Last data update: Apr 22, 2024. (Total: 46599 publications since 2009)
Records 1-30 (of 81 Records) |
Query Trace: Kersh EN[original query] |
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Novel strain of multidrug non-susceptible Neisseria gonorrhoeae in the USA
Reimche JL , Pham CD , Joseph SJ , Hutton S , Cartee JC , Ruan Y , Breaux M , Ivanof C , Joshi A , DeMartino M , Kirby JE , Barbee LA , Kersh EN , Roosevelt KA , Hsu KK . Lancet Infect Dis 2024 Unsuccessful treatment of gonorrhoea has not yet occurred in the USA, and cases of gonorrhoea that are non-susceptible to cephalosporins have been rare. In 2019, non-susceptibility to ceftriaxone conferred by the mosaic penA 60.001 allele was found in a Neisseria gonorrhoeae multilocus sequence type (MLST) 1901 isolate from Nevada.1 In this Correspondence, we present two additional US cases of the penA 60.001 allele identified in MLST 8123, an emerging international multidrug non-susceptible N gonorrhoeae lineage. Although these cases responded to ceftriaxone treatment, N gonorrhoeae isolates from the first known patient (case 1) demonstrated in-vitro non-susceptibility to ceftriaxone as well as non-susceptibility or resistance to drugs previously recommended for front-line treatment. | | In August, 2022, N gonorrhoeae grown from urine culture from a patient with urethritis in primary care in Massachusetts displayed non-susceptibility to cephalosporins (the minimum inhibitory concentrations were 1·0 μg/mL for ceftriaxone and >1·0 μg/mL for cefixime by agar dilution; the minimum inhibitory concentration for cefixime was 1·5 μg/mL by gradient strip) and azithromycin and resistance to ciprofloxacin, penicillin, and tetracycline (appendix pp 6–7). Antimicrobial susceptibility testing was done with gradient strips at the state public health laboratory Massachusetts and then confirmed via agar dilution at the US Centers for Disease Control and Prevention (CDC). The patient (case 1) had already been successfully diagnosed on nucleic acid amplification test (NAAT) with gonorrhoea and was given 500 mg ceftriaxone intramuscularly and asked to return to primary care where, 9 days after treatment, he was asymptomatic, had normal results during examination, and tested negative by urine culture and pharyngeal and rectal NAAT recommended by the Massachusetts sexually transmitted diseases programme to document N gonorrhoeae clearance from any site of infection. The patient reported that he had not travelled outside USA in the 60 days before onset of symptoms. He disclosed female sex worker contacts, but insufficient information was provided to trace the contacts. |
Advantages and limitations of current diagnostic laboratory approaches in syphilis and congenital syphilis
Cao W , Thorpe PG , O'Callaghan K , Kersh EN . Expert Rev Anti Infect Ther 2023 21 (12) 1339-1354 INTRODUCTION: The reemergence of syphilis, especially congenital syphilis, presents a significant public health threat. Accurate diagnosis of syphilis depends on recognition of a constellation of symptoms, review of medical and sexual history, and multiple laboratory tests. While reliable, current tests for syphilis can be difficult to interpret, which can lead to delays in treatment. AREA COVERED: This review summarizes the major advantages and limitations of available diagnostic laboratory methods for syphilis, provides an update on recent advances in laboratory tools, and highlights the urgent need for coordinated efforts to create new tools to halt the resurgence of syphilis. EXPERT OPINION: In syphilis, the wide variety of short-lived signs and symptoms followed by periods of latency create diagnostics challenges. Currently available laboratory tests, when positive, require additional information to interpret (prior testing, treatment, and sexual history). Point-of-care tests that can rapidly and accurately detect both treponemal and non-treponemal antibodies would be a huge step toward reducing test turnaround time and time to treatment. Incorporating biological insights and technology innovations to advance the development of direct detection assays is urgently needed. A comprehensive coordinated effort is critical to stem the tide of rising syphilis in the United States and globally. |
Global emergence and dissemination of Neisseria gonorrhoeae ST-9363 isolates with reduced susceptibility to azithromycin (preprint)
Joseph SJ , Thomas Iv JC , Schmerer MW , Cartee J , St Cyr S , Schlanger K , Kersh EN , Raphael BH , Gernert KM . bioRxiv 2021 2021.08.05.455198 Neisseria gonorrhoeae multi-locus sequence type (ST) 9363 genogroup isolates have been associated with reduced azithromycin susceptibility (AZMrs) and show evidence of clonal expansion in the U.S. Here we analyze a global collection of ST-9363 genogroup genomes to shed light on the emergence and dissemination of this strain. The global population structure of ST-9363 genogroup falls into three lineages: Basal, European, and North American; with 32 clades within all lineages. Although, ST-9363 genogroup is inferred to have originated from Asia in the mid-19th century; we estimate the three modern lineages emerged from Europe in the late 1970s to early 1980s. The European lineage appears to have emerged and expanded from around 1986 to 1998, spreading into North America and Oceania in the mid-2000s with multiple introductions, along with multiple secondary reintroductions into Europe. Our results suggest two separate acquisition events of mosaic mtrR and mtrR promoter alleles: first during 2009-2011 and again during the 2012-2013 time, facilitating the clonal expansion of this genogroup with AZMrs in the U.S. By tracking phylodynamic evolutionary trajectories of clades that share distinct demography as well as population-based genomic statistics, we demonstrate how recombination and selective pressures in the mtrCDE efflux operon granted a fitness advantage to establish ST-9363 as a successful gonococcal lineage in the U.S. and elsewhere. Although it is difficult to pinpoint the exact timing and emergence of this young genogroup, it remains critically important to continue monitoring it, as it could acquire additional resistance markers.Competing Interest StatementThe authors have declared no competing interest. |
