Gonococcal Isolate Surveillance Project Research Articles

Whole-genome sequencing resolves biochemical misidentification of Neisseria species from urogenital specimens.

Neisseria meningitidis (Nm) and Neisseria gonorrhoeae (Ng) are human pathogens that sometimes occupy the same anatomical niche. Ng, the causative agent of gonorrhea, infects 87 million individuals annually worldwide and is an urgent threat due to increasing drug resistance. Ng is a pathogen of the urogenital tract and may infect the oropharyngeal or rectal site, often asymptomatically. Conversely, Nm is an opportunistic pathogen. While often a commensal in the oropharyngeal tract, it is also the leading cause of bacterial meningitis with 1.2 million cases globally, causing significant morbidity and mortality. Horizontal gene transfer (HGT) is likely to occur between Ng and Nm due to their shared anatomical niches and genetic similarity, which poses challenges for accurate detection and treatment. Routine surveillance through the Gonococcal Isolate Surveillance Project and Strengthening the U.S. Response to Resistant Gonorrhea detected six concerning urogenital Neisseria isolates with contradicting species identification in Milwaukee (MIL). While all six isolates were positive for Ng using nucleic acid amplification testing (NAAT) and matrix-assisted laser desorption/ionization time of flight identified the isolates as Ng, two biochemical tests, Gonochek-II and API NH, classified them as Nm. To address this discrepancy, we performed whole-genome sequencing (WGS) using Illumina MiSeq on all isolates and employed various bioinformatics tools. Species detection analysis using BMScan, which uses WGS data, identified all isolates as Ng. Furthermore, Kraken revealed over 98% of WGS reads mapped to the Ng genome and <1% to Nm. Recombination analysis identified putative HGT in all MIL isolates within the γ-glutamyl transpeptidase (ggt) gene, a key component in the biochemical tests used to differentiate between Nm and Ng. Further analysis identified Nm as the source of HGT event. Specifically, the active Nm ggt gene replaced the Ng pseudogenes, ggt1 and ggt2. Together, this study demonstrates that closely related Neisseria species sharing a niche underwent HGT, which led to the misidentification of species following biochemical testing. Importantly, NAAT accurately detected Ng. The misidentification highlights the importance of using WGS to continually evaluate diagnostic or bacterial identification tests.

Personalizing the empiric treatment of gonorrhea using machine learning models.

Despite the emergence of antimicrobial-resistant (AMR) strains of Neisseria gonorrhoeae, the treatment of gonorrhea remains empiric and according to standardized guidelines, which are informed by the national prevalence of resistant strains. Yet, the prevalence of AMR varies substantially across geographic and demographic groups. We investigated whether data from the national surveillance system of AMR gonorrhea in the US could be used to personalize the empiric treatment of gonorrhea. We used data from the Gonococcal Isolate Surveillance Project collected between 2000-2010 to train and validate machine learning models to identify resistance to ciprofloxacin (CIP), one of the recommended first-line antibiotics until 2007. We used these models to personalize empiric treatments based on sexual behavior and geographic location and compared their performance with standardized guidelines, which recommended treatment with CIP, ceftriaxone (CRO), or cefixime (CFX) between 2005-2006, and either CRO or CFX between 2007-2010. Compared with standardized guidelines, the personalized treatments could have replaced 33% of CRO and CFX use with CIP while ensuring that 98% of patients were prescribed effective treatment during 2005-2010. The models maintained their performance over time and across geographic regions. Predictive models trained on data from national surveillance systems of AMR gonorrhea could be used to personalize the empiric treatment of gonorrhea based on patients' basic characteristics at the point of care. This approach could reduce the unnecessary use of newer antibiotics while maintaining the effectiveness of first-line therapy.

2687. Tetracycline Resistance in Neisseria gonorrhoeae Isolates Among Transgender Women and Men Who Have Sex with Men — eGISP and SURRG, 2018–2021

