You are leaving Medscape Education
Cancel Continue
Log in to save activities Your saved activities will show here so that you can easily access them whenever you're ready. Log in here CME & Education Log in to keep track of your credits.
 

Table 1.  

Characteristic Value
Median age, y (IQR) 81.0 (72.0–88.0)
Age group, y
   <30 1 (0.8)
   30–39 4 (3.0)
   40–49 5 (3.6)
   50–59 6 (4.5)
   60–69 12 (9.0)
   70–79 29 (21.8)
   80–89 50 (37.6)
   ≥90 26 (19.5)
Sex
   M 72 (54.1)
   F 61 (45.9)
Medical history
   No underlying conditions 15 (11.3)
   Solid organ tumor† 36 (27.1)
   History of surgery, n = 36 15 (41.7)
   Active malignancy, n = 36‡ 22 (61.1)
   Metastasis, n = 36 10 (27.8)
   Hematologic malignancy 6 (4.5)
   Hematopoietic stem cell transplant, n = 6  
   Cardiovascular disease 21 (15.8)
   Cerebral artery diseases 38 (28.6)
   Chronic kidney diseases 27 (20.3)
   Diabetes mellitus 22 (16.5)
   Dementia 31 (23.3)
   Collagen diseases 8 (6.0)
   Chronic lung diseases 7 (5.3)
   HIV 0
   Chemotherapy 12 (9.0)
   Immune suppressive therapy 6 (4.5)
   Neutropenia, neutrophil count <500 cells/µL 5 (3.8)

Table 1. Characteristics of 133 patients with Streptococcus dysgalactiae subspecies equisimilis bacteremia, Japan, 2005–2021*

*Values are no. (%) except as indicated. For patients with multiple episodes, variables for the first episode are described. †Ten patients with prostate cancer; 8 with cervical cancer; 7 with colon, rectal, or anal cancer; 3 with lung cancer; 2 with stomach cancer; 2 with endometrial cancer; 2 with bladder cancer; 2 with breast cancer; and 1 with cancer categorized as other (esophageal cancer, ovarian cancer, pharyngeal cancer, salivary gland cancer, vaginal cancer, and extramammary Paget’s disease), including duplicates. ‡Treated within 5 years.

Table 2.  

Characteristics No. (%)
Type of infection
   Community-acquired 136 (93.2)
   Nosocomial 10 (6.8)
Clinical source of bacteremia†
   Cellulitis 74 (50.7)
   Primary bacteremia without focus 27 (18.5)
   Necrotizing fasciitis 10 (6.8)
   Vertebral osteomyelitis and discitis 10 (6.8)
   Psoas abscess 6 (4.1)
   Septic arthritis 11 (7.5)
   Infectious endocarditis 4 (2.7)
   Urinary tract infection 7 (4.8)
   Pneumonia 1 (0.7)
   Others‡ 14 (9.6)
Clinical characteristics
   Body temperature ≥38°C, n = 143 100 (69.9)
   Mean arterial pressure <80 mm Hg, n = 140 42 (30.0)
   Heart rate >90 beats/min, n = 138 83 (60.1)
   Disturbance of consciousness, n = 141 54 (38.3)
Severe disease, n = 142
   Streptococcus toxic shock syndrome 7 (4.9)
   Vasopressor support required 11 (7.7)
   Ventilator support required 6 (4.2)
   Admission to intensive care unit required 9 (6.3)
Death
   In-hospital death, n = 143 10 (7.0)
   30-d mortality, n = 138 5 (3.6)

Table 2. Clinical manifestations and severity markers for 146 episodes of multidrug-resistant Streptococcus dysgalactiae subspecies equisimilis bacteremia, Japan, 2005–2021*

*Data include 13 relapse or reinfection episodes among 9 patients (details are available in Appendix 2 Table 1). †Data include ≥1 instance per patient, including 3 case-patients with cellulitis and septic arthritis; 2 with vertebral osteomyelitis and psoas abscess; and 1 with each of the following co-infections: cellulitis and vertebral osteomyelitis; cellulitis and psoas abscess; cellulitis and urinary tract infection; necrotizing fasciitis and septic arthritis; vertebral osteomyelitis and septic arthritis; psoas abscess and septic arthritis; infective endocarditis and vertebral osteomyelitis; cellulitis and mycotic aneurysm; vertebral osteomyelitis, psoas abscess, and pyogenic lymphadenitis; vertebral osteomyelitis, psoas abscess, and urinary tract infection; vertebral osteomyelitis, septic arthritis, and empyema. ‡Other infections were 3 cases of catheter-related bloodstream infection; 3 cases of decubitus infection; 2 cases of secondary peritonitis; and 1 case each of empyema; surgical site infection; retroperitoneal abscess; pyogenic lymphadenitis; and mycotic aneurysm.

