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Kalladeen M, Cheddie P, Akpaka PE. Group A streptococcus isolated in Guyana with reduced susceptibility to β-lactam antibiotics. Access Microbiol 2024; 6:000746.v3. [PMID: 39045256 PMCID: PMC11261736 DOI: 10.1099/acmi.0.000746.v3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 04/30/2024] [Indexed: 07/25/2024] Open
Abstract
Introduction. Streptococcus pyogenes [group A streptococci (GAS)] is the causative agent of pharyngitis and various other syndromes involving cellulitis, streptococcal toxic shock syndrome (STSS), and necrotising fasciitis. Although the prevalence of GAS infections globally remains high, necessitating the widespread use of β-lactam antibiotics, GAS have remained largely susceptible to these agents. However, there have been several reports of GAS with reduced susceptibility harbouring mutations in genes for penicillin-binding proteins (PBPs). The objectives of this study were to examine the in vitro β-lactam susceptibility patterns of group A streptococci, determine the prevalence of drug resistance, and ascertain whether such resistance could be attributed to mutations in specific PBP genes. Methods. In this study, we sought to use Sanger sequencing to identify mutations in PBP genes of Streptococcus pyogenes isolated from patients that required inpatient and outpatient care that could confer reduced PBP affinity for penicillin and/or cephalosporin antibiotics. All isolates were screened for susceptibility to penicillin, amoxicillin, and cefazolin using E-test strips. Results. While there were no documented cases of reduced susceptibility to penicillin or amoxicillin, 13 isolates had reduced susceptibility to cefazolin. Examination of pbp1a by Sanger sequencing revealed several isolates with single amino acid substitutions, which could potentially reduce the affinity of PBP 1A for cefazolin and possibly other first-generation cephalosporins. Conclusion. Penicillin and penicillin-derived antibiotics remain effective treatment options for GAS infections, but active surveillance is needed to monitor for changes to susceptibility patterns against these and other antibiotics and understand the genetic mechanisms contributing to them.
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Affiliation(s)
- Melissa Kalladeen
- Department of Paraclinical Sciences, University of the West Indies, St Augustine, Trinidad and Tobago
| | - Paul Cheddie
- Department of Medical Laboratory Science, University of Guyana, Turkeyen, Guyana
| | - Patrick Eberechi Akpaka
- Department of Paraclinical Sciences, University of the West Indies, St Augustine, Trinidad and Tobago
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2
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Xie O, Davies MR, Tong SYC. Streptococcus dysgalactiae subsp. equisimilis infection and its intersection with Streptococcus pyogenes. Clin Microbiol Rev 2024:e0017523. [PMID: 38856686 DOI: 10.1128/cmr.00175-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2024] Open
Abstract
SUMMARYStreptococcus dysgalactiae subsp. equisimilis (SDSE) is an increasingly recognized cause of disease in humans. Disease manifestations range from non-invasive superficial skin and soft tissue infections to life-threatening streptococcal toxic shock syndrome and necrotizing fasciitis. Invasive disease is usually associated with co-morbidities, immunosuppression, and advancing age. The crude incidence of invasive disease approaches that of the closely related pathogen, Streptococcus pyogenes. Genomic epidemiology using whole-genome sequencing has revealed important insights into global SDSE population dynamics including emerging lineages and spread of anti-microbial resistance. It has also complemented observations of overlapping pathobiology between SDSE and S. pyogenes, including shared virulence factors and mobile gene content, potentially underlying shared pathogen phenotypes. This review provides an overview of the clinical and genomic epidemiology, disease manifestations, treatment, and virulence determinants of human infections with SDSE with a particular focus on its overlap with S. pyogenes. In doing so, we highlight the importance of understanding the overlap of SDSE and S. pyogenes to inform surveillance and disease control strategies.