Abstract Background Doxycycline, a tetracycline analog, is being considered for use as post-exposure prophylaxis (PEP) to reduce bacterial sexually transmitted infections (STIs) among gay, bisexual, and other men who have sex with men (MSM) and transgender women. Pre-existing tetracycline resistance may contribute to the varied effectiveness of doxycycline in preventing Neisseria gonorrhoeae (GC). We examined trends in tetracycline resistance (TetR) and tetM plasmid-mediated high-level tetracycline resistance (TetHLR) among GC isolates collected from MSM and transgender women through national sentinel surveillance. Methods Genital (urethral, urine, vaginal or endocervical), pharyngeal and rectal GC isolates were collected from MSM and transgender women during 2018–2021 at 12 Enhanced Gonococcal Isolate Surveillance Project (eGISP) and 8 Strengthening the U.S. Response to Resistant Gonorrhea (SURRG) sites. We determined overall prevalence of TetR and TetHLR (minimum inhibitory concentration, MIC ≥2 µg/mL and MIC ≥16 µg/mL, respectively) among MSM and transgender women by anatomic site of infection and described annual trends among MSM. Results Among 10,853 isolates collected from 8,667 MSM, overall TetR prevalence was 31% (genital: 31%, pharyngeal: 32%, rectal: 29%), and annual TetR prevalence decreased during 2018–2021 (Table 1). Overall TetHLR prevalence among MSM was 13% (genital: 13%, pharyngeal: 12%, rectal: 12%) and annual TetHLR prevalence for genital and pharyngeal infections increased during 2018–2021. Among 108 isolates collected from 89 transgender women, overall TetR prevalence was 23% (genital: 19%, pharyngeal: 23%, rectal: 25%) and TetHLR prevalence was 9% (genital: 0%, pharyngeal: 10%, rectal: 12%), though numbers were small. Conclusion Approximately 1/3 of GC isolates collected from MSM and 1/4 of GC isolates collected from transgender women were tetracycline resistant. Prevalence of tetracycline resistance was similar across anatomic sites. Providers should continue to follow recommended screening and treatment guidelines for gonorrhea among persons using doxycycline as STI PEP. Additionally, given high levels of TetHLR, enhanced tetracycline resistance surveillance is needed with implementation of doxycycline as STI PEP. Disclosures All Authors: No reported disclosures

Genomic analysis of 1710 surveillance-based Neisseria gonorrhoeae isolates from the USA in 2019 identifies predominant strain types and chromosomal antimicrobial-resistance determinants.

This study characterized high-quality whole-genome sequences of a sentinel, surveillance-based collection of 1710 Neisseria gonorrhoeae (GC) isolates from 2019 collected in the USA as part of the Gonococcal Isolate Surveillance Project (GISP). It aims to provide a detailed report of strain diversity, phylogenetic relationships and resistance determinant profiles associated with reduced susceptibilities to antibiotics of concern. The 1710 isolates represented 164 multilocus sequence types and 21 predominant phylogenetic clades. Common genomic determinants defined most strains' phenotypic, reduced susceptibility to current and historic antibiotics (e.g. bla TEM plasmid for penicillin, tetM plasmid for tetracycline, gyrA for ciprofloxacin, 23S rRNA and/or mosaic mtr operon for azithromycin, and mosaic penA for cefixime and ceftriaxone). The most predominant phylogenetic clade accounted for 21 % of the isolates, included a majority of the isolates with low-level elevated MICs to azithromycin (2.0 µg ml-1), carried a mosaic mtr operon and variants in PorB, and showed expansion with respect to data previously reported from 2018. The second largest clade predominantly carried the GyrA S91F variant, was largely ciprofloxacin resistant (MIC ≥1.0 µg ml-1), and showed significant expansion with respect to 2018. Overall, a low proportion of isolates had medium- to high-level elevated MIC to azithromycin ((≥4.0 µg ml-1), based on C2611T or A2059G 23S rRNA variants). One isolate carried the penA 60.001 allele resulting in elevated MICs to cefixime and ceftriaxone of 1.0 µg ml-1. This high-resolution snapshot of genetic profiles of 1710 GC sequences, through a comparison with 2018 data (1479 GC sequences) within the sentinel system, highlights change in proportions and expansion of select GC strains and the associated genetic mechanisms of resistance. The knowledge gained through molecular surveillance may support rapid identification of outbreaks of concern. Continued monitoring may inform public health responses to limit the development and spread of antibiotic-resistant gonorrhoea.

Assessing the National Representativeness of Estimates of Antimicrobial-Resistant Urogenital Neisseria gonorrhoeae in US Men, Gonococcal Isolate Surveillance Project, 2008-2018.

The percentage of Neisseria gonorrhoeae (GC) isolates with resistance or elevated minimum inhibitory concentrations to antimicrobials has steadily increased. Current estimates are based on the Gonococcal Isolate Surveillance Project (GISP), a sentinel surveillance study of male GC in the United States. This analysis seeks to assess for adjustment before treating aggregated GISP estimates as nationally representative of all reported male urogenital infections. We used multilevel regression with poststratification (MRP) to compute national estimates of the proportion of antimicrobial resistance (AMR) (defined as exceeding minimum inhibitory concentration thresholds) in male GC using data from 2008 to 2018 GISP and case reports. Sensitivity analyses investigated the impact of analysis assumptions and unmeasured variables. We additionally produced estimates of 2018 AMR GC cases among US men. National estimates were consistent with unweighted estimates. The estimated proportion of incident AMR GC infections in men with urogenital GC in 2018 was 51.5% (95% confidence interval [CI], 50.1%-52.9%), equating to an estimated 366,300 incident AMR GC infections in US men aged 15 to 39 years. Estimates of AMR for tested antimicrobials in male GC infections in 2018 ranged from 0.16% (95% CI, 0.08%-0.24%) for ceftriaxone to 29.9% (95% CI, 28.6%-31.1%) for ciprofloxacin. Sensitivity analyses revealed that unmeasured data on sex of sex partners could substantially impact weighted estimates. Antimicrobial resistance among reported incident male urogenital GC infections remains rare for ceftriaxone, the current standard of care. Aggregated GISP data are generally representative of men in the US who are reported with urogenital gonorrhea.