Mechanistic basis for decreased antimicrobial susceptibility in a clinical isolate of Neisseria gonorrhoeae possessing a mosaic-like mtr efflux pump locus (preprint)
Rouquette-Loughlin CE , Reimche JL , Balthazar JT , Dhulipala V , Gernert KM , Kersh EN , Pham CD , Pettus K , Abrams AJ , Trees DL , St Cyr S , Shafer WM . bioRxiv 2018 448712 Recent reports suggest that mosaic-like sequences within the mtr (multiple transferable resistance) efflux pump locus of Neisseria gonorrhoeae likely originating from commensal Neisseria sp. by transformation can increase the ability of gonococci to resist structurally diverse antimicrobials. Thus, acquisition of numerous nucleotide changes within the mtrR gene encoding the transcriptional repressor (MtrR) of the mtrCDE efflux pump-encoding operon or overlapping promoter region for both along with those that cause amino acid changes in the MtrD transporter protein were recently reported to decrease gonococcal susceptibility to numerous antimicrobials, including azithromycin (Azi) (Wadsworth et al. 2018. MBio. doi.org/10.1128/mBio.01419-18). We performed detailed genetic and molecular studies to define the mechanistic basis for why such strains can exhibit decreased susceptibility to MtrCDE antimicrobial substrates including Azi. We report that a strong cis-acting transcriptional impact of a single nucleotide change within the -35 hexamer of the mtrCDE promoter as well gain-of-function amino acid changes at the C-terminal region of MtrD can mechanistically account for the decreased antimicrobial susceptibility of gonococci with a mosaic-like mtr locus.IMPORTANCE Historically, after introduction of an antibiotic for treatment of gonorrhea, strains of N. gonorrhoeae emerge that display clinical resistance due to spontaneous mutation or acquisition of resistance genes. Genetic exchange between members of the Neisseria genus occurring by transformation can cause significant changes in gonococci that impact the structure of an antibiotic target or expression of genes involved in resistance. The results presented herein provide a framework for understanding how mosaic-like DNA sequences from commensal Neisseria that recombine within the gonococcal mtr efflux pump locus function to decrease bacterial susceptibility to antimicrobials including antibiotics used in therapy of gonorrhea. |
Selective whole genome amplification as a tool to enrich specimens with low Treponema pallidum genomic DNA copies for whole genome sequencing (preprint)
Thurlow CM , Joseph SJ , Ganova-Raeva L , Katz SS , Pereira L , Chen C , Debra A , Vilfort K , Workowski K , Cohen SE , Reno H , Sun Y , Burroughs M , Sheth M , Chi KH , Danavall D , Philip SS , Cao W , Kersh EN , Pillay A . bioRxiv 2021 10 Downstream next generation sequencing (NGS) of the syphilis spirochete Treponema pallidum subspecies pallidum (T. pallidum) is hindered by low bacterial loads and the overwhelming presence of background metagenomic DNA in clinical specimens. In this study, we investigated selective whole genome amplification (SWGA) utilizing multiple displacement amplification (MDA) in conjunction with custom oligonucleotides with an increased specificity for the T. pallidum genome, and the capture and removal of CpG-methylated host DNA using the NEBNext Microbiome DNA Enrichment Kit followed by MDA with the REPLI-g Single Cell Kit as enrichment methods to improve the yields of T. pallidum DNA in isolates and lesion specimens from syphilis patients. Sequencing was performed using the Illumina MiSeq v2 500 cycle or NovaSeq 6000 SP platform. These two enrichment methods led to 93-98% genome coverage at 5 reads/site in 5 clinical specimens from the United States and rabbit propagated isolates, containing >14 T. pallidum genomic copies/ul of sample for SWGA and >129 genomic copies/ul for CpG methylation capture with MDA. Variant analysis using sequencing data derived from SWGA-enriched specimens, showed that all 5 clinical strains had the A2058G mutation associated with azithromycin resistance. SWGA is a robust method that allows direct whole genome sequencing (WGS) of specimens containing very low numbers of T. pallidum, which have been challenging until now. Copyright The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. This article is a US Government work. It is not subject to copyright under 17 USC 105 and is also made available for use under a CC0 license. |
Considerations for endpoint titer determination in syphilis testing using newly marketed, automated rapid plasma reagin instruments
Shukla M , Pereira L , Sun Y , Fakile YF , Kersh EN , Cao W . Public Health Rep 2023 333549231176007 Syphilis is a sexually transmitted disease (STD) caused by the bacterium Treponema pallidum, subspecies pallidum (T. pallidum).1 The resurgence of syphilis in the last 2 decades is a major public health concern in the United States. In 2020, a total of 133 945 cases of all stages of syphilis were reported in the United States, an increase of more than 70% since 2015. The national rate of congenital syphilis has increased 254% since 2016. In 2020, a total of 2148 cases of congenital syphilis were reported, including 149 congenital syphilis–related stillbirths and infant deaths.2 However, syphilis diagnosis is still challenging, partially because of overlapping and ambiguous clinical presentation, particularly during early infection.3 For laboratory testing, darkfield microscopy examinations and direct molecular detection of T. pallidum from clinical specimens are definitive methods for diagnosing early syphilis, but both methods are currently not widely performed at local, reference, or public health laboratories and have challenges in identifying asymptomatic or early-stage infection without the presence of visible lesions for suitable specimen collection.4 Darkfield microscopy requires special equipment and experienced operators for reliable results.5 US Food and Drug Administration (FDA)–cleared molecular tests for syphilis are still not available, and laboratory-developed molecular tests are limited in availability. Therefore, serological tests that detect treponemal and nontreponemal antibodies remain the mainstay for routine laboratory diagnosis of active syphilis infection.6 |
Evaluation of three automated nontreponemal rapid plasma reagin (RPR) tests for the laboratory diagnosis of syphilis