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Affiliation(s)
- Ouli Xie
- Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Monash Infectious Diseases, Monash Health, Melbourne, Australia
| | - Mark R Davies
- Department of Microbiology and Immunology, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
| | - Steven Y C Tong
- Department of Infectious Diseases, The University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
- Victorian Infectious Disease Service, The Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Australia
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3
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Brouwer S, Rivera-Hernandez T, Curren BF, Harbison-Price N, De Oliveira DMP, Jespersen MG, Davies MR, Walker MJ. Pathogenesis, epidemiology and control of Group A Streptococcus infection. Nat Rev Microbiol 2023; 21:431-447. [PMID: 36894668 PMCID: PMC9998027 DOI: 10.1038/s41579-023-00865-7] [Citation(s) in RCA: 53] [Impact Index Per Article: 53.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/06/2023] [Indexed: 03/11/2023]
Abstract
Streptococcus pyogenes (Group A Streptococcus; GAS) is exquisitely adapted to the human host, resulting in asymptomatic infection, pharyngitis, pyoderma, scarlet fever or invasive diseases, with potential for triggering post-infection immune sequelae. GAS deploys a range of virulence determinants to allow colonization, dissemination within the host and transmission, disrupting both innate and adaptive immune responses to infection. Fluctuating global GAS epidemiology is characterized by the emergence of new GAS clones, often associated with the acquisition of new virulence or antimicrobial determinants that are better adapted to the infection niche or averting host immunity. The recent identification of clinical GAS isolates with reduced penicillin sensitivity and increasing macrolide resistance threatens both frontline and penicillin-adjunctive antibiotic treatment. The World Health Organization (WHO) has developed a GAS research and technology road map and has outlined preferred vaccine characteristics, stimulating renewed interest in the development of safe and effective GAS vaccines.
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Affiliation(s)
- Stephan Brouwer
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | | | - Bodie F Curren
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
| | - Nichaela Harbison-Price
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - David M P De Oliveira
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
| | - Magnus G Jespersen
- Department of Microbiology and Immunology, The University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Mark R Davies
- Department of Microbiology and Immunology, The University of Melbourne, at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Mark J Walker
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland, Australia.
- Australian Infectious Diseases Research Centre, The University of Queensland, Brisbane, Queensland, Australia.
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia.
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4
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Yu D, Guo D, Zheng Y, Yang Y. A review of penicillin binding protein and group A Streptococcus with reduced-β-lactam susceptibility. Front Cell Infect Microbiol 2023; 13:1117160. [PMID: 37065204 PMCID: PMC10102528 DOI: 10.3389/fcimb.2023.1117160] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 03/21/2023] [Indexed: 04/03/2023] Open
Abstract
With the widespread use of antibiotics, antimicrobial resistance (AMR) has become a global problem that endangers public health. Despite the global high prevalence of group A Streptococcus (GAS) infections and the global widespread use of β-lactams, β-lactams remain the first-line treatment option for GAS infection. β-hemolytic streptococci maintain a persistent susceptibility to β-lactams, which is an extremely special phenomenon in the genus Streptococci, while the exact current mechanism is not known. In recent years, several studies have found that the gene encoding penicillin binding protein 2X (pbp2x) is associated with GAS with reduced-β-lactam susceptibility. The purpose of this review is to summarize the current published data on GAS penicillin binding proteins and β-lactam susceptibility, to explore the relationship between them, and to be alert to the emergence of GAS with reduced susceptibility to β-lactams.
