Last data update: Jun 03, 2024. (Total: 46935 publications since 2009)
Records 1-14 (of 14 Records) |
Query Trace: Schmerer MW [original query] |
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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. |
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. |
Erratum: Vol. 71, No. 6.
Lambrou AS , Shirk P , Steele MK , Paul P , Paden CR , Cadwell B , Reese HE , Aoki Y , Hassell N , Caravas J , Kovacs NA , Gerhart JG , Ng HJ , Zheng XY , Beck A , Chau R , Cintron R , Cook PW , Gulvik CA , Howard D , Jang Y , Knipe K , Lacek KA , Moser KA , Paskey AC , Rambo-Martin BL , Nagilla RR , Rethchless AC , Schmerer MW , Seby S , Shephard SS , Stanton RA , Stark TJ , Uehara A , Unoarumhi Y , Bentz ML , Burhgin A , Burroughs M , Davis ML , Keller MW , Keong LM , Le SS , Lee JS , Madden Jr JC , Nobles S , Owouor DC , Padilla J , Sheth M , Wilson MM , Talarico S , Chen JC , Oberste MS , Batra D , McMullan LK , Halpin AL , Galloway SE , MacCannell DR , Kondor R , Barnes J , MacNeil A , Silk BJ , Dugan VG , Scobie HM , Wentworth DE . MMWR Morb Mortal Wkly Rep 2022 71 (14) 528 The report “Genomic Surveillance for SARS-CoV-2 Variants: Predominance of the Delta (B.1.617.2) and Omicron (B.1.1.529) Variants — United States, June 2021–January 2022” contained several errors. |
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. |
Genomic Surveillance for SARS-CoV-2 Variants: Predominance of the Delta (B.1.617.2) and Omicron (B.1.1.529) Variants - United States, June 2021-January 2022.
Lambrou AS , Shirk P , Steele MK , Paul P , Paden CR , Cadwell B , Reese HE , Aoki Y , Hassell N , Caravas J , Kovacs NA , Gerhart JG , Ng HJ , Zheng XY , Beck A , Chau R , Cintron R , Cook PW , Gulvik CA , Howard D , Jang Y , Knipe K , Lacek KA , Moser KA , Paskey AC , Rambo-Martin BL , Nagilla RR , Rethchless AC , Schmerer MW , Seby S , Shephard SS , Stanton RA , Stark TJ , Uehara A , Unoarumhi Y , Bentz ML , Burhgin A , Burroughs M , Davis ML , Keller MW , Keong LM , Le SS , Lee JS , Madden Jr JC , Nobles S , Owouor DC , Padilla J , Sheth M , Wilson MM , Talarico S , Chen JC , Oberste MS , Batra D , McMullan LK , Halpin AL , Galloway SE , MacCannell DR , Kondor R , Barnes J , MacNeil A , Silk BJ , Dugan VG , Scobie HM , Wentworth DE . MMWR Morb Mortal Wkly Rep 2022 71 (6) 206-211 Genomic surveillance is a critical tool for tracking emerging variants of SARS-CoV-2 (the virus that causes COVID-19), which can exhibit characteristics that potentially affect public health and clinical interventions, including increased transmissibility, illness severity, and capacity for immune escape. During June 2021-January 2022, CDC expanded genomic surveillance data sources to incorporate sequence data from public repositories to produce weighted estimates of variant proportions at the jurisdiction level and refined analytic methods to enhance the timeliness and accuracy of national and regional variant proportion estimates. These changes also allowed for more comprehensive variant proportion estimation at the jurisdictional level (i.e., U.S. state, district, territory, and freely associated state). The data in this report are a summary of findings of recent proportions of circulating variants that are updated weekly on CDC's COVID Data Tracker website to enable timely public health action.(†) The SARS-CoV-2 Delta (B.1.617.2 and AY sublineages) variant rose from 1% to >50% of viral lineages circulating nationally during 8 weeks, from May 1-June 26, 2021. Delta-associated infections remained predominant until being rapidly overtaken by infections associated with the Omicron (B.1.1.529 and BA sublineages) variant in December 2021, when Omicron increased from 1% to >50% of circulating viral lineages during a 2-week period. As of the week ending January 22, 2022, Omicron was estimated to account for 99.2% (95% CI = 99.0%-99.5%) of SARS-CoV-2 infections nationwide, and Delta for 0.7% (95% CI = 0.5%-1.0%). The dynamic landscape of SARS-CoV-2 variants in 2021, including Delta- and Omicron-driven resurgences of SARS-CoV-2 transmission across the United States, underscores the importance of robust genomic surveillance efforts to inform public health planning and practice. |
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. |
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. |
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. |
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. |
Atypical Mutation in Neisseria gonorrhoeae 23S rRNA Associated with High-Level Azithromycin Resistance.