Shukla MR , Pereira L , Gaynor AM , Sun Y , Edwards D , Simmons T , Andrews CW , Park IU , Hong J , Cao W , Kersh EN , Fakile Y . J Clin Microbiol 2023 61 (6) e0016823 Automated nontreponemal rapid plasma reagin (RPR) tests were recently introduced in the United States for syphilis testing and limited performance data are available. In collaboration with the Association of Public Health Laboratories, three public health laboratories (PHL) were chosen through a competitive selection process to evaluate the performance of three FDA-cleared automated RPR test systems: BioPlex 2200 Syphilis Total & RPR assay (Bio-Rad Laboratories), AIX 1000 (Gold Standard Diagnostics), and ASI Evolution (Arlington Scientific). Panels prepared at the CDC included: a qualitative panel comprised of 734 syphilis reactive/nonreactive sera; a quantitative panel of 50 syphilis reactive sera (RPR titer 1:64 to 1:1,024); and a reproducibility panel of 15 nonreactive and reactive sera (RPR titer 1:1 to 1:64). Panels were shipped frozen to the PHL and tested on the automated RPR systems following manufacturers' instructions. Prior test results were blinded to all laboratories. When compared to manual RPR (Arlington Scientific) performed at the CDC as a reference test, the qualitative panel results demonstrated an overall concordance of 95.9% for AIX 1000, 94.6% for ASI Evolution, and 92.6% for Bioplex RPR; quantitative panel showed within range titer of 2-fold for 94% of specimens for AIX 1000, 68% for ASI Evolution, and 64% for BioPlex RPR, and the reproducibility testing panel demonstrated point estimates ranging from 69 to 95%. Automated RPR instruments could reduce turnaround time and minimize interpretation errors. However, additional evaluations with more specimens could assist laboratories with implementing automated RPR tests and understanding their limitations. |
Genomic analysis of 1710 surveillance-based Neisseria gonorrhoeae isolates from the USA in 2019 identifies predominant strain types and chromosomal antimicrobial-resistance determinants
Reimche JL , Clemons AA , Chivukula VL , Joseph SJ , Schmerer MW , Pham CD , Schlanger K , St Cyr SB , Kersh EN , Gernert KM . Microb Genom 2023 9 (5) 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. |
Advances in Sexually Transmitted Infection Testing at Home and in Nonclinical Settings Close to the Home.
Kersh EN . Sex Transm Dis 2022 49 S12-s14 A commentary on recent successes and challenges for home STI specimen collection, for point-of-care test usage close to the home, and implications of COVID-19 self-tests for future STI self-test development. |
Selective Whole-Genome Amplification as a Tool to Enrich Specimens with Low Treponema pallidum Genomic DNA Copies for Whole-Genome Sequencing.
Thurlow CM , Joseph SJ , Ganova-Raeva L , Katz SS , Pereira L , Chen C , Debra A , Vilfort K , Workowski K , Cohen SE , Reno H , Sun Y , Burroughs M , Sheth M , Chi KH , Danavall D , Philip SS , Cao W , Kersh EN , Pillay A . mSphere 2022 7 (3) e0000922 Downstream next-generation sequencing (NGS) of the syphilis spirochete Treponema pallidum subspecies pallidum (T. pallidum) is hindered by low bacterial loads and the overwhelming presence of background metagenomic DNA in clinical specimens. In this study, we investigated selective whole-genome amplification (SWGA) utilizing multiple displacement amplification (MDA) in conjunction with custom oligonucleotides with an increased specificity for the T. pallidum genome and the capture and removal of 5'-C-phosphate-G-3' (CpG) methylated host DNA using the NEBNext Microbiome DNA enrichment kit followed by MDA with the REPLI-g single cell kit as enrichment methods to improve the yields of T. pallidum DNA in isolates and lesion specimens from syphilis patients. Sequencing was performed using the Illumina MiSeq v2 500 cycle or NovaSeq 6000 SP platform. These two enrichment methods led to 93 to 98% genome coverage at 5 reads/site in 5 clinical specimens from the United States and rabbit-propagated isolates, containing >14 T. pallidum genomic copies/μL of sample for SWGA and >129 genomic copies/μL for CpG methylation capture with MDA. Variant analysis using sequencing data derived from SWGA-enriched specimens showed that all 5 clinical strains had the A2058G mutation associated with azithromycin resistance. SWGA is a robust method that allows direct whole-genome sequencing (WGS) of specimens containing very low numbers of T. pallidum, which has been challenging until now. IMPORTANCE Syphilis is a sexually transmitted, disseminated acute and chronic infection caused by the bacterial pathogen Treponema pallidum subspecies pallidum. Primary syphilis typically presents as single or multiple mucocutaneous lesions and, if left untreated, can progress through multiple stages with various clinical manifestations. Molecular studies often rely on direct amplification of DNA sequences from clinical specimens; however, this can be impacted by inadequate samples due to disease progression or timing of patients seeking clinical care. While genotyping has provided important data on circulating strains over the past 2 decades, WGS data are needed to better understand strain diversity, perform evolutionary tracing, and monitor antimicrobial resistance markers. The significance of our research is the development of an SWGA DNA enrichment method that expands the range of clinical specimens that can be directly sequenced to include samples with low numbers of T. pallidum. |
Characterization of a Neisseria gonorrhoeae Ciprofloxacin panel for an antimicrobial resistant Isolate Bank.
Liu H , Tang K , Pham CD , Schmerer M , Kersh EN , Raphael BH . PLoS One 2022 17 (3) e0264149 OBJECTIVES: Neisseria 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. METHOD: The 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. RESULTS: We 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 g/mL), 8 isolates with susceptible phenotypes (MIC < = 0.06 g/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. CONCLUSIONS: This 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. |
Gonococcal Clinical Strains Bearing a Common gdhR Single Nucleotide Polymorphism That Results in Enhanced Expression of the Virulence Gene lctP Frequently Possess a mtrR Promoter Mutation That Decreases Antibiotic Susceptibility.