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Affiliation(s)
- Dingle Yu
- Shenzhen Children’s Hospital, Shenzhen, China
| | - Danchun Guo
- Shenzhen Children’s Hospital, Shenzhen, China
| | - Yuejie Zheng
- Shenzhen Children’s Hospital, Shenzhen, China
- *Correspondence: Yuejie Zheng, ; Yonghong Yang,
| | - Yonghong Yang
- Shenzhen Children’s Hospital, Shenzhen, China
- Microbiology Laboratory, National Center for Children’s Health, Beijing Pediatric Research Institute, Beijing Children’s Hospital, Capital Medical University, Beijing, China
- *Correspondence: Yuejie Zheng, ; Yonghong Yang,
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5
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Beres SB, Olsen RJ, Long SW, Eraso JM, Boukthir S, Faili A, Kayal S, Musser JM. Analysis of the Genomics and Mouse Virulence of an Emergent Clone of Streptococcus dysgalactiae Subspecies equisimilis. Microbiol Spectr 2023; 11:e0455022. [PMID: 36971562 PMCID: PMC10100674 DOI: 10.1128/spectrum.04550-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Accepted: 03/04/2023] [Indexed: 03/29/2023] Open
Abstract
Streptococcus dysgalactiae subsp. equisimilis is a bacterial pathogen that is increasingly recognized as a cause of severe human infections. Much less is known about the genomics and infection pathogenesis of S. dysgalactiae subsp. equisimilis strains compared to the closely related bacterium Streptococcus pyogenes. To address these knowledge deficits, we sequenced to closure the genomes of seven S. dysgalactiae subsp. equisimilis human isolates, including six that were emm type stG62647. Recently, for unknown reasons, strains of this emm type have emerged and caused an increasing number of severe human infections in several countries. The genomes of these seven strains vary between 2.15 and 2.21 Mbp. The core chromosomes of these six S. dysgalactiae subsp. equisimilis stG62647 strains are closely related, differing on average by only 495 single-nucleotide polymorphisms, consistent with a recent descent from a common progenitor. The largest source of genetic diversity among these seven isolates is differences in putative mobile genetic elements, both chromosomal and extrachromosomal. Consistent with the epidemiological observations of increased frequency and severity of infections, both stG62647 strains studied were significantly more virulent than a strain of emm type stC74a in a mouse model of necrotizing myositis, as assessed by bacterial CFU burden, lesion size, and survival curves. Taken together, our genomic and pathogenesis data show the strains of emm type stG62647 we studied are closely genetically related and have enhanced virulence in a mouse model of severe invasive disease. Our findings underscore the need for expanded study of the genomics and molecular pathogenesis of S. dysgalactiae subsp. equisimilis strains causing human infections. IMPORTANCE Our studies addressed a critical knowledge gap in understanding the genomics and virulence of the bacterial pathogen Streptococcus dysgalactiae subsp. equisimilis. S. dysgalactiae subsp. equisimilis strains are responsible for a recent increase in severe human infections in some countries. We determined that certain S. dysgalactiae subsp. equisimilis strains are genetically descended from a common ancestor and that these strains can cause severe infections in a mouse model of necrotizing myositis. Our findings highlight the need for expanded studies on the genomics and pathogenic mechanisms of this understudied subspecies of the Streptococcus family.
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Affiliation(s)
- Stephen B. Beres
- Laboratory of Molecular and Translational Human Infectious Disease Research, Center for Infectious Diseases, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, USA
| | - Randall J. Olsen
- Laboratory of Molecular and Translational Human Infectious Disease Research, Center for Infectious Diseases, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, USA
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, New York, USA
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, USA
| | - S. Wesley Long
- Laboratory of Molecular and Translational Human Infectious Disease Research, Center for Infectious Diseases, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, USA
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, New York, USA
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, USA
| | - Jesus M. Eraso
- Laboratory of Molecular and Translational Human Infectious Disease Research, Center for Infectious Diseases, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, USA
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, New York, USA
| | - Sarrah Boukthir
- CHU de Rennes, Service de Bacteriologie-Hygiène Hospitalière, Rennes, France
- INSERM, CIC 1414, Rennes, France
- Université Rennes 1, Faculté de Médecine, Rennes, France
| | - Ahmad Faili
- INSERM, CIC 1414, Rennes, France
- Université Rennes 1, Faculté de Pharmacie, Rennes, France
- Chemistry, Oncogenesis, Stress, and Signaling, INSERM 1242, Rennes, France
| | - Samer Kayal
- CHU de Rennes, Service de Bacteriologie-Hygiène Hospitalière, Rennes, France
- INSERM, CIC 1414, Rennes, France
- Université Rennes 1, Faculté de Médecine, Rennes, France
