Lab Matters Summer 2018 | Page 40

APHL 2018 Annual Meeting Poster Abstracts

Antimicrobial Resistance

Antimicrobial Resistance

Expanding Public Health Laboratory Capacity to Combat the Threat of Antibiotic-Resistant Neisseria gonorrhoeae: Antibiotic Resistance Laboratory Network, 2016 – 2017

C. D. Pham, J. Papp, K. Schlanger, E. Torrone, D. Trees, K. Gernert, E. Nash, K. Pettus, S. Sharpe, T. Hennig, E. Kersh, CDC AR-Ng Workgroup, AR Lab Network, Centers for Disease Control and Prevention, Atlanta, GA

Background: Antimicrobial susceptibility testing( AST) is not routinely performed for patient diagnosis and management of uncomplicated gonorrhea. Nonetheless, AST is critical for public health actions including preparedness, surveillance and control of antibiotic-resistant Neisseria gonorrhoeae( AR-Ng). The threat of AR-Ng, categorized as“ urgent” by the Centers for Disease Control and Prevention( CDC), has further highlighted the need to increase AST activity. In 2016, CDC established the Antibiotic Resistance Laboratory Network( ARLN) to support national lab capacity to detect and prevent the spread of AR threats. One of the goals of the ARLN is to build and maintain capacity for N. gonorrhoeae AST at the state public health labs.

Methods: In an effort to increase AR-Ng detection capacity, four of the seven regional labs in the ARLN are funded to perform AST on up to 20,000 N. gonorrhoeae isolates per year. Gonococcal isolates are obtained from patients presenting at 32 clinics that participate in CDC’ s Gonococcal Isolate Surveillance Project( GISP), enhanced GISP and the new AR gonorrhea response program, Strengthening the U. S. Response to Resistant Gonorrhea. These four labs perform agar dilution AST for ceftriaxone( CRO), cefixime( CFX), azithromycin( AZM), tetracycline, penicillin, gentamicin and ciprofloxacin to determine the minimum inhibitory concentrations( MICs). Isolates with MICs ≥ 0.125, ≥ 0.25, or ≥ 2 mg / ml to CRO, CFM and AZM, respectively are considered“ alert” isolates and are subjected to further examination and archival storage at CDC. These labs also have capacity for whole genome sequencing( WGS) on up to 5,000 N. gonorrhoeae isolates per year for analysis of AR markers.

Results: Washington State, Maryland, Tennessee and Texas public health labs successfully competed to perform AR-Ng testing. The Laboratory Reference and Research Branch at CDC provided laboratory support, AST training and proficiency testing panels to expedite capacity building. AR-Ng activities were initiated at all four labs by the end of 2017. From January-November 2017, AST was performed on 6,671 N. gonorrhoeae isolates and 290 identified alert isolates were sent to CDC. A majority of the identified alert isolates displayed elevated MIC for AZM. These four labs also performed WGS on 337 N. gonorrhoeae isolates.

Conclusions: The remarkable ability of N. gonorrhoeae to develop antibiotic resistance, in conjunction with the waning antibiotic arsenal against this pathogen, have necessitated public health action to increase AST laboratory capacity. In 2017, the CDC successfully implemented a robust program at four regional labs, within the AR Lab Network, to monitor AR-Ng. The ARLN is a national effort to both maintain traditional culture-based AST and expand genomic monitoring of AR markers in N. gonorrhoeae.

Presenter: Ellen Kersh, PhD, Centers for Disease Control and Prevention, Atlanta, GA, Phone: 404.639.2728, Email: egk6 @ cdc. gov

Surveillance Trends and Prevalence of Carbapenemase- Producing Enterobacteriaceae and other Carbapenemase- Producing Organisms in Washington State, 2012 – 2017

M. Precit 1, K. Kauber 2, M. D’ Angeli 2, K. Robinson 2, M. Tran 2, S. Weissman 3, B. Hiatt 2, S. Hun 1, T. Robinson 2, R. Gautom 2, W. Glover 2; 1 Centers for Disease Control and Prevention, Atlanta, GA,

2

Washington State Public Health Laboratories, Shoreline, WA,

3

University of Washington, Seattle, WA

Background: Carbapenemase-producing Enterobacteriaceae( CPE) and other carbapenemase-producing organisms( CPO) like Pseudomonas and Acinetobacter spp. are increasingly common causes of healthcare-associated infections. CPE and CPO isolates are often multidrug-resistant resulting in limited therapeutic options and poor clinical outcomes; moreover carbapenem-resistance( CR) can spread rapidly by horizontal gene transfer and clonal expansion amongst Gram-negative bacteria. Taken together, CPE / CPO pose significant public health concerns and systematic surveillance and prevalence studies are critical for tracking resistance and coordinating response.

Objective: Washington State Public Health Laboratories( WAPHL) began carbapenemase testing and surveillance for CR Gramnegative organisms in Oct. 2012 to study prevalence and distribution of carbapenemase genes, support infection prevention and capture population-based CPE / CPO infection incidence in WA State.

Methods: Bacterial isolates meeting the latest surveillance case definition of that time were solicited from clinical labs and tested using a phenotypic assay to detect carbapenemase production, if available( i. e., Modified Hodge Test or later the Modified Carbapenem Inactivation Method) and PCR to identify the five most common carbapenemase genes, KPC, NDM, OXA-48, VIM and IMP. Additionally, case-patient investigations were completed on carbapenemase-positive cases to determine suspected carbapenemase source( s). It should be noted that surveillance case definitions and testing methods have evolved over time and the data presented here captures results from various practices used between 2012-2017.

Results: From Oct. 2012- Dec. 2017, a total of 1,186 unique CR-isolates were tested at WAPHL. Enterobacter spp. were most common( 38.8 %), followed by Pseudomonas spp.( 23.6 %), E. coli( 20.8 %), Klebsiella spp.( 11.1 %), other Enterobacteriaceae( 2.8 %) and Acinetobacter spp.( 2.9 %). Overall, 105 isolates( 8.9 %) were positive for a carbapenemase by PCR. Klebsiella spp. were most likely to be carbapenamase-positive. A carbapenemase was detected in 36.4 % CR-Klebsiella spp., compared to 15.2 % in Other CR-Enterobacteriaceae, 12.1 % in CR-E. coli, 3.0 % in CR- Enterobacter spp., 5.9 % in CR-Acinetobacter spp. and 2.1 % in CR-Pseudomonas spp. KPC was the most common carbapenemase detected( 42.9 %), followed by NDM( 34.3 %), OXA-48( 15.2 %), VIM( 2.9 %), SME( 2.9 %) and IMP( 1.9 %). In WA, healthcare was the most likely source of KPC, while international healthcare or travel were probable sources of non KPC-carbapenemases.

Conclusions: CPE / CPO testing and surveillance are critical to determine prevalence and coordinate infection prevention of CR within an institution, state, or region. We report here that KPC, the most prevalent mechanism in the US, accounts for over a third of the carbapenemases in WA State.