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Nakashima N, Jin W, Wachino JI, Koyama S, Tamai K, Arakawa Y, Kimura K. β-Lactam Susceptibility of Streptococcus dysgalactiae subsp. equisimilis. Jpn J Infect Dis 2024; 77:236-239. [PMID: 38296542 DOI: 10.7883/yoken.jjid.2023.339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/26/2024]
Abstract
All clinical isolates of Streptococcus dysgalactiae subsp. equisimilis (SDSE) are considered susceptible to β-lactams, the first-line drugs used to treat SDSE infections. However, given that penicillin-non-susceptible SDSE strains have been isolated in Denmark, in this study, we aimed to identify β-lactam-non-susceptible clinical isolates of SDSE in Japan. In 2018, we collected 150 clinical isolates of S. dysgalactiae, and species identification was performed using a Rapid ID Strep API kit. The minimum inhibitory concentrations (MIC) of six β-lactams (penicillin G, oxacillin, ceftizoxime, ceftibuten, cefoxitin, and cefaclor) were determined for the 85 clinical isolates identified as SDSE using the agar dilution method standardized by the Clinical & Laboratory Standards Institute. The MIC ranges of penicillin G, oxacillin, ceftizoxime, ceftibuten, cefoxitin, and cefaclor were 0.007-0.06, 0.03-0.12, 0.015-0.06, 0.25-2, 0.12-2, and 0.06-0.5 μg/mL, respectively. None of the clinical isolates of SDSE were non-susceptible to penicillin G, indicating that all 85 clinical isolates of SDSE were susceptible to β-lactams. Our findings indicate that almost all clinical isolates of SDSE, from several prefectures of Japan, are still susceptible to β-lactams. Nevertheless, there remains a need for continuous and careful monitoring of drug susceptibility among clinical SDSE isolates in Japan.
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Affiliation(s)
- Natsumi Nakashima
- Department of Bacteriology, Nagoya University Graduate School of Medicine, Japan
| | - Wanchun Jin
- Department of Bacteriology, Nagoya University Graduate School of Medicine, Japan
| | - Jun-Ichi Wachino
- Department of Bacteriology, Nagoya University Graduate School of Medicine, Japan
| | | | | | - Yoshichika Arakawa
- Department of Bacteriology, Nagoya University Graduate School of Medicine, Japan
| | - Kouji Kimura
- Department of Bacteriology, Nagoya University Graduate School of Medicine, Japan
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Humphries RM, Lu J, Martin I, Rauch CA, Wojewoda C, McCarter Y, Long T, Simner PJ. Detection of Penicillin Nonsusceptible Streptococcus agalactiae by Laboratories That Participate in the College of American Pathologist's Proficiency Testing Program. J Clin Microbiol 2023; 61:e0059523. [PMID: 37428032 PMCID: PMC10446872 DOI: 10.1128/jcm.00595-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/11/2023] Open
Affiliation(s)
- Romney M. Humphries
- Pathology, Microbiology and Immunology, Vanderbilt Medical Center, Nashville, Tennessee, USA
| | - Jennifer Lu
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
| | - Isabella Martin
- Department of Pathology and Laboratory Medicine, Dartmouth Health, New Hampshire, USA
| | | | - Christina Wojewoda
- Department of Pathology and Laboratory Medicine, University of Vermont, Burlington, Vermont, USA
| | - Yvette McCarter
- Department of Pathology, University of Florida Health-Jacksonville, Jacksonville, Florida, USA
| | - Thomas Long
- Department of Biostatistics, College of American Pathologists, Chicago, Illinois, USA
| | - Patricia J. Simner
- Department of Pathology, Johns Hopkins University, Baltimore, Maryland, USA