- Chemistry, Oncogenesis, Stress, and Signaling, INSERM 1242, Rennes, France
| | - James M. Musser
- Laboratory of Molecular and Translational Human Infectious Disease Research, Center for Infectious Diseases, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas, USA
- Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, New York, USA
- Department of Microbiology and Immunology, Weill Cornell Medical College, New York, New York, USA
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6
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Genome-Wide Transposon Mutagenesis Screens Identify Group A Streptococcus Genes Affecting Susceptibility to β-Lactam Antibiotics. J Bacteriol 2022; 204:e0028722. [PMID: 36374114 PMCID: PMC9765115 DOI: 10.1128/jb.00287-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Group A streptococcus (GAS) is a Gram-positive human bacterial pathogen responsible for more than 700 million infections annually worldwide. Beta-lactam antibiotics are the primary agents used to treat GAS infections. Naturally occurring GAS clinical isolates with decreased susceptibility to beta-lactam antibiotics attributed to mutations in PBP2X have recently been documented. This prompted us to perform a genome-wide screen to identify GAS genes that alter beta-lactam susceptibility in vitro. Using saturated transposon mutagenesis, we screened for GAS gene mutations conferring altered in vitro susceptibility to penicillin G and/or ceftriaxone, two beta-lactam antibiotics commonly used to treat GAS infections. In the aggregate, we found that inactivating mutations in 150 GAS genes are associated with altered susceptibility to penicillin G and/or ceftriaxone. Many of the genes identified were previously not known to alter beta-lactam susceptibility or affect cell wall biosynthesis. Using isogenic mutant strains, we confirmed that inactivation of clpX (Clp protease ATP-binding subunit) or cppA (CppA proteinase) resulted in decreased in vitro susceptibility to penicillin G and ceftriaxone. Deletion of murA1 (UDP-N-acetylglucosamine 1-carboxyvinyltransferase) conferred increased susceptibility to ceftriaxone. Our results provide new information about the GAS genes affecting susceptibility to beta-lactam antibiotics. IMPORTANCE Beta-lactam antibiotics are the primary drugs prescribed to treat infections caused by group A streptococcus (GAS), an important human pathogen. However, the molecular mechanisms of GAS interactions with beta-lactam antibiotics are not fully understood. In this study, we performed a genome-wide mutagenesis screen to identify GAS mutations conferring altered susceptibility to beta-lactam antibiotics. In the aggregate, we discovered that mutations in 150 GAS genes were associated with altered beta-lactam susceptibility. Many identified genes were previously not known to alter beta-lactam susceptibility or affect cell wall biosynthesis. Our results provide new information about the molecular mechanisms of GAS interaction with beta-lactam antibiotics.
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7
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Olsen RJ, Zhu L, Mangham RE, Faili A, Kayal S, Beres SB, Musser JM. A Chimeric Penicillin Binding Protein 2X Significantly Decreases in Vitro Beta-Lactam Susceptibility and Increases in Vivo Fitness of Streptococcus pyogenes. THE AMERICAN JOURNAL OF PATHOLOGY 2022; 192:1397-1406. [PMID: 35843262 PMCID: PMC9552024 DOI: 10.1016/j.ajpath.2022.06.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 06/27/2022] [Accepted: 06/29/2022] [Indexed: 06/15/2023]
Abstract
All tested strains of Streptococcus pyogenes (group A streptococcus, GAS) remain susceptible to penicillin. However, GAS strains with amino acid substitutions in penicillin-binding proteins that confer decreased susceptibility to beta-lactam antibiotics have been identified recently. This discovery raises concerns about emergence of beta-lactam antibiotic resistance in GAS. Whole genome sequencing recently identified GAS strains with a chimeric penicillin-binding protein 2X (PBP2X) containing a recombinant segment from Streptococcus dysgalactiae subspecies equisimilis (SDSE). To directly test the hypothesis that the chimeric SDSE-like PBP2X alters beta-lactam susceptibility in vitro and fitness in vivo, an isogenic mutant strain was generated and virulence assessed in a mouse model of necrotizing myositis. Compared with naturally occurring and isogenic strains with a wild-type GAS-like PBP2X, strains with the chimeric SDSE-like PBP2X had reduced susceptibility in vitro to nine beta-lactam antibiotics. In a mouse model of necrotizing myositis, the strains had identical fitness in the absence of benzylpenicillin treatment. However, mice treated intermittently with a subtherapeutic dose of benzylpenicillin had significantly more colony-forming units recovered from limbs infected with strains with the chimeric SDSE-like PBP2X. These results show that mutations such as the PBP2X chimera may result in significantly decreased beta-lactam susceptibility and increased fitness and virulence. Expanded diagnostic laboratory surveillance, genome sequencing, and molecular pathogenesis study of potentially emergent beta-lactam antibiotic resistance among GAS are needed.
