We hope this model for indoor air monitoring can be utilized by other organizations to improve respiratory pathogen surveillance using a novel and non-invasive approach .

Presenter : Kendall Anderson , kendall . anderson @ cityofchicago . org