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Hsu JF, Tsai MH, Lin LC, Chu SM, Lai MY, Huang HR, Chiang MC, Yang PH, Lu JJ. Genomic Characterization of Serotype III/ST-17 Group B Streptococcus Strains with Antimicrobial Resistance Using Whole Genome Sequencing. Biomedicines 2021; 9:biomedicines9101477. [PMID: 34680594 PMCID: PMC8533585 DOI: 10.3390/biomedicines9101477] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 10/11/2021] [Accepted: 10/12/2021] [Indexed: 12/25/2022] Open
Abstract
Background: Antibiotic-resistant type III/ST-17 Streptococcus agalactiae (group B Streptococcus, GBS) strain is predominant in neonatal invasive GBS diseases. We aimed to investigate the antibiotic resistance profiles and genetic characteristics of type III/ST-17 GBS strains. Methods: A total of 681 non-duplicate GBS isolates were typed (MLST, capsular types) and their antibiotic resistances were performed. Several molecular methods (WGS, PCR, sequencing and sequence analysis) were used to determine the genetic context of antibiotic resistant genes and pili genes. Results: The antibiotic resistant rates were significantly higher in type Ib (90.1%) and type III (71.1%) GBS isolates. WGS revealed that the loss of PI-1 genes and absence of ISSag5 was found in antibiotic-resistant III/ST-17 GBS isolates, which is replaced by a ~75-kb integrative and conjugative element, ICESag37, comprising multiple antibiotic resistance and virulence genes. Among 190 serotype III GBS isolates, the most common pilus island was PI-2b (58.4%) alone, which was found in 81.3% of the III/ST-17 GBS isolates. Loss of PI-1 and ISSag5 was significantly associated with antibiotic resistance (95.5% vs. 27.8%, p < 0.001). The presence of ICESag37 was found in 83.6% of all III/ST-17 GBS isolates and 99.1% (105/106) of the antibiotic-resistant III/ST-17 GBS isolates. Conclusions: Loss of PI-1 and ISSag5, which is replaced by ICESag37 carrying multiple antibiotic resistance genes, accounts for the high antibiotic resistance rate in III/ST-17 GBS isolates. The emerging clonal expansion of this hypervirulent strain with antibiotic resistance after acquisition of ICESag37 highlights the urgent need for continuous surveillance of GBS infections.
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Affiliation(s)
- Jen-Fu Hsu
- Division of Pediatric Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan; (J.-F.H.); (S.-M.C.); (M.-Y.L.); (H.-R.H.); (M.-C.C.); (P.-H.Y.)
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan;
| | - Ming-Horng Tsai
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan;
- Division of Neonatology and Pediatric Hematology/Oncology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan 638, Taiwan
| | - Lee-Chung Lin
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan 333, Taiwan;
| | - Shih-Ming Chu
- Division of Pediatric Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan; (J.-F.H.); (S.-M.C.); (M.-Y.L.); (H.-R.H.); (M.-C.C.); (P.-H.Y.)
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan;
| | - Mei-Yin Lai
- Division of Pediatric Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan; (J.-F.H.); (S.-M.C.); (M.-Y.L.); (H.-R.H.); (M.-C.C.); (P.-H.Y.)
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan;
| | - Hsuan-Rong Huang
- Division of Pediatric Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan; (J.-F.H.); (S.-M.C.); (M.-Y.L.); (H.-R.H.); (M.-C.C.); (P.-H.Y.)
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan;
| | - Ming-Chou Chiang
- Division of Pediatric Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan; (J.-F.H.); (S.-M.C.); (M.-Y.L.); (H.-R.H.); (M.-C.C.); (P.-H.Y.)
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan;
| | - Peng-Hong Yang
- Division of Pediatric Neonatology, Department of Pediatrics, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan; (J.-F.H.); (S.-M.C.); (M.-Y.L.); (H.-R.H.); (M.-C.C.); (P.-H.Y.)