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Affiliation(s)
- Randall J Olsen
- Laboratory of Molecular and Translational Human Infectious Disease Research, Center for Infectious Diseases, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas; Departments of Pathology and Laboratory Medicine and Microbiology and Immunology, Weill Cornell Medical College, New York, New York.
| | - Luchang Zhu
- Laboratory of Molecular and Translational Human Infectious Disease Research, Center for Infectious Diseases, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas; Departments of Pathology and Laboratory Medicine and Microbiology and Immunology, Weill Cornell Medical College, New York, New York
| | - Regan E Mangham
- Laboratory of Molecular and Translational Human Infectious Disease Research, Center for Infectious Diseases, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas
| | - Ahmad Faili
- Inserm, CIC 1414, Rennes, France; Faculty of Pharmacy, Université Rennes 1, Rennes, France; CHU de Rennes, Rennes, France
| | - Samer Kayal
- Inserm, CIC 1414, Rennes, France; CHU de Rennes, Rennes, France; Faculty of Medicine, Université Rennes 1, Rennes, France
| | - Stephen B Beres
- Laboratory of Molecular and Translational Human Infectious Disease Research, Center for Infectious Diseases, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas
| | - James M Musser
- Laboratory of Molecular and Translational Human Infectious Disease Research, Center for Infectious Diseases, Department of Pathology and Genomic Medicine, Houston Methodist Research Institute and Houston Methodist Hospital, Houston, Texas; Departments of Pathology and Laboratory Medicine and Microbiology and Immunology, Weill Cornell Medical College, New York, New York
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8
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Chochua S, Metcalf B, Li Z, Mathis S, Tran T, Rivers J, Fleming-Dutra KE, Li Y, McGee L, Beall B. Invasive Group A Streptococcal Penicillin Binding Protein 2× Variants Associated with Reduced Susceptibility to β-Lactam Antibiotics in the United States, 2015-2021. Antimicrob Agents Chemother 2022; 66:e0080222. [PMID: 35969070 PMCID: PMC9487518 DOI: 10.1128/aac.00802-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 07/18/2022] [Indexed: 11/20/2022] Open
Abstract
All known group A streptococci [GAS] are susceptible to β-lactam antibiotics. We recently identified an invasive GAS (iGAS) variant (emm43.4/PBP2x-T553K) with unusually high minimum inhibitory concentrations (MICs) for ampicillin and amoxicillin, although clinically susceptible to β-lactams. We aimed to quantitate PBP2x variants, small changes in β-lactam MICs, and lineages within contemporary population-based iGAS. PBP2x substitutions were comprehensively identified among 13,727 iGAS recovered during 2015-2021, in the USA. Isolates were subjected to antimicrobial susceptibility testing employing low range agar diffusion and PBP2x variants were subjected to phylogenetic analyses. Fifty-five variants were defined based upon substitutions within an assigned PBP2x transpeptidase domain. Twenty-nine of these variants, representing 338/13,727 (2.5%) isolates and 16 emm types, exhibited slightly elevated β-lactam MICs, none of which were above clinical breakpoints. The emm43.4/PBP2x-T553K variant, comprised of two isolates, displayed the most significant phenotype (ampicillin MIC 0.25 μg/ml) and harbored missense mutations within 3 non-PBP genes with known involvement in antibiotic efflux, membrane insertion of PBP2x, and peptidoglycan remodeling. The proportion of all PBP2x variants with elevated MICs remained stable throughout 2015-2021 (<3.0%). The predominant lineage (emm4/PBP2x-M593T/ermT) was resistant to macrolides/lincosamides and comprised 129/340 (37.9%) of isolates with elevated β-lactam MICs. Continuing β-lactam selective pressure is likely to have selected PBP2x variants that had escaped scrutiny due to MICs that remain below clinical cutoffs. Higher MICs exhibited by emm43.4/PBP2x-T553K are probably rare due to the requirement of additional mutations. Although elevated β-lactam MICs remain uncommon, emm43.4/PBP2x-T553K and emm4/PBP2x-M593T/ermT lineages indicate that antibiotic stewardship and strain monitoring is necessary.
