Azithromycin susceptibility of in the USA in 2017: a genomic analysis of surveillance data.

Background: The number of cases of gonorrhoea in the USA and worldwide caused by is increasing (555 608 reported US cases in 2017, and 87 million cases worldwide in 2016). Many countries report declining in vitro susceptibility of azithromycin, which is a concern because azithromycin and ceftriaxone are the recommended dual treatment in many countries. We aimed to identify strain types associated with decreased susceptibility to azithromycin.

Rationale for a Neisseria gonorrhoeae Susceptible-only Interpretive Breakpoint for Azithromycin.

Background: Azithromycin (AZI) is recommended with ceftriaxone (CRO) for treatment of uncomplicated gonococcal urethritis and cervicitis in the United States, and an AZI-susceptibility breakpoint is needed. Neither the Food and Drug Administration (FDA) nor the Clinical and Laboratory Standards Institute (CLSI) has set interpretive breakpoints for AZI susceptibility. As a result, AZI antimicrobial susceptibility testing (AST) cannot be interpreted using recognized standards.

Evidence of Recent Genomic Evolution in Gonococcal Strains With Decreased Susceptibility to Cephalosporins or Azithromycin in the United States, 2014-2016.

Background: Given the lack of new antimicrobials or a vaccine, understanding the evolutionary dynamics of Neisseria gonorrhoeae is a significant public and global health priority. We investigated the emergence and spread of gonococcal strains with decreased susceptibility to cephalosporins and azithromycin using detailed genomic analyses of gonococcal isolates collected in the United States, 2014-2016.

Methods: We sequenced genomes of 649 isolates collected through the Gonococcal Isolate Surveillance Project.