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan;
| | - Jang-Jih Lu
- College of Medicine, Chang Gung University, Taoyuan 333, Taiwan;
- Department of Laboratory Medicine, Chang Gung Memorial Hospital at Linkou, Taoyuan 333, Taiwan;
- Department of Medical Biotechnology and Laboratory Science, Chang Gung University, Taoyuan 333, Taiwan
- Correspondence: ; Tel.: +886-3-328-1200 (ext. 2554); Fax: +886-3-397-1827
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Nishiyama N, Kinjo T, Uechi K, Parrott G, Nakamatsu M, Tateyama M, Fujita J. Clinical and bacterial features of Group B streptococci with reduced penicillin susceptibility from respiratory specimens: a case-control study. Eur J Clin Microbiol Infect Dis 2021; 41:1-8. [PMID: 34383176 DOI: 10.1007/s10096-021-04321-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Accepted: 07/20/2021] [Indexed: 10/20/2022]
Abstract
Streptococcus agalactiae (Group B Streptococcus, GBS) is an invasive pathogen that causes sepsis and meningitis among infants, elderly adults, and immunosuppressed patients. Generally, GBS is susceptible to penicillin; however, GBS with reduced penicillin susceptibility (PRGBS) has been reported. PRGBS are commonly isolated from respiratory specimens, but clinical features of patients with PRGBS remain unclear. In this case-control study, clinical features of patients with PRGBS and bacterial characteristics of these isolates from respiratory specimens were investigated. Patients with GBS at the University of the Ryukyus Hospital between January 2017 and June 2018 were retrospectively investigated. GBS were further classified into penicillin-susceptible GBS (PSGBS) and PRGBS using a drug susceptibility test. Moreover, serotypes, genotypes, and drug resistance genes of PRGBS isolates were determined. In total, 362 GBS were isolated, of which 46 were collected from respiratory specimens, which had the highest rate of PRGBS (24%). Compared to patients with PSGBS, those with PRGBS were more likely to have neuromuscular disease, poor performance status, risk of multidrug-resistant pathogen infection, prior pneumonia history within 1 year, and prior penicillin use within 1 year. Among eight PRGBS isolates, multilocus sequence typing revealed that five isolates were sequence type (ST) 358, two were ST3 and ST10, respectively, and one isolate was ST1404. All PRGBS isolates belonged to the ST1/ST19/ST10 group. This study reveals clinical characteristics of patients with PRGBS from respiratory specimens. Because invasive GBS infection cases are increasing, especially in the elderly, more attention should be paid to this infection.
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Affiliation(s)
- Naoya Nishiyama
- Department of Infectious, Respiratory and Digestive Medicine, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa, 903-0215, Japan
| | - Takeshi Kinjo
- Department of Infectious, Respiratory and Digestive Medicine, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa, 903-0215, Japan.
| | - Kohei Uechi
- Division of Clinical Laboratory and Blood Transfusion, University of the Ryukyus Hospital, Okinawa, Japan.,Infection Control Center, University of the Ryukyus Hospital, Okinawa, Japan
| | - Gretchen Parrott
- Department of Infectious, Respiratory and Digestive Medicine, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa, 903-0215, Japan
| | - Masashi Nakamatsu
- Department of Infectious, Respiratory and Digestive Medicine, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa, 903-0215, Japan.,Infection Control Center, University of the Ryukyus Hospital, Okinawa, Japan
| | - Masao Tateyama
- Department of Infectious, Respiratory and Digestive Medicine, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa, 903-0215, Japan.,Infection Control Center, University of the Ryukyus Hospital, Okinawa, Japan
| | - Jiro Fujita
- Department of Infectious, Respiratory and Digestive Medicine, Graduate School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa, 903-0215, Japan.,Infection Control Center, University of the Ryukyus Hospital, Okinawa, Japan