Pham CD , Nash E , Liu H , Schmerer MW , Sharpe S , Woods G , Roland B , Schlanger K , St Cyr SB , Carlson J , Sellers K , Olsen A , Sanon R , Hardin H , Soge OO , Raphael BH , Kersh EN . Antimicrob Agents Chemother 2020 65 (2) A2059G mutation in the 23S rRNA gene is the only reported mechanism conferring high-level azithromycin resistance (HL-AZMR) in Neisseria gonorrhoea Through U.S. gonococcal antimicrobial resistance surveillance projects, we identified four HL-AZMR gonococcal isolates lacking this mutational genotype. Genetic analysis revealed an A2058G mutation of 23S rRNA alleles in all four isolates. In vitro selected gonococcal strains with homozygous A2058G recapitulated the HL-AZMR phenotype. Taken together, we postulate that A2058G mutation confers HL-AZMR in N. gonorrhoeae. |
Azithromycin susceptibility of Neisseria gonorrhoeae in the USA in 2017: a genomic analysis of surveillance data.
Gernert KM , Seby S , Schmerer MW , Thomas JCth , Pham CD , Cyr SS , Schlanger K , Weinstock H , Shafer WM , Raphael BH , Kersh EN . Lancet Microbe 2020 1 (4) e154-e164 BACKGROUND: 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. METHODS: 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. FINDINGS: 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. INTERPRETATION: 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. FUNDING: 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. |
A Culture Collection of 50 Neisseria gonorrhoeae Isolates.
Liu H , Vidyaprakash E , Schmerer MW , Pham DC , St Cyr S , Kersh EN . Microbiol Resour Announc 2020 9 (40) A culture collection of 50 Neisseria gonorrhoeae isolates is available from the CDC & FDA Antibiotic Resistance Isolate Bank. Associated data include antibiotic susceptibility information for azithromycin, cefixime, cefpodoxime, ceftriaxone, tetracycline, ciprofloxacin, penicillin, and spectinomycin and linked whole-genome sequences. |
First Case of High-Level Azithromycin Resistant Neisseria gonorrhoeae in North Carolina.
Palavecino EL , Kilic A , Schmerer MW , Dobre-Buonya O , Toler C , McNeil CJ . Sex Transm Dis 2020 47 (5) 326-328 We report on the first high-level azithromycin resistant Neisseria gonorrhoeae isolate (MIC >/= 256 mug/ml) in North Carolina isolated from a pharyngeal swab of a 33-year-old HIV-negative man who has sex with men. In addition, the isolate was found to be susceptible to cefixime, ceftriaxone, and penicillin and resistant to tetracycline. By whole genome sequencing, the strain was assigned as MLST ST9363, NG-MAST ST5035 and a novel NG-STAR sequence type, ST1993. |
Genomic characterization of Neisseria gonorrhoeae Strains from 2016 United States Sentinel Surveillance Displaying Reduced Susceptibility to Azithromycin.
Schmerer MW , Abrams AJ , Seby S , Thomas JC4th , Cartee J , Lucking S , Vidyaprakash E , Pham CD , Sharpe S , Pettus K , St Cyr SB , Torrone EA , Kersh EN , Gernert KM . Antimicrob Agents Chemother 2020 64 (5) In 2016, the proportion of Neisseria gonorrhoeae isolates with reduced susceptibility to azithromycin rose to 3.6%. A phylogenetic analysis of 334 N. gonorrhoeae isolates collected in 2016 revealed a single, geographically diverse lineage of isolates with MICs of 2-16 mug/mL that carried a mosaic-like mtr locus, whereas the majority of isolates with MICs >/= 16 mug/mL appeared sporadically and carried 23S rRNA mutations. Continued molecular surveillance of N. gonorrheae will identify new resistance mechanisms. |
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