Ayala JC , Schmerer MW , Kersh EN , Unemo M , Shafer WM . mBio 2022 13 (2) e0027622 GdhR is a transcriptional repressor of the virulence factor gene lctP, which encodes a unique l-lactate permease that has been linked to pathogenesis of Neisseria gonorrhoeae, and loss of gdhR can confer increased fitness of gonococci in a female mouse model of lower genital tract infection. In this work, we identified a single nucleotide polymorphism (SNP) in gdhR, which is often present in both recent and historical gonococcal clinical strains and results in a proline (P)-to-serine (S) change at amino acid position 6 (P6S) of GdhR. This mutation (gdhR6) was found to reduce GdhR transcriptional repression at lctP in gonococcal strains containing the mutant protein compared to wild-type GdhR. By using purified recombinant proteins and in vitro DNA-binding and cross-linking experiments, we found that gdhR6 impairs the DNA-binding activity of GdhR at lctP without an apparent effect on protein oligomerization. By analyzing a panel of U.S. (from 2017 to 2018) and Danish (1928 to 2013) clinical isolates, we observed a statistical association between gdhR6 and the previously described adenine deletion in the promoter of mtrR (mtrR-P A-del), encoding the repressor (MtrR) of the mtrCDE operon that encodes the MtrCDE multidrug efflux pump that can export antibiotics, host antimicrobials, and biocides. The frequent association of gdhR6 with the mtrR promoter mutation in these clinical isolates suggests that it has persisted in this genetic background to enhance lctP expression, thereby promoting virulence. IMPORTANCE We report the frequent appearance of a novel SNP in the gdhR gene (gdhR6) possessed by Neisseria gonorrhoeae. The resulting amino acid change in the GdhR protein resulted in enhanced expression of a virulence gene (lctP) that has been suggested to promote gonococcal survival during infection. The mutant GdhR protein expressed by gdhR6 had a reduced ability to bind to its target DNA sequence upstream of lctP. Interestingly, gdhR6 was found in clinical gonococcal strains isolated in the United States and Denmark at a high frequency and was frequently associated with a mutation in the promoter of the gene encoding a repressor (MtrR) of both the mtrCDE antimicrobial efflux pump operon and gdhR. Given this frequent association and the known impact of these regulatory mutations, we propose that virulence and antibiotic resistance properties are often phenotypically linked in contemporary gonococcal strains. |
Chlamydia trachomatis variants escaping detection in the Aptima Combo 2® assay in the United States.
Katz SS , Danavall DC , Morris MR , Herrod BP , Dale SE , Nye MB , Kersh EN , Kirkcaldy RD , Raphael BH . Sex Transm Dis 2022 49 (6) 448-452 BACKGROUND: The Aptima Combo 2 (AC2) assay manufactured by Hologic, Inc. detects Neisseria gonorrhoeae (NG) and/or Chlamydia trachomatis (CT) in urogenital and extragenital specimens by targeting either a 16S rRNA (NG) or 23S rRNA (CT) region. In 2019, a mutation (C1515T) in the 23S rRNA region was reported to cause false negative/equivocal results in specimens collected in Finland. Specimens containing this variant (Fl-nvCT) were also discovered internationally. Working with specimens submitted to a large commercial laboratory, we sought to determine if this variant was also present in the United States. METHODS: A subset (N = 401) of specimens tested with the AC2 assay collected during a five-week period in late 2019/early 2020 were evaluated using an updated AC2 assay. RESULTS: While the FI-nvCT variant was not detected within this specimen panel, two CT variants containing 23S rRNA mutations (A1518G, G1526A) were identified. The updated AC2 assay targeting an additional region of the 23S rRNA detected both of these variants. A retrospective study of >18 million AC2 results tested between 2018-2019 did not display a decrease in CT positivity. CONCLUSIONS: Although we did not detect the Fl-nvCT variant among US specimens, we show evidence that the low occurrence of similar diagnostic escape mutants can be detected with an updated AC2 assay using multiple 23S rRNA targets. |
Evaluation of the effect of extended refrigerated storage of serum and plasma specimens on syphilis serologic test results
Sun Y , Shukla MR , Deutsch J , Cao W , Fakile Y , Kersh EN , Pereira LE . Diagn Microbiol Infect Dis 2022 102 (2) 115588 The effect of extended refrigerated storage of 14 serum and plasma specimens on 5 syphilis serologic tests was evaluated for 16 weeks. Higher stability of nontreponemal and treponemal antibodies in serum was recorded compared to plasma. Described work may provide insights on refrigerated specimens' stability and suitability for syphilis tests. |
Global emergence and dissemination of Neisseria gonorrhoeae ST-9363 isolates with reduced susceptibility to azithromycin.
Joseph SJ , Thomas Iv JC , Schmerer MW , Cartee J , St Cyr S , Schlanger K , Kersh EN , Raphael BH , Gernert KM . Genome Biol Evol 2021 14 (1) Neisseria gonorrhoeae multi-locus sequence type (ST) 9363 core-genogroup isolates have been associated with reduced azithromycin susceptibility (AZMrs) and show evidence of clonal expansion in the U.S. Here we analyze a global collection of ST-9363 core-genogroup genomes to shed light on the emergence and dissemination of this strain. The global population structure of ST-9363 core-genogroup falls into three lineages: Basal, European, and North American; with 32 clades within all lineages. Although, ST-9363 core-genogroup is inferred to have originated from Asia in the mid-19th century; we estimate the three modern lineages emerged from Europe in the late 1970s to early 1980s. The European lineage appears to have emerged and expanded from around 1986 to 1998, spreading into North America and Oceania in the mid-2000s with multiple introductions, along with multiple secondary reintroductions into Europe. Our results suggest two separate acquisition events of mosaic mtrR and mtrR promoter alleles: first during 2009-2011 and again during the 2012-2013 time, facilitating the clonal expansion of this core-genogroup with AZMrs in the U.S. By tracking phylodynamic evolutionary trajectories of clades that share distinct demography as well as population-based genomic statistics, we demonstrate how recombination and selective pressures in the mtrCDE efflux operon granted a fitness advantage to establish ST-9363 as a successful gonococcal lineage in the U.S. and elsewhere. Although it is difficult to pinpoint the exact timing and emergence of this young core-genogroup, it remains critically important to continue monitoring it, as it could acquire additional resistance markers. |
Evaluation of a laboratory-developed multiplex real-time PCR assay for diagnosis of syphilis, herpes and chancroid genital ulcers in four public health laboratories in the USA.