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van der Linden M, Mamede R, Levina N, Helwig P, Vila-Cerqueira P, Carriço JA, Melo-Cristino J, Ramirez M, Martins ER. Heterogeneity of penicillin-non-susceptible group B streptococci isolated from a single patient in Germany. J Antimicrob Chemother 2021; 75:296-299. [PMID: 31740946 PMCID: PMC6966095 DOI: 10.1093/jac/dkz465] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 10/10/2019] [Accepted: 10/11/2019] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVES Streptococcus agalactiae [group B streptococci (GBS)] have been considered uniformly susceptible to penicillin. However, increasing reports from Asia and North America are documenting penicillin-non-susceptible GBS (PRGBS) with mutations in pbp genes. Here we report, to the best of our knowledge, the first two PRGBS isolates recovered in Europe (AC-13238-1 and AC-13238-2), isolated from the same patient. METHODS Two different colony morphologies of GBS were noted from a surgical abscess drainage sample. Both were serotyped and antimicrobial susceptibility testing was performed by different methodologies. High-throughput sequencing was done to compare the isolates at the genomic level, to identify their capsular type and ST, to evaluate mutations in the pbp genes and to compare the isolates with the genomes of other PRGBS isolates sharing the same serotype and ST. RESULTS Isolates AC-13238-1 and AC-13238-2 presented MICs above the EUCAST and CLSI breakpoints for penicillin susceptibility. Both shared the capsular type Ia operon and ST23. Genomic analysis uncovered differences between the two isolates in seven genes, including altered pbp genes. Deduced amino acid sequences revealed critical substitutions in PBP2X in both isolates. Comparison with serotype Ia clonal complex 23 PRGBS from the USA reinforced the similarity between AC-13238-1 and AC-13238-2, and their divergence from the US strains. CONCLUSIONS Our results support the in-host evolution of β-lactam-resistant GBS, with two PRGBS variants being isolated from one patient.
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Affiliation(s)
- Mark van der Linden
- German National Reference Centre for Streptococci, Department of Medical Microbiology, University Hospital RWTH Aachen, Aachen, Germany
| | - Rafael Mamede
- Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Natascha Levina
- German National Reference Centre for Streptococci, Department of Medical Microbiology, University Hospital RWTH Aachen, Aachen, Germany
| | - Peter Helwig
- Department of Orthopaedic and Trauma Surgery, Heidenheim Hospital, Heidenheim, Germany
| | - Pedro Vila-Cerqueira
- Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - João André Carriço
- Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - José Melo-Cristino
- Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Mário Ramirez
- Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Elisabete R Martins
- Instituto de Microbiologia, Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
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Ushino T, Jin W, Wachino JI, Arakawa Y, Kimura K. Daptomycin Susceptibility of Group B Streptococcus. Jpn J Infect Dis 2020; 74:233-235. [PMID: 32999183 DOI: 10.7883/yoken.jjid.2020.371] [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: 11/17/2022]
Abstract
We previously reported the emergence and high prevalence of group B streptococci (GBS) with reduced penicillin susceptibility (PRGBS) clinical isolates in Japan. PRGBS tend to be non-susceptible to macrolides and fluoroquinolones. In our previous study, we found that the minimum inhibitory concentration (MIC) of daptomycin for one clinical isolate of GBS was above the susceptible breakpoint settled by the Clinical and Laboratory Standards Institute (CLSI). This suggests the possibility of the unrecognized spread of daptomycin-non-susceptible clinical GBS isolates in Japan. This study aimed to analyze the daptomycin susceptibility in 1,046 clinical GBS isolates that were recovered after the approval of daptomycin in Japan. MICs of daptomycin for the 1,046 clinical isolates were determined by the microdilution method recommended by the CLSI. The MIC range was 0.12-1 µg/mL, and the MIC50 and MIC90 were 0.5 µg/mL and 1 µg/mL, respectively. All the GBS isolates evaluated in this study were susceptible to daptomycin. Therefore, at present, daptomycin might be considered as a new option to treat GBS infections, especially multidrug-resistant PRGBS infections.
