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Cheng K, Sun Y, Yu H, Hu Y, He Y, Shen Y. Staphylococcus aureus SOS response: Activation, impact, and drug targets. MLIFE 2024; 3:343-366. [PMID: 39359682 PMCID: PMC11442139 DOI: 10.1002/mlf2.12137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 03/17/2024] [Accepted: 04/10/2024] [Indexed: 10/04/2024]
Abstract
Staphylococcus aureus is a common cause of diverse infections, ranging from superficial to invasive, affecting both humans and animals. The widespread use of antibiotics in clinical treatments has led to the emergence of antibiotic-resistant strains and small colony variants. This surge presents a significant challenge in eliminating infections and undermines the efficacy of available treatments. The bacterial Save Our Souls (SOS) response, triggered by genotoxic stressors, encompasses host immune defenses and antibiotics, playing a crucial role in bacterial survival, invasiveness, virulence, and drug resistance. Accumulating evidence underscores the pivotal role of the SOS response system in the pathogenicity of S. aureus. Inhibiting this system offers a promising approach for effective bactericidal treatments and curbing the evolution of antimicrobial resistance. Here, we provide a comprehensive review of the activation, impact, and key proteins associated with the SOS response in S. aureus. Additionally, perspectives on therapeutic strategies targeting the SOS response for S. aureus, both individually and in combination with traditional antibiotics are proposed.
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Affiliation(s)
- Kaiying Cheng
- Zhejiang Key Laboratory of Medical Epigenetics, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Affiliated Hospital of Hangzhou Normal UniversityHangzhou Normal UniversityHangzhouChina
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of MedicineZhejiang UniversityHangzhouChina
| | - Yukang Sun
- Zhejiang Key Laboratory of Medical Epigenetics, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Affiliated Hospital of Hangzhou Normal UniversityHangzhou Normal UniversityHangzhouChina
| | - Huan Yu
- Zhejiang Key Laboratory of Medical Epigenetics, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Affiliated Hospital of Hangzhou Normal UniversityHangzhou Normal UniversityHangzhouChina
| | - Yingxuan Hu
- Zhejiang Key Laboratory of Medical Epigenetics, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Affiliated Hospital of Hangzhou Normal UniversityHangzhou Normal UniversityHangzhouChina
| | - Yini He
- Zhejiang Key Laboratory of Medical Epigenetics, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Affiliated Hospital of Hangzhou Normal UniversityHangzhou Normal UniversityHangzhouChina
| | - Yuanyuan Shen
- Zhejiang Key Laboratory of Medical Epigenetics, Department of Immunology and Pathogen Biology, School of Basic Medical Sciences, Affiliated Hospital of Hangzhou Normal UniversityHangzhou Normal UniversityHangzhouChina
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2
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Lynch JP, Zhanel GG. Escalation of antimicrobial resistance among MRSA part 2: focus on infections and treatment. Expert Rev Anti Infect Ther 2023; 21:115-126. [PMID: 36469648 DOI: 10.1080/14787210.2023.2154654] [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: 12/12/2022]
Abstract
INTRODUCTION MRSA is associated with causing a variety of infections including skin and skin structure infections, catheter and device-related (e.g. central venous catheter, prosthetic heart valve) infections, infectious endocarditis, blood stream infections, bone, and joint infections (e.g. osteomyelitis, prosthetic joint, surgical site), central nervous system infections (e.g. meningitis, brain/spinal cord abscess, ventriculitis, hydrocephalus), respiratory tract infections (e.g. hospital-acquired pneumonia, ventilator-associated pneumonia), urinary tract infections, and gastrointestinal infections. The emergence and spread of multidrug resistant (MDR) MRSA clones has limited therapeutic options. Older agents such as vancomycin, linezolid and daptomycin and a variety of newer MRSA antimicrobials and combination therapy are available to treat serious MRSA infections. AREAS COVERED The authors discuss infections caused by MRSA as well as common older and newer antimicrobials and combination therapy for MRSA infections. A literature search of MRSA was performed via PubMed (up to September 2022), using the keywords: antimicrobial resistance; β-lactams; multidrug resistance, Staphylococcus aureus, vancomycin; glycolipopeptides. EXPERT OPINION Innovation, discovery, and development of new and novel classes of antimicrobial agents are critical to expand effective therapeutic options. The authors encourage the judicious use of antimicrobials in accordance with antimicrobial stewardship programs along with infection-control measures to minimize the spread of MRSA.
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Affiliation(s)
- Joseph P Lynch
- Division of Pulmonary, Critical Care Medicine, Allergy, and Clinical Immunology, Department of Internal Medicine, the David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - George G Zhanel
- Department of Medical Microbiology/Infectious Diseases, Max Rady College of Medicine, University of Manitoba, Professor-Department of Medical Microbiology and Infectious Diseases, Winnipeg, Manitoba, Canada
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3
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Abdizadeh N, Haeili M, Kafil HS, Ahmadi A, Feizabadi MM. Evaluation of in vitro activity of ceftaroline on methicillin resistant Staphylococcus aureus blood isolates from Iran. IRANIAN JOURNAL OF MICROBIOLOGY 2021; 13:442-448. [PMID: 34557271 PMCID: PMC8421581 DOI: 10.18502/ijm.v13i4.6967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Background and Objectives: Ceftaroline (CPT) is a novel cephalosporin with potent activity against methicillin-resistant Staphylococcus aureus (MRSA). Despite its recent introduction, CPT resistance in MRSA has been described worldwide. We aimed in the current study to evaluate the in vitro activity of CPT against 91 clinical MRSA and 3 MSSA isolates. Materials and Methods: Susceptibility of isolates to CPT was tested using E-test and disk diffusion (DD) method. The nucleotide sequence of the mecA gene and molecular types of isolates with reduced susceptibility to CPT were further studied to identify resistance conferring mutations in PBP2a and the genetic relatedness of the isolates respectively. Results: Overall, 92.5% of isolates were found to be CPT susceptible (MICs≤1mg/l) and 7 MRSA isolates were characterized with MIC=2mg/l and categorized as susceptible dose dependent. Compared to E-test, DD revealed a categorical agreement rate of 93.6% and the obtained rates for minor, major /very major error were found to be 6.3% and 0% respectively. The MRSA isolates with increased CPT MICs (n=7), belonged to spa types t030 (n=6) and t13927 (n=1) and all carried N146K substitution in PBP2a allosteric domain, except for one isolate which harbored a wild-type PBP2a. Conclusion: While resistance to CPT was not detected we found increased CPT MICs in 7.69% of MRSA isolates. Reduced susceptibility to CPT in the absence of mecA mutations is indicative of contribution of secondary chromosomal mutations in resistance development.