Management of Neisseria gonorrhoeae in the United States: Summary of Evidence From the Development of the 2020 Gonorrhea Treatment Recommendations and the 2021 Centers for Disease Control and Prevention Sexually Transmitted Infection Treatment Guidelines.

Neisseria gonorrhoeae has developed resistance to all first-line recommended therapies, making gonococcal antimicrobial resistance a major public health concern given limited antibiotic options currently and an even smaller antimicrobial development pipeline. Since the release of the Centers for Disease Control and Prevention (CDC) 2015 STD Treatment Guidelines, azithromycin, part of the 2015 dual-drug treatment regimen, has had a rapid rise in resistance. The 2020 CDC Gonorrhea Treatment Recommendations and the 2021 Sexually Transmitted Infections (STI) Treatment Guidelines were developed weighing the priorities of treating the individual, protecting the population, and preventing antimicrobial resistance. Gonorrhea subject matter experts (SME) generated 8 key questions and conducted a literature review of updated data from 2013 to 2019 on gonorrhea antimicrobial resistance, treatment failures, clinical trials, and other key topics. More than 2200 abstracts were assessed, and 248 clinically relevant articles were thoroughly reviewed. SMEs also evaluated N gonorrhoeae antimicrobial resistance data from the Gonococcal Isolate Surveillance Project (GISP). Although there have been reports of ceftriaxone treatment failures internationally, GISP data suggest that ceftriaxone minimal inhibitory concentrations (MICs) have remained stable in the United States, with < 0.1% exhibiting an "alert value" MIC (> 0.25 mcg/mL). However, GISP documented a rapid rise in the proportion of isolates with an elevated MIC (≥ 2.0 mcg/mL) to azithromycin-nearly 5% in 2018. At the same time, new pharmacokinetic/pharmacodynamic data are available, and there is greater recognition of the need for antimicrobial stewardship. The 2021 CDC STI Treatment Guidelines now recommend 500mg ceftriaxone intramuscularly once for the treatment of uncomplicated gonorrhea at all anatomic sites. If coinfection with chlamydia has not been excluded, cotreatment with doxycycline 100mg twice daily for 7 days should be added. Few alternative therapies exist for persons with cephalosporin allergies; there are no recommended alternative therapies for N gonorrhoeae infection of the throat.

Loci for prediction of penicillin and tetracycline susceptibility in Neisseria gonorrhoeae: a genome-wide association study

SummaryBackgroundNeisseria gonorrhoeae poses an urgent public health threat because of increasing antimicrobial resistance; however, much of the circulating population remains susceptible to historical treatment regimens. Point-of-care diagnostics that report susceptibility could allow for reintroduction of these regimens, but development of such diagnostics has been restricted to ciprofloxacin, for which susceptibility can be predicted from a single locus. We aimed to define genetic variants associated with susceptibility to penicillin and tetracycline.MethodsWe collected publicly available global whole-genome sequencing data (n=12 045) from clinical N gonorrhoeae isolates, with phenotypic resistance data for penicillin (n=6935), and tetracycline (n=5727). Using conditional genome-wide association studies, we defined genetic variants associated with susceptibility to penicillin and tetracycline. We excluded isolates that could not be classified as either susceptible or resistant. To validate our results, we assembled 1479 genomes from the US Centers for Disease Control and Prevention (CDC)’s Gonococcal Isolate Surveillance Project, for which urethral specimens are collected at sentinel surveillance sites across the USA. We evaluated the sensitivity and specificity of susceptibility-associated alleles using Clinical & Laboratory Standards Institute breakpoints for susceptibility and non-resistance in both the global and validation datasets.FindingsIn our conditional penicillin genome-wide association study, the presence of a genetic variant defined by a non-mosaic penA allele without an insertion at codon 345 was associated with penicillin susceptibility and had the highest negative effect size (β) of significant variants (p=5·0×10–14, β –2·5). In combination with the absence of blaTEM, this variant predicted penicillin susceptibility with high specificity (99·8%) and modest sensitivity (36·7%). For tetracycline, the wildtype allele at rpsJ codon 57, encoding valine, was associated with tetracycline susceptibility (p=5·6×10–16, β –1·6) after conditioning on the presence of tetM. The combination of rpsJ codon 57 allele and tetM absence predicted tetracycline susceptibility with high specificity (97·2%) and sensitivity (88·7%).InterpretationAs few as two genetic loci can predict susceptibility to penicillin and tetracycline in N gonorrhoeae with high specificity. Molecular point-of-care diagnostics targeting these loci have the potential to increase available treatments for gonorrhoea.FundingNational Institute of Allergy and Infectious Diseases, the National Science Foundation, and the Smith Family Foundation.

