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Chen J, Du W, Li Y, Zhou H, Ouyang D, Yao Z, Fu J, Ye X. Genome-based model for differentiating between infection and carriage Staphylococcus aureus. Microbiol Spectr 2024; 12:e0049324. [PMID: 39248515 PMCID: PMC11448440 DOI: 10.1128/spectrum.00493-24] [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] [Received: 02/23/2024] [Accepted: 08/02/2024] [Indexed: 09/10/2024] Open
Abstract
Staphylococcus aureus (S. aureus) is a clinically significant opportunistic pathogen, which can colonize multiple body sites in healthy individuals and cause various life-threatening diseases in both children and adults worldwide. The genetic backgrounds of S. aureus that cause infection versus asymptomatic carriage vary widely, but the potential genetic elements (k-mers) associated with S. aureus infection remain unknown, which leads to difficulties in differentiating infection isolates from harmless colonizers. Here, we address the disease-associated k-mers by using a comprehensive genome-wide association study (GWAS) to compare the genetic variation of S. aureus isolates from clinical infection sites (272 isolates) with nasal carriage (240 isolates). This study uncovers consensus evidence that certain k-mers are overrepresented in infection isolates compared with carriage isolates, indicating the presence of specific genetic elements associated with S. aureus infection. Moreover, the random forest (RF) model achieved a classification accuracy of 77% for predicting disease status (infection vs carriage), with 68% accuracy for a single highest-ranked k-mer, providing a simple target for identifying high-risk genotypes. Our findings suggest that the disease-causing S. aureus is a pathogenic subpopulation harboring unique genomic variation that promotes invasion and infection, providing novel targets for clinical interventions. IMPORTANCE Defining the disease-causing isolates is the first step toward disease control. However, the disease-associated genetic elements of Staphylococcus aureus remain unknown, which leads to difficulties in differentiating infection isolates from harmless carriage isolates. Our comprehensive genome-wide association study (GWAS) found consensus evidence that certain genetic elements are overrepresented among infection isolates than carriage isolates, suggesting that the enrichment of disease-associated elements may promote infection. Notably, a single k-mer predictor achieved a high classification accuracy, which forms the basis for early diagnostics and interventions.
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Affiliation(s)
- Jianyu Chen
- Laboratory of Molecular Epidemiology, School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China
| | - Wenyin Du
- Laboratory of Molecular Epidemiology, School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China
| | - Yuehe Li
- Laboratory of Molecular Epidemiology, School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China
| | - Huiliu Zhou
- Laboratory of Molecular Epidemiology, School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China
| | - Dejia Ouyang
- Laboratory of Molecular Epidemiology, School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China
| | - Zhenjiang Yao
- Laboratory of Molecular Epidemiology, School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China
| | - Jinjian Fu
- Department of Laboratory Science, Maoming Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
- Guangzhou Women and Children's Medical Center Liuzhou Hospital, Liuzhou, China
| | - Xiaohua Ye
- Laboratory of Molecular Epidemiology, School of Public Health, Guangdong Pharmaceutical University, Guangzhou, China
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Peng KT, Chen PC, Chen JL, Huang TY, Peng YH, Liu JF, Lee CW, Chang PJ. A Comparative Phenotypic and Genomic Analysis of Methicillin-Resistant Staphylococcus aureus ST45 Isolates From Cellulitis and Osteomyelitis in Taiwan. J Infect Dis 2024; 230:e568-e578. [PMID: 38409272 PMCID: PMC11420812 DOI: 10.1093/infdis/jiae096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 01/23/2024] [Accepted: 02/24/2024] [Indexed: 02/28/2024] Open
Abstract
BACKGROUND Methicillin-resistant Staphylococcus aureus (MRSA) sequence type (ST) 45 is a globally disseminated MRSA lineage. Herein, we investigated whether MRSA ST45 isolates from cellulitis and from osteomyelitis display distinctive phenotypic and genomic characteristics. METHODS A total of 15 MRSA ST45 isolates from cellulitis (CL-MRSA; n = 6) or osteomyelitis (OM-MRSA; n = 9) were collected in a Taiwan hospital. These MRSA ST45 isolates were characterized for their antimicrobial susceptibility, biofilm-forming ability, cellular infectivity in vitro, and pathogenicity in vivo. Four CL-MRSA and 6 OM-MRSA ST45 isolates were selected for whole-genome sequencing (WGS). RESULTS Antibiotic resistance tests showed that all OM-MRSA ST45 strains, but not CL-MRSA ST45 strains, were resistant to ciprofloxacin, levofloxacin, gentamicin, and doxycycline. Compared to the CL-MRSA ST45 isolates, the OM-MRSA ST45 isolates had stronger biofilm-forming ability and cellular infectivity and caused more severe disease in mice. WGS analysis revealed that these OM-MRSA ST45 isolates carry multiple common mutations or polymorphisms in genes associated with antibiotic resistance and virulence. Moreover, the transposable elements IS256 and IS257R2 were found only in the OM-MRSA ST45 isolates. CONCLUSIONS The emergence and spread of the highly pathogenic and multidrug-resistant ST45 MRSAs identified from osteomyelitis may pose a serious threat on public health.
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Affiliation(s)
- Kuo-Ti Peng
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Chiayi
- College of Medicine, Chang Gung University, Taoyuan
| | - Pei-Chun Chen
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Chiayi
| | - Jiun-Liang Chen
- Department of Orthopedic Surgery, Chang Gung Memorial Hospital, Chiayi
| | - Tsung-Yu Huang
- Division of Infectious Diseases, Department of Internal Medicine, Chang Gung Memorial Hospital, Chiayi
| | - Yi-Ho Peng
- National Chia-Yi Girls Senior High School, Chiayi
| | - Ju-Fang Liu
- School of Oral Hygiene, College of Oral Medicine, Taipei Medical University, Taipei
| | - Chiang-Wen Lee
- Department of Nursing, Division of Basic Medical Sciences, Recurrent Diseases and Health Promotion Research Center, Chang Gung University of Science and Technology, Chiayi
- Research Center for Industry of Human Ecology and Research Center for Chinese Herbal Medicine, Chang Gung University of Science and Technology, Taoyuan
- Department of Rehabilitation, Chang Gung Memorial Hospital, Chiayi
| | - Pey-Jium Chang
- Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan
- Department of Nephrology, Chang Gung Memorial Hospital, Chiayi, Taiwan
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3
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Nguyen A, Roy JJS, Kim JH, Yun KH, Lee W, Kim KK, Kim T, Chaurasia AK. Repeated Exposure of Vancomycin to Vancomycin-Susceptible Staphylococcus aureus (VSSA) Parent Emerged VISA and VRSA Strains with Enhanced Virulence Potentials. J Microbiol 2024; 62:535-553. [PMID: 38814539 DOI: 10.1007/s12275-024-00139-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2023] [Revised: 04/18/2024] [Accepted: 04/21/2024] [Indexed: 05/31/2024]
Abstract
The emergence of resistance against the last-resort antibiotic vancomycin in staphylococcal infections is a serious concern for human health. Although various drug-resistant pathogens of diverse genetic backgrounds show higher virulence potential, the underlying mechanism behind this is not yet clear due to variability in their genetic dispositions. In this study, we investigated the correlation between resistance and virulence in adaptively evolved isogenic strains. The vancomycin-susceptible Staphylococcus aureus USA300 was exposed to various concentrations of vancomycin repeatedly as a mimic of the clinical regimen to obtain mutation(s)-accrued-clonally-selected (MACS) strains. The phenotypic analyses followed by expression of the representative genes responsible for virulence and resistance of MACS strains were investigated. MACS strains obtained under 2 and 8 µg/ml vancomycin, named Van2 and Van8, respectively; showed enhanced vancomycin minimal inhibitory concentrations (MIC) to 4 and 16 µg/ml, respectively. The cell adhesion and invasion of MACS strains increased in proportion to their MICs. The correlation between resistance and virulence potential was partially explained by the differential expression of genes known to be involved in both virulence and resistance in MACS strains compared to parent S. aureus USA300. Repeated treatment of vancomycin against vancomycin-susceptible S. aureus (VSSA) leads to the emergence of vancomycin-resistant strains with variable levels of enhanced virulence potentials.
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Affiliation(s)
- An Nguyen
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea
- Department of Biophysics, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - J Jean Sophy Roy
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea
| | - Ji-Hoon Kim
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Kyung-Hee Yun
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea
| | - Wonsik Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Republic of Korea
| | - Kyeong Kyu Kim
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea.
- Department of Biophysics, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
| | - Truc Kim
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea.
| | - Akhilesh Kumar Chaurasia
- Department of Precision Medicine, Graduate School of Basic Medical Science (GSBMS), Institute for Antimicrobial Resistance Research and Therapeutics, Sungkyunkwan University School of Medicine, Suwon, 16419, Republic of Korea.