Koralur M , Chen CY , Pillay A , White B , Pettus K , Chi KH , Stringer J , Aroh C , Dasu T , Bhattacharyya S , Perkins K , Chen J , Riner D , Soehnlen M , Cao W , Gaynor AM , Kersh EN . Sex Transm Infect 2021 98 (6) 448-450 OBJECTIVE: To evaluate the field performance of a multiplex PCR (M-PCR) assay for detection of herpes simplex virus (HSV)-1 and HSV-2, Treponema pallidum (T. pallidum) and Haemophilus ducreyi (H. ducreyi) in genital ulcer disease (GUD) specimens. METHODS: GUD M-PCR was performed on 186 remnant specimens, previously collected for HSV testing, by four public health laboratories (PHLs) and the Laboratory Reference and Research Branch (LRRB) at the Centers for Disease Control and Prevention. The results from the PHLs were compared with those of LRRB, which served as the reference testing method, and percentage agreement was calculated. RESULTS: HSV was detected in 31 of 52 (59.6%), 20 of 40 (50%), 43 of 44 (97.7%) and 19 of 50 (38.0%) specimens from PHL1, PHL2, PHL3 and PHL4, respectively. There were seven discrepant results for HSV, and the overall percent agreement between the PHLs and the LRRB was 94%-100%, with a kappa value of 0.922, which demonstrates high agreement. T. pallidum was identified in 7 of 51 (13.7%) specimens from PHL1 with 94.1% agreement and in 2 of 40 (5.0%) specimens from PHL2 with 100% agreement. The LRRB identified three additional T. pallidum-positive specimens from PHL1. The kappa value (0.849) for T. pallidum testing suggests good agreement. Consistent with the LRRB results, no T. pallidum was detected in specimens from PHL3 and PHL4, and H. ducreyi was not detected at any of the study sites. CONCLUSIONS: The GUD M-PCR assay performed well in four independent PHLs and 12 suspected syphilis cases were identified in this study. The M-PCR assay could provide improved diagnostic options for GUD infections in state and local PHLs. |
Implementation and evaluation of gradient strip antimicrobial susceptibility testing in US public health laboratories to respond to resistant gonorrhea
Raphael BH , Pham CD , Sharpe S , Mauk K , Harvey A , Khubbar M , Triplett L , Soge OO , Denny M , Palavecino EL , Finney R , Olsen A , Carlson J , St Cyr SB , Schlanger K , Kersh EN . Sex Transm Dis 2021 48 S157-S160 BACKGROUND: Gradient strip antimicrobial susceptibility testing (AST) using Etest® is conducted by local public health jurisdictions participating in the Strengthening the U.S. Response to Resistant Gonorrhea (SURRG) program to inform public health responses to resistant gonorrhea. Proficiency testing results across the participating laboratories were analyzed and a comparison of Etest® with the agar dilution method was conducted. METHODS: Laboratories participating in SURRG performed Etest® for azithromycin (AZM), cefixime (CFX), and ceftriaxone (CRO). Concurrence between minimum inhibitory concentrations (MICs) obtained with Etest® versus the agar dilution method using corresponding isolates was defined as +/- 1 double dilution. Specific levels of reduced susceptibility were termed "alerts" and included isolates with the following MICs: ≥ 2.0 μg/ml (AZM), ≥ 0.25 μg/ml (CFX), and ≥ 0.125 μg/ml (CRO). Categorical (alert/non-alert) agreement was calculated for MICs determined using Etest® and agar dilution methods. RESULTS: SURRG laboratories had high proficiency testing scores (≥98%) and low levels of inter-laboratory variations in MICs. The overall concurrence of MICs (essential agreement) determined using agar dilution and Etest® was 96% (CRO), 96% (CFX), and 95% (AZM). Depending on the antibiotic tested, between 27-66% of isolates with alert MICs determined by Etest® also had alert MICs using the reference agar dilution methodology, however most of these alert MICs were detected at threshold levels. CONCLUSIONS: This study demonstrates that MICs produced by SURRG laboratories using Etest® have a high level of concurrence with agar dilution. Although confirmation of specific alert MICs varied, Etest® facilities rapid detection and response to emerging resistant gonorrhea. |
A commentary on current diagnostic challenges and research needs for evaluating reproductive sequelae of sexually transmitted infections
Kersh EN , Geisler WM . J Infect Dis 2021 224 S72-s74 Advancing the understanding of pelvic inflammatory disease (PID) requires access to advanced diagnostic approaches for evaluating reproductive sequelae of sexually transmitted infections (STIs). Current limitations of clinical criteria and advanced imaging technologies for diagnosing reproductive sequelae make diagnosis and surveillance of PID a challenge. We summarize and comment on major challenges in diagnostic evaluation of reproductive sequelae: limited point-of-care clinical diagnostic options for reproductive sequelae, economic and geographical obstacles to accessing state-of-the-art diagnostics, an expanding list of STIs that may cause reproductive sequelae and the complexities in evaluating them, and the need for coordinated research efforts to systematically evaluate biomarkers with gold-standard, well-defined specimens and associated clinical data. The future use of biomarkers in readily accessible mucosal or blood-derived specimens as a noninvasive approach to determining STI etiologies may be fruitful and requires more research. Biomarkers under consideration include cytokines, STI-specific antibody responses, and mRNA transcriptional profiles of inflammatory markers. |
