Lab Matters Fall 2023 | Page 88

APHL 2023 POSTER ABSTRACTS

Students were required to perform isolate identification using gram stains , ancillary testing and laboratory identification systems . The students completed trainings in the microbiology , molecular biology , immunology and virology departments . The program started in January 2022 . Since then , we have completed rotations for eight students . Each practicum participant ’ s understanding of the training information was evaluated before and after training was complete . Students were given pre-training exams to obtain a knowledge reference point and a post-training exam to demonstrate improvement . We also used this information to measure program efficacy . Students were required to pass a post-training test with a score of 90 % or greater and to correctly identify five unknown isolates . The average pre-training exam result was 48.3 %, and the average post-training exam result was 96.1 %. The students showed 47.8 % improvement in post-training exam scores . Each student remarked positively about their learning experience after the practicum was complete . Four of the eight students have graduated and work as medical laboratory scientists adding to the available work force . The other four students are scheduled to graduate in this spring and all plan to work in the field as well . We are currently evaluating the program and making improvements to provide the best training possible for the next generation of laboratory professionals .

Presenter : Reginald Blackwell , reginald . blackwell @ dc . gov

POLIO , MPOX , SARS-COV-2 , EXPANDED TARGETS NWSS , STIs

Automated HPV DNA Extraction and Detection from Cervical , Anal , and Throat Samples

E . Fischer , J . Mook ; Promega Corporation

Human papillomavirus ( HPV ) is the most common sexually transmitted infection in the United States . The 14 high-risk HPV types cause 91 % of anal and cervical cancers and 70 % of genital and throat cancers annually . Traditionally , the Pap smear has been used to screen for early cellular changes that may progress to cervical cancer , but this method is prone to human error due to its visual result interpretation . The World Health Organization recently recommended DNA-based HPV testing as the first-choice screening method for cervical infection with high-risk HPV types , which can guide additional surveillance measures for early detection of cancer . However , the recommendations do not address testing of other affected areas like the anus , genitals , and throat . Here we describe methods developed for automated extraction of HPV DNA from cervical , anal , and throat samples and detection by multiplex qPCR . The use of automation in DNA extraction saves time while reducing the potential for errors in processing . DNA was extracted from throat samples collected in Universal Transport Medium ®, or cervical and anal samples collected in SurePath™ and ThinPrep ® preservative using the Maxwell ® RSC Instrument , an automated benchtop nucleic acid purification platform or using a high-throughput extraction method developed for the KingFisher™ Flex System . The HPV DNA type present within each sample was successfully detected using a multiplex qPCR assay with primers and probes specific to high-risk HPV types 16 , 18 , and 45 . This study demonstrates the development of straightforward and efficient workflows for HPV DNA extraction and qPCR detection from cervical , anal , and throat samples using benchtop and highthroughput automation , helping to address the need for HPV DNA detection methods for multiple affected areas .

Presenter : Emma Fischer , emma . fischer @ promega . com

Detection of Antibody Responses Against SARS-CoV-2 in Serosurvey Participants from Distinct Periods of the COVID-19 Pandemic – New York City , New York

E . Kopping 1 , 2 , J . Wu 2 , J . Caton 2 , E . Spear 2 , A . Schuster 2 , R . Fowler 2 , S . Hughes 2 ; 1 US Centers for Disease Control and Prevention , 2 New York City Department of Health and Mental Hygiene Public Health Laboratory

Background : Antibody responses after SARS-CoV-2 vaccination and infection target the viral spike ( S ) protein ( anti-S antibodies ). Neutralizing antibodies ( nAb ) capable of blocking infection develop in a subset of anti-S antibody responses and contribute to immunity . Antibodies against the SARS-CoV-2 nucleocapsid ( N ) protein ( anti-N antibodies ) only develop after viral exposure . The 2020 ( June 2020 – October 2020 ) and 2021 ( April 2021 – October 2021 ) New York City ( NYC ) COVID-19 serosurveys were conducted during two distinct pandemic periods , including pre- ( 2020 ) and post-vaccine availability ( 2021 ). This study characterized and compared three anti-SARS-CoV-2 antibody responses ( anti-S , nAb , and anti-N ) among participants during these periods . Methods : Blood samples were collected from 1,532 NYC residents during the 2020 ( n = 497 ) and 2021 ( n = 1,035 ) serosurveys . Serum was separated from blood and used to detect anti-S antibodies and anti-N antibodies using the LIAISON ® SARS-CoV-2 S1 / S2 IgG assay and the VITROS™ Immunodiagnostic Products Anti-SARS- CoV-2 Total N Antibody Test , respectively . Anti-S antibody positive serospecimens ( n = 1,059 ) were tested for nAbs using the SARS- CoV-2 Surrogate Virus Neutralization Test ( sVNT ) Kit . Results : Anti-S and anti-N antibodies were each detected in 20 % ( 100 / 497 ) of 2020 serosurvey participants . Anti-S seropositivity increased to 93 % ( 959 / 1,035 ) in 2021 serosurvey participants . Anti-N seropositivity increased to 26 % ( 273 / 1,035 ) in 2021 participants . nAbs were detected in specimens with detectable anti-S antibodies from both periods , 91 % ( 91 / 100 ) and 98 % ( 944 / 959 ), respectively . Average nAb concentrations from both serosurvey periods were 3,529 U / ml ( 95 % CI : 2,867 – 4,191 ) and 23,523 U / ml ( 95 % CI : 20,573-26,473 ), respectively . In the 2021 serosurvey , history of prior SARS-CoV-2 exposure ( i . e ., detectable anti-N antibodies ) yielded approximately 5-fold higher nAb concentrations , compared with no history of prior viral exposure ( 54,947 U / ml [ 95 % CI : 46423 – 63458 ] vs 11,272 U / ml [ 95 % CI 9,579 – 12,695 ]). Conclusion : In the 2020 serosurvey , conducted before vaccine availability , one in five participants had detectable anti-S and anti-N antibodies . Anti-S positivity ( 93 %) increased substantially in the 2021 serosurvey conducted after vaccines became widely available , whereas anti-N positivity remained stable . The high anti-S positivity is likely attributed to widespread vaccination in NYC during this period . Most participants with detectable anti-S antibodies produced functional nAbs against the SARS-CoV-2 S protein . Notably , nAb levels were higher in 2021 serosurvey participants with detectable anti-N antibodies , suggesting that prior exposure to SARS-CoV-2 may have provided better immunity in this cohort .

Presenter : Scott Hughes , shughes @ health . nyc . gov