Characterization of a Neisseria gonorrhoeae Ciprofloxacin panel for an antimicrobial resistant Isolate Bank.

ObjectivesNeisseria gonorrhoeae (gonococcus) infection is one of the most commonly reported nationally notifiable conditions in the United States. Gonococcus has developed antimicrobial resistance to each previously used antibiotic for gonorrhea therapy. However, some isolates may be still susceptible to no longer recommended, yet still effective antibiotics. This in turn suggests that targeted therapy could slow resistance development to currently recommended empirical treatments. We curated a gonococcal Ciprofloxacin Antibiotic Resistance Isolate Bank panel (Cipro-panel) as a tool for validating or developing new tests to determine ciprofloxacin susceptibility.MethodThe Cipro-panel was selected using whole genome sequencing, bioinformatic tools, and antimicrobial susceptibility testing (AST) data. Isolates were further selected based on nucleotide variations in gyrA and parC genes.ResultsWe selected 14 unique N. gonorrhoeae isolates from the 2006–2012 Gonococcal Isolate Surveillance Project (GISP) collection. They represented a wide range of antimicrobial susceptibility to ciprofloxacin and commonly observed nucleotide variations of gyrA and parC genes. This Cipro-panel consists of 5 isolates with resistant phenotypes (MIC > = 1 μg/mL), 8 isolates with susceptible phenotypes (MIC < = 0.06 μg/mL), and 1 isolate falling in the Clinical and Laboratory Standards Institute defined intermediate range. Among the gyrA variations we observed a total of 18 SNPs. Four positions had nonsynonymous changes (nucleotide positions 272, 284, 1093, and 1783). The first two positions (272 and 284) have been linked previously with resistance to ciprofloxacin (i.e. amino acid positions 91 and 95). For the parC gene, we observed a total of 21 possible SNPs. Eight of those SNPs resulted in non-synonymous amino acid changes. One location (amino acid 87) has been previously reported to be associated with ciprofloxacin resistance.ConclusionsThis Cipro-Panel is useful for researchers interested in developing clinical tests related to ciprofloxacin. It could also provide additional choices for validation, quality assurance purposes and improve antibiotic usage.

164. Antimicrobial Susceptibility of Urogenital and Extragenital Neisseria gonorrhoeae Isolates Among Men Who Have Sex with Men – SURRG and eGISP, 2018–2019

BackgroundExtragenital gonococcal infections are common among men who have sex with men (MSM); however, data comparing antimicrobial susceptibilities of urogenital and extragenital Neisseria gonorrhoeae isolates are limited. We investigated differences in gonococcal antimicrobial susceptibility by anatomic site among cisgender MSM using specimens collected through CDC’s enhanced Gonococcal Isolate Surveillance Project (eGISP) and Strengthening the U.S. Response to Resistant Gonorrhea (SURRG). MethodsDuring January 1, 2018–December 31, 2019, 12 eGISP and 8 SURRG sites collected urogenital, pharyngeal, and rectal isolates from cisgender MSM in STD clinics. Gonococcal isolates were sent to regional laboratories for antimicrobial susceptibility testing by agar dilution. To account for correlated observations, linear mixed-effects models were used to calculate geometric mean minimum inhibitory concentrations (MICs) and mixed-effects logistic regression models were used to calculate the proportion of isolates with elevated or resistant MICs; comparisons were made across anatomic sites.ResultsParticipating clinics collected 3,974 urethral, 1,553 rectal, and 1,049 pharyngeal isolates from 5,456 unique cisgender MSM. There were no significant differences in the geometric mean MICs for azithromycin, ciprofloxacin, penicillin, and tetracycline by anatomic site. For cefixime and ceftriaxone, geometric mean MICs for pharyngeal isolates were higher compared to anogenital isolates (p< 0.05). The proportion of isolates with elevated ceftriaxone MICs (≥ 0.125 µg/ml) at the pharynx (0.67%) was higher than at rectal (0.13%) and urethral (0.18%) sites (p< 0.05). ConclusionBased on data collected from multi-jurisdictional sentinel surveillance projects, antimicrobial susceptibility patterns of N. gonorrhoeae isolates may differ among MSM at extragenital sites, particularly at the pharynx. Continued investigation into gonococcal susceptibility patterns by anatomic site may be an important strategy to monitor and detect the emergence of antimicrobial resistant gonorrhea over time.Disclosures Olusegun O. Soge, PhD, Hologic Inc. (Grant/Research Support)SpeeDx Inc. (Grant/Research Support) Stephanie N. Taylor, MD, GARDP - GC Antibiotic Development (Scientific Research Study Investigator, To my institution.)GlaxoSmithKline (Grant/Research Support, Funds to my institution.)