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Affiliation(s)
- Negin Abdizadeh
- Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran
| | - Mehri Haeili
- Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran
| | - Hossein Samadi Kafil
- Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Amin Ahmadi
- Pharmaceutical Nanotechnology Research Center, Biomedicine Institute, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Mehdi Feizabadi
- Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.,Thoracic Research Center, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran
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Varela MC, Roch M, Taglialegna A, Long SW, Saavedra MO, Rose WE, Davis JJ, Hoffman LR, Hernandez RE, Rosato RR, Rosato AE. Carbapenems drive the collateral resistance to ceftaroline in cystic fibrosis patients with MRSA. Commun Biol 2020; 3:599. [PMID: 33093601 PMCID: PMC7582194 DOI: 10.1038/s42003-020-01313-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 07/30/2020] [Indexed: 01/14/2023] Open
Abstract
Chronic airways infection with methicillin-resistant Staphylococcus aureus (MRSA) is associated with worse respiratory disease cystic fibrosis (CF) patients. Ceftaroline is a cephalosporin that inhibits the penicillin-binding protein (PBP2a) uniquely produced by MRSA. We analyzed 335 S. aureus isolates from CF sputum samples collected at three US centers between 2015-2018. Molecular relationships demonstrated that high-level resistance of preceding isolates to carbapenems were associated with subsequent isolation of ceftaroline resistant CF MRSA. In vitro evolution experiments showed that pre-exposure of CF MRSA to meropenem with further selection with ceftaroline implied mutations in mecA and additional mutations in pbp1 and pbp2, targets of carbapenems; no effects were achieved by other β-lactams. An in vivo pneumonia mouse model showed the potential therapeutic efficacy of ceftaroline/meropenem combination against ceftaroline-resistant CF MRSA infections. Thus, the present findings highlight risk factors and potential therapeutic strategies offering an opportunity to both prevent and address antibiotic resistance in this patient population.
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Affiliation(s)
- Maria Celeste Varela
- Department of Pathology and Genomic Medicine, Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, USA
| | - Melanie Roch
- Department of Pathology and Genomic Medicine, Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, USA
| | - Agustina Taglialegna
- Department of Pathology and Genomic Medicine, Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, USA
| | - Scott W Long
- Department of Pathology and Genomic Medicine, Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, USA
| | - Matthew Ojeda Saavedra
- Department of Pathology and Genomic Medicine, Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, USA
| | - Warren E Rose
- School of Pharmacy, University of Wisconsin-Madison, Madison, WI, USA
| | - James J Davis
- Argonne National Laboratory (DOE), Lemont, IL, USA
- Computation Institute, University of Chicago, Chicago, IL, USA
| | - Lucas R Hoffman
- Department of Pediatrics and Department of Microbiology, University of Washington, Seattle, WA, USA
- Center for Clinical and Translational Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Rafael E Hernandez
- Department of Pediatrics and Department of Microbiology, University of Washington, Seattle, WA, USA
- Center for Clinical and Translational Research, Seattle Children's Research Institute, Seattle, WA, USA
| | - Roberto R Rosato
- Houston Methodist Cancer Center, Houston Methodist Hospital, Houston, USA
| | - Adriana E Rosato
- Department of Pathology and Genomic Medicine, Center for Molecular and Translational Human Infectious Diseases Research, Houston Methodist Research Institute, Houston, TX, USA.
- Riverside University Health System-Medical Center, 26520 Cactus Avenue, Moreno Valley, CA, 92555, USA.
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Gagetti P, Wattam AR, Giacoboni G, De Paulis A, Bertona E, Corso A, Rosato AE. Identification and molecular epidemiology of methicillin resistant Staphylococcus pseudintermedius strains isolated from canine clinical samples in Argentina. BMC Vet Res 2019; 15:264. [PMID: 31351494 PMCID: PMC6660709 DOI: 10.1186/s12917-019-1990-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 07/02/2019] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Staphylococcus pseudintermedius is the leading cause of pyoderma in dogs and the frequent use of antimicrobial treatment is associated to the development of resistance to nearly all classes of antibiotics. Despite S. pseudintermedius significance, our understanding of the molecular mechanism of β-lactam resistance and its genetic diversity remains limited. We aimed to: i) determine the phenotypic resistance profile of methicillin resistant Staphylococcus pseudintermedius (MRSP) isolated from infected dogs in three different veterinary hospitals in Buenos Aires, Argentina; ii) identify the SCCmec elements and resistance genes; and iii) analyze the clonal relationship between isolates and in regard of dominant lineages found in the world. RESULTS In addition to the differential levels of β-lactam resistance, MRSP isolates (n = 10) showed resistance to 5-6 families of antibiotics, and were therefore categorized as multidrug-resistant. All the isolates were variant of SCCmec V homologous to S. aureus; additional SCCmecFinder analysis classified five of the genomes as SCCmec type V (5C2&5) with mecA (encodes for PBP2a), mecRI and mecI and all the genes closely related to the reference SCCmec type V S. aureus TSGH17 strain. In the remaining five strains, mecA was present, although other genes associated with SCCmec V including mecR1 and mecI were missing. PBP2a was inducible in low level resistance strains (MRSP 8151), and constitutively expressed in MRSP 8150, suggesting different mecA regulatory mechanisms. MRSP isolates showed significant genetic diversity: eight PFGE clonal types and six multilocus-sequence typing (MLST) sequence types (STs) (339, 649, 919, 920, 921 and 922), including four new STs genetically distinct from STs reported in other geographic areas. Comparative genomics and phylogenetic analyses of the MRSP showed a correlation between the genetic content and the phenotypes, and established the genetic relationship between the isolates. CONCLUSIONS MRSP could be a threat to animal health due to it concerning level of antimicrobial resistance. Our study highlights genetic and epidemiological aspects of multidrug-resistant MRSP strains from Argentina showing high degree of correlation between the resistance genes and the phenotype of the isolates and, furthermore, they appeared evolutionary closer to major worldwide reported ST68 and ST71.