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Affiliation(s)
- Takumi Ushino
- Department of Bacteriology, Nagoya University Graduate School of Medicine, Japan
| | - Wanchun Jin
- Department of Bacteriology, Nagoya University Graduate School of Medicine, Japan
| | - Jun-Ichi Wachino
- Department of Bacteriology, Nagoya University Graduate School of Medicine, Japan
| | - Yoshichika Arakawa
- Department of Bacteriology, Nagoya University Graduate School of Medicine, Japan
| | - Kouji Kimura
- Department of Bacteriology, Nagoya University Graduate School of Medicine, Japan
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Olsen RJ, Zhu L, Musser JM. A Single Amino Acid Replacement in Penicillin-Binding Protein 2X in Streptococcus pyogenes Significantly Increases Fitness on Subtherapeutic Benzylpenicillin Treatment in a Mouse Model of Necrotizing Myositis. THE AMERICAN JOURNAL OF PATHOLOGY 2020; 190:1625-1631. [PMID: 32407732 DOI: 10.1016/j.ajpath.2020.04.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 04/14/2020] [Accepted: 04/21/2020] [Indexed: 12/15/2022]
Abstract
Invasive strains of Streptococcus pyogenes with significantly reduced susceptibility to β-lactam antibiotics have been recently described. These reports have caused considerable concern in the international infectious disease, medical microbiology, and public health communities because S. pyogenes has remained universally susceptible to β-lactam antibiotics for 70 years. Virtually all analyzed strains had single amino acid replacements in penicillin-binding protein 2X (PBP2X), a major target of β-lactam antibiotics in pathogenic bacteria. We used isogenic strains to test the hypothesis that a single amino acid replacement in PBP2X conferred a fitness advantage in a mouse model of necrotizing myositis. We determined that when mice were administered intermittent subtherapeutic dosing of benzylpenicillin, the strain with a Pro601Leu amino acid replacement in PBP2X that confers reduced β-lactam susceptibility in vitro was more fit, as assessed by the magnitude of colony-forming units recovered from disease tissue. These data provide important pathogenesis information that bears on this emerging global infectious disease problem.
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Affiliation(s)
- Randall J Olsen
- Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, Texas; Clinical Microbiology Laboratory, Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, Texas; Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, New York
| | - Luchang Zhu
- Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, Texas
| | - James M Musser
- Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, Texas; Clinical Microbiology Laboratory, Department of Pathology and Genomic Medicine, Houston Methodist Hospital, Houston, Texas; Department of Pathology and Laboratory Medicine, Weill Cornell Medical College, New York, New York.
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Hayes K, O'Halloran F, Cotter L. A review of antibiotic resistance in Group B Streptococcus: the story so far. Crit Rev Microbiol 2020; 46:253-269. [PMID: 32363979 DOI: 10.1080/1040841x.2020.1758626] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Group B Streptococcus (GBS) is the leading cause of neonatal disease worldwide, and invasive disease in adults is becoming more prevalent. Currently, some countries adopt an intrapartum antibiotic prophylaxis regime to help prevent the transmission of GBS from mother to neonate during delivery. This precaution has reduced the incidence of GBS-associated early-onset disease; however, rates of late-onset disease and stillbirths associated with GBS infections remain unchanged. GBS is still recognized as being universally susceptible to beta-lactam antibiotics; however, there have been reports of reduced susceptibility to beta-lactams, including penicillin, in some countries. Resistance to second-line antibiotics, such as erythromycin and clindamycin, remains high amongst GBS, with several countries noting increased resistance rates in recent years. Moreover, resistance to other antibiotic classes, such as fluoroquinolones and aminoglycosides, also continues to rise. In instances where patients are allergic to penicillin and second-line antibiotics are ineffective, vancomycin is administered. While vancomycin, a last resort antibiotic, still remains largely effective, there have been two documented cases of vancomycin resistance in GBS. This review provides a comprehensive analysis of the prevalence of antibiotic resistance in GBS and outlines the specific resistance mechanisms identified in GBS isolates to date.