Antimicrobial Susceptibility of Urogenital and Extragenital Neisseria gonorrhoeae Isolates Among Men Who Have Sex With Men: Strengthening the US Response to Resistant Gonorrhea and Enhanced Gonococcal Isolate Surveillance Project, 2018 to 2019.

We investigated differences in gonococcal antimicrobial susceptibility by anatomic site among cisgender men who have sex with men (MSM) using specimens collected through the Centers for Disease Control and Prevention's enhanced Gonococcal Isolate Surveillance Project and Strengthening the US Response to Resistant Gonorrhea. During the period January 1, 2018-December 31, 2019, 12 enhanced Gonococcal Isolate Surveillance Project and 8 Strengthening the US Response to Resistant Gonorrhea sites collected urogenital, pharyngeal, and rectal isolates from cisgender MSM in sexually transmitted disease clinics. Gonococcal isolates were sent to regional laboratories for antimicrobial susceptibility testing by agar dilution. To account for correlated observations, linear mixed-effects models were used to calculate geometric mean minimum inhibitory concentrations (MICs), and mixed-effects logistic regression models were used to calculate the proportion of isolates with elevated or resistant MICs; comparisons were made across anatomic sites. Participating clinics collected 3974 urethral, 1553 rectal, and 1049 pharyngeal isolates from 5456 unique cisgender MSM. There were no significant differences in the geometric mean MICs for azithromycin, ciprofloxacin, penicillin, and tetracycline by anatomic site. For cefixime and ceftriaxone, geometric mean MICs for pharyngeal isolates were higher compared with anogenital isolates (P < 0.05). The proportion of isolates with elevated ceftriaxone MICs (≥0.125 μg/mL) at the pharynx (0.67%) was higher than at rectal (0.13%) and urethral (0.18%) sites (P < 0.05). Based on data collected from multijurisdictional sentinel surveillance projects, antimicrobial susceptibility patterns of Neisseria gonorrhoeae isolates may differ among MSM at extragenital sites, particularly at the pharynx. Continued investigation into gonococcal susceptibility patterns by anatomic site may be an important strategy to monitor and detect the emergence of antimicrobial resistant gonorrhea over time.

Genomic Analysis of the Predominant Strains and Antimicrobial Resistance Determinants Within 1479 Neisseria gonorrhoeae Isolates From the US Gonococcal Isolate Surveillance Project in 2018.

The prevalence of Neisseria gonorrhoeae (GC) isolates with elevated minimum inhibitory concentrations to various antibiotics continues to rise in the United States and globally. Genomic analysis provides a powerful tool for surveillance of circulating strains, antimicrobial resistance determinants, and understanding of transmission through a population. Neisseria gonorrhoeae isolates collected from the US Gonococcal Isolate Surveillance Project in 2018 (n = 1479) were sequenced and characterized. Whole-genome sequencing was used to identify sequence types, antimicrobial resistance profiles, and phylogenetic relationships across demographic and geographic populations. Genetic characterization identified that (1) 80% of the GC isolates were represented in 33 multilocus sequence types, (2) isolates clustered in 23 major phylogenetic clusters with select phenotypic and demographic prevalence, and (3) common antimicrobial resistance determinants associated with low-level or high-level decreased susceptibility or resistance to relevant antibiotics. Characterization of this 2018 Gonococcal Isolate Surveillance Project genomic data set, which is the largest US whole-genome sequence data set to date, sets the basis for future prospective studies, and establishes a genomic baseline of GC populations for local and national monitoring.