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Balogh H, Anthony A, Stempel R, Vossen L, Federico VA, Valenzano GZ, Blackledge MS, Miller HB. Novel Anti-virulence Compounds Disrupt Exotoxin Expression in MRSA. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.15.594412. [PMID: 38798408 PMCID: PMC11118326 DOI: 10.1101/2024.05.15.594412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Hemolysins are lytic exotoxins expressed in most strains of S. aureus , but hemolytic activity varies between strains. We have previously reported several novel anti-virulence compounds that disrupt the S. aureus transcriptome, including hemolysin gene expression. This report delves further into our two lead compounds, loratadine and a structurally related brominated carbazole, and their effects on hemolysin production in MRSA. To gain understanding into how these compounds affect hemolysis, we analyzed these exotoxins at the DNA, RNA, and protein level after in vitro treatment. While lysis of red blood cells varied between strains, DNA sequence variation did not account for it. We hypothesized that our compounds would modulate gene expression of multiple hemolysins in a laboratory strain and a clinically relevant hospital-acquired strain of MRSA, both with SCC mec type II. RNA-seq analysis of differential gene expression in untreated and compound-treated cultures revealed hundreds of differentially expressed genes, with a significant enrichment in genes involved in hemolysis. The brominated carbazole and loratadine both displayed the ability to reduce hemolysis in the laboratory strain, but displayed differential activity in a hospital-acquired strain. These results corroborate gene expression studies as well as western blots of alpha hemolysin. Together, this work suggests that small molecules may alter exotoxin production in MRSA, but that the directionality and/or magnitude of the difference is likely strain-dependent.
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Chin JL, Tan ZC, Chan LC, Ruffin F, Parmar R, Ahn R, Taylor SD, Bayer AS, Hoffmann A, Fowler VG, Reed EF, Yeaman MR, Meyer AS. Tensor modeling of MRSA bacteremia cytokine and transcriptional patterns reveals coordinated, outcome-associated immunological programs. PNAS NEXUS 2024; 3:pgae185. [PMID: 38779114 PMCID: PMC11109816 DOI: 10.1093/pnasnexus/pgae185] [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: 11/23/2023] [Accepted: 04/17/2024] [Indexed: 05/25/2024]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) bacteremia is a common and life-threatening infection that imposes up to 30% mortality even when appropriate therapy is used. Despite in vitro efficacy determined by minimum inhibitory concentration breakpoints, antibiotics often fail to resolve these infections in vivo, resulting in persistent MRSA bacteremia. Recently, several genetic, epigenetic, and proteomic correlates of persistent outcomes have been identified. However, the extent to which single variables or their composite patterns operate as independent predictors of outcome or reflect shared underlying mechanisms of persistence is unknown. To explore this question, we employed a tensor-based integration of host transcriptional and cytokine datasets across a well-characterized cohort of patients with persistent or resolving MRSA bacteremia outcomes. This method yielded high correlative accuracy with outcomes and immunologic signatures united by transcriptomic and cytokine datasets. Results reveal that patients with persistent MRSA bacteremia (PB) exhibit signals of granulocyte dysfunction, suppressed antigen presentation, and deviated lymphocyte polarization. In contrast, patients with resolving bacteremia (RB) heterogeneously exhibit correlates of robust antigen-presenting cell trafficking and enhanced neutrophil maturation corresponding to appropriate T lymphocyte polarization and B lymphocyte response. These results suggest that transcriptional and cytokine correlates of PB vs. RB outcomes are complex and may not be disclosed by conventional modeling. In this respect, a tensor-based integration approach may help to reveal consensus molecular and cellular mechanisms and their biological interpretation.
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Affiliation(s)
- Jackson L Chin
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90024, USA
| | - Zhixin Cyrillus Tan
- Bioinformatics Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA 90024, USA
| | - Liana C Chan
- The Lundquist Institute for Biomedical Innovation, Harbor-UCLA Medical Center, Torrance, CA 90502, USA
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
- Division of Infectious Diseases, Department of Medicine, Harbor-UCLA Medical Center, Torrance, CA 90502, USA
- Division of Molecular Medicine, Department of Medicine, Harbor-UCLA Medical Center, Torrance, CA 90502, USA
| | - Felicia Ruffin
- Division of Infectious Diseases, Duke University School of Medicine, Durham, NC 27710, USA
| | - Rajesh Parmar
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Richard Ahn
- Institute for Quantitative and Computational Biosciences, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Scott D Taylor
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90024, USA
| | - Arnold S Bayer
- The Lundquist Institute for Biomedical Innovation, Harbor-UCLA Medical Center, Torrance, CA 90502, USA
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - Alexander Hoffmann
- Institute for Quantitative and Computational Biosciences, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Vance G Fowler
- Division of Infectious Diseases, Duke University School of Medicine, Durham, NC 27710, USA
| | - Elaine F Reed
- Department of Pathology and Laboratory Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Michael R Yeaman
- The Lundquist Institute for Biomedical Innovation, Harbor-UCLA Medical Center, Torrance, CA 90502, USA
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
- Division of Infectious Diseases, Department of Medicine, Harbor-UCLA Medical Center, Torrance, CA 90502, USA
- Division of Molecular Medicine, Department of Medicine, Harbor-UCLA Medical Center, Torrance, CA 90502, USA
- Division of Infectious Diseases, Duke University School of Medicine, Durham, NC 27710, USA
| | - Aaron S Meyer
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA 90024, USA
- Bioinformatics Interdepartmental Program, University of California, Los Angeles, Los Angeles, CA 90024, USA
- Jonsson Comprehensive Cancer Center, University of California, Los Angeles, Los Angeles, CA 90024, USA
- Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA 90024, USA
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Piper KR, Ikhimiukor OO, Souza SSR, Garcia-Aroca T, Andam CP. Evolutionary dynamics of the accessory genomes of Staphylococcus aureus. mSphere 2024; 9:e0075123. [PMID: 38501935 PMCID: PMC11036810 DOI: 10.1128/msphere.00751-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 02/24/2024] [Indexed: 03/20/2024] Open
Abstract
Staphylococcus aureus is a ubiquitous commensal and opportunistic bacterial pathogen that can cause a wide gamut of infections, which are exacerbated by the presence of multidrug-resistant and methicillin-resistant S. aureus. S. aureus is genetically heterogeneous and consists of numerous distinct lineages. Using 558 complete genomes of S. aureus, we aim to determine how the accessory genome content among phylogenetic lineages of S. aureus is structured and has evolved. Bayesian hierarchical clustering identified 10 sequence clusters, of which seven contained major sequence types (ST 1, 5, 8, 30, 59, 239, and 398). The seven sequence clusters differed in their accessory gene content, including genes associated with antimicrobial resistance and virulence. Focusing on the two largest clusters, BAPS8 and BAPS10, and each consisting mostly of ST5 and ST8, respectively, we found that the structure and connected components in the co-occurrence networks of accessory genomes varied between them. These differences are explained, in part, by the variation in the rates at which the two sequence clusters gained and lost accessory genes, with the highest rate of gene accumulation occurring recently in their evolutionary histories. We also identified a divergent group within BAPS10 that has experienced high gene gain and loss early in its history. Together, our results show highly variable and dynamic accessory genomes in S. aureus that are structured by the history of the specific lineages that carry them.IMPORTANCEStaphylococcus aureus is an opportunistic, multi-host pathogen that can cause a variety of benign and life-threatening infections. Our results revealed considerable differences in the structure and evolution of the accessory genomes of major lineages within S. aureus. Such genomic variation within a species can have important implications on disease epidemiology, pathogenesis of infection, and interactions with the vertebrate host. Our findings provide important insights into the underlying genetic basis for the success of S. aureus as a highly adaptable and resistant pathogen, which will inform current efforts to control and treat staphylococcal diseases.
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Affiliation(s)
- Kathryn R. Piper
- Department of Biological Sciences, University at Albany, State University of New York, Albany, New York, USA
| | - Odion O. Ikhimiukor
- Department of Biological Sciences, University at Albany, State University of New York, Albany, New York, USA
| | - Stephanie S. R. Souza
- Department of Biological Sciences, University at Albany, State University of New York, Albany, New York, USA
| | - Teddy Garcia-Aroca
- Department of Biological Sciences, University at Albany, State University of New York, Albany, New York, USA
- Department of Plant Pathology, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | - Cheryl P. Andam
- Department of Biological Sciences, University at Albany, State University of New York, Albany, New York, USA
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Kim G, Lee S, Lee Y, Kim JH, Lee J. The molecular epidemiology and clinical implication of methicillin-resistant Staphylococcus aureus (MRSA) sequence types in pediatric bacteremia: a restrospective observational study, 2016-2021. BMC Infect Dis 2024; 24:259. [PMID: 38402154 PMCID: PMC10894466 DOI: 10.1186/s12879-023-08914-5] [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] [Received: 09/18/2023] [Accepted: 12/14/2023] [Indexed: 02/26/2024] Open
Abstract
BACKGROUND While there is a high burden of methicillin-resistant Staphylococcus aureus (MRSA) infections among pediatric patients, studies on the molecular epidemiology of MRSA infections in Korean children since the 2010s are lacking. This study aimed to investigate the molecular genotypes and clinical characteristics of MRSA isolates from children with MRSA bacteremia at Asan Medical Center Children's Hospital from 2016 to 2021. METHODS Clinical data were retrospectively reviewed, and the molecular types of MRSA were determined using multilocus sequence typing (MLST) and Staphylococcal cassette chromosome mec (SCCmec) typing. RESULTS The overall methicillin resistance rate of S. aureus bacteremia was 44.8% (77/172); 49.5% in the period 2016-2018 (period 1) and 37.3% in the period 2019-2021 (period 2) (P = 0.116). Community-acquired infections accounted for only 3.9% of cases. The predominant ST group was ST72 group (67.6%), followed by ST5 group (18.9%) and ST1 group (5.4%). The proportion of ST5 was significantly lower in period 2 compared to period 1 (P = 0.02). Compared to the ST5 and ST1 groups, the ST72 group exhibited lower overall antibiotic resistance and multidrug-resistant (MDR) rates (12.0% [6/50] in ST72 group vs. 100.0% [14/14] in ST5 group vs. 50.0% [2/4] in ST1 group; P < 0.001). In the multivariate analysis, the ST1 group was an independent risk factor for 30-day all-cause mortality (aOR, 44.12; 95% CI, 3.46-562.19). CONCLUSION The ST72-MRSA strain remained the most frequently isolated genotype in Korean children, while the ST1 group emerged as an independent risk factor for 30-day all-cause mortality in pediatric MRSA bacteremia. Ongoing efforts to uncover the evolving epidemiology of MRSA are essential for developing effective strategies for prevention and treatment.