Table 3.  

Characteristics No. (%) isolates p value
2005–2017, n = 58 2018–2021, n = 88
CC or ST
   CC17 23 (39.7) 27 (30.7) 0.288
   CC25 13 (22.4) 28 (31.8) 0.261
   CC29 5 (8.6) 8 (9.1) 1.000
   ST525 1 (1.7) 15 (17.1) 0.001
   Others 16 (27.6) 10 (11.4) 0.015
Antimicrobial nonsusceptibility
   Erythromycin 16 (27.6) 30 (34.1) 0.469
   Minocycline 17 (29.3) 28 (31.8) 0.855
   Clindamycin 11 (19.0) 26 (29.5) 0.176
   MDR† 5 (8.6) 19 (21.6) 0.042

Table 3. Temporal changes in clonal complexes and sequence types and antimicrobial nonsusceptibility rates of Streptococcus dysgalactiae subspecies equisimilis bacteremia, Japan, 2005–2021*

*CC, clonal complex; MDR, multidrug resistance; ST, sequence type. †Resistant to erythromycin, minocycline, and clindamycin.

Table 4.  

CC or ST Penicillin G Cefotaxime Meropenem Erythromycin Minocycline Clindamycin
CC17, n = 50 0 0 0 9 (18.0) 2 (4.0) 8 (16.0)
CC25, n = 41 0 0 0 12 (29.3) 16 (39.0) 12 (29.3)
ST525, n = 16 0 0 0 16 (100) 16 (100) 16 (100)
CC29, n = 13 0 0 0 1 (7.7) 1 (7.7) 1 (7.7)
Others, n = 26 0 0 0 8 (30.8) 10 (38.5) 0
Total, n = 146 0 0 0 46 (31.5) 45 (30.8) 37 (25.5)

Table 4. Antimicrobial nonsusceptibility rates among Streptococcus dysgalactiae subspecies equisimilis clonal complexes and sequence types, Japan, 2005–2021*

*Values are no. (%) isolates. CC, clonal complex; ST, sequence type.

Table 5.  

CC or ST ermB ermA mef(A/E) tetM tetL Tn916-like ICE
CC17, n = 50 2 (4.0) 7 (14.0) 0 2 (4.0) 0 2 (4.0)
CC25, n = 41 12 (29.3) 0 0 18 (43.9) 0 17 (41.5)
ST525, n = 16 16 (100) 0 0 16 (100) 0 16 (100)
CC29, n = 13 0 1 (7.7) 0 0 0 0
Others, n = 26 0 5 (19.2) 5 (19.2) 10 (38.5) 2 (7.7) 3 (11.5)
Total, n = 146 30 (20.5) 13 (8.9) 5 (3.4) 46 (31.5) 2 (1.4) 38 (26.0)

Table 5. Prevalence of antimicrobial resistance determinant genes and Tn916-like integrative and conjugative elements among Streptococcus dysgalactiae subspecies equisimilis clonal complexes and sequence types, Japan, 2005–2021*

*Values are no. (%) isolates. CC, clonal complex; ICE, integrative and conjugative element; ST, sequence type.

CME / ABIM MOC

Multidrug-Resistant Streptococcus dysgalactiae subspecies equisimilis Causing Bacteremia, Kyoto-Shiga Region, Japan, 2005-2021

  • Authors: Koh Shinohara, MD; Kazunori Murase, PhD; Yasuhiro Tsuchido, MD, PhD; Taro Noguchi, MD, PhD; Satomi Yukawa, MD, PhD; Masaki Yamamoto, MD, PhD; Yasufumi Matsumura, MD, PhD; Ichiro Nakagawa, DDS, PhD; Miki Nagao, MD, PhD
  • CME / ABIM MOC Released: 2/23/2023
  • Valid for credit through: 2/23/2024, 11:59 PM EST
Start Activity

  • Credits Available

    Physicians - maximum of 1.00 AMA PRA Category 1 Credit(s)™

    ABIM Diplomates - maximum of 1.00 ABIM MOC points

    You Are Eligible For

    • Letter of Completion
    • ABIM MOC points

Target Audience and Goal Statement

This activity is intended for infectious disease physicians, internists, intensivists, and other physicians caring for patients with or at risk for Streptococcus dysgalactiae subspecies equisimilis (SDSE).

The goal of this activity is for learners to be better able to describe clinical features of SDSE bacteremia and comparative genomic analyses for antimicrobial resistance, according to a retrospective analysis of 146 bacteremia episodes in 133 patients from 2005 to 2021.