Phylogenomic analysis reveals persistence of gonococcal strains with reduced-susceptibility to extended-spectrum cephalosporins and mosaic penA-34

The recent emergence of strains of Neisseria gonorrhoeae associated with treatment failures to ceftriaxone, the foundation of current treatment options, has raised concerns over a future of untreatable gonorrhea. Current global data on gonococcal strains suggest that several lineages, predominately characterized by mosaic penA alleles, are associated with elevated minimum inhibitory concentrations (MICs) to extended spectrum cephalosporins (ESCs). Here we report on whole genome sequences of 813 N. gonorrhoeae isolates collected through the Gonococcal Isolate Surveillance Project in the United States. Phylogenomic analysis revealed that one persisting lineage (Clade A, multi-locus sequence type [MLST] ST1901) with mosaic penA-34 alleles, contained the majority of isolates with elevated MICs to ESCs. We provide evidence that an ancestor to the globally circulating MLST ST1901 clones potentially emerged around the early to mid-20th century (1944, credibility intervals [CI]: 1935–1953), predating the introduction of cephalosporins, but coinciding with the use of penicillin. Such results indicate that drugs with novel mechanisms of action are needed as these strains continue to persist and disseminate globally.

2020 STD Prevention Conference: Disrupting Epidemics and Dismantling Disparities in the Time of COVID-19.

2020 STD Prevention Conference: Disrupting Epidemics and Dismantling Disparities in the Time of COVID-19.

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

The number of cases of gonorrhoea in the USA and worldwide caused by Neisseria gonorrhoeae 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. We did a genomic analysis of N gonorrhoeae isolates obtained by the US Gonococcal Isolate Surveillance Project. Isolates were whole-genome sequenced based on decreased susceptibility to azithromycin (minimal inhibitory concentration [MIC] ≥2 μg/mL, using agar dilution antibiotic susceptibility testing) and geographical representation. Bioinformatic analyses established genomic diversity, strain population dynamics, and antimicrobial resistance profiles. 410 isolates were sorted into more than 20 unique phylogenetic clades. One predominant persistent clade (consisting of 97 isolates) included the most isolates with azithromycin MICs of 2 μg/mL or higher (61 of 97 [63%] vs 59 of 311 [19%]; p<0·0001) and carried a mosaic mtr (multiple transferable resistance) locus (68 of 97 [70%] vs two of 313 [1%]; p<0·0001). Of the remaining 313 isolates, 57 (18%) had decreased susceptibility to azithromycin (MIC ≥4 μg/mL), which was attributed to 23S rRNA variants (56 of 57 [98%]) and formed phylogenetically diverse clades, showing various levels of clonal expansion. Reduced azithromycin susceptibility was associated with expanding and persistent clades harbouring two well described resistance mechanisms, mosaic mtr locus and 23S rRNA variants. Understanding the role of recombination, particularly within the mtr locus, on the fitness and expansion of strains with decreased susceptibility has important implications for the public health response to minimise gonorrhoea transmission. US Centers for Disease Control and Prevention (CDC), CDC Combating Antibiotic Resistant Bacteria initiative, Oak Ridge Institute for Science Education, US Department of Energy/CDC/Emory University, National Institutes of Health, and Biomedical Laboratory Research and Development Service of the US Department of Veterans Affairs.

Utility of MALDI-TOF MS for differentiation of Neisseria gonorrhoeae isolates with dissimilar azithromycin susceptibility profiles.

Antibiotic-resistant gonorrhoea has been a chronic public health burden since the mid-1930s. Recent emergence of isolates resistant to the current recommended antibiotics for gonorrhoea further magnifies the threat of untreatable gonorrhoea. The lack of new, effective antibiotics highlights the need for better understanding of the population structure of Neisseria gonorrhoeae in order to provide greater insight on how to curtail the spread of antimicrobial-resistant N. gonorrhoeae. To explore a potential application of MALDI-TOF MS to differentiate N. gonorrhoeae displaying different levels of susceptibility to the antibiotic azithromycin. We conducted MALDI-TOF MS using the Bruker Biotyper on 392 N. gonorrhoeae isolates collected through the Gonococcal Isolate Surveillance Project (GISP) and/or the Strengthening the United States Response to Resistant Gonorrhea (SURRG) project. The MALDI-TOF MS spectra were visually analysed to assess the presence of distinctive peak(s). Statistical analysis was performed to assess the relationship between gonococcal isolates with the distinct protein peak and antibiotic susceptibility. In this study, we were able to differentiate N. gonorrhoeae isolates into two distinct subpopulations using MALDI-TOF MS. Isolates were distinguished by the presence or absence of a spectral peak at 11 300 Da. Notably, these two groups exhibited different levels of susceptibility to azithromycin. We have shown that in addition to its ability to identify N. gonorrhoeae, MALDI-TOF MS could also be used to differentiate gonococcal isolates with different levels of susceptibility to azithromycin.