Assessment and utility of 2 Chlamydia trachomatis Pgp3 serological assays for seroprevalence studies among women in the United States
Danavall DC , Gwyn S , Anyalechi GE , Bowden KE , Hong J , Kirkcaldy RD , Bernstein KT , Kersh EN , Martin D , Raphael BH . Diagn Microbiol Infect Dis 2021 101 (2) 115480 Two plasmid gene protein (Pgp3)-based serological assays, the Pgp3-ELISA and multiplex bead assay (Pgp3-MBA), were compared and used to estimate seropositivity of Chlamydia trachomatis (CT) among females 14 to 39 years old participating in the National Health and Nutrition Examination Survey between 2013-2016. Of the 2,201 specimens tested, 502 (29.5%, 95% CI 27.6-31.5) were positive using Pgp3-ELISA and 624 (28.4%, 95% CI 26.5-30.3) were positive using Pgp3-MBA. The overall agreement between the assays was 87.7%. Corresponding nucleic acid amplification test (NAAT) results were available for 1,725 specimens (from women 18-39 years old); of these, 42 (2.4%, 95% CI 1.8-3.3) were CT NAAT-positive. Most of the CT NAAT-positive specimens had corresponding positive serological assay results; 33 (78.6%, 95% CI 62.8-89.2) were Pgp3-ELISA-positive and 36 (85.7%, 95% CI 70.8-94.1) were Pgp3-MBA-positive. Although Pgp3-ELISA and Pgp3-MBA demonstrated equivalent performance in this study, an advantage of the Pgp3-MBA over Pgp3-ELISA is that it is well suited for high sample throughput applications. |
Exploring and comparing the structure of sexual networks affected by Neisseria gonorrhoeae using sexual partner services investigation and genomic data.
Town K , Learner ER , Chivukula VL , Mauk K , Reimche JL , Schmerer MW , Black J , Pathela P , Bhattacharyya S , Kerani RP , Gieseker KE , Fukuda A , Sankaran M , McNeil CJ , Spicknall IH , Raphael BH , St Cyr SB , Bernstein K , Kersh EN , Kirkcaldy RD , Schlanger K , Gernert KM . Sex Transm Dis 2021 48 S131-S136 BACKGROUND: Sexual networks are difficult to construct due to incomplete sexual partner data. The proximity of people within a network may be inferred from genetically similar infections. We explored genomic data combined with partner services investigation (PSI) data to extend our understanding of sexual networks affected by Neisseria gonorrhoeae (NG). METHODS: We used 2017-2019 PSI and whole-genome sequencing (WGS) data from eight jurisdictions participating in CDC's Strengthening the United States Response to Resistant Gonorrhea (SURRG) project. Clusters were identified from sexual contacts and through genetically similar NG isolates. Sexual mixing patterns were characterized by describing the clusters by the individual's gender and gender of their sex partners. RESULTS: Our study included 4,627 diagnoses of NG infection (81% sequenced), 2,455 people received a PSI, 393 people were negative contacts of cases, and 495 contacts with unknown NG status. We identified 823 distinct clusters using PSI data combined with WGS data. Of cases that were not linked to any other case using PSI data, 37% were linked when using WGS data. Overall, 40% of PSI cases were allocated to a larger cluster when PSI and WGS data were combined compared with PSI data alone. Mixed clusters containing women, men who report sex with women, and men who report sex with men were common when using the WGS data either alone or in combination with the PSI data. CONCLUSIONS: Combining PSI and WGS data improves our understanding of sexual network connectivity. |
A New Call to Action to Combat an Old Nemesis: Addressing Rising Congenital Syphilis Rates in the United States
Machefsky AM , Loosier PS , Cramer R , Bowen VB , Kersh EN , Tao G , Gift TL , Hogben M , Carry M , Ludovic JA , Thorpe P , Bachmann LH . J Womens Health (Larchmt) 2021 30 (7) 920-926 Congenital syphilis (CS) is on the rise in the United States and is a growing public health concern. CS is an infection with Treponema pallidum in an infant or fetus, acquired via transplacental transmission when a pregnant woman has untreated or inadequately treated syphilis. Pregnant women with untreated syphilis are more likely to experience pregnancies complicated by stillbirth, prematurity, low birth weight, and early infant death, while their children can develop clinical manifestations of CS such as hepatosplenomegaly, bone abnormalities, developmental delays, and hearing loss. One of the ways CS can be prevented is by identifying and treating infected women during pregnancy with a benzathine penicillin G regimen that is both appropriate for the maternal stage of syphilis and initiated at least 30 days prior to delivery. In this article we discuss many of the challenges faced by both public health and healthcare systems with regards to this preventable infection, summarize missed opportunities for CS prevention, and provide practical solutions for future CS prevention strategies. |
Phylogenomic analysis reveals persistence of gonococcal strains with reduced-susceptibility to extended-spectrum cephalosporins and mosaic penA-34.
Thomas 4th JC , Joseph SJ , Cartee JC , Pham CD , Schmerer MW , Schlanger K , St Cyr SB , Kersh EN , Raphael BH . Nat Commun 2021 12 (1) 3801 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. |
At-home Specimen Self-Collection and Self-Testing for STI Screening Demand Accelerated by the COVID-19 Pandemic - A Review of Laboratory Implementation Issues.
