Poster presentations | 2021
P139\u2005A Phylogenomic Survey of Disseminated Gonococcal Infection Isolates in the United States (2019–2020)
Abstract
Background In December 2019, Centers for Disease Control and Prevention (CDC) released a Dear Colleagues Letter describing best practices for investigation of Disseminated Gonococcal Infection (DGI) cases which stressed the importance of culture from sterile and mucosal sites for additional analysis including genomic sequencing. The objective of sequencing was to understand the diversity of DGI isolates and explore the extent of genetically related isolate clusters in the US. Methods Between 2019 and 2020, CDC conducted sequencing on submitted DGI isolates using the Illumina MiSeq platform. Separately, the Michigan Department of Health and Human Services sequenced isolates submitted by laboratories in Michigan. Core genome Single Nucleotide Polymorphism (SNP) analysis was performed using snippy and the FA19 strain as a reference sequence. Detection of selected antibiotic resistance markers and multilocus sequencing typing (MLST) alleles was conducted using the Gonorrhea AMR Profiler and Typing Tool. Results We analyzed 45 isolates submitted by 7 states representing a total of 12 MLST sequence types (ST). The majority (66.7%) of these STs are among the top 25 STs found in a representative dataset of isolates sequenced from the Gonococcal Isolate Surveillance Program in 2018. We also identified 3 clusters of genetically related DGI isolates including 14 isolates from Michigan with a mean difference of 22 SNPs (range: 4–32), 5 isolates from North Carolina with a mean difference of 12 SNPs (range:8–28), and 2 isolates from North Carolina differing by 11 SNPs. All genomes examined contained wild type 23S rRNA markers (positions 2059 and 2611) and non-mosaic penA alleles. Notably, >85% of the sequences contained the porB1a allele, previously associated with serum resistance. Conclusion Isolates recovered from DGI cases are genetically diverse and frequently share STs associated with circulating isolates recovered from uncomplicated gonorrhea. The detection of DGI isolate clusters highlights the need for further epidemiological investigation.