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Affiliation(s)
- Paula Gagetti
- Servicio Antimicrobianos INEI-ANLIS "Dr. Carlos G. Malbran" , CABA, Argentina.,Department of Pathology and Genomic Medicine, Houston Methodist Research Institute, Houston, TX, USA
| | - Alice R Wattam
- Biocomplexity Institute, University of Virginia, Virginia, USA
| | - Gabriela Giacoboni
- Departamento de Microbiologia, Facultad de Ciencias Veterinarias-UNLP, La Plata, Argentina
| | - Adriana De Paulis
- Departamento Microbiología, Instituto de Investigaciones Médicas Alfredo Lanari-UBA, CABA, Argentina
| | - Eugenia Bertona
- Departamento Microbiología, Instituto de Investigaciones Médicas Alfredo Lanari-UBA, CABA, Argentina
| | - Alejandra Corso
- Servicio Antimicrobianos INEI-ANLIS "Dr. Carlos G. Malbran" , CABA, Argentina
| | - Adriana E Rosato
- Department of Pathology and Genomic Medicine, Houston Methodist Research Institute, Houston, TX, USA.
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6
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Protective immunity in recurrent Staphylococcus aureus infection reflects localized immune signatures and macrophage-conferred memory. Proc Natl Acad Sci U S A 2018; 115:E11111-E11119. [PMID: 30297395 DOI: 10.1073/pnas.1808353115] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Staphylococcus aureus is the leading cause of skin and skin structure infection (SSSI), a primary portal of entry for invasive infection. Our prior studies discovered a role for protective innate memory against recurrent methicillin-resistant S. aureus (MRSA) SSSI. In the present study, the dynamics and mechanisms of this response were explored in recurrent SSSI in WT mice. Priming by prior infection reduced skin lesion severity and MRSA burden, and protected against dissemination at day 7 but not day 2. Cytokine and cellular signatures in SSSI differed at day 2 versus 7, and were distinct in skin versus blood or spleen. Cytokines associated with protection in skin included increased IL-17, IL-6, monokine inducible by IFN-γ (MIG), and RANTES, while increased IP-10 correlated with protection from dissemination. Cellular signatures of protection included increased Th17, M1 macrophage, and dendritic cell populations in abscesses, and total macrophages in lymph nodes. Priming potentiated S. aureus-specific phagocytic killing by bone marrow-derived macrophages in vitro, and their adoptive transfer into naïve skin afforded protective efficacy in vivo. Present findings indicate that protective immunity in recurrent S. aureus infection is locally targeted, and involves specific memory conferred by macrophages. These insights provide targets for vaccine and immunotherapeutic development against MRSA.
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7
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Lin LC, Chang SC, Ge MC, Liu TP, Lu JJ. Novel single-nucleotide variations associated with vancomycin resistance in vancomycin-intermediate Staphylococcus aureus. Infect Drug Resist 2018; 11:113-123. [PMID: 29403293 PMCID: PMC5783010 DOI: 10.2147/idr.s148335] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Prolonged vancomycin usage may cause methicillin-resistant Staphylococcus aureus to become vancomycin-intermediate S. aureus (VISA) and heterogeneous VISA (hVISA). Mechanisms of vancomycin resistance of VISA and hVISA are still unclear. In this study, analyses of nucleotide sequence variations in 30 vancomycin-sensitive S. aureus (VSSA), 41 hVISA and 16 VISA isolates revealed 29 single-nucleotide variations in 12 genes (fmtC, graR, graS, htrA, mecA, pbp2, pbp4, srtA, tcaA, upps, vicK and vraR) that are related to cell wall synthesis or the two-component system. Six of these 29 single-nucleotide variations were novel and resulted in the following amino acid changes: Q692E in FmtC; T278I, P306L and I311T in HtrA; and I63V and K101E in Upps. Since P306L and I311T in HtrA and I63V in Upps were present in the majority (76.7%–86.7%) of VSSA isolates, these three amino acid variations may not be associated with vancomycin resistance. The other three amino acid variations (T278I in HtrA, K101E in Upps and Q692E in FmtC) were present in the majority (87.5%–93.8%) of hVISA and VISA isolates, but only in a small number (22.9%–25.7%) of VSSA isolates, suggesting that they are associated with vancomycin resistance.
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Affiliation(s)
- Lee-Chung Lin
- Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan
| | - Shih-Cheng Chang
- Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan.,Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Mao-Cheng Ge
- Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan
| | - Tsui-Ping Liu
- Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan
| | - Jang-Jih Lu
- Department of Laboratory Medicine, Chang Gung Memorial Hospital, Linkou, Taoyuan, Taiwan.,Department of Medical Biotechnology and Laboratory Science, College of Medicine, Chang Gung University, Taoyuan, Taiwan.,Department of Medicine, College of Medicine, Chang Gung University, Taoyuan, Taiwan
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8
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High-Level Resistance of Staphylococcus aureus to β-Lactam Antibiotics Mediated by Penicillin-Binding Protein 4 (PBP4). Antimicrob Agents Chemother 2017; 61:AAC.02727-16. [PMID: 28373193 DOI: 10.1128/aac.02727-16] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Accepted: 03/26/2017] [Indexed: 02/05/2023] Open
Abstract
Penicillin-binding protein 4 (PBP4), a nonessential, low-molecular-weight penicillin-binding protein of Staphylococcus aureus, has been implicated in low-level resistance to β-lactam antibiotics, although the mechanism is unknown. Mutations in PBP4 and its promoter were identified in a laboratory-generated mutant strain, CRB, which expresses high-level resistance to β-lactams, including resistance to the new-generation cephalosporins active against methicillin-resistant strains of S. aureus These mutations did not appreciably alter the β-lactam antibiotic binding affinity of purified recombinant mutant PBP4 compared to that of wild-type PBP4. Compared to the susceptible parent strain, COLnex, the CRB strain produces a highly cross-linked cell wall peptidoglycan, indicative of increased transpeptidase activity. The pbp4 promoter mutation of CRB was associated with greatly increased amounts of PBP4 in membranes compared to those in the COLnex parent. Replacement of the native promoter of COLnex with the mutant promoter of CRB resulted in increased amounts of PBP4 in membranes and a highly cross-linked cell wall. PBP4 can be repurposed to provide essential transpeptidase activity in vivo and confer high-level resistance to β-lactam antibiotics, such as ceftobiprole and ceftaroline.
