Lab Matters Fall 2023 | Page 56

APHL 2023 POSTER ABSTRACTS

against other non-target pathogens . The time required from sample input to detection is 58 minutes . Conclusions : We have developed a completely integrated , sensitive , specific and a rapid < 1h test , which can be used for routine surveillance of C . auris in health care facilities .

Presenter : Sukalyani Banik , sb1712 @ njms . rutgers . edu

Development of Screening and Sequencing Capacity for Candida auris Epidemiology in Nevada

A . Gorzalski , M . Pandori , D . Siao ; Nevada State Public Health Laboratory

In 2021 , the largest outbreak of Candida auris in the United States started in Southern Nevada . The outbreak necessitated the development , validation , and implementation of a diagnostic screening test for C . auris . Here we discuss a CLIA validation of a laboratory developed test for the diagnostic detection of C . auris . Our validated methods include scalable extractions using the Maxwell RSC 48 ( Promega ) on axilla and groin swabs . C . auris DNA is detected using a modified version of CDC ’ s real-time quantitative PCR . Nevada State Public Health Lab has now performed this test on over 2000 specimens , and even used this method to conduct environmental surveillance in a long-term healthcare facility . In addition , we developed , implemented , and validated C . auris DNA extraction methods ( Promega ) and automated library preparation ( Hamilton ) of isolated C . auris cultures for next generation sequencing using the Illumina MiniSeq and NovaSeq platforms . Whole genome analysis of patient isolates has allowed for robust genetic epidemiology of this ongoing outbreak , revealing early on that the outbreak is actually two concurrent outbreaks of distinct C . auris clades . As of now , Nevada State Epidemiology requires our PCR screening be performed on all intakes at long-term healthcare facilities , and NSPHL has a goal to sequence every C . auris specimen in Nevada to continue this real-time disease surveillance .

Presenter : Danielle Denise Siao , danielle . siao @ gmail . com

Development of the First Automated Antibiotic Susceptibility Test System for Neisseria gonorrhoeae

S . Puttaswamy , M . D . Newton , A . Isakson , J . McPeake , T . Hadfield and R . R . Swiger ; Acenxion Biosystems

Here we describe the development of the first automated Antibiotic Susceptibility Test system specific to Neisseria gonorrhoeae . The system consists of hardware ; software & firmware ; and consumables that are single-use disposable . The hardware consists of expandable or scalable instrumentation providing environmental conditions that house individual reader units . The software & firmware ensure reliable real-time monitoring of system parameters and results including real-time data display and automated report generation . The consumable is a single-use , disposable , multiwell microfluidic cassette permitting simultaneous testing of multiple antibiotics and concentrations together with controls . The results of analysis of gonococcal strains are typically generated in under 6 hours and are based on phenotypic and microbroth dilution methodology and analysis . The microfluidic cassettes can be formatted to acquire results from minimal inhibitory concentrations ( MIC ) or susceptibility / intermediate / resistant ( S / I / R ) analysis . We show results from analysis of strains including those from the CDC / FDA Antibiotic Resistance ( AR ) Bank .

Presenter : Sachidevi Puttaswamy , sachi @ acxbio . com

Early Detection and Diagnosis of Acute Human Immunodeficiency Virus , Type 1 Infections Using a Pooling Algorithm — Dallas , Texas

M . C . Ty 1 , C . Lopez 2 , C . Nwankwo 2 , S . Berno 2 , D . A . Silva 2 , J . Stringer 2 , L . Short 2 ; 1 US Centers for Disease Control and Prevention , 2 Dallas County Health and Human Services Public Health Laboratory

Background : Acute Human Immunodeficiency Virus type 1 infection ( AHI ) contributes to 40 % of new HIV transmissions ; early detection of AHI is necessary to reduce new HIV infections . As AHIs cannot be detected by traditional serological markers , Dallas County ( Texas ) Public Health Laboratory ( PHL ) previously used the Aptima HIV-1 RNA Qualitative Assay to differentially detect HIV-1 RNA to identify AHIs . Since this assay was recently discontinued , DCHHS PHL will transition to the Aptima HIV-1 Quant Dx Assay , which detects and quantifies HIV-1 RNA in vitro with the automated Panther Hologic system . Given a relatively low local AHI prevalence rate and assay expense , DCHHS PHL developed and validated two serum specimen pooling algorithms to reduce the cost per detected AHI . The use of a more sensitive and fully automated test for pooled immunoassay HIV-1 negative specimens could dramatically increase the number of AHIs detected and contribute to the comprehensive national End the HIV epidemic ( EHE ) initiative . Methods : Two pooling algorithms ( pools of five and 10 immunoassay HIV-1 negative specimens ) were tested for accuracy , precision , analytical specificity and analytical sensitivity . If a pooled sample yielded a positive result , all samples in the pool were retested individually to identify the AHI specimens . Results : Validations found that the pooling algorithm for the Aptima HIV-1 Quant Dx were precise and had analytical specificity of 100 %. Test accuracy was 98.75 % with an individual sample limit of detection of 63.86 copies / mL for pools of five and 295.34 copies / mL for pools of 10 specimens . DCHHS PHL decided to implement the pools of five approach in their clinical testing algorithm . During June – November 2022 , a total of 7,651 specimens were tested using the five-pooled algorithm . Of 1,522 pools assayed , seven pools were positive , and 13 AHIs were detected . Two detected AHIs had virus levels below the Aptima HIV-1 RNA Qualitative Assay detection limit and would not have been detected with this previous approach . Conclusions : The HIV-1 Quant Dx Assay testing of pooled immunoassay negative specimens is an automated , more sensitive test and will better support Dallas County ’ s efforts to detect AHIs and contribute to the EHE initiative .

Presenter : Maureen Ty , riv9 @ cdc . gov

Establishing a Workflow for Analysis of the Nasal Microbial and Viral Species , and Host Transcriptome from a Single Human Nasal Swab

K . Griffith , Y . Wang , R . Kumari , M . Sheth , P . Ranjan , J . Pohl , S . Gangappa , S . Sambhara , A . Kumar ; US Centers for Disease Control and Prevention

The human microbiome is composed of unique combinations of microbial and a viral species that inhabit human skin and mucosal surfaces , such as the nasal passages and