434. Concurrent Gonococcal Infections with Differing Susceptibility Results from the Enhanced Gonococcal Isolate Surveillance Project (eGISP)

BackgroundConcurrent gonococcal infections could impact treatment success in cases of anatomic site-specific strains with different antimicrobial susceptibilities; however, little is known about same-patient differences in susceptibility as most antibiotic resistance surveillance is based on only male urethral isolates.MethodsIn August 2017, the enhanced Gonococcal Isolate Surveillance Project (eGISP) began collecting male and female genital and extragenital gonococcal isolates from patients in 12 STD clinics. Minimum Inhibitory Concentrations (MICs) for penicillin, tetracycline, ciprofloxacin, gentamicin, cefixime, ceftriaxone and azithromycin were determined by agar dilution. We identified patients with isolates from multiple anatomic sites of infection collected during the same clinic visit. Isolate sets were categorized as pairs or triplets based on the number of culture positive anatomic sites. We identified same-patient isolate sets with differing MICs (≥2 dilution difference) for each antibiotic, and identified if the difference affected susceptibility categorization. All isolates in a set were tested in the same batch run by the same laboratory.ResultsFrom August 2017-February 2019, 280 isolates were collected from 135 patients, representing 136 isolate sets (128 pairs and 8 triplets); one patient contributed 2 isolate sets. Of the 136 isolate sets, the majority (72; 53%) were grouped as genital and pharyngeal isolates (Table 1). Overall, 33 isolate sets (24%) had differing MICs for ≥1 antibiotic and 21 sets (15%) for ≥2 antibiotics. Across all anatomical site combinations, differing MICs were most common for ciprofloxacin (10.3%), penicillin (9.6%) and azithromycin (9.6%). Only 18 isolate sets (13%) demonstrated differing MICs where an isolate was considered susceptible and another was considered resistant or reduced-susceptible.ConclusionAmong persons with concurrent gonococcal infections, MICs can vary by ≥2 dilutions between sites and may change susceptibility interpretation. Variation by the anatomic site can result from initial infection with multiple strains or differential development of resistance after infection. Continued surveillance of multi-site infections could help understand resistance development and inform patient management. Disclosures All authors: No reported disclosures.

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

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. We sequenced genomes of 649 isolates collected through the Gonococcal Isolate Surveillance Project. We examined the genetic relatedness of isolates and assessed associations between clades and various genotypic and phenotypic combinations. We identified a large and clonal lineage of strains (MLST ST9363) associated with elevated azithromycin minimum inhibitory concentration (AZIem), characterized by a mosaic mtr locus (C substitution in the mtrR promoter, mosaic mtrR and mtrD). Mutations in 23S rRNA were sporadically distributed among AZIem strains. Another clonal group (MLST ST1901) possessed 7 unique PBP2 patterns, and it shared common mutations in other genes associated with cephalosporin resistance. Whole-genome sequencing methods can enhance monitoring of antimicrobial resistant gonococcal strains by identifying gonococcal populations containing mutations of concern. These methods could inform the development of point-of-care diagnostic tests designed to determine the specific antibiotic susceptibility profile of a gonococcal infection in a patient.

1167. Trends in Multi-Drug-Resistant Gonorrhea, Gonococcal Isolate Surveillance Project, United States, 1987–2016

Background Neisseria gonorrhoeae’s ability to develop resistance to antibiotics used for treatment and a limited development of new therapies have made this organism one of three urgent threat pathogens in the United States. We provide the first report of US trends in multi-drug-resistant (MDR) and extensively-drug-resistant (XDR) gonorrhea.MethodsThe Gonococcal Isolate Surveillance Project (GISP) monitors trends in antimicrobial susceptibility in N. gonorrhoeae in the United States. Antimicrobial susceptibility testing by agar dilution is performed on urethral isolates from male patients at participating STD clinics. Minimum inhibitory concentration (MIC) are used to identify isolates with resistance or reduced susceptibility using the following criteria: fluoroquinolones (ciprofloxacin [MIC ≥1.0 μg/mL]) and elevated MICs to cephalosporins (cefixime [MIC ≥0.25 μg/mL], ceftriaxone [MIC ≥0.25 μg/mL]) and macrolides (azithromycin [MIC ≥1.0 μg/mL before 2005 and ≥2.0 μg/mL 2005–2016]). In this analysis, MDR is defined as resistance or elevated MICs to ≥2 classes of antimicrobials; XDR as resistance or elevated MICs to ≥3 classes. This classification excludes penicillin and tetracycline due to their long history and high prevalence of gonococcal resistance.ResultsDuring 1987–2016, 159,445 isolates were collected through GISP. In 1998, the first MDR strains were identified. Although only 0.04% of isolates that year, these isolates showed elevated MICs to both cephalosporins and macrolides. By 2010, 1.0% of GISP isolates were MDR with elevated MICs or resistance to two of the cephalosporins, macrolides, or fluoroquinolones. In 2011, the proportion of isolates that were MDR peaked at 1.3%. In 2016, after minor fluctuations, 1.1% of GISP isolates were considered MDR. Only one occurrence of XDR, in 2011, has been seen in GISP. The strain was resistant to fluoroquinolones with elevated MICs to both cephalosporins and macrolides.ConclusionMDR and XDR gonorrhea have remained low over the past three decades; however, dual treatment with cephalosporins and macrolides is the last remaining recommended therapy for N. gonorrhoeae. Until new treatment options become available, a combination of surveillance and ensuring appropriate treatment are needed to delay further resistance.Disclosures All authors: No reported disclosures.