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Affiliation(s)
- Gahee Kim
- Department of Pediatrics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
- Department of Pediatrics, Chosun University hospital, Gwangju, Republic of Korea
| | - Sanghoon Lee
- Department of Pediatrics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Yonghee Lee
- Department of Pediatrics, Gangwon National University hospital, Chunchen, Gangwon-do, Republic of Korea
| | - Jung Hwa Kim
- Department of Pediatrics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Jina Lee
- Department of Pediatrics, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea.
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Barcudi D, Blasko E, Gonzalez MJ, Gagetti P, Lamberghini R, Garnero A, Sarkis C, Faccone D, Lucero C, Tosoroni D, Bocco JL, Corso A, Sola C. Different evolution of S. aureus methicillin-resistant and methicillin-susceptible infections, Argentina. Heliyon 2024; 10:e22610. [PMID: 38163174 PMCID: PMC10755277 DOI: 10.1016/j.heliyon.2023.e22610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 11/14/2023] [Accepted: 11/15/2023] [Indexed: 01/03/2024] Open
Abstract
Staphylococcus aureus-(SA) is widespread among healthcare-associated-(HA) and the community-associated-(CA) infections. However, the contributions of MRSA and MSSA to the SA overall burden remain unclear. In a nationally-representative-survey conducted in Argentina, 668 SA clinical isolates from 61 hospitals were examined in a prospective, cross-sectional, multicenter study in April 2015. The study aimed to analyze MRSA molecular epidemiology, estimate overall SA infection incidence (MSSA, MRSA, and genotypes) in community-onset (CO: HACO, Healthcare-Associated-CO and CACO, Community-Associated-CO) and healthcare-onset (HO: HAHO, Healthcare-associated-HO) infections, stratified by age groups. Additionally temporal evolution was estimated by comparing this study's (2015) incidence values with a previous study (2009) in the same region. Erythromycin-resistant-MSSA and all MRSA strains were genetically typed. The SA total-infections (TI) overall-incidence was 49.1/100,000 monthly-visits, 25.1 and 24.0 for MRSA and MSSA respectively (P = 0.5889), in April 2015. In adults with invasive-infections (INVI), MSSA was 15.7 and MRSA was 11.8 (P = 0.0288), 1.3-fold higher. HA SA infections, both MSSA and MRSA, surpassed CA infections by over threefold. During 2009-2015, there was a significant 23.4 % increase in the SA infections overall-incidence, mainly driven by MSSA, notably a 54.2 % increase in INVI among adults, while MRSA infection rates remained stable. The MSSA rise was accompanied by increased antimicrobial resistance, particularly to erythromycin, linked to MSSA-CC398-t1451-ermT + -IEC+-pvl- emergence. The SA-infections rise was primarily attributed to community-onset-infections (37.3 % and 62.4 % increase for TI and INVI, respectively), particularly HACO-MSSA and HACO-MRSA in adults, as well as CACO-MSSA. The main CA-MRSA-PFGE-typeN-ST30-SCCmecIVc-PVL+/- clone along with other clones (USA300-ST8-IV-LV-PVL+/-, PFGE-typeDD-ST97-IV- PVL-) added to rather than replaced CA-MRSA-PFGE-typeI-ST5-SCCmecIVa-PVL+/- clone in HA invasive-infections. They also displaced clone HA-MRSA-PFGE-typeA-ST5-SCCmecI, mainly in HAHO infections. The overall-burden of SA infections is rising in Argentina, driven primarily by community-onset MSSA, particularly in adults, linked to increased erythromycin-resistance and MSSA-CC398-t1451-ermT + -IEC+-pvl- emergence. Novel knowledge and transmission-control strategies are required for MSSA.
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Affiliation(s)
- Danilo Barcudi
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI) CONICET and Universidad Nacional de Córdoba, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Haya de La Torre y Medina Allende, Ciudad Universitaria, X5000, Córdoba, Argentina
| | - Enrique Blasko
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI) CONICET and Universidad Nacional de Córdoba, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Haya de La Torre y Medina Allende, Ciudad Universitaria, X5000, Córdoba, Argentina
| | - María José Gonzalez
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI) CONICET and Universidad Nacional de Córdoba, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Haya de La Torre y Medina Allende, Ciudad Universitaria, X5000, Córdoba, Argentina
| | - Paula Gagetti
- Servicio Antimicrobianos, Instituto Nacional de Enfermedades Infecciosas (INEI)-ANLIS “Dr. Carlos G. Malbrán”, Ciudad Autónoma de Buenos Aires, Argentina
| | - Ricardo Lamberghini
- Cátedra de Infectología I, Hospital Rawson, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Bajada Pucará 2025, X5000, Córdoba, Argentina
| | - Analía Garnero
- Servicio de Infectología, Hospital de Niños de la Santísima Trinidad de Córdoba, Córdoba, Bajada Pucará 787, X 5000, ANN, Argentina
| | - Claudia Sarkis
- Hospital de Pediatría S.A.M.I.C."Prof. Dr. Juan P. Garrahan”, Combate de los Pozos 1881, C1245, AAM, CABA, Argentina
| | - Diego Faccone
- Servicio Antimicrobianos, Instituto Nacional de Enfermedades Infecciosas (INEI)-ANLIS “Dr. Carlos G. Malbrán”, Ciudad Autónoma de Buenos Aires, Argentina
| | - Celeste Lucero
- Servicio Antimicrobianos, Instituto Nacional de Enfermedades Infecciosas (INEI)-ANLIS “Dr. Carlos G. Malbrán”, Ciudad Autónoma de Buenos Aires, Argentina
| | - Dario Tosoroni
- Informática Médica, Facultad de Medicina, Universidad Católica de Córdoba, Jacinto Ríos 555, X5004, ASK, Córdoba, Argentina
| | | | - José L. Bocco
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI) CONICET and Universidad Nacional de Córdoba, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Haya de La Torre y Medina Allende, Ciudad Universitaria, X5000, Córdoba, Argentina
| | - Alejandra Corso
- Servicio Antimicrobianos, Instituto Nacional de Enfermedades Infecciosas (INEI)-ANLIS “Dr. Carlos G. Malbrán”, Ciudad Autónoma de Buenos Aires, Argentina
| | - Claudia Sola
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI) CONICET and Universidad Nacional de Córdoba, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Haya de La Torre y Medina Allende, Ciudad Universitaria, X5000, Córdoba, Argentina
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Herrera AL, Chaussee MS, Pietri JE. Experimental Acquisition, Maintenance, and Transmission of Methicillin-Resistant Staphylococcus aureus by the Common Bed Bug, Cimex lectularius. J Infect Dis 2024; 229:245-251. [PMID: 37523766 DOI: 10.1093/infdis/jiad302] [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] [Received: 06/09/2023] [Revised: 07/18/2023] [Accepted: 07/28/2023] [Indexed: 08/02/2023] Open
Abstract
Here, we fed bed bugs through a membrane contaminated with methicillin-resistant Staphylococcus aureus (MRSA) at a concentration naturally present on human skin. We then determined the amount of viable MRSA present on their surface and internally over a period of 7 days. We also determined whether bed bugs that fed through the contaminated membrane could transmit MRSA to an uncontaminated membrane when taking a second blood meal 7 days later. Bed bugs acquired MRSA both externally on the cuticle surface as well as internally when feeding. MRSA was found to persist for 7 days both externally and internally in some bed bugs. Furthermore, MRSA replicated internally but not externally. Most importantly, bed bugs were able to transmit MRSA to an uncontaminated membrane feeder in 2 of 3 trials. These findings provide the first experimental support for the hypothesis that bed bugs may contribute to the transmission of MRSA in some settings.
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Affiliation(s)
- Andrea L Herrera
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion
| | - Michael S Chaussee
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion
| | - Jose E Pietri
- Division of Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion
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10
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Jiang JH, Cameron DR, Nethercott C, Aires-de-Sousa M, Peleg AY. Virulence attributes of successful methicillin-resistant Staphylococcus aureus lineages. Clin Microbiol Rev 2023; 36:e0014822. [PMID: 37982596 PMCID: PMC10732075 DOI: 10.1128/cmr.00148-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of severe and often fatal infections. MRSA epidemics have occurred in waves, whereby a previously successful lineage has been replaced by a more fit and better adapted lineage. Selection pressures in both hospital and community settings are not uniform across the globe, which has resulted in geographically distinct epidemiology. This review focuses on the mechanisms that trigger the establishment and maintenance of current, dominant MRSA lineages across the globe. While the important role of antibiotic resistance will be mentioned throughout, factors which influence the capacity of S. aureus to colonize and cause disease within a host will be the primary focus of this review. We show that while MRSA possesses a diverse arsenal of toxins including alpha-toxin, the success of a lineage involves more than just producing toxins that damage the host. Success is often attributed to the acquisition or loss of genetic elements involved in colonization and niche adaptation such as the arginine catabolic mobile element, as well as the activity of regulatory systems, and shift metabolism accordingly (e.g., the accessory genome regulator, agr). Understanding exactly how specific MRSA clones cause prolonged epidemics may reveal targets for therapies, whereby both core (e.g., the alpha toxin) and acquired virulence factors (e.g., the Panton-Valentine leukocidin) may be nullified using anti-virulence strategies.