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9
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Andrey DO, François P, Manzano C, Bonetti EJ, Harbarth S, Schrenzel J, Kelley WL, Renzoni A. Antimicrobial activity of ceftaroline against methicillin-resistant Staphylococcus aureus (MRSA) isolates collected in 2013-2014 at the Geneva University Hospitals. Eur J Clin Microbiol Infect Dis 2017; 36:343-350. [PMID: 27744604 PMCID: PMC5253141 DOI: 10.1007/s10096-016-2807-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 09/27/2016] [Indexed: 11/30/2022]
Abstract
Ceftaroline is a broad-spectrum antibiotic with activity against methicillin-resistant Staphylococcus aureus (MRSA) strains. Ceftaroline susceptibility of an MRSA set archived between 1994 and 2003 in the Geneva University Hospitals detected a high percentage (66 %) of ceftaroline resistance in clonotypes ST228 and ST247 and correlated with mutations in PBP2a. The ceftaroline mechanism of action is based on the inhibition of PBP2a; thus, the identification of PBP2a mutations of recently circulating clonotypes in our institution was investigated. We analyzed ceftaroline susceptibility in MRSA isolates (2013 and 2014) and established that resistant strains correlated with PBP2a mutations and specific clonotypes. Ninety-six MRSA strains were analyzed from independent patients and were isolated from blood cultures (23 %), deep infections (38.5 %), and superficial (skin or wound) infections (38.5 %). This sample showed a ceftaroline minimum inhibitory concentration (MIC) range between 0.25 and 2 μg/ml and disk diameters ranging from 10 to 30 mm, with a majority of strains showing diameters ≥20 mm. Based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints, 76 % (73/96) of isolates showed susceptibility to ceftaroline. Nevertheless, we still observed 24 % (23/96) of resistant isolates (MIC = 2 μg/ml). All resistant isolates were assigned to clonotype ST228 and carried the N146K mutation in PBP2a. Only two ST228 isolates showed ceftaroline susceptibility. The decreasing percentage of ceftaroline-resistant isolates in our hospital can be explained by the decline of ST228 clonotype circulating in our hospital since 2008. We present evidence that ceftaroline is active against recent MRSA strains from our hospital; however, the presence of PBP2a variants in particular clonotypes may affect ceftaroline efficacy.
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Affiliation(s)
- D O Andrey
- Service of Infectious Diseases, Department of Medical Specialties, Geneva University Hospitals and Medical School, Geneva, Switzerland
| | - P François
- Genomic Research Laboratory, Service of Infectious Diseases, Department of Medical Specialties, Geneva University Hospitals and Medical School, Geneva, Switzerland
| | - C Manzano
- Service of Infectious Diseases, Department of Medical Specialties, Geneva University Hospitals and Medical School, Geneva, Switzerland
| | - E J Bonetti
- Genomic Research Laboratory, Service of Infectious Diseases, Department of Medical Specialties, Geneva University Hospitals and Medical School, Geneva, Switzerland
| | - S Harbarth
- Service of Infectious Diseases, Department of Medical Specialties, Geneva University Hospitals and Medical School, Geneva, Switzerland
- Infection Control Program, Geneva University Hospitals and Medical School, Geneva, Switzerland
| | - J Schrenzel
- Service of Infectious Diseases, Department of Medical Specialties, Geneva University Hospitals and Medical School, Geneva, Switzerland
- Genomic Research Laboratory, Service of Infectious Diseases, Department of Medical Specialties, Geneva University Hospitals and Medical School, Geneva, Switzerland
- Bacteriology Laboratory, Department of Laboratories and Genetic Medicine, Geneva University Hospitals, Geneva, Switzerland
| | - W L Kelley
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, Geneva University, Geneva, Switzerland
| | - A Renzoni
- Service of Infectious Diseases, Department of Medical Specialties, Geneva University Hospitals and Medical School, Geneva, Switzerland.
- Service of Infectious Diseases, Geneva University Hospital and Medical School, 4 Rue Gabrielle Perret Gentil, Geneva, Switzerland.
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10
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Innate Immune Memory Contributes to Host Defense against Recurrent Skin and Skin Structure Infections Caused by Methicillin-Resistant Staphylococcus aureus. Infect Immun 2017; 85:IAI.00876-16. [PMID: 27849182 DOI: 10.1128/iai.00876-16] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 11/09/2016] [Indexed: 12/31/2022] Open
Abstract
Staphylococcus aureus is the leading cause of skin and skin structure infections (SSSI). The high frequency of recurring SSSI due to S. aureus, including methicillin-resistant S. aureus (MRSA) strains, despite high titers of specific antibodies and circulating T cells, implies that traditional adaptive immunity imparts incomplete protection. We hypothesized that innate immune memory contributes to the protective host defense against recurring MRSA infection. To test this hypothesis, SSSI was induced in wild-type and rag1-/- mice in the BALB/c and C57BL/6 backgrounds. Prior infection (priming) of wild-type and rag1-/- mice of either background afforded protection against repeat infection, as evidenced by reduced abscess severities and decreased CFU densities compared to those in naive controls. Interestingly, protection was greater on the previously infected flank than on the naive flank for wild-type and rag1-/- mice. For wild-type mice, protective efficacy corresponded to increased infiltration of neutrophils (polymorphonuclear leukocytes [PMN]), macrophages (MΦ), Langerin+ dendritic cells (LDC), and natural killer (NK) cells. Protection was associated with the induction of interleukin-17A (IL-17A), IL-22, and gamma interferon (IFN-γ) as well as the antimicrobial peptides CRAMP and mβD-3. Priming also protected rag1-/- mice against recurring SSSI, with increased MΦ and LDC infiltration and induction of IL-22, CRAMP, and mβD-3. These findings suggest that innate immune memory, mediated by specific cellular and molecular programs, likely contributes to the localized host defense in recurrent MRSA SSSI. These insights support the development of targeted immunotherapeutic strategies to address the challenge of MRSA infection.