125. eGISP: Enhanced Surveillance of Neisseria gonorrhoeae Antimicrobial Susceptibility in the United States

BackgroundThe Gonococcal Isolate Surveillance Project (GISP), which monitors trends in N. gonorrhoeae susceptibility among men with gonococcal urethritis in sexually transmitted disease (STD) clinics, has informed treatment recommendations for 3 decades. However, it has been speculated that susceptibility patterns may differ in women, as well as in the pharynx and rectum. We describe preliminary findings from the enhanced GISP (eGISP), which expands surveillance to pharyngeal, rectal, and endocervical isolates.MethodsIn August 2017, select jurisdictions were funded to collect urogenital and extragenital specimens from men and women seen in participating STD clinics. Positive gonorrhea cultures were sent to regional laboratories for antimicrobial susceptibility testing (AST) by agar dilution. Isolates with elevated minimum inhibitory concentration (MIC) to azithromycin (AZI) (MIC ≥2.0 μg/mL), cefixime (CFX) (MIC ≥0.25 μg/mL), and/or ceftriaxone (CRO) (MIC ≥0.125 μg/mL) were designated as Alert isolates. Clinical and epidemiological data were linked to AST results.ResultsFrom August 2017 to February 2018, 4 clinics in 4 jurisdictions submitted 468 positive gonococcal specimens for AST; 36.1% were from men who have sex with men (MSM), 51.9% from men who have sex with women (MSW), and 12.0% from women. Overall, 71.8% were urethral, 7.9% endocervical, 7.1% rectal, and 13.2% pharyngeal. Seventy-two isolates (15.4%) were Alerts: 97.2% (N = 70) had elevated MICs to AZI, 2.8% (N = 2) had elevated MICs to CFX, and none had elevated MICs to CRO. No isolate had elevated MICs to both AZI and CFX. Among MSM, 15.9% of urogenital isolates and 16.1% of extragenital isolates had an elevated AZI MIC. Among MSW, 11.8% of urogenital isolates and 14.3% of pharyngeal isolates had an elevated AZI MIC. Among women, 24.3% of endocervical isolates and 26.3% of extragenital isolates had an elevated AZI MIC.ConclusionPreliminary eGISP data suggest that enhanced surveillance of pharyngeal, rectal, and endocervical isolates is feasible and that elevated MICs to azithromycin are common among males and females. Including isolates from extragenital anatomic sites and women may help strengthen N. gonorrhoeae surveillance capacity.Disclosures All authors: No reported disclosures.

Narrative Review: Assessment of Neisseria gonorrhoeae Infections Among Men Who Have Sex With Men in National and Sentinel Surveillance Systems in the United States.

To assess trends in Neisseria gonorrhoeae among gay, bisexual, and other men who have sex with men (MSM), we reviewed existing and published gonorrhea surveillance data in the United States. Data identified in this review include the following: national gonorrhea case report data and data from 3 other surveillance programs, the Gonococcal Isolate Surveillance Project (GISP), the STD Surveillance Network (SSuN), and National HIV Behavioral Surveillance.Rates of reported cases of gonorrhea among men increased 54.8% in 2006 to 2015 compared with a 2.6% increase among women. Since 2012, the rate of reported gonorrhea cases among men surpassed the rate among women; the male-to-female case rate ratio increased from 0.97 in 2012 to 1.31 in 2015. The proportion of gonococcal urethral isolates collected in the Gonococcal Isolate Surveillance Project that were collected from MSM increased from 21.5% to 38.1% in 2006 to 2015. In 2009 to 2015, the percent of MSM who tested positive for rectal and oropharyngeal gonorrhea in sexually transmitted disease (STD) clinics increased by 73.4% and 12.6%, respectively. Estimated rates of gonorrhea among MSM increased by 151% in 2010 to 2015 in jurisdictions participating in the STD Surveillance Network. Data from the National HIV Behavioral Surveillance demonstrate that testing for gonorrhea among MSM increased by 23.1% between 2011 and 2014.Together, surveillance data suggest a disproportionate burden of gonorrhea among MSM in the United States and suggest increases in both screening and disease in recent years. Because each data source has inherent limitations and biases, examining these data from different systems together strengthens this conclusion.