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Affiliation(s)
- Sopio Chochua
- Respiratory Disease Branch, National Center for Immunizations and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Benjamin Metcalf
- Respiratory Disease Branch, National Center for Immunizations and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Zhongya Li
- ASRT Inc., Contractor to Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Saundra Mathis
- ASRT Inc., Contractor to Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Theresa Tran
- ASRT Inc., Contractor to Respiratory Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Joy Rivers
- Respiratory Disease Branch, National Center for Immunizations and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Katherine E. Fleming-Dutra
- Respiratory Disease Branch, National Center for Immunizations and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Yuan Li
- Respiratory Disease Branch, National Center for Immunizations and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Lesley McGee
- Respiratory Disease Branch, National Center for Immunizations and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Bernard Beall
- Respiratory Disease Branch, National Center for Immunizations and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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9
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Integrative Reverse Genetic Analysis Identifies Polymorphisms Contributing to Decreased Antimicrobial Agent Susceptibility in Streptococcus pyogenes. mBio 2022; 13:e0361821. [PMID: 35038921 PMCID: PMC8764543 DOI: 10.1128/mbio.03618-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Identification of genetic polymorphisms causing increased antibiotic resistance in bacterial pathogens traditionally has proceeded from observed phenotype to defined mutant genotype. The availability of large collections of microbial genome sequences that lack antibiotic susceptibility metadata provides an important resource and opportunity to obtain new information about increased antimicrobial resistance by a reverse genotype-to-phenotype bioinformatic and experimental workflow. We analyzed 26,465 genome sequences of Streptococcus pyogenes, a human pathogen causing 700 million infections annually. The population genomic data identified amino acid changes in penicillin-binding proteins 1A, 1B, 2A, and 2X with signatures of evolution under positive selection as potential candidates for causing decreased susceptibility to β-lactam antibiotics. Construction and analysis of isogenic mutant strains containing individual amino acid replacements in penicillin-binding protein 2X (PBP2X) confirmed that the identified residues produced decreased susceptibility to penicillin. We also discovered the first chimeric PBP2X in S. pyogenes and show that strains containing it have significantly decreased β-lactam susceptibility. The novel integrative reverse genotype-to-phenotype strategy presented is broadly applicable to other pathogens and likely will lead to new knowledge about antimicrobial agent resistance, a massive public health problem worldwide. IMPORTANCE The recent demonstration that naturally occurring amino acid substitutions in Streptococcus pyogenes PBP2X are sufficient to cause severalfold reduced susceptibility to multiple β-lactam antibiotics in vitro raises the concern that these therapeutic agents may become compromised. Substitutions in PBP2X are common first-step mutations that, with the incremental accumulation of additional adaptive mutations within the PBPs, can result in high-level resistance. Because β-lactam susceptibility testing is not routinely performed, the nature and extent of such substitutions within the PBPs of S. pyogenes are poorly characterized. To address this knowledge deficit, polymorphisms in the PBPs were identified among the most comprehensive cohort of S. pyogenes genome sequences investigated to date. The mutational processes and selective forces acting on the PBPs were assessed to identify specific substitutions likely to influence β-lactam susceptibility and to evaluate factors posited to be impediments to resistance emergence.