Upon completion of this activity, participants will:

  • Describe clinical features of Streptococcus dysgalactiae subspecies equisimilis (SDSE) bacteremia and temporal trends in incidence in hospitals in Kyoto-Shiga Region, according to a retrospective analysis of 146 bacteremia episodes in 133 patients from 2005 to 2021
  • Determine comparative genomic analyses for phylogenetic relationships and recent antimicrobial resistance emergence, according to a retrospective analysis of clinical SDSE isolates preserved in 3 hospitals in the Kyoto-Shiga region from 2005 to 2021
  • Identify clinical implications of clinical features of SDSE bacteremia and comparative genomic analyses for phylogenetic relationships and antimicrobial resistance emergence, according to a retrospective analysis of 146 bacteremia episodes in 133 patients from 2005 to 2021


Disclosures

Medscape, LLC requires every individual in a position to control educational content to disclose all financial relationships with ineligible companies that have occurred within the past 24 months. Ineligible companies are organizations whose primary business is producing, marketing, selling, re-selling, or distributing healthcare products used by or on patients.

All relevant financial relationships for anyone with the ability to control the content of this educational activity are listed below and have been mitigated. Others involved in the planning of this activity have no relevant financial relationships.


Faculty

  • Koh Shinohara, MD

    Kyoto University Graduate School of Medicine
    Kyoto, Japan

  • Kazunori Murase, PhD

    Kyoto University Graduate School of Medicine
    Kyoto, Japan

  • Yasuhiro Tsuchido, MD, PhD

    Kyoto University Graduate School of Medicine
    Kyoto, Japan

  • Taro Noguchi, MD, PhD

    Kyoto University Graduate School of Medicine
    Kyoto, Japan

  • Satomi Yukawa, MD, PhD

    Kyoto University Graduate School of Medicine
    Kyoto, Japan

  • Masaki Yamamoto, MD, PhD

    Kyoto University Graduate School of Medicine
    Kyoto, Japan

  • Yasufumi Matsumura, MD, PhD

    Kyoto University Graduate School of Medicine
    Kyoto, Japan

  • Ichiro Nakagawa, DDS, PhD

    Kyoto University Graduate School of Medicine
    Kyoto, Japan

  • Miki Nagao, MD, PhD

    Kyoto University Graduate School of Medicine
    Kyoto, Japan

CME Author

  • Laurie Barclay, MD

    Freelance writer and reviewer
    Medscape, LLC

    Disclosures

    Laurie Barclay, MD, has no relevant financial relationships.

Editor

  • Amy J. Guinn, BA, MA

    Copyeditor
    Emerging Infectious Diseases

Compliance Reviewer

  • Amanda Jett, PharmD, BCACP

    Associate Director, Accreditation and Compliance, Medscape, LLC

    Disclosures

    Amanda Jett, PharmD, BCACP, has no relevant financial relationships.


Accreditation Statements

Medscape

Interprofessional Continuing Education

In support of improving patient care, this activity has been planned and implemented by Medscape, LLC and Emerging Infectious Diseases. Medscape, LLC is jointly accredited with commendation by the Accreditation Council for Continuing Medical Education (ACCME), the Accreditation Council for Pharmacy Education (ACPE), and the American Nurses Credentialing Center (ANCC), to provide continuing education for the healthcare team.

    For Physicians

  • Medscape, LLC designates this Journal-based CME activity for a maximum of 1.0 AMA PRA Category 1 Credit(s)™ . Physicians should claim only the credit commensurate with the extent of their participation in the activity.

    Successful completion of this CME activity, which includes participation in the evaluation component, enables the participant to earn up to 1.0 MOC points in the American Board of Internal Medicine's (ABIM) Maintenance of Certification (MOC) program. Participants will earn MOC points equivalent to the amount of CME credits claimed for the activity. It is the CME activity provider's responsibility to submit participant completion information to ACCME for the purpose of granting ABIM MOC credit.

    Contact This Provider

For questions regarding the content of this activity, contact the accredited provider for this CME/CE activity noted above. For technical assistance, contact [email protected]


Instructions for Participation and Credit

There are no fees for participating in or receiving credit for this online educational activity. For information on applicability and acceptance of continuing education credit for this activity, please consult your professional licensing board.

This activity is designed to be completed within the time designated on the title page; physicians should claim only those credits that reflect the time actually spent in the activity. To successfully earn credit, participants must complete the activity online during the valid credit period that is noted on the title page. To receive AMA PRA Category 1 Credit™, you must receive a minimum score of 70% on the post-test.

Follow these steps to earn CME/CE credit*:

  1. Read about the target audience, learning objectives, and author disclosures.
  2. Study the educational content online or print it out.
  3. Online, choose the best answer to each test question. To receive a certificate, you must receive a passing score as designated at the top of the test. We encourage you to complete the Activity Evaluation to provide feedback for future programming.