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11
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Argudín MA, Dodémont M, Taguemount M, Roisin S, de Mendonça R, Deplano A, Nonhoff C, Denis O. In vitro activity of ceftaroline against clinical Staphylococcus aureus isolates collected during a national survey conducted in Belgian hospitals. J Antimicrob Chemother 2017; 72:56-59. [PMID: 27634917 DOI: 10.1093/jac/dkw380] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 07/27/2016] [Accepted: 08/12/2016] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES The aim of this study was to estimate the in vitro activity of ceftaroline against clinical Staphylococcus aureus isolates collected during national surveillance in Belgian acute-care hospitals. Ceftaroline-resistant isolates were further investigated for their resistance mechanisms. METHODS From October 2013 to March 2014, 155 laboratories of Belgian acute-care hospitals were invited to send to the National Reference Centre-Staphylococcus aureus (Belgium) up to five non-duplicate S. aureus including three MRSA and two MSSA from hospitalized patients. Isolates were analysed by spa typing, SCCmec typing (for MRSA) and PCR for detection of 16S-mecA-nuc and 16S-mecC. MICs of oxacillin, cefoxitin and ceftaroline were determined by the broth microdilution method. The nucleotide sequences of mecA, native pbp and gdpP genes of isolates with reduced susceptibility to ceftaroline were analysed for the presence of mutations responsible for amino acid substitutions. RESULTS Ninety-nine percent of isolates, including MRSA (n = 284) and MSSA (n = 131), were susceptible to ceftaroline. Only four MRSA isolates showed resistance to ceftaroline (MIC = 2 mg/L). These four isolates belonged to lineages CC5 (n = 1), CC22 (n = 2) and CC8 (n = 1). Two isolates (CC22 and CC8) carried mutations in mecA, as well as in other pbp genes. The remaining isolates carried mutations in native pbp genes or in gdpP. CONCLUSIONS This is the first Belgian in vitro survey on ceftaroline activity against S. aureus. This antibiotic showed excellent activity against MRSA and MSSA, and only a few MRSA isolates with resistance were found. Reduced susceptibility to ceftaroline seems a complex phenomenon due to the accumulation of mutations in genes involved in β-lactam tolerance.
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Affiliation(s)
- M Angeles Argudín
- National Reference Centre-Staphylococcus aureus, Department of Microbiology, Hôpital Erasme, Université Libre de Bruxelles, Route de Lennik 808, 1070 Brussels, Belgium
| | - M Dodémont
- National Reference Centre-Staphylococcus aureus, Department of Microbiology, Hôpital Erasme, Université Libre de Bruxelles, Route de Lennik 808, 1070 Brussels, Belgium
| | - M Taguemount
- National Reference Centre-Staphylococcus aureus, Department of Microbiology, Hôpital Erasme, Université Libre de Bruxelles, Route de Lennik 808, 1070 Brussels, Belgium
| | - S Roisin
- National Reference Centre-Staphylococcus aureus, Department of Microbiology, Hôpital Erasme, Université Libre de Bruxelles, Route de Lennik 808, 1070 Brussels, Belgium
| | - R de Mendonça
- National Reference Centre-Staphylococcus aureus, Department of Microbiology, Hôpital Erasme, Université Libre de Bruxelles, Route de Lennik 808, 1070 Brussels, Belgium
| | - A Deplano
- National Reference Centre-Staphylococcus aureus, Department of Microbiology, Hôpital Erasme, Université Libre de Bruxelles, Route de Lennik 808, 1070 Brussels, Belgium
| | - C Nonhoff
- National Reference Centre-Staphylococcus aureus, Department of Microbiology, Hôpital Erasme, Université Libre de Bruxelles, Route de Lennik 808, 1070 Brussels, Belgium
| | - O Denis
- National Reference Centre-Staphylococcus aureus, Department of Microbiology, Hôpital Erasme, Université Libre de Bruxelles, Route de Lennik 808, 1070 Brussels, Belgium
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12
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Lahiri SD, Alm RA. Identification of non-PBP2a resistance mechanisms in Staphylococcus aureus after serial passage with ceftaroline: involvement of other PBPs. J Antimicrob Chemother 2016; 71:3050-3057. [PMID: 27494915 DOI: 10.1093/jac/dkw282] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Revised: 05/12/2016] [Accepted: 06/11/2016] [Indexed: 12/16/2023] Open
Abstract
OBJECTIVES Ceftaroline (the active metabolite of ceftaroline fosamil) is a cephalosporin that possesses activity against MRSA due to its differentiating high affinity for PBP2a. It is known that PBP2a sequence variations, including some outside of the transpeptidase-binding pocket, impact ceftaroline susceptibility and recent evidence suggests involvement of non-PBP2a mechanisms in ceftaroline resistance. This study evaluated the potential of ceftaroline to select for resistant Staphylococcus aureus clones during serial passage. METHODS Selection experiments were performed by up to 20 daily passages of three S. aureus isolates (two MRSA and one MSSA) in broth with increasing selective pressure. Mutants that emerged were tested for changes in ceftaroline susceptibility and genetically characterized. RESULTS The MSSA isolate developed mutations in PBP2 and PBP3 that increased the ceftaroline MIC by 16-fold and increased the MICs of other β-lactams. A Glu447Lys substitution in the PBP2a transpeptidase pocket in one MRSA isolate elevated the ceftaroline MIC to 8 mg/L. Selective pressure in a ceftaroline-resistant MRSA isolate generated mutations in LytD, as well as changes in the pbp4 promoter previously shown to result in PBP4 overexpression, the one PBP not inhibited by ceftaroline. Elevated ceftaroline MIC was reversed when tested in combination with extremely low levels of methicillin or meropenem that could inhibit the function of PBP4. CONCLUSIONS These studies demonstrate that resistance to ceftaroline can be manifested through numerous mechanisms. Further, they support a hypothesis where PBP4 can functionally provide the essential transpeptidase activity required for MRSA cell wall biogenesis when PBP2a is inhibited.