Kersh EN , Shukla M , Raphael BH , Habel M , Park I . J Clin Microbiol 2021 59 (11) Jcm0264620 The idea of specimen self-collection or self-STI testing is not new. In 2019, the World Health Organization (WHO) published the "WHO Consolidated Guideline on Self-Care Interventions for Health" as a first installment in a planned series for various diseases (8). The first document focused on "Sexual and Reproductive Health and Rights". Self-care including self-testing has the readily apparent benefits of privacy, confidentiality, speed, convenience, and access if the price is affordable. It is "people-centered" (9) and enables active participation in one's own health. It is also a health system approach as it can reduce burden on stretched systems with world-wide shortages in medical personnel or other barriers to health care access. Potential risks include: low specimen return rates, uncertain follow-up (linkage to care including treatment, repeat testing including test of cure, partner notification, counseling on risk reduction), unintended/unnecessary use (resulting in false positives with their own set of associated problems), incorrect use, lack of understanding of window periods (resulting in false negatives), lack of surveillance data generation, among other issues (9). The WHO systematically reviewed evidence for self-testing or specimen self-collection for GC, CT and syphilis, including US studies, and published a meta-analysis of available evidence (9). Programs offering self-collection of samples increased overall uptake of STI testing services (RR: 2.941, 95% CI 1.188 to 7.281) and case finding (RR: 2.166, 95% CI1.043 to 4.498), prior to the pandemic (9). U. S. laboratory research on the equivalence and/or superiority of self-collected versus provider-collected specimens for test sensitivity was reported by Gaydos et al (summarized or referenced in (10)). Based on this evidence, WHO issued a new recommendation in 2019 "Self-collection of samples for Neisseria gonorrhoeae and Chlamydia trachomatis should be made available as an additional approach to deliver STI testing services for individuals using STI testing services" (8). In addition, WHO issued a new and conditional recommendation: "Self-collection of samples for Treponema pallidum (syphilis) and Trichomonas vaginalis may be considered as an additional approach to deliver STI testing services for Individuals using STI testing services" (8). Thus, even before the COVID-19 pandemic, substantial expert agreement existed concerning benefits of this approach. |
Genomic analysis of the predominant strains and antimicrobial resistance determinants within 1479 Neisseria gonorrhoeae isolates from the U.S. Gonococcal Isolate Surveillance Project in 2018.
Reimche JL , Chivukula VL , Schmerer MW , Joseph SJ , Pham CD , Schlanger K , St Cyr SB , Weinstock HS , Raphael BH , Kersh EN , Gernert KM . Sex Transm Dis 2021 48 S78-S87 BACKGROUND: The prevalence of Neisseria gonorrhoeae (GC) isolates with elevated minimum inhibitory concentrations (MICs) to various antibiotics continues to rise in the U.S. and globally. Genomic analysis provides a powerful tool for surveillance of circulating strains, antimicrobial resistance determinants, and understanding of transmission through a population. METHODS: GC isolates collected from the U.S. Gonococcal Isolate Surveillance Project (GISP) 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. RESULTS: 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. CONCLUSIONS: Characterization of this 2018 GISP genomic dataset, which is the largest U.S. 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. |
High Pgp3 Chlamydia trachomatis seropositivity, pelvic inflammatory disease and infertility among women, National Health and Nutrition Examination Survey, United States, 2013-2016
Anyalechi GE , Hong J , Danavall DC , Martin DL , Gwyn SE , Horner PJ , Raphael BH , Kirkcaldy RD , Kersh EN , Bernstein KT . Clin Infect Dis 2021 73 (8) 1507-1516 BACKGROUND: Chlamydia trachomatis causes pelvic inflammatory disease (PID) and tubal infertility. Pgp3 antibody (Pgp3Ab) detects prior chlamydial infections. We evaluated for an association of high chlamydial seropositivity with sequelae using a Pgp3Ab multiplex bead array (Pgp3AbMBA). METHODS: We performed chlamydia Pgp3AbMBA on sera from women 18-39 years old participating in the 2013-2016 National Health and Nutrition Examination Survey (NHANES) with urine chlamydia nucleic acid amplification test results. High chlamydial seropositivity was defined as a median fluorescence intensity (MFI ≥ 50,000; low-positive was MFI > 551-<50,000. Weighted US population high-positive, low-positive, and negative Pgp3Ab chlamydia seroprevalence and 95% confidence intervals (95% CI) were compared for women with chlamydial infection, self-reported PID, and infertility. RESULTS: Of 2,339 women aged 18-39 years, 1,725 (73.7%) had sera and 1,425 were sexually experienced. Overall, 104 women had high positive Pgp3Ab (5.4% [95% CI 4.0-7.0] of US women); 407 had low positive Pgp3Ab (25.1% [95% CI 21.5-29.0]), and 914 had negative Pgp3Ab (69.5% [95% CI 65.5-73.4]).Among women with high Pgp3Ab, infertility prevalence was 2.0 (95% CI 1.1-3.7) times higher than among Pgp3Ab-negative women (19.6% [95% CI 10.5-31.7] versus 9.9% [95% CI 7.7-12.4]). For women with low Pgp3Ab, PID prevalence was 7.9% (95% CI 4.6-12.6) compared to 2.3% (95% CI 1.4-3.6) in negative Pgp3Ab. CONCLUSIONS: High chlamydial Pgp3Ab seropositivity was associated with infertility although small sample size limited evaluation of an association of high seropositivity with PID. In infertile women, Pgp3Ab may be a marker of prior chlamydial infection. |
Detection of Lymphogranuloma Venereum- associated Chlamydia trachomatis L2 Serovars in Remnant Rectal Specimens Collected from Seven United States Public Health Laboratories