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10
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Johnson AF, LaRock CN. Antibiotic Treatment, Mechanisms for Failure, and Adjunctive Therapies for Infections by Group A Streptococcus. Front Microbiol 2021; 12:760255. [PMID: 34803985 PMCID: PMC8601407 DOI: 10.3389/fmicb.2021.760255] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 09/28/2021] [Indexed: 11/13/2022] Open
Abstract
Group A Streptococcus (GAS; Streptococcus pyogenes) is a nearly ubiquitous human pathogen responsible for a significant global disease burden. No vaccine exists, so antibiotics are essential for effective treatment. Despite a lower incidence of antimicrobial resistance than many pathogens, GAS is still a top 10 cause of death due to infections worldwide. The morbidity and mortality are primarily a consequence of the immune sequelae and invasive infections that are difficult to treat with antibiotics. GAS has remained susceptible to penicillin and other β-lactams, despite their widespread use for 80 years. However, the failure of treatment for invasive infections with penicillin has been consistently reported since the introduction of antibiotics, and strains with reduced susceptibility to β-lactams have emerged. Furthermore, isolates responsible for outbreaks of severe infections are increasingly resistant to other antibiotics of choice, such as clindamycin and macrolides. This review focuses on the challenges in the treatment of GAS infection, the mechanisms that contribute to antibiotic failure, and adjunctive therapeutics. Further understanding of these processes will be necessary for improving the treatment of high-risk GAS infections and surveillance for non-susceptible or resistant isolates. These insights will also help guide treatments against other leading pathogens for which conventional antibiotic strategies are increasingly failing.
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Affiliation(s)
- Anders F Johnson
- Microbiology and Molecular Genetics Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, GA, United States
| | - Christopher N LaRock
- Microbiology and Molecular Genetics Program, Graduate Division of Biological and Biomedical Sciences, Laney Graduate School, Emory University, Atlanta, GA, United States.,Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA, United States.,Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, United States.,Emory Antibiotic Resistance Center, Atlanta, GA, United States
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11
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Jespersen MG, Lacey JA, Tong SYC, Davies MR. Global genomic epidemiology of Streptococcus pyogenes. INFECTION GENETICS AND EVOLUTION 2020; 86:104609. [PMID: 33147506 DOI: 10.1016/j.meegid.2020.104609] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 10/20/2020] [Accepted: 10/23/2020] [Indexed: 02/04/2023]
Abstract
Streptococcus pyogenes is one of the Top 10 human infectious disease killers worldwide causing a range of clinical manifestations in humans. Colonizing a range of ecological niches within its sole host, the human, is key to the ability of this opportunistic pathogen to cause direct and post-infectious manifestations. The expansion of genome sequencing capabilities and data availability over the last decade has led to an improved understanding of the evolutionary dynamics of this pathogen within a global framework where epidemiological relationships and evolutionary mechanisms may not be universal. This review uses the recent publication by Davies et al., 2019 as an updated global framework to address S. pyogenes population genomics, highlighting how genomics is being used to gain new insights into evolutionary processes, transmission pathways, and vaccine design.
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Affiliation(s)
- Magnus G Jespersen
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Jake A Lacey
- Doherty Department, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia
| | - Steven Y C Tong
- Doherty Department, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia; Victorian Infectious Diseases Service, The Royal Melbourne Hospital, at the Peter Doherty Institute for Infection and Immunity, VIC, Australia
| | - Mark R Davies
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia.
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Population Genomic Molecular Epidemiological Study of Macrolide-Resistant Streptococcus pyogenes in Iceland, 1995 to 2016: Identification of a Large Clonal Population with a pbp2x Mutation Conferring Reduced In Vitro β-Lactam Susceptibility. J Clin Microbiol 2020; 58:JCM.00638-20. [PMID: 32522827 PMCID: PMC7448646 DOI: 10.1128/jcm.00638-20] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 06/04/2020] [Indexed: 12/16/2022] Open
Abstract
Resistance to macrolide antibiotics is a global concern in the treatment of Streptococcus pyogenes (group A Streptococcus [GAS]) infections. In Iceland, since the detection of the first macrolide-resistant isolate in 1998, three epidemic waves of macrolide-resistant GAS infections have occurred, with peaks in 1999, 2004, and 2008. We conducted whole-genome sequencing of all 1,575 available GAS macrolide-resistant clinical isolates of all infection types collected at the national reference laboratory in Reykjavik, Iceland, from 1998 to 2016. Among 1,515 erythromycin-resistant isolates, 90.3% were of only three emm types, emm4 (n = 713), emm6 (n = 324), and emm12 (n = 332), with each being predominant in a distinct epidemic peak. The antibiotic efflux pump genes, mef(A) and msr(D), were present on chimeric mobile genetic elements in 99.3% of the macrolide-resistant isolates of these emm types. Of note, in addition to macrolide resistance, virtually all emm12 isolates had a single amino acid substitution in penicillin-binding protein PBP2X that conferred a 2-fold increased penicillin G and ampicillin MIC among the isolates tested. We conclude that each of the three large epidemic peaks of macrolide-resistant GAS infections occurring in Iceland since 1998 was caused by the emergence and clonal expansion of progenitor strains, with macrolide resistance being conferred predominantly by inducible Mef(A) and Msr(D) drug efflux pumps. The occurrence of emm12 strains with macrolide resistance and decreased beta-lactam susceptibility was unexpected and is of public health concern.
