infectious diseases

by Anne M . Gaynor , PhD , manager , HHST

A final report of Gono-Caucus 2017 will be published in the future by APHL along with all of the presentations . The report will include a more complete summary , including the associated antibiotics . A public comment period on proposed changes will follow .

N . gonorrhoeae continues to develop resistance to the antibiotics used for treatment , necessitating ongoing surveillance of drug-resistance to inform treatment recommendations . Antimicrobial resistance acquired by N . gonorrhoeae tends to remain within the microbial population even in the absence of selective antimicrobial pressure . The terms “ multidrug resistant ” ( MDR ) and “ extensively drug resistant ” ( XDR ) have been used to describe N . gonorrhoeae that have become resistant to more than one class of antimicrobial agents . However , the classification of N . gonorrhoeae resistant phenotypes into MDR- or XDR- N . gonorrhoeae is complicated by changing treatment options that reflect the evolution of antimicrobial resistance . While there is a standardized classification scheme , 4 the use of the terms MDR and XDR have been inconsistent .

APHL , in collaboration with the CDC Division of STD Prevention , hosted Gono-Caucus 2017 in early January to bring together experts in the field of N . gonorrhoeae antimicrobial resistance to better define and discuss communication strategies involving standardized MDR and XDR definitions . The first day covered the current definitions of MDR bacteria used for other healthcare-associated infections and tuberculosis , implications of MDR N . gonorrhoeae , as well as data trends from the US and international surveillance systems of MDR N . gonorrhoeae , and genetic mutations associated with drugresistance . The second day moved to topics such as identifying treatment failures , drug distribution and penetration in various anatomic sites , the role of minimum inhibitory concentration ( MIC ) and its potential relevance to clinical outcomes , and clinical and public health responses to MDR N . gonorrhoeae . Discussion points included the standardization of MIC values used to define drug-resistance , the potential value of categorical resistance or use of terms such as “ reduced susceptibility ,” and the importance of a classification scheme that can be clearly and succinctly conveyed to Congress , the media , the US public , healthcare providers and laboratorians .

At the conclusion of the meeting , participants came up with two proposals for a classification scheme . Groups were asked to clearly and succinctly state their proposal for both MDR and XDR classification . In developing these proposals , the following topics were discussed :

• Inclusion and / or the role of genetic or genotypic data

• Potential changes in antimicrobial breakpoints ( which vary by country and by regulatory / oversight body ) or methodology to detect resistance

• Flexibility to address new or changing treatment recommendations

• The varied ability and usage of certain antibiotics .

Current and Proposed New Multi-Drug Resistant Classifications

Current 4 Proposal : New Proposal 2 : Modified Tapsall 4

Potential Outcomes N / A

Initial modeling indicates that the definition would result in stable level of MDR-GC over time . a

Initial modeling indicates that the definition would result in an increase in MDR-GC isolates over time . a

a . Trends in N . gonorrhoeae antimicrobial resistance demonstrate few remaining treatment options and increasing numbers of isolates resistant to multiple antimicrobial agents

References 1 . Centers for Disease Control and Prevention . Antibiotic Resistance Threats in the United States , 2013 . Available at : https :// www . cdc . gov / drugresistance / pdf / ar-threats-2013-508 . pdf 2 . World Health Organization . Antimicrobial Resistance : Global Report on Surveillance . 2014 . Available at : http :// apps . who . int / iris / bitstream / 10665 / 112642 / 1 / 9789241564748 _ eng . pdf

3 . Task Force for Combating Antibiotic-Resistant Bacteria . National Action Plan to Combat Antibiotic-Resistant Bacteria . 2015 . Available at : https :// obamawhitehouse . archives . gov / sites / default / files / docs / national _ action _ plan _ for _ combating _ antibotic-resistant _ bacteria . pdf

4 . Tapsall JW , Ndowa F , Lewis DA , Unemo M . Meeting the public health challenge of multidrug-and extensively drug-resistant Neisseria gonorrhoeae . Expert Rev Anti Infect Ther ., 2009:7 ( 7 ); 821-834