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Affiliation(s)
- Jhih-Hang Jiang
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - David R. Cameron
- Department of Biomedical Research, University of Bern, Bern, Switzerland
| | - Cara Nethercott
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Marta Aires-de-Sousa
- Laboratory of Molecular Genetics, Institutode Tecnologia Químicae Biológica António Xavier (ITQB-NOVA), Universidade Nova de Lisboa, Oeiras, Portugal
- Escola Superior de Saúde da Cruz Vermelha Portuguesa-Lisboa (ESSCVP-Lisboa), Lisbon, Portugal
| | - Anton Y. Peleg
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Centre to Impact Antimicrobial Resistance, Monash University, Clayton, Melbourne, Victoria, Australia
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11
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Moran MC, Brewer MG, Schlievert PM, Beck LA. S. aureus virulence factors decrease epithelial barrier function and increase susceptibility to viral infection. Microbiol Spectr 2023; 11:e0168423. [PMID: 37737609 PMCID: PMC10581065 DOI: 10.1128/spectrum.01684-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 07/03/2023] [Indexed: 09/23/2023] Open
Abstract
Individuals with atopic dermatitis (AD) are highly colonized by Staphylococcus aureus and are more susceptible to severe viral complications. We hypothesized that S. aureus secreted virulence factors may alter keratinocyte biology to enhance viral susceptibility through disruption of the skin barrier, impaired keratinocyte differentiation, and/or inflammation. To address this hypothesis, human keratinocytes were exposed to conditioned media from multiple S. aureus strains that vary in virulence factor production (USA300, HG003, and RN4220) or select purified virulence factors. We have identified the S. aureus enterotoxin-like superantigen SElQ, as a virulence factor of interest, since it is highly produced by USA300 and was detected on the skin of 53% of AD subjects (n = 72) in a study conducted by our group. Treatment with USA300 conditioned media or purified SElQ resulted in a significant increase in keratinocyte susceptibility to infection with vaccinia virus, and also significantly decreased barrier function. Importantly, we have previously demonstrated that keratinocyte differentiation influences susceptibility to viral infection, and our qPCR observations indicated that USA300 S. aureus and SElQ alter differentiation in keratinocytes. CRISPR/Cas9 was used to knock out CD40, a potential enterotoxin receptor on epithelial cells. We found that CD40 expression on keratinocytes was not completely necessary for SElQ-mediated responses, as measured by proinflammatory cytokine expression and barrier function. Together, these findings support that select S. aureus virulence factors, particularly SElQ, enhance the susceptibility of epidermal cells to viral infection, which may contribute to the increased cutaneous infections observed in individuals with AD. IMPORTANCE Staphylococcus aureus skin colonization and infection are frequently observed in individuals with atopic dermatitis. Many S. aureus strains belong to the clonal group USA300, and these strains produce superantigens including the staphylococcal enterotoxin-like Q (SElQ). Our studies highlight that SElQ may play a key role by altering keratinocyte differentiation and reducing barrier function; collectively, this may explain the AD-specific enhanced infection risk to cutaneous viruses. It is unclear what receptor mediates SElQ's effects on keratinocytes. We have shown that one putative surface receptor, CD40, was not critical for its effects on proinflammatory cytokine production or barrier function.
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Affiliation(s)
- Mary C. Moran
- Department of Dermatology, University of Rochester Medical Center, Rochester, New York, USA
- Department of Microbiology & Immunology, University of Rochester Medical Center, Rochester, New York, USA
| | - Matthew G. Brewer
- Department of Dermatology, University of Rochester Medical Center, Rochester, New York, USA
| | | | - Lisa A. Beck
- Department of Dermatology, University of Rochester Medical Center, Rochester, New York, USA
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12
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Schouls LM, Witteveen S, van Santen-Verheuvel M, de Haan A, Landman F, van der Heide H, Kuijper EJ, Notermans DW, Bosch T, Hendrickx APA. Molecular characterization of MRSA collected during national surveillance between 2008 and 2019 in the Netherlands. COMMUNICATIONS MEDICINE 2023; 3:123. [PMID: 37700016 PMCID: PMC10497500 DOI: 10.1038/s43856-023-00348-z] [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: 05/03/2023] [Accepted: 08/14/2023] [Indexed: 09/14/2023] Open
Abstract
BACKGROUND Although the Netherlands is a country with a low endemic level, methicillin-resistant Staphylococcus aureus (MRSA) poses a significant health care problem. Therefore, high coverage national MRSA surveillance has been in place since 1989. To monitor possible changes in the type-distribution and emergence of resistance and virulence, MRSA isolates are molecularly characterized. METHODS All 43,321 isolates from 36,520 persons, collected 2008-2019, were typed by multiple-locus variable number tandem repeats analysis (MLVA) with simultaneous PCR detection of the mecA, mecC and lukF-PV genes, indicative for PVL. Next-generation sequencing data of 4991 isolates from 4798 persons were used for whole genome multi-locus sequence typing (wgMLST) and identification of resistance and virulence genes. RESULTS We show temporal change in the molecular characteristics of the MRSA population with the proportion of PVL-positive isolates increasing from 15% in 2008-2010 to 25% in 2017-2019. In livestock-associated MRSA obtained from humans, PVL-positivity increases to 6% in 2017-2019 with isolates predominantly from regions with few pig farms. wgMLST reveals the presence of 35 genogroups with distinct resistance, virulence gene profiles and specimen origin. Typing shows prolonged persistent MRSA carriage with a mean carriage period of 407 days. There is a clear spatial and a weak temporal relationship between isolates that clustered in wgMLST, indicative for regional spread of MRSA strains. CONCLUSIONS Using molecular characterization, this exceptionally large study shows genomic changes in the MRSA population at the national level. It reveals waxing and waning of types and genogroups and an increasing proportion of PVL-positive MRSA.
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Affiliation(s)
- Leo M Schouls
- Centre for Infectious Disease Control. National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands.
| | - Sandra Witteveen
- Centre for Infectious Disease Control. National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Marga van Santen-Verheuvel
- Centre for Infectious Disease Control. National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Angela de Haan
- Centre for Infectious Disease Control. National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Fabian Landman
- Centre for Infectious Disease Control. National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Han van der Heide
- Centre for Infectious Disease Control. National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Ed J Kuijper
- Department of Medical Microbiology and Experimental Bacteriology, Leiden University Medical Center, Leiden, The Netherlands
| | - Daan W Notermans
- Centre for Infectious Disease Control. National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Thijs Bosch
- Centre for Infectious Disease Control. National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Antoni P A Hendrickx
- Centre for Infectious Disease Control. National Institute for Public Health and the Environment (RIVM), Bilthoven, The Netherlands
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Niño-Arias FC, Alves VF, Pereira MG, De Martinis ECP. Gene expression and cell culture assays reveal cheese isolate Lactococcus lactis MC5 may influence the virulence of Staphylococcus aureus. Braz J Microbiol 2023; 54:2027-2034. [PMID: 37171534 PMCID: PMC10484841 DOI: 10.1007/s42770-023-01004-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 04/29/2023] [Indexed: 05/13/2023] Open
Abstract
Staphylococcus aureus (SA) can thrive in a wide variety of hosts and environments, causing clinical infections and foodborne intoxications. In Brazil, SA is commonly isolated from traditional soft cheeses, especially those prepared from unpasteurized milk. In this research, the isolate S. aureus SABRC1 was evaluated for virulence traits under different conditions, including co-inoculation with Lactococcus lactis MC5 (isolated from "Fresh Minas Cheese"), which produces antibacterial peptides. Results from experiments with Caco-2 culture indicated S. aureus SABRC1 was able to adhere (42.83 ± 1.79%) and to invade (48.57 ± 0.41%) the intestinal cells. On the other hand, L. lactis MC5 presented anti-staphylococcal activity as indicated by agar assays, and it was also able to antagonize intestinal cell invasion by S. aureus. Moreover, Reverse Transcriptase-PCR experiments showed virulence genes of S. aureus SABRC1 (hla, icaA and sea) were differentially expressed under diverse culture conditions, which included Brain Heart Infusion modified or not by the addition of glucose, sodium chloride, milk or cheese. This suggests the virulence of S. aureus SABRC1 is influenced by compounds commonly found in daily diets, and not only by its genetic repertoire, adding a novel level of complexity for controlling infection by this pathogen.