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Li Y, Rivers J, Mathis S, Li Z, Velusamy S, Nanduri SA, Van Beneden CA, Snippes-Vagnone P, Lynfield R, McGee L, Chochua S, Metcalf BJ, Beall B. Genomic Surveillance of Streptococcus pyogenes Strains Causing Invasive Disease, United States, 2016-2017. Front Microbiol 2020; 11:1547. [PMID: 32849323 PMCID: PMC7396493 DOI: 10.3389/fmicb.2020.01547] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Accepted: 06/16/2020] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Streptococcus pyogenes is a major cause of severe, invasive infections in humans. The bacterial pathogen harbors a wide array of virulence factors and exhibits high genomic diversity. Rapid changes of circulating strains in a community are common. Understanding the current prevalence and dynamics of S. pyogenes lineages could inform vaccine development and disease control strategies. METHODS We used whole-genome sequencing (WGS) to characterize all invasive S. pyogenes isolates obtained through the United States Center for Disease Control and Prevention's Active Bacterial Core surveillance (ABCs) in 2016 and 2017. We determined the distribution of strain features, including emm type, antibiotic resistance determinants, and selected virulence factors. Changes in strain feature distribution between years 2016 and 2017 were evaluated. Phylogenetic analysis was used to identify expanding lineages within emm type. RESULTS Seventy-one emm types were identified from 3873 isolates characterized. The emm types targeted by a 30-valent M protein-based vaccine accounted for 3230 (89%) isolates. The relative frequencies of emm types collected during the 2 years were similar. While all isolates were penicillin-susceptible, erythromycin-resistant isolates increased from 273 (16% of 2016 isolates) to 432 (23% of 2017 isolates), mainly driven by increase of the erm-positive emm types 92 and 83. The prevalence of 24 virulence factors, including 11 streptococcal pyrogenic toxins, ranged from 6 to 90%. In each of three emm types (emm 49, 82, and 92), a subgroup of isolates significantly expanded between 2016 and 2017 compared to isolates outside of the subgroup (P-values < 0.0001). Specific genomic sequence changes were associated with these expanded lineages. CONCLUSIONS While the overall population structure of invasive S. pyogenes isolates in the United States remained stable, some lineages, including several that were antibiotic-resistant, increased between 2016 and 2017. Continued genomic surveillance can help monitor and characterize bacterial features associated with emerging strains from invasive infections.
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Affiliation(s)
- Yuan Li
- Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, United States Department of Health and Human Services, Atlanta, GA, United States
| | - Joy Rivers
- Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, United States Department of Health and Human Services, Atlanta, GA, United States
| | - Saundra Mathis
- Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, United States Department of Health and Human Services, Atlanta, GA, United States
| | - Zhongya Li
- Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, United States Department of Health and Human Services, Atlanta, GA, United States
| | - Srinivasan Velusamy
- Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, United States Department of Health and Human Services, Atlanta, GA, United States
| | - Srinivas A. Nanduri
- Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, United States Department of Health and Human Services, Atlanta, GA, United States
| | - Chris A. Van Beneden
- Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, United States Department of Health and Human Services, Atlanta, GA, United States
| | | | - Ruth Lynfield
- Minnesota Department of Health, St Paul, MN, United States
| | - Lesley McGee
- Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, United States Department of Health and Human Services, Atlanta, GA, United States
| | - Sopio Chochua
- Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, United States Department of Health and Human Services, Atlanta, GA, United States
| | - Benjamin J. Metcalf
- Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, United States Department of Health and Human Services, Atlanta, GA, United States
| | - Bernard Beall
- Respiratory Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, United States Department of Health and Human Services, Atlanta, GA, United States
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