Chi KH , de Voux A , Morris M , Katz SS , Pillay A , Danavall D , Bowden KE , Gaynor AM , Kersh EN . Sex Transm Dis 2021 49 (1) e26-e28 The frequency of lymphogranuloma venereum (LGV) or invasive Chlamydia trachomatis (CT) infection with serovar L1, L2 or L3 is unknown in the United States. While no diagnostic test is commercially available, we used a laboratory-developed test and detected LGV-associated serovar L2 in 14% of 132 remnant CT-positive rectal swabs. |
Prevalence of urogenital Mycoplasma genitalium infection, United States, 2017-2018
Torrone E , Kruszon-Moran D , Philips C , Morris M , Bowden K , Papp J , Bachmann LH , Weinstock H , Kersh EN . Sex Transm Dis 2021 48 (11) e160-e162 During the 2017-2018 National Health and Nutrition Examination Survey, urine samples from participants aged 14-59 years were tested for Mycoplasma genitalium infection. Overall prevalence was 1.7% (95% CI: 1.1%, 2.7%). Prevalence was similar between males (1.8%, 95% CI: 0.9%, 3.1%) and females (1.7%, 95% CI: 0.8%, 3.0%). |
Update to CDC's Treatment Guidelines for Gonococcal Infection, 2020
St Cyr S , Barbee L , Workowski KA , Bachmann LH , Pham C , Schlanger K , Torrone E , Weinstock H , Kersh EN , Thorpe P . MMWR Morb Mortal Wkly Rep 2020 69 (50) 1911-1916 Sexually transmitted infections (STIs) caused by the bacteria Neisseria gonorrhoeae (gonococcal infections) have increased 63% since 2014 and are a cause of sequelae including pelvic inflammatory disease, ectopic pregnancy, and infertility and can facilitate transmission of human immunodeficiency virus (HIV) (1,2). Effective treatment can prevent complications and transmission, but N. gonorrhoeae's ability to acquire antimicrobial resistance influences treatment recommendations and complicates control (3). In 2010, CDC recommended a single 250 mg intramuscular (IM) dose of ceftriaxone and a single 1 g oral dose of azithromycin for treatment of uncomplicated gonococcal infections of the cervix, urethra, and rectum as a strategy for preventing ceftriaxone resistance and treating possible coinfection with Chlamydia trachomatis (4). Increasing concern for antimicrobial stewardship and the potential impact of dual therapy on commensal organisms and concurrent pathogens (3), in conjunction with the continued low incidence of ceftriaxone resistance and the increased incidence of azithromycin resistance, has led to reevaluation of this recommendation. This report, which updates previous guidelines (5), recommends a single 500 mg IM dose of ceftriaxone for treatment of uncomplicated urogenital, anorectal, and pharyngeal gonorrhea. If chlamydial infection has not been excluded, concurrent treatment with doxycycline (100 mg orally twice a day for 7 days) is recommended. Continuing to monitor for emergence of ceftriaxone resistance through surveillance and health care providers' reporting of treatment failures is essential to ensuring continued efficacy of recommended regimens. |
Reply: Evidence of Recent Genomic Evolution in Gonococcal Strains With Decreased Susceptibility to Cephalosporins or Azithromycin in the United States, 2014-2016
Thomas JC , Kersh EN , Gernert KM , Shafer WM , Raphael BH . J Infect Dis 2020 221 (5) 852-853 We would like to extend our gratitude to Drs. Deng and Klausner for their interest in our article, in which we phylogenetically characterized gonococcal isolates collected through national sentinel surveillance and circulating in the United States, between 2014 and 2016 [1]. We identified 2 major subpopulations of strains associated with reduced susceptibility to either azithromycin (multilocus sequence typing [MLST] ST9363) or cephalosporins (MLST ST1901), and we detailed the evolution of several strains that possessed mutations that were not observed in the United States in 2000–2013. | | Antimicrobial resistance (AMR) in the gonococcus represents a major public health threat, chiefly due to its rapidly evolving nature and the increasingly limited number of available treatment options. Although routine surveillance of AMR in circulating strains is essential in monitoring this threat, an equally important practice involves the promotion of antibiotic stewardship in limiting the spread of resistance. It is notable that the Centers for Disease Control and Prevention’s Gonococcal Isolate Surveillance Project, a historic sentinel surveillance program, has tracked AMR trends for over 30 years and, more recently, included whole-genome sequencing (WGS) of a subset of isolates [2]. As a result, the implementation of WGS has generated massive quantities of genomic data that can be used in tandem with data from traditional antimicrobial susceptibility testing to examine AMR trends. In addition, the release of these data to the public repositories has facilitated the ability of other investigators to conduct a myriad of follow-up studies. |
Notes from the field: First case in the United States of Neisseria gonorrhoeae harboring emerging mosaic penA60 allele, conferring reduced susceptibility to cefixime and ceftriaxone
Picker MA , Knoblock RJ , Hansen H , Bautista I , Griego R , Barber L , Bendik W , Lam K , Adelman E , Qiu-Shultz Z , Raphael BH , Pham CD , Kersh EN , Weinstock H , St Cyr SB . MMWR Morb Mortal Wkly Rep 2020 69 (49) 1876-1877 In November 2019, the Southern Nevada Public Health Laboratory of the Southern Nevada Health District (SNHD) identified a male urethral gonococcal isolate later demonstrating reduced susceptibility to cefixime (minimum inhibitory concentration [MIC] = 2.0 μg/mL) and ceftriaxone (MIC = 1.0 μg/mL) but susceptible to azithromycin (MIC = 0.25 μg/mL). Molecular testing by CDC in the United States revealed the emerging mosaic penA60 allele, first identified in Japan in 2016 (1), which confers reduced susceptibility to cephalosporins and increases the risk for treatment failure. The penA60 allele has been identified in China (2), Canada (3,4), Denmark (5), Australia (6), France (7), and the United Kingdom (8). The Nevada case is the first identified case of a Neisseria gonorrhoeae isolate harboring the mosaic penA60 allele reported in the United States. |
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