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Affiliation(s)
- Fabian Camilo Niño-Arias
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto (FCFRP-USP), Brazil
| | - Virgínia Farias Alves
- Faculdade de Farmácia, Universidade Federal de Goiás, Rua 240 Esquina Com a 5ª Avenida, S/N, Setor Leste Universitário, Goiânia/GO, CEP: 74605-170, Brazil.
| | - Marita Gimenez Pereira
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto (FCFRP-USP), Brazil
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14
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Huang J, Zhang W, Sun B, Jiang Q, Cao Y, Shang J, Zhang Y, Gu X, Lv C, Guo C, Li M, Li H, Guo X, Zhu Y, Huang S, Li Q. Genetic diversity, antibiotic resistance, and virulence characteristics of Staphylococcus aureus from raw milk over 10 years in Shanghai. Int J Food Microbiol 2023; 401:110273. [PMID: 37295267 DOI: 10.1016/j.ijfoodmicro.2023.110273] [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: 02/25/2023] [Revised: 05/25/2023] [Accepted: 05/28/2023] [Indexed: 06/12/2023]
Abstract
Staphylococcus aureus (S. aureus) is a major cause of foodborne infections and its persistence in raw milk is a multifaceted phenomenon that poses a considerable public health challenge. Our study investigated the prevalence, virulence genes, antibiotic resistance, and genetic characterization of S. aureus in raw milk in six Shanghai districts from 2013 to 2022. At 18 dairy farms, a total of 704 S. aureus strains were isolated from 1799 samples tested for drug sensitivity. The highest rates of antibiotic resistance were ampicillin (96.7 %), sulfamethoxazole (65 %), and erythromycin (21.6 %). Between 2018 and 2022, there was a significant decrease in the resistance rates of ceftiofur, ofloxacin, tilmicosin, erythromycin, clindamycin, amoxicillin-clavulanic acid, and sulfamethoxazole in comparison to the period from 2013 to 2017. There were 205 S. aureus strains chosen for whole genome sequencing (WGS), with no more than 2 strains of the same resistance phenotype from each farm per year. The prevalence of mecA-positive strains was 14.15 %, while other antibiotic resistance-associated genes were observed as follows: blaI (70.21 %), lnu(B) (5.85 %), lsa(E) (5.75 %), fexA (6.83 %), erm(C) (4.39 %), tet(L) (9.27 %), and dfrG (5.85 %). Isolates harboring the immune evasion cluster (IEC) genes (scn, chp, and sak) were predominantly categorized as sequence types (STs) 7, 188, 15, 59, and 398. The predominant cluster complexes were CC97, CC1, CC398, and CC1651. In 2017-2022, there was a transition in CC1 from the highly antibiotic-resistant ST9 strain that emerged between 2013 and 2018 to the low-resistant but highly virulent ST1 strain. Retrospective phylogenetic analysis elucidated the evolutionary history of the isolates and demonstrated that the human-animal host transition of S. aureus was linked to the genesis of MRSA CC398. The implementation of extended surveillance will aid in the development of innovative strategies to avoid the transmission of S. aureus along the dairy food chain and the occurrence of public health events.
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Affiliation(s)
- Jiewen Huang
- Department of Laboratory Medicine, College of Health Science and Technology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Wengang Zhang
- Shanghai Animal Disease Control Center, Shanghai 201103, China
| | - Bingqing Sun
- Shanghai Animal Disease Control Center, Shanghai 201103, China
| | - Qin Jiang
- Shanghai Animal Disease Control Center, Shanghai 201103, China
| | - Ying Cao
- Shanghai Animal Disease Control Center, Shanghai 201103, China
| | - Jun Shang
- Shanghai Animal Disease Control Center, Shanghai 201103, China
| | - Yu Zhang
- Shanghai Animal Disease Control Center, Shanghai 201103, China
| | - Xin Gu
- Shanghai Animal Disease Control Center, Shanghai 201103, China
| | - Chao Lv
- Department of Animal Health and Food Safety, School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Chaoyi Guo
- Department of Animal Health and Food Safety, School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Min Li
- Department of Animal Health and Food Safety, School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Hui Li
- Department of Laboratory Medicine, College of Health Science and Technology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xiaokui Guo
- Department of Animal Health and Food Safety, School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yongzhang Zhu
- Department of Animal Health and Food Safety, School of Global Health, Chinese Center for Tropical Diseases Research, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
| | - Shixin Huang
- Shanghai Animal Disease Control Center, Shanghai 201103, China.
| | - Qingtian Li
- Department of Laboratory Medicine, College of Health Science and Technology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.
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15
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Darnowski MG, Lanosky TD, Paquette AR, Boddy CN. Armeniaspirol analogues disrupt the electrical potential (ΔΨ) of the proton motive force. Bioorg Med Chem Lett 2023; 84:129210. [PMID: 36858079 DOI: 10.1016/j.bmcl.2023.129210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 02/22/2023] [Accepted: 02/25/2023] [Indexed: 03/02/2023]
Abstract
The armeniaspirol family of natural product antibiotics have been shown to inhibit the ATP-dependent proteases ClpXP and ClpYQ and disrupt membrane potential through shuttling of protons across the membrane. Herein we investigate their ability to disrupt the proton motive force (PMF). We show, using a voltage sensitive, that armeniaspiols disrupt the electrical membrane potential (ΔΨ) component of the PMF and not the transmembrane proton gradient (ΔpH). Using checkerboard assays, we confirm this by showing antagonism, with kanamycin, an antibiotic that required ΔΨ for penetration. By evaluating the antibiotic activity and disruption of the PMF by sixteen armeniaspirol analogs, we find that disruption of the PMF is necessary but not sufficient for antibiotic activity. Analogs that are potent disruptors of the PMF without possessing the ability to inhibit ClpXP and ClpYQ are not potent antibiotics. Thus we propose that the armeniaspirols utilize a dual mechanism of action where they disrupt PMF and inhibit the ATP-dependent proteases ClpXP and ClpYQ. This type of dual mechanism has been observed in other natural product-based antibiotics, most notably chelocardin.
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Affiliation(s)
- Michael G Darnowski
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5 Canada
| | - Taylor D Lanosky
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5 Canada
| | - André R Paquette
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5 Canada
| | - Christopher N Boddy
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5 Canada.
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16
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Phylogenetic Analysis and Virulence Characteristics of Methicillin-Resistant Staphylococcus aureus ST45 in China: a Hyper-Virulent Clone Associated with Bloodstream Infections. mSystems 2023; 8:e0002923. [PMID: 36877043 PMCID: PMC10134793 DOI: 10.1128/msystems.00029-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) sequence type 45 (ST45) was rarely found in China. This study was conducted to trace the transmission and evolution of emerging MRSA ST45 strains in mainland China and explore its virulence. A total of 27 ST45 isolates were included for whole-genome sequencing and genetic characteristic analysis. Epidemiological results showed that MRSA ST45 isolates were often obtained from blood, primarily originated in Guangzhou, and carried diverse virulence and drug resistance genes. Staphylococcal cassette chromosome mec type IV (SCCmec IV) dominated in MRSA ST45 (23/27, 85.2%). ST45-SCCmec V was located on a phylogenetic clade distinct from the SCCmec IV cluster. We selected two representative isolates, MR370 (ST45-SCCmec IV) and MR387 (ST45-SCCmec V), and performed hemolysin activity, a blood killing assay, a Galleria mellonella infection model, and a mouse bacteremia model, as well as real-time fluorescence quantitative PCR. MR370 was proved to have extreme virulence in the phenotypic assays and at the mRNA level compared with ST59, ST5, and USA300 MRSA strains. MR387 was comparable to USA300-LAC on the phenotype and was verified to have higher expression of scn, chp, sak, saeR, agrA, and RNAIII than USA300-LAC. The results emphasized the extraordinary performance of MR370 and the good potential of MR387 in virulence causing bloodstream infection. Meanwhile, we conclude that China MRSA ST45 showed two different clonotypes, which may be widespread in the future. The entire study is valuable as a timely reminder and reports virulence phenotypes of China MRSA ST45 for the first time. IMPORTANCE Methicillin-resistant Staphylococcus aureus ST45 is epidemic worldwide. This study contributed to the awareness of the Chinese hyper-virulent MRSA ST45 strains and served as a timely reminder of its wide dissemination of clonotypes. Further, we provide novel insights for prevention from the perspective of bloodstream infections. ST45-SCCmec V is a clonotype deserving special attention in China, and we performed genetic and phenotypic analyses for the first time on it.
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17
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vom Werth KL, Kemper B, Kampmeier S, Mellmann A. Application of Digital Holographic Microscopy to Analyze Changes in T-Cell Morphology in Response to Bacterial Challenge. Cells 2023; 12:cells12050762. [PMID: 36899897 PMCID: PMC10000559 DOI: 10.3390/cells12050762] [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] [Received: 01/25/2023] [Revised: 02/16/2023] [Accepted: 02/24/2023] [Indexed: 03/06/2023] Open
Abstract
Quantitative phase imaging (QPI) is a non-invasive, label-free technique used to detect aberrant cell morphologies caused by disease, thus providing a useful diagnostic approach. Here, we evaluated the potential of QPI to differentiate specific morphological changes in human primary T-cells exposed to various bacterial species and strains. Cells were challenged with sterile bacterial determinants, i.e., membrane vesicles or culture supernatants, derived from different Gram-positive and Gram-negative bacteria. Timelapse QPI by digital holographic microscopy (DHM) was applied to capture changes in T-cell morphology over time. After numerical reconstruction and image segmentation, we calculated single cell area, circularity and mean phase contrast. Upon bacterial challenge, T-cells underwent rapid morphological changes such as cell shrinkage, alterations of mean phase contrast and loss of cell integrity. Time course and intensity of this response varied between both different species and strains. The strongest effect was observed for treatment with S. aureus-derived culture supernatants that led to complete lysis of the cells. Furthermore, cell shrinkage and loss of circular shape was stronger in Gram-negative than in Gram-positive bacteria. Additionally, T-cell response to bacterial virulence factors was concentration-dependent, as decreases in cellular area and circularity were enhanced with increasing concentrations of bacterial determinants. Our findings clearly indicate that T-cell response to bacterial stress depends on the causative pathogen, and specific morphological alterations can be detected using DHM.