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Affiliation(s)
- Sushmita D Lahiri
- Infection Innovative Medicines Unit, AstraZeneca R&D Boston, Waltham, MA, USA
| | - Richard A Alm
- Infection Innovative Medicines Unit, AstraZeneca R&D Boston, Waltham, MA, USA
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13
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Scott LJ. Ceftaroline Fosamil: A Review in Complicated Skin and Soft Tissue Infections and Community-Acquired Pneumonia. Drugs 2016; 76:1659-1674. [PMID: 27766567 DOI: 10.1007/s40265-016-0654-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Intravenous ceftaroline fosamil (Zinforo™), a prodrug that is rapidly converted to its active metabolite ceftaroline, is approved for use in adults and children (from 2 months of age) with complicated skin and soft tissue infections (cSSTIs) or community-acquired pneumonia (CAP). In several multinational trials, ceftaroline fosamil was an effective and generally well tolerated treatment in adult and paediatric patients with cSSTIs or CAP. In the phase 3 CANVAS trials, ceftaroline fosamil treatment was noninferior to vancomycin plus aztreonam in adults with cSSTIs. Based on a meta-analysis of three similarly designed, phase 3 trials (FOCUS 1, FOCUS 2 and an Asian trial), ceftaroline fosamil treatment was superior to ceftriaxone in adults with CAP of Pneumonia Outcomes Research Teams (PORT) risk class III or IV. Ceftaroline fosamil was also associated with high clinical cure rates in hospitalized children (aged 2 months to 17 years) with cSSTIs or CAP. With its broad spectrum of in vitro activity against clinically relevant Gram-positive [including methicillin-resistant Staphylococcus aureus (MRSA) and drug-resistant Streptococcus pneumoniae isolates] and Gram-negative pathogens implicated in cSSTIs and CAP, ceftaroline fosamil is an important treatment option for cSSTI and CAP in adults and children from the age of 2 months.
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Affiliation(s)
- Lesley J Scott
- Springer, Private Bag 65901, Mairangi Bay, Auckland, 0754, New Zealand.
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14
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PBP 4 Mediates High-Level Resistance to New-Generation Cephalosporins in Staphylococcus aureus. Antimicrob Agents Chemother 2016; 60:3934-41. [PMID: 27067335 DOI: 10.1128/aac.00358-16] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Accepted: 04/08/2016] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus is an important cause of both hospital- and community-associated methicillin-resistant S. aureus (MRSA) infections worldwide. β-Lactam antibiotics are the drugs of choice to treat S. aureus infections, but resistance to these and other antibiotics make treatment problematic. High-level β-lactam resistance of S. aureus has always been attributed to the horizontally acquired penicillin binding protein 2a (PBP 2a) encoded by the mecA gene. Here, we show that S. aureus can also express high-level resistance to β-lactams, including new-generation broad-spectrum cephalosporins that are active against methicillin-resistant strains, through an uncanonical core genome-encoded penicillin binding protein, PBP 4, a nonessential enzyme previously considered not to be important for staphylococcal β-lactam resistance. Our results show that PBP 4 can mediate high-level resistance to β-lactams.
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15
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Negi B, Kumar D, Kumbukgolla W, Jayaweera S, Ponnan P, Singh R, Agarwal S, Rawat DS. Anti-methicillin resistant Staphylococcus aureus activity, synergism with oxacillin and molecular docking studies of metronidazole-triazole hybrids. Eur J Med Chem 2016; 115:426-37. [DOI: 10.1016/j.ejmech.2016.03.041] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 02/12/2016] [Accepted: 03/16/2016] [Indexed: 01/09/2023]
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16
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Fisher JF, Mobashery S. β-Lactam Resistance Mechanisms: Gram-Positive Bacteria and Mycobacterium tuberculosis. Cold Spring Harb Perspect Med 2016; 6:cshperspect.a025221. [PMID: 27091943 DOI: 10.1101/cshperspect.a025221] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The value of the β-lactam antibiotics for the control of bacterial infection has eroded with time. Three Gram-positive human pathogens that were once routinely susceptible to β-lactam chemotherapy-Streptococcus pneumoniae, Enterococcus faecium, and Staphylococcus aureus-now are not. Although a fourth bacterium, the acid-fast (but not Gram-positive-staining) Mycobacterium tuberculosis, has intrinsic resistance to earlier β-lactams, the emergence of strains of this bacterium resistant to virtually all other antibiotics has compelled the evaluation of newer β-lactam combinations as possible contributors to the multidrug chemotherapy required to control tubercular infection. The emerging molecular-level understanding of these resistance mechanisms used by these four bacteria provides the conceptual framework for bringing forward new β-lactams, and new β-lactam strategies, for the future control of their infections.
