Lab Matters Fall 2023 | Page 106

APHL 2023 POSTER ABSTRACTS

Prediction and Characterization of Proteae Tribe Isolates Carrying Class D carbapenemase genes — Antimicrobial Resistance Laboratory Network , 2017-2021

G . Orazi , A . G . Kent , K . Berhe , C . Longa , N . Wilmott , A . Bhatnagar , A . Laufer , A . C . Brown and S . Sabour , US Centers for Disease Control and Prevention

Through their ability to hydrolyze carbapenems , Ambler class D beta-lactamases endanger the clinical efficacy of these antibiotics . blaOXA-23-like , blaOXA-24 / 40-like , and blaOXA-58-like are predominantly found in Acinetobacter spp .; however , these genes have also been reported in Enterobacterales . At least ten reports from outside the United States describe their detection in Proteus mirabilis . These isolates were susceptible to carbapenems and third generation cephalosporins , but resistant to penicillins . Using this unique antimicrobial susceptibility testing ( AST ) profile , we investigated whether Proteae tribe ( Proteus , Providencia , and Morganella ) isolates tested in CDC ’ s Antimicrobial Resistance Laboratory Network harbored these Acinetobacter-associated class D genes . We also describe the frequency of Enterobacteralesassociated blaOXA-48-like among Proteae tribe isolates using PCR testing data . We analyzed AST and PCR data on 4,943 Proteae tribe isolates collected through the Network from 2017 — 2021 . Whole-genome sequencing ( WGS ) samples from over 10,000 Enterobacterales isolates collected through surveillance , outbreak , reference , and the Network were analyzed using CDC ’ s in-house bioinformatics pipeline ( QuAISAR-H ). All data were generated by public health laboratories or CDC . AST profiles of individual P . mirabilis isolates carrying blaOXA-23-like or blaOXA-58-like and current Clinical and Laboratory Standards Institute M100 breakpoints were used to identify isolates in CDC ’ s collection that met the above AST criteria . Among 4,943 Proteae tribe isolates , seven ( three P . mirabilis , three P . stuartii , and one P . rettgeri ) were PCR positive for blaOXA-48-like . WGS data were available for one of these isolates , a P . mirabilis found to carry the blaOXA-48-like variant , blaOXA-181 , on a 13-kb plasmid-associated contig . This isolate was susceptible to meropenem , ceftazidime , and cefepime . Although no other class D genes were detected among Proteae tribe isolates with available WGS data , two other Enterobacterales , one Klebsiella and one E . coli , were found to harbor Acinetobacterassociated class D genes . These WGS data were biased towards carbapenem-resistant isolates . One hundred additional isolates from the Network met the described AST criteria for potentially harboring other class D genes and are undergoing supplementary testing to identify and characterize any with a class D gene present . Using a large collection of contemporary isolates , we found that blaOXA-48-like are circulating in Proteae tribe members infrequently . The finding of blaOXA-181 on a 13-kb plasmid highlights the potential for rapid spread of class D genes . The presence of AST phenotypes that are potentially predictive of the presence of other class D genes indicates a need for targeted surveillance to better understand their frequency and molecular epidemiology .

Presenter : Giulia Orazi , tzn7 @ cdc . gov

Prevalence of Mycoplasma genitalium among High-risk Persons in Dallas County

M . Gearhart 1 , S . Athale 1 , D . A . Silva 1 , L . Short 1 , Emily Adhikari 2 ;

1

Dallas County Health and Human Services Public Health Laboratory , 2 Parkland Health and Hospital System

Background : Mycoplasma genitalium ( MG ), while not a nationally reportable or notifiable disease , is highly prevalent compared to other sexually transmitted infections ( STI ), e . g ., Chlamydia , Gonorrhea , and Trichomonas . A previous national meta-analysis of MG by Lisa Manhart , PhD , and colleagues in 2020 reported a prevalence of sexually active women ( 19.80 %) and men ( 16.50 %) between the ages of 15 and 24 . From these data , it is expected that prevalence in the population of individuals tested at the Dallas County Health and Human Services ( DCHHS ) Sexual Health Clinic ( SHC ) would represent high-risk for MG , and therefore warrant monitoring . Considering that persistent MG infection has been associated with adverse reproductive outcomes , determining prevalence is imperative to implement testing and direct treatment . It is the goal of this study to provide supportive evidence of MG prevalence in the DCHHS SHC population to justify a monitoring program . Aims / Purpose : To conduct a prevalence study , determining the burden of and risk factors for MG among the high-risk cohort of DCHHS SHC patients . Methods : Collect ten ( 10 ) reserve urine specimens submitted for Gonorrhea , Chlamydia , and Trichomonas testing at the DCHHS SHC every day until 400 specimens are collected . To obtain clinical and demographic data , a retrospective review will be conducted using Greenway Laboratory Information System ( LIS ). All specimens will be deidentified and tested for MG utilizing the Aptima MG NAAT Assay on the Hologic Panther System . Results will be analyzed for prevalence and adjusted ratios for sex , age , race , ethnicity , co-infection and symptom status using logistic regression via STATA . Results : This cohort , comprised of female ( 53.75 %) and male ( 46.25 %) groups , has the following disease prevalence for each STI : Chlamydia ( 11.00 %), Gonorrhea ( 6.75 %) and Trichomonas ( 4.50 %). Prevalence of co-infection is 3.50 %, with the most common co-infection being Chlamydia and Gonorrhea ( 2.75 %). The prevalence of all STIs is the highest in those 25 – 34 years of age ( 47.19 %), and second highest in those 15 – 24 years of age ( 34.83 %). Conclusions : In the reviewed literature , MG prevalence is similar to Chlamydia , often exceeding Gonorrhea ( Getman , et al ., 2016 ). If this trend follows in Dallas County , then MG is expected to be as prevalent as Chlamydia ( 11 %)— constituting a public health concern . Risk factors for MG include young age and coinfection with other STIs ( Manhart , et al ., 2020 ). This trend is currently being observed in the data to date . Young age , specifically between ages of 25 and 34 , have the highest prevalence of STIs . Though coinfection is currently observed to be low ( 3.50 %), it is anticipated to rise with the addition of MG results . The results of this study will aid in providing a reference range for subsequent verification studies and onboarding of the Aptima MG Assay for patient testing .

Presenter : Margaret Gearhart , gearhartm33 @ outlook . com