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Affiliation(s)
| | - Björn Kemper
- Biomedical Technology Center of the Medical Faculty, University of Münster, 48149 Münster, Germany
| | - Stefanie Kampmeier
- Institute of Hygiene, University Hospital Münster, 48149 Münster, Germany
| | - Alexander Mellmann
- Institute of Hygiene, University Hospital Münster, 48149 Münster, Germany
- Correspondence: ; Tel.: +49-251-83-55361
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18
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Schlievert PM. Staphylococcal Enterotoxin B and C Mutants and Vaccine Toxoids. Microbiol Spectr 2023; 11:e0444622. [PMID: 36815779 PMCID: PMC10101070 DOI: 10.1128/spectrum.04446-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 01/26/2023] [Indexed: 02/24/2023] Open
Abstract
Three mutants individually of both staphylococcal enterotoxins B and C were prepared by site-specific mutagenesis of enterotoxin amino acids that contact host T lymphocyte immune cell receptor sites (N23A, Q210A, and N23A/Q210A); these amino acids are shared between the two enterotoxins, and mutations reduce the interaction with the variable part of the β-chain of the T lymphocyte receptor. The mutant proteins, as expressed in Staphylococcus aureus RN4220, lacked biological toxicity as measured by the loss of (i) stimulation of rabbit splenocyte proliferation, (ii) pyrogenicity, and (iii) the ability to enhance the lethality of endotoxin shock, compared to wild-type enterotoxins. In addition, the mutants were able to vaccinate rabbits against pyrogenicity, the enhancement of endotoxin shock, and lethality in a pneumonia model when animals were challenged with methicillin-resistant S. aureus. Three vaccine injections (one primary and two boosters) protected rabbits for at least 3.5 months postvaccination when challenged with wild-type enterotoxins (last time point tested). These mutant proteins have the potential to function as toxoid vaccines against these two causes of nonmenstrual toxic shock syndrome (TSS). IMPORTANCE Toxic shock syndrome toxin 1 (TSST-1) and staphylococcal enterotoxins B and C cause the majority of cases of staphylococcal toxic shock syndrome. Previously, vaccine toxoids of TSST-1 have been prepared. In this study, vaccine toxoids of enterotoxins B and C were prepared. The toxoids lost biological toxicity but were able to vaccinate rabbits against lethal TSS.
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Affiliation(s)
- Patrick M. Schlievert
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
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19
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Wang GZ, Warren EA, Haas AL, Peña AS, Kiedrowski MR, Lomenick B, Chou TF, Bomberger JM, Tirrell DA, Limoli DH. Staphylococcal secreted cytotoxins are competition sensing signals for Pseudomonas aeruginosa. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.29.526047. [PMID: 36747623 PMCID: PMC9900984 DOI: 10.1101/2023.01.29.526047] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Coinfection with two notorious opportunistic pathogens, the Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus , dominates chronic pulmonary infections. While coinfection is associated with poor patient outcomes, the interspecies interactions responsible for such decline remain unknown. Here, we dissected molecular mechanisms of interspecies sensing between P. aeruginosa and S. aureus . We discovered that P. aeruginosa senses S. aureus secreted peptides and, counterintuitively, moves towards these toxins. P. aeruginosa tolerates such a strategy through "competition sensing", whereby it preempts imminent danger/competition by arming cells with type six secretion (T6S) and iron acquisition systems. Intriguingly, while T6S is predominantly described as weaponry targeting Gram-negative and eukaryotic cells, we find that T6S is essential for full P. aeruginosa competition with S. aureus , a previously undescribed role for T6S. Importantly, competition sensing was activated during coinfection of bronchial epithelia, including T6S islands targeting human cells. This study reveals critical insight into both interspecies competition and how antagonism may cause collateral damage to the host environment.
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20
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Molendijk MM, Phan MVT, Bode LGM, Strepis N, Prasad DK, Worp N, Nieuwenhuijse DF, Schapendonk CME, Boekema BKHL, Verbon A, Koopmans MPG, de Graaf M, van Wamel WJB. Microcalorimetry: A Novel Application to Measure In Vitro Phage Susceptibility of Staphylococcus aureus in Human Serum. Viruses 2022; 15:14. [PMID: 36680055 PMCID: PMC9865112 DOI: 10.3390/v15010014] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/14/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
Infections involving antibiotic resistant Staphylococcus aureus (S. aureus) represent a major challenge to successful treatment. Further, although bacteriophages (phages) could be an alternative to antibiotics, there exists a lack of correlation in phage susceptibility results between conventional in vitro and in vivo assays. This discrepancy may hinder the potential implementation of bacteriophage therapy. In this study, the susceptibility of twelve S. aureus strains to three commercial phage cocktails and two single phages was assessed. These S. aureus strains (including ten clinical isolates, five of which were methicillin-resistant) were compared using four assays: the spot test, efficiency of plating (EOP), the optical density assay (all in culture media) and microcalorimetry in human serum. In the spot test, EOP and optical density assay, all cocktails and single phages lysed both methicillin susceptible and methicillin resistant S. aureus strains. However, there was an absence of phage-mediated lysis in high concentrations of human serum as measured using microcalorimetry. As this microcalorimetry-based assay more closely resembles in vivo conditions, we propose that microcalorimetry could be included as a useful addition to conventional assays, thereby facilitating more accurate predictions of the in vivo susceptibility of S. aureus to phages during phage selection for therapeutic purposes.
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Affiliation(s)
- Michèle M. Molendijk
- Department Medical Microbiology and Infectious Diseases, Erasmus MC, 3015 Rotterdam, The Netherlands
- Department of Viroscience, Erasmus MC, 3015 Rotterdam, The Netherlands
| | - My V. T. Phan
- Department of Viroscience, Erasmus MC, 3015 Rotterdam, The Netherlands
- Medical Research Council/Uganda Virus Research Institute, London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe P.O. Box 49, Uganda
| | - Lonneke G. M. Bode
- Department Medical Microbiology and Infectious Diseases, Erasmus MC, 3015 Rotterdam, The Netherlands
| | - Nikolas Strepis
- Department Medical Microbiology and Infectious Diseases, Erasmus MC, 3015 Rotterdam, The Netherlands
| | - Divyae K. Prasad
- Department of Viroscience, Erasmus MC, 3015 Rotterdam, The Netherlands
| | - Nathalie Worp
- Department of Viroscience, Erasmus MC, 3015 Rotterdam, The Netherlands
| | | | | | | | - Annelies Verbon
- Department Medical Microbiology and Infectious Diseases, Erasmus MC, 3015 Rotterdam, The Netherlands
| | | | - Miranda de Graaf
- Department of Viroscience, Erasmus MC, 3015 Rotterdam, The Netherlands
| | - Willem J. B. van Wamel
- Department Medical Microbiology and Infectious Diseases, Erasmus MC, 3015 Rotterdam, The Netherlands
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21
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Costa M, Meirinhos C, Cunha E, Gomes D, Pereira M, Dias R, Tavares L, Oliveira M. Nisin Mutant Prevention Concentration and the Role of Subinhibitory Concentrations on Resistance Development by Diabetic Foot Staphylococci. Antibiotics (Basel) 2022; 11:antibiotics11070972. [PMID: 35884226 PMCID: PMC9311964 DOI: 10.3390/antibiotics11070972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/14/2022] [Accepted: 07/15/2022] [Indexed: 12/10/2022] Open
Abstract
The most prevalent microorganism in diabetic foot infections (DFI) is Staphylococcus aureus, an important multidrug-resistant pathogen. The antimicrobial peptide nisin is a promising compound for DFI treatment, being effective against S. aureus. However, to avoid the selection of resistant mutants, correct drug therapeutic doses must be established, being also important to understand if nisin subinhibitory concentrations (subMIC) can potentiate resistant genes transfer between clinical isolates or mutations in genes associated with nisin resistance. The mutant selection window (MSW) of nisin was determined for 23 DFI S. aureus isolates; a protocol aiming to prompt vanA horizontal transfer between enterococci to clinical S. aureus was performed; and nisin subMIC effect on resistance evolution was assessed through whole-genome sequencing (WGS) applied to isolates subjected to a MEGA-plate assay. MSW ranged from 5–360 μg/mL for two isolates, from 5–540 μg/mL for three isolates, and from 5–720 μg/mL for one isolate. In the presence of nisin subMIC values, no transconjugants were obtained, indicating that nisin does not seem to promote vanA transfer. Finally, WGS analysis showed that incubation in the presence of nisin subMIC did not promote the occurrence of significant mutations in genes related to nisin resistance, supporting nisin application to DFI treatment.
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Affiliation(s)
- Margarida Costa
- CIISA—Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade de Lisboa, Av. da Universidade Técnica de Lisboa, 1300-477 Lisboa, Portugal; (M.C.); (C.M.); (D.G.); (L.T.); (M.O.)
- Laboratório Associado para Ciência Animal e Veterinária (AL4AnimalS), 1300-477 Lisbon, Portugal
| | - Cláudia Meirinhos
- CIISA—Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade de Lisboa, Av. da Universidade Técnica de Lisboa, 1300-477 Lisboa, Portugal; (M.C.); (C.M.); (D.G.); (L.T.); (M.O.)
- Laboratório Associado para Ciência Animal e Veterinária (AL4AnimalS), 1300-477 Lisbon, Portugal
| | - Eva Cunha
- CIISA—Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade de Lisboa, Av. da Universidade Técnica de Lisboa, 1300-477 Lisboa, Portugal; (M.C.); (C.M.); (D.G.); (L.T.); (M.O.)
- Laboratório Associado para Ciência Animal e Veterinária (AL4AnimalS), 1300-477 Lisbon, Portugal
- Correspondence:
| | - Diana Gomes
- CIISA—Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade de Lisboa, Av. da Universidade Técnica de Lisboa, 1300-477 Lisboa, Portugal; (M.C.); (C.M.); (D.G.); (L.T.); (M.O.)