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Reduced In Vitro Susceptibility of Streptococcus pyogenes to β-Lactam Antibiotics Associated with Mutations in the pbp2x Gene Is Geographically Widespread. J Clin Microbiol 2020; 58:JCM.01993-19. [PMID: 31996443 DOI: 10.1128/jcm.01993-19] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 01/15/2020] [Indexed: 12/31/2022] Open
Abstract
Recently, two related Streptococcus pyogenes strains with reduced susceptibility to ampicillin, amoxicillin, and cefotaxime, antibiotics commonly used to treat S. pyogenes infections, were reported. The two strains had the same nonsynonymous (amino acid-substituting) mutation in the pbp2x gene, encoding penicillin-binding protein 2X (PBP2X). This concerning report led us to investigate our library of 7,025 genome sequences of type emm1, emm28, and emm89 S. pyogenes clinical strains recovered from intercontinental sources for mutations in pbp2x We identified 137 strains that, combined, had 37 nonsynonymous mutations in 36 codons in pbp2x Although to a lesser magnitude than the two previously published isolates, many of our strains had decreased susceptibility in vitro to multiple beta-lactam antibiotics. Many pbp2x mutations were found only in single strains, but 16 groups of two or more isolates of the same emm type had an identical amino acid replacement. Phylogenetic analysis showed that, with one exception, strains of the same emm type with the same amino acid replacement were clonally related by descent. This finding indicates that strains with some amino acid changes in PBP2X can successfully spread to new human hosts and cause invasive infections. Mapping of the amino acid changes onto a three-dimensional structure of the related Streptococcus pneumoniae PBP2X suggests that some substitutions are located in regions functionally important in related pathogenic bacterial species. Decreased beta-lactam susceptibility is geographically widespread in strains of numerically common emm gene subtypes. Enhanced surveillance and further epidemiological and molecular genetic study of this potential emergent antimicrobial problem are warranted.
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Arakawa Y. Systematic research to overcome newly emerged multidrug-resistant bacteria. Microbiol Immunol 2020; 64:231-251. [PMID: 32068266 DOI: 10.1111/1348-0421.12781] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 01/05/2020] [Accepted: 02/08/2020] [Indexed: 11/30/2022]
Abstract
In the 1980s, I found that the chromosomal β-lactamase of Klebsiella pneumoniae LEN-1 showed a very high similarity to the R-plasmid-mediated penicillinase TEM-1 on the amino acid sequence level, and this strongly suggested the origination of TEM-1 from the chromosomal penicillinases of K. pneumoniae or related bacteria. Moreover, the chromosomal K1 β-lactamase (KOXY) of Klebsiella oxytoca was found to belong to the class A β-lactamases that include LEN-1 and TEM-1, although KOXY can hydrolyze cefoperazone (CPZ) like the chromosomal AmpC-type cephalosporinases of various Enterobacteriaceae that can hydrolyze several cephalosporins including CPZ. Furthermore, my collaborators and I found plural novel serine-type β-lactamases, such as MOX-1, SHV-24, TEM-91, CTX-M-64, CMY-9, CMY-19, GES-3, GES-4, and TLA-3, mediated by plasmids. Besides these serine-type β-lactamases, we also first identified exogenously acquired metallo-β-lactamases (MBLs), IMP-1 and SMB-1, in imipenem-resistant Serratia marcescens, and the IMP-1-producing S. marcescens TN9106 became the index case for carbapenemase-producing Enterobacteriaceae. I developed the sodium mercaptoacetic acid (SMA)-disk test for the simple identification of MBL-producing bacteria. We were also the first to identify a variety of plasmid-mediated 16S ribosomal RNA methyltransferases, RmtA, RmtB, RmtC, and NpmA, from various Gram-negative bacteria that showed very high levels of resistance to a wide range of aminoglycosides. Furthermore, we first found plasmid-mediated quinolone efflux pump (QepA) and fosfomycin-inactivating enzymes (FosA3 and FosK). We also first characterized penicillin reduced susceptible Streptococcus agalactiae, macrolide-resistant Mycoplasma pneumoniae, as well as Campylobacter jejuni, and Helicobacter pylori, together with carbapenem-resistant Haemophilus influenzae. We constructed a PCR-based open reading frame typing method for rapid identification of Acinetobacter baumannii international clones.
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Affiliation(s)
- Yoshichika Arakawa
- Department of Bacteriology, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
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