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Affiliation(s)
- Jed F Fisher
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556-5670
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556-5670
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17
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Karlowsky JA, Biedenbach DJ, Bouchillon SK, Iaconis JP, Reiszner E, Sahm DF. In vitro activity of ceftaroline against bacterial pathogens isolated from skin and soft tissue infections in Europe, Russia and Turkey in 2012: results from the Assessing Worldwide Antimicrobial Resistance Evaluation (AWARE) surveillance programme. J Antimicrob Chemother 2016; 71:162-9. [PMID: 26503667 DOI: 10.1093/jac/dkv311] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 08/28/2015] [Indexed: 08/30/2023] Open
Abstract
OBJECTIVES The objective of this study was to analyse antimicrobial susceptibility testing data generated by the Assessing Worldwide Antimicrobial Resistance Evaluation (AWARE) global surveillance programme for pathogens causing skin and soft tissue infections (SSTIs) in European countries in 2012. METHODS Confirmation of pathogen identity by MALDI-TOF and antimicrobial susceptibility testing following the CLSI broth microdilution method were performed by a central laboratory. RESULTS Using CLSI breakpoint criteria, ceftaroline was active against MSSA (n = 1116; MIC90, 0.25 mg/L; 99.8% susceptible), MRSA (n = 1467; MIC90, 1 mg/L; 92.2% susceptible) and Streptococcus pyogenes (n = 312; MIC90, 0.008 mg/L; 100% susceptible). By CLSI interpretative criteria, two S. aureus isolates (2/2583, 0.08%) were ceftaroline resistant (MIC, ≥4 mg/L) and 114 isolates (114/2583, 4.4%) were ceftaroline intermediate (2 mg/L). By EUCAST interpretative criteria (MIC, >1 mg/L), 4.5% (116/2583) of S. aureus isolates were ceftaroline resistant. Most ceftaroline-non-susceptible isolates (81.0%, 94/116) were from Russia, Turkey, Italy and Hungary. Ceftaroline susceptibility was equal to or exceeded 99% for S. aureus isolates submitted by 7 of 17 countries. Against Escherichia coli (n = 349), Klebsiella pneumoniae (n = 215), Klebsiella oxytoca (n = 74) and Proteus mirabilis (n = 121), ceftaroline activity was dependent upon ESBL production. For ESBL-negative E. coli, K. pneumoniae, K. oxytoca and P. mirabilis, 87.5% (MIC90, 1 mg/L), 92.3% (MIC90, 0.5 mg/L), 93.2% (MIC90, 0.5 mg/L) and 85.1% (MIC90, 2 mg/L) of isolates were susceptible to ceftaroline, respectively. CONCLUSIONS Ceftaroline demonstrated potent in vitro activity against a contemporary collection of bacterial pathogens from patients with SSTIs in European countries, Russia and Turkey. Surveillance programmes such as AWARE are essential to global efforts to improve antimicrobial stewardship.
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Affiliation(s)
- James A Karlowsky
- International Health Management Associates, Inc., Schaumburg, IL, USA
| | | | | | | | | | - Daniel F Sahm
- International Health Management Associates, Inc., Schaumburg, IL, USA
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18
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Chan LC, Chaili S, Filler SG, Barr K, Wang H, Kupferwasser D, Edwards JE, Xiong YQ, Ibrahim AS, Miller LS, Schmidt CS, Hennessey JP, Yeaman MR. Nonredundant Roles of Interleukin-17A (IL-17A) and IL-22 in Murine Host Defense against Cutaneous and Hematogenous Infection Due to Methicillin-Resistant Staphylococcus aureus. Infect Immun 2015; 83:4427-37. [PMID: 26351278 PMCID: PMC4598415 DOI: 10.1128/iai.01061-15] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 08/28/2015] [Indexed: 12/12/2022] Open
Abstract
Staphylococcus aureus is the leading cause of skin and skin structure infections (SSSI) in humans. Moreover, the high frequency of recurring SSSI due to S. aureus, particularly methicillin-resistant S. aureus (MRSA) strains, suggests that infection induces suboptimal anamnestic defenses. The present study addresses the hypothesis that interleukin-17A (IL-17A) and IL-22 play distinct roles in immunity to cutaneous and invasive MRSA infection in a mouse model of SSSI. Mice were treated with specific neutralizing antibodies against IL-17A and/or IL-22 and infected with MRSA, after which the severity of infection and host immune response were determined. Neutralization of either IL-17A or IL-22 reduced T cell and neutrophil infiltration and host defense peptide elaboration in lesions. These events corresponded with increased abscess severity, MRSA viability, and CFU density in skin. Interestingly, combined inhibition of IL-17A and IL-22 did not worsen abscesses but did increase gamma interferon (IFN-γ) expression at these sites. The inhibition of IL-22 led to a reduction in IL-17A expression, but not vice versa. These results suggest that the expression of IL-17A is at least partially dependent on IL-22 in this model. Inhibition of IL-17A but not IL-22 led to hematogenous dissemination to kidneys, which correlated with decreased T cell infiltration in renal tissue. Collectively, these findings indicate that IL-17A and IL-22 have complementary but nonredundant roles in host defense against cutaneous versus hematogenous infection. These insights may support targeted immune enhancement or other novel approaches to address the challenge of MRSA infection.