- Laboratório Associado para Ciência Animal e Veterinária (AL4AnimalS), 1300-477 Lisbon, Portugal
| | - Marcelo Pereira
- Biosystems and Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; (M.P.); (R.D.)
| | - Ricardo Dias
- Biosystems and Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, Campo Grande, 1749-016 Lisboa, Portugal; (M.P.); (R.D.)
| | - Luís Tavares
- CIISA—Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade de Lisboa, Av. da Universidade Técnica de Lisboa, 1300-477 Lisboa, Portugal; (M.C.); (C.M.); (D.G.); (L.T.); (M.O.)
- Laboratório Associado para Ciência Animal e Veterinária (AL4AnimalS), 1300-477 Lisbon, Portugal
| | - Manuela Oliveira
- CIISA—Centro de Investigação Interdisciplinar em Sanidade Animal, Faculdade de Medicina Veterinária, Universidade de Lisboa, Av. da Universidade Técnica de Lisboa, 1300-477 Lisboa, Portugal; (M.C.); (C.M.); (D.G.); (L.T.); (M.O.)
- Laboratório Associado para Ciência Animal e Veterinária (AL4AnimalS), 1300-477 Lisbon, Portugal
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22
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Kinney KJ, Stach JM, Kulhankova K, Brown M, Salgado-Pabón W. Vegetation Formation in Staphylococcus Aureus Endocarditis Inversely Correlates With RNAIII and sarA Expression in Invasive Clonal Complex 5 Isolates. Front Cell Infect Microbiol 2022; 12:925914. [PMID: 35860377 PMCID: PMC9289551 DOI: 10.3389/fcimb.2022.925914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/14/2022] [Indexed: 01/29/2023] Open
Abstract
Infective endocarditis (IE) is one of the most feared and lethal diseases caused by Staphylococcus aureus. Once established, the infection is fast-progressing and tissue destructive. S. aureus of the clonal complex 5 (CC5) commonly cause IE yet are severely understudied. IE results from bacterial colonization and formation of tissue biofilms (known as vegetations) on injured or inflamed cardiac endothelium. S. aureus IE is promoted by adhesins, coagulases, and superantigens, with the exotoxins and exoenzymes likely contributing to tissue destruction and dissemination. Expression of the large repertoire of virulence factors required for IE and sequelae is controlled by complex regulatory networks. We investigated the temporal expression of the global regulators agr (RNAIII), rot, sarS, sarA, sigB, and mgrA in 8 invasive CC5 isolates and established intrinsic expression patterns associated with IE outcomes. We show that vegetation formation, as tested in the rabbit model of IE, inversely correlates with RNAIII and sarA expression during growth in Todd-Hewitt broth (TH). Large vegetations with severe sequelae arise from strains with high-level expression of colonization factors but slower transition towards expression of the exotoxins. Overall, strains proficient in vegetation formation, a hallmark of IE, exhibit lower expression of RNAIII and sarA. Simultaneous high expression of RNAIII, sarA, sigB, and mgrA is the one phenotype assessed in this study that fails to promote IE. Thus, RNAIII and sarA expression that provides for rheostat control of colonization and virulence genes, rather than an on and off switch, promote both vegetation formation and lethal sepsis.
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Affiliation(s)
- Kyle J. Kinney
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Jessica M. Stach
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Katarina Kulhankova
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Matthew Brown
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
| | - Wilmara Salgado-Pabón
- Department of Microbiology and Immunology, University of Iowa Carver College of Medicine, Iowa City, IA, United States
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, United States
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23
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Abstract
Staphylococcus aureus causes a variety of debilitating and life-threatening diseases, and thus remains a challenging global health threat. S. aureus is remarkably diverse, yet only a minority of methicillin-resistant S. aureus (MRSA) clones have caused pandemic proportions of diseases. The genetic drivers of the successful dissemination of some clones across wide geographical expanses remain poorly understood. We analyzed 386 recently published MRSA genomes from bloodstream infections sampled in North, Central, and South America from 2011 to 2018. Here, we show that MRSA-associated bloodstream infections were attributable to two genetically distinct lineages. One lineage consisted almost exclusively of sequence type (ST) 8, which emerged in 1964. A second lineage emerged in 1986 and consisted of STs 5, 105, and 231. The two lineages have simultaneously disseminated across geographically distant sites. Sublineages rapidly diverged within locations in the early 2000s. Their diversification was associated with independent acquisitions of unique variants of the mobile mecA-carrying chromosomal cassette and distinct repertoires of antimicrobial resistance genes. We show that the evolution and spread of invasive multidrug-resistant MRSA in the Americas was driven by transcontinental dissemination, followed by more recent establishment and divergence of local pathogen populations. Our study highlights the need for continued international surveillance of high-risk clones to control the global health threat of multidrug resistance. IMPORTANCE Bloodstream infections due to S. aureus cause significant patient morbidity and mortality worldwide, exacerbated by the emergence and spread of methicillin resistant S. aureus (MRSA). This study provides important insights on the evolution and long-distance geographic expansion of two distinct MRSA lineages that predominate in bloodstream infections in the past 5 decades. The success of these two lineages partly lies on their acquisition of a diverse set of antimicrobial resistance genes and of unique variants of the mobile genetic element SCCmec that carries the gene mecA conferring resistance to beta-lactams. High-risk antimicrobial resistant clones can therefore rapidly disseminate across long distances and establish within local communities within a short period of time. These results have important implications for global initiatives and local epidemiological efforts to monitor and control invasive MRSA infections and transcontinental spread of multidrug resistance.
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24
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Abstract
Staphylococcus hominis is frequently isolated from human skin, and we hypothesize that it may protect the cutaneous barrier from opportunistic pathogens. We determined that S. hominis makes six unique autoinducing peptide (AIP) signals that inhibit the major virulence factor accessory gene regulator (agr) quorum sensing system of Staphylococcus aureus. We solved and confirmed the structures of three novel AIP signals in conditioned medium by mass spectrometry and then validated synthetic AIP activity against all S. aureus agr classes. Synthetic AIPs also inhibited the conserved agr system in a related species, Staphylococcus epidermidis. We determined the distribution of S. hominis agr types on healthy human skin and found S. hominis agr-I and agr-II were highly represented across subjects. Further, synthetic AIP-II was protective in vivo against S. aureus-associated dermonecrotic or epicutaneous injury. Together, these findings demonstrate that a ubiquitous colonizer of human skin has a fundamentally protective role against opportunistic damage. IMPORTANCE Human skin is home to a variety of commensal bacteria, including many species of coagulase-negative staphylococci (CoNS). While it is well established that the microbiota as a whole maintains skin homeostasis and excludes pathogens (i.e., colonization resistance), relatively little is known about the unique contributions of individual CoNS species to these interactions. Staphylococcus hominis is the second most frequently isolated CoNS from healthy skin, and there is emerging evidence to suggest that it may play an important role in excluding pathogens, including Staphylococcus aureus, from colonizing or infecting the skin. Here, we identified that S. hominis makes 6 unique peptide inhibitors of the S. aureus global virulence factor regulation system (agr). Additionally, we found that one of these peptides can prevent topical or necrotic S. aureus skin injury in a mouse model. Our results demonstrate a specific and broadly protective role for this ubiquitous, yet underappreciated skin commensal.
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25
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Mills KB, Jia F, Stein ME, Keim KC, Davidson RM, Horswill AR. Genome Sequences of Two Methicillin-Sensitive Staphylococcus aureus Healthy Skin Isolates. Microbiol Resour Announc 2022; 11:e0040222. [PMID: 35575560 PMCID: PMC9202384 DOI: 10.1128/mra.00402-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 04/30/2022] [Indexed: 11/20/2022] Open
Abstract
The USA300 and USA600 clonal lineages are the cause of many serious Staphylococcus aureus infections. Here, we report the complete genomes of two methicillin-sensitive S. aureus strains isolated from the healthy skin of adults in Colorado, which are most phylogenetically similar to the USA300 and USA600 lineages.
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Affiliation(s)
- Krista B. Mills
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Fan Jia
- Center for Genes, Environment, and Health, Department of Immunology and Genomic Medicine, National Jewish Health, Denver, Colorado, USA
| | - Michelle E. Stein
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Klara C. Keim
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Rebecca M. Davidson
- Center for Genes, Environment, and Health, Department of Immunology and Genomic Medicine, National Jewish Health, Denver, Colorado, USA
| | - Alexander R. Horswill
- Department of Immunology and Microbiology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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26
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Han X, Ortines R, Mukherjee I, Kanipakala T, Kort T, Sherchand SP, Liao G, Mednikov M, Chenine AL, Aman MJ, Nykiforuk CL, Adhikari RP. Hyperimmune Targeting Staphylococcal Toxins Effectively Protect Against USA 300 MRSA Infection in Mouse Bacteremia and Pneumonia Models. Front Immunol 2022; 13:893921. [PMID: 35655774 PMCID: PMC9152286 DOI: 10.3389/fimmu.2022.893921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 04/07/2022] [Indexed: 11/13/2022] Open
Abstract
Staphylococcus aureus has been acquiring multiple drug resistance and has evolved into superbugs such as Methicillin/Vancomycin-resistant S. aureus (MRSA/VRSA) and, consequently, is a major cause of nosocomial and community infections associated with high morbidity and mortality for which no FDA-approved vaccines or biotherapeutics are available. Previous efforts targeting the surface-associated antigens have failed in clinical testing. Here, we generated hyperimmune products from sera in rabbits against six major S. aureus toxins targeted by an experimental vaccine (IBT-V02) and demonstrated significant efficacy for an anti-virulence passive immunization strategy. Extensive in vitro binding and neutralizing titers were analyzed against six extracellular toxins from individual animal sera. All IBT-V02 immunized animals elicited the maximum immune response upon the first boost dose against all pore-forming vaccine components, while for superantigen (SAgs) components of the vaccine, second and third doses of a boost were needed to reach a plateau in binding and toxin neutralizing titers. Importantly, both anti-staphylococcus hyperimmune products consisting of full-length IgG (IBT-V02-IgG) purified from the pooled sera and de-speciated F(ab')2 (IBT-V02-F(ab')2) retained the binding and neutralizing titers against IBT-V02 target toxins. F(ab')2 also exhibited cross-neutralization titers against three leukotoxins (HlgAB, HlgCB, and LukED) and four SAgs (SEC1, SED, SEK, and SEQ) which were not part of IBT-V02. F(ab')2 also neutralized toxins in bacterial culture supernatant from major clinical strains of S. aureus. In vivo efficacy data generated in bacteremia and pneumonia models using USA300 S. aureus strain demonstrated dose-dependent protection by F(ab')2. These efficacy data confirmed the staphylococcal toxins as viable targets and support the further development effort of hyperimmune products as a potential adjunctive therapy for emergency uses against life-threatening S. aureus infections.