You may now view or print the certificate from your CME/CE Tracker. You may print the certificate, but you cannot alter it. Credits will be tallied in your CME/CE Tracker and archived for 6 years; at any point within this time period, you can print out the tally as well as the certificates from the CME/CE Tracker.

*The credit that you receive is based on your user profile.

CME / ABIM MOC

Multidrug-Resistant Streptococcus dysgalactiae subspecies equisimilis Causing Bacteremia, Kyoto-Shiga Region, Japan, 2005-2021

Authors: Koh Shinohara, MD; Kazunori Murase, PhD; Yasuhiro Tsuchido, MD, PhD; Taro Noguchi, MD, PhD; Satomi Yukawa, MD, PhD; Masaki Yamamoto, MD, PhD; Yasufumi Matsumura, MD, PhD; Ichiro Nakagawa, DDS, PhD; Miki Nagao, MD, PhDFaculty and Disclosures

CME / ABIM MOC Released: 2/23/2023

Valid for credit through: 2/23/2024, 11:59 PM EST

processing....

Abstract and Introduction

Incidence of Streptococcus dysgalactiae subspecies equisimilis (SDSE) bacteremia is increasing in the Kyoto-Shiga region of Japan. We retrospectively analyzed clinical features of SDSE bacteremia and conducted comparative genomic analyses of isolates collected from 146 bacteremia episodes among 133 patients during 2005–2021. Of those patients, 7.7% required vasopressor support, and 7.0% died while in the hospital. The prevalence of isolates resistant to erythromycin, minocycline, and clindamycin increased from 8.6% during 2005–2017 to 21.6% during 2018–2021. Our genomic analysis demonstrated that sequence type 525 and clonal complex 25 were predominant in SDSE isolates collected during 2018–2021. In addition, those isolates had acquired 2 antimicrobial-resistance genes, ermB and tetM, via Tn916-like integrative and conjugative elements (ICEs). Phylogenetic analysis revealed clonal distribution of Tn916-like ICEs in SDSE isolates. Our findings suggest that Tn916-like ICEs contributed to the emergence and recent increase of multidrug-resistant SDSE bacteremia in this region of Japan.

Introduction

Streptococcus dysgalactiae subspecies equisimilis (SDSE) is a member of the pyogenic group of streptococci that typically is agglutinated by serum against Lancefield group G or C antigens (rarely A or L antigens)[1]. Although SDSE has been considered a part of the commensal flora and is much less virulent than S. pyogenes, SDSE increasingly has been recognized as a clinically relevant pathogenic bacterium[2–4]. SDSE can cause a broad range of diseases, from milder illnesses such as pharyngitis and skin and soft-tissue infections to severe conditions such as streptococcal toxic shock syndrome (STSS) and necrotizing fasciitis that can resemble infections caused by S. pyogenes [2,4–6].

Invasive SDSE infections mainly affect elderly persons with underlying illnesses[2,4,6]; fatality rates of 2%–20% have been reported[4,7]. Moreover, multiple countries, including Israel, Denmark, Norway, and Canada, have reported increasing incidence of invasive diseases caused by SDSE or group C or G Streptococcus (GCGS)[8–11]. In Japan, a single-center study in Tokyo reported a substantial increase in the age-adjusted incidence of invasive group G Streptococcus from 2003–2007 to 2008–2013[12]. An aging population with multiple underlying conditions only partially explains those reports[8,12] and other reasons for the growing prevalence of invasive SDSE infections remain unclear.

SDSE is essentially susceptible to penicillin and other β-lactam antibiotics, but resistance to other antimicrobial agents has emerged. Multiple countries, including the United States, Japan, and Norway, have reported increased prevalence of erythromycin- and clindamycin-resistant isolates[2,5,13]. Moreover, recent studies in countries in eastern Asia showed much higher prevalence of resistance to multiple antimicrobial agents, including macrolides, tetracyclines, and lincosamide[14,15]. A multicenter study in China showed resistance rates of 71.4% to erythromycin, 71.4% to clindamycin, and 60.7% to tetracycline[15]. The prevalent genes responsible for macrolide resistance in those studies were mefA/E, ermA, and ermB[5,13–15]; ermA and ermB are also responsible for clindamycin resistance and typically confer inducible and constitutive resistance.

We conducted a retrospective, multicenter, surveillance study of SDSE bacteremia cases in the Kyoto-Shiga region of Japan. We also performed a comparative genomic analysis of clinical SDSE isolates preserved in 3 hospitals in the region to explore the phylogenetic relationships and emergence of antimicrobial resistance (AMR).