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Affiliation(s)
- Liana C Chan
- Division of Molecular Medicine, Harbor-UCLA Medical Center, Torrance, California, USA St. John's Cardiovascular Research Center, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Siyang Chaili
- Division of Infectious Diseases, Harbor-UCLA Medical Center, Torrance, California, USA St. John's Cardiovascular Research Center, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, USA
| | - Scott G Filler
- Division of Infectious Diseases, Harbor-UCLA Medical Center, Torrance, California, USA St. John's Cardiovascular Research Center, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, USA Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Kevin Barr
- Division of Molecular Medicine, Harbor-UCLA Medical Center, Torrance, California, USA
| | - Huiyuan Wang
- Division of Molecular Medicine, Harbor-UCLA Medical Center, Torrance, California, USA
| | - Deborah Kupferwasser
- Division of Molecular Medicine, Harbor-UCLA Medical Center, Torrance, California, USA
| | - John E Edwards
- Division of Infectious Diseases, Harbor-UCLA Medical Center, Torrance, California, USA St. John's Cardiovascular Research Center, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, USA Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Yan Q Xiong
- Division of Infectious Diseases, Harbor-UCLA Medical Center, Torrance, California, USA St. John's Cardiovascular Research Center, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, USA Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Ashraf S Ibrahim
- Division of Infectious Diseases, Harbor-UCLA Medical Center, Torrance, California, USA St. John's Cardiovascular Research Center, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, USA Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Lloyd S Miller
- Department of Dermatology, Johns Hopkins University, Baltimore, Maryland, USA
| | | | | | - Michael R Yeaman
- Division of Molecular Medicine, Harbor-UCLA Medical Center, Torrance, California, USA Division of Infectious Diseases, Harbor-UCLA Medical Center, Torrance, California, USA St. John's Cardiovascular Research Center, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California, USA Department of Medicine, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
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19
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Lahiri SD, McLaughlin RE, Whiteaker JD, Ambler JE, Alm RA. Molecular characterization of MRSA isolates bracketing the current EUCAST ceftaroline-susceptible breakpoint for Staphylococcus aureus: the role of PBP2a in the activity of ceftaroline. J Antimicrob Chemother 2015; 70:2488-98. [PMID: 26045529 DOI: 10.1093/jac/dkv131] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 04/20/2015] [Indexed: 11/14/2022] Open
Abstract
OBJECTIVES The objectives of this study were to characterize contemporary MRSA isolates and understand the prevalence and impact of sequence variability in PBP2a on ceftaroline susceptibility. METHODS A total of 184 MRSA isolates collected from 28 countries were collected and characterized. RESULTS WT PBP2a proteins were found in MRSA distributed evenly over the ceftaroline MIC range of 0.5-2 mg/L (n=56). PBP2a variations found in 124 isolates fell into two categories: (i) 12 isolates contained a substitution in the transpeptidase pocket located in the penicillin-binding domain and exhibited significantly decreased ceftaroline susceptibility (typically 8 mg/L); and (ii) isolates with substitutions in the non-penicillin-binding domain (nPBD) in a region proposed to be functionally important for cell wall biogenesis. The majority (71%) of isolates containing only nPBD variations were inhibited by 2 mg/L ceftaroline, 23% by ≤1 mg/L and 6% by 4 mg/L. These data suggest that the WT MRSA distribution extends beyond the current EUCAST and CLSI susceptible breakpoints and includes isolates inhibited by 2 mg/L ceftaroline. SCCmec type IV was the predominant type in the ceftaroline-susceptible population (68%), whereas it only represented 6% of the non-susceptible population. The variations of MLST lineages were fewer among the non-susceptible group. CONCLUSIONS This study suggests that MRSA populations with a WT PBP2a and those with nPBD variations overlap significantly and that PBP2a sequence-independent factors contribute to ceftaroline susceptibility. Whereas characterization of isolates with a ceftaroline MIC of 2 mg/L enriched for isolates with nPBD variations, it was not a discrete population. In contrast, the rare isolates containing a substitution in the transpeptidase-binding pocket were readily differentiated.
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Affiliation(s)
- Sushmita D Lahiri
- Infection Innovative Medicines Unit, AstraZeneca R&D Boston, Waltham, MA 02451, USA
| | - Robert E McLaughlin
- Infection Innovative Medicines Unit, AstraZeneca R&D Boston, Waltham, MA 02451, USA
| | - James D Whiteaker
- Infection Innovative Medicines Unit, AstraZeneca R&D Boston, Waltham, MA 02451, USA
| | - Jane E Ambler
- Infection Innovative Medicines Unit, AstraZeneca R&D Boston, Waltham, MA 02451, USA
| | - Richard A Alm
- Infection Innovative Medicines Unit, AstraZeneca R&D Boston, Waltham, MA 02451, USA
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20
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Kelley WL, Jousselin A, Barras C, Lelong E, Renzoni A. Missense mutations in PBP2A Affecting ceftaroline susceptibility detected in epidemic hospital-acquired methicillin-resistant Staphylococcus aureus clonotypes ST228 and ST247 in Western Switzerland archived since 1998. Antimicrob Agents Chemother 2015; 59:1922-30. [PMID: 25583724 PMCID: PMC4356817 DOI: 10.1128/aac.04068-14] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Accepted: 01/07/2015] [Indexed: 12/28/2022] Open
Abstract
The development and maintenance of an arsenal of antibiotics is a major health care challenge. Ceftaroline is a new cephalosporin with activity against methicillin-resistant Staphylococcus aureus (MRSA); however, no reports concerning MRSA ceftaroline susceptibility have been reported in Switzerland. We tested the in vitro activity of ceftaroline against an archived set of 60 MRSA strains from the University Hospital of Geneva collected from 1994 to 2003. Our results surprisingly revealed ceftaroline-resistant strains (MIC, >1 μg/ml in 40/60 strains; EUCAST breakpoints, susceptible [S], ≤1 μg/ml; resistant [R], >1 μg/ml) were present from 1998 to 2003. The detected resistant strains predominantly belonged to sequence type 228 (ST228) (South German clonotype) but also to ST247 (Iberian clonotype). A sequence analysis of these strains revealed missense mutations in the penicillin-binding protein 2A (PBP2A) allosteric domain (N146K or E239K and N146K-E150K-G246E). The majority of our ST228 PBP2A mutations (N146K or E150K) were distinct from ST228 PBP2A allosteric domain mutations (primarily E239K) recently described for MRSA strains collected in Thailand and Spain during the 2010 Assessing Worldwide Antimicrobial Resistance Evaluation (AWARE) global surveillance program. We also found that similar allosteric domain PBP2A mutations (N146K) correlated with ceftaroline resistance in an independent external ST228 MRSA set obtained from the nearby University Hospital of Lausanne, Lausanne, Switzerland, collected from 2003 to 2008. Thus, ceftaroline resistance was observed in our archived strains (including two examples of an MIC of 4 µg/ml for the Iberian ST247 clonotype with the triple mutation N146K/E150K/G246E), at least as far back as 1998, considerably predating the commercial introduction of ceftaroline. Our results reinforce the notion that unknown parameters can potentially exert selective pressure on PBP2A that can subsequently modulate ceftaroline resistance.
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Affiliation(s)
- William L Kelley
- Service of Infectious Diseases, University Hospital and Medical School of Geneva, Geneva, Switzerland
| | - Ambre Jousselin
- Service of Infectious Diseases, University Hospital and Medical School of Geneva, Geneva, Switzerland
| | - Christine Barras
- Service of Infectious Diseases, University Hospital and Medical School of Geneva, Geneva, Switzerland
| | - Emmanuelle Lelong
- Service of Infectious Diseases, University Hospital and Medical School of Geneva, Geneva, Switzerland
| | - Adriana Renzoni
- Service of Infectious Diseases, University Hospital and Medical School of Geneva, Geneva, Switzerland
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