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Affiliation(s)
- Xiaobing Han
- Research and Development, Emergent BioSolutions Canada Inc., Winnipeg, MB, Canada.,Department of Immunology, Max Rady College of Medicine, University of Manitoba, Winnipeg, MB, Canada
| | - Roger Ortines
- Integrated Biotherapeutics Inc. (IBT), Rockville, MD, United States
| | - Ipsita Mukherjee
- Integrated Biotherapeutics Inc. (IBT), Rockville, MD, United States
| | | | - Thomas Kort
- Integrated Biotherapeutics Inc. (IBT), Rockville, MD, United States
| | | | - Grant Liao
- Integrated Biotherapeutics Inc. (IBT), Rockville, MD, United States
| | - Mark Mednikov
- Integrated Biotherapeutics Inc. (IBT), Rockville, MD, United States
| | - Agnes L Chenine
- Integrated Biotherapeutics Inc. (IBT), Rockville, MD, United States
| | - M Javad Aman
- Integrated Biotherapeutics Inc. (IBT), Rockville, MD, United States
| | - Cory L Nykiforuk
- Research and Development, Emergent BioSolutions Canada Inc., Winnipeg, MB, Canada
| | - Rajan P Adhikari
- Integrated Biotherapeutics Inc. (IBT), Rockville, MD, United States
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27
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Silva V, Correia E, Pereira JE, González-Machado C, Capita R, Alonso-Calleja C, Igrejas G, Poeta P. Biofilm Formation of Staphylococcus aureus from Pets, Livestock, and Wild Animals: Relationship with Clonal Lineages and Antimicrobial Resistance. Antibiotics (Basel) 2022; 11:antibiotics11060772. [PMID: 35740178 PMCID: PMC9219840 DOI: 10.3390/antibiotics11060772] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/24/2022] [Accepted: 05/26/2022] [Indexed: 12/14/2022] Open
Abstract
This study aimed to compare the biofilm formation ability of Staphylococcus aureus isolated from a wide range of animals and study the association between biofilm formation and antimicrobial resistance and genetic lineages. A total of 214 S. aureus strains isolated from pets, livestock, and wild animals were evaluated regarding their ability to form biofilms by the microtiter biofilm assay and their structure via confocal scanning laser microscopy. Statistical analysis was used to find an association between biofilm formation and antimicrobial resistance, multidrug resistance, sequence types (STs), spa and agr-types of the isolates. The antimicrobial susceptibility of 24 h-old biofilms was assessed against minimum inhibitory concentrations (MIC) and 10× MIC of amikacin and tetracycline, and the biomass reduction was measured. The metabolic activity of biofilms after antimicrobial treatment was evaluated by the XTT assay. All isolates were had the ability to form biofilms. Yet, significant differences in biofilm biomass production were detected among animal species. Multidrug resistance had a positive association with biofilm formation as well as methicillin-resistance. Significant differences were also detected among the clonal lineages of the isolates. Both tetracycline and amikacin were able to significantly reduce the biofilm mass. However, none of the antimicrobials were able to eradicate the biofilm at the maximum concentration used. Our results provide important information on the biofilm-forming capacity of animal-adapted S. aureus isolates, which may have potential implications for the development of new biofilm-targeted therapeutics.
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Affiliation(s)
- Vanessa Silva
- Microbiology and Antibiotic Resistance Team (MicroART), Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal;
- Department of Genetics and Biotechnology, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal;
- Functional Genomics and Proteomics Unit, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
- LAQV-REQUIMTE, Department of Chemistry, NOVA School of Science and Technology, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Elisete Correia
- Center for Computational and Stochastic Mathematics (CEMAT), Department of Mathematics, University of Trás-os-Montes and Alto Douro (UTAD), 5001-801 Vila Real, Portugal;
| | - José Eduardo Pereira
- CECAV—Veterinary and Animal Research Centre, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal;
- Associate Laboratory for Animal and Veterinary Science (AL4AnimalS), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
| | - Camino González-Machado
- Department of Food Hygiene and Technology, Veterinary Faculty, University of León, E-24071 León, Spain; (C.G.-M.); (R.C.); (C.A.-C.)
- Institute of Food Science and Technology, University of León, E-24071 León, Spain
| | - Rosa Capita
- Department of Food Hygiene and Technology, Veterinary Faculty, University of León, E-24071 León, Spain; (C.G.-M.); (R.C.); (C.A.-C.)
- Institute of Food Science and Technology, University of León, E-24071 León, Spain
| | - Carlos Alonso-Calleja
- Department of Food Hygiene and Technology, Veterinary Faculty, University of León, E-24071 León, Spain; (C.G.-M.); (R.C.); (C.A.-C.)
- Institute of Food Science and Technology, University of León, E-24071 León, Spain
| | - Gilberto Igrejas
- Department of Genetics and Biotechnology, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal;
- Functional Genomics and Proteomics Unit, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
- LAQV-REQUIMTE, Department of Chemistry, NOVA School of Science and Technology, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Patrícia Poeta
- Microbiology and Antibiotic Resistance Team (MicroART), Department of Veterinary Sciences, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal;
- CECAV—Veterinary and Animal Research Centre, University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal;
- Associate Laboratory for Animal and Veterinary Science (AL4AnimalS), University of Trás-os-Montes and Alto Douro (UTAD), 5000-801 Vila Real, Portugal
- Correspondence:
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28
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Kinney KJ, Tang SS, Wu XJ, Tran PM, Bharadwaj NS, Gibson-Corley KN, Forsythe AN, Kulhankova K, Gumperz JE, Salgado-Pabón W. SEC is an antiangiogenic virulence factor that promotes Staphylococcus aureus endocarditis independent of superantigen activity. SCIENCE ADVANCES 2022; 8:eabo1072. [PMID: 35544579 PMCID: PMC9094652 DOI: 10.1126/sciadv.abo1072] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 03/24/2022] [Indexed: 06/15/2023]
Abstract
The superantigen staphylococcal enterotoxin C (SEC) is critical for Staphylococcus aureus infective endocarditis (SAIE) in rabbits. Superantigenicity, its hallmark function, was proposed to be a major underlying mechanism driving SAIE but was not directly tested. With the use of S. aureus MW2 expressing SEC toxoids, we show that superantigenicity does not sufficiently account for vegetation growth, myocardial inflammation, and acute kidney injury in the rabbit model of native valve SAIE. These results highlight the critical contribution of an alternative function of superantigens to SAIE. In support of this, we provide evidence that SEC exerts antiangiogenic effects by inhibiting branching microvessel formation in an ex vivo rabbit aortic ring model and by inhibiting endothelial cell expression of one of the most potent mediators of angiogenesis, VEGF-A. SEC's ability to interfere with tissue revascularization and remodeling after injury serves as a mechanism to promote SAIE and its life-threatening systemic pathologies.
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Affiliation(s)
- Kyle J. Kinney
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, USA
| | - Sharon S. Tang
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Xiao-Jun Wu
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Phuong M. Tran
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, USA
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Nikhila S. Bharadwaj
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
| | - Katherine N. Gibson-Corley
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Ana N. Forsythe
- Department of Microbiology and Immunology, University of Iowa, Iowa City, IA, USA
| | | | - Jenny E. Gumperz
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, WI, USA
| | - Wilmara Salgado-Pabón
- Department of Pathobiological Sciences, University of Wisconsin-Madison, Madison, WI, USA
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29
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Darnowski MG, Lanosky TD, Labana P, Brazeau-Henrie JT, Calvert ND, Dornan MH, Natola C, Paquette AR, Shuhendler AJ, Boddy CN. Armeniaspirol analogues with more potent Gram-positive antibiotic activity show enhanced inhibition of the ATP-dependent proteases ClpXP and ClpYQ. RSC Med Chem 2022; 13:436-444. [PMID: 35647545 PMCID: PMC9020616 DOI: 10.1039/d1md00355k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 02/07/2022] [Indexed: 11/21/2022] Open
Abstract
Antibiotics with fundamentally new mechanisms of action such as the armeniaspirols, which target the ATP-dependent proteases ClpXP and ClpYQ, must be developed to combat antimicrobial resistance. While the mechanism of action of armeniaspirol against Gram-positive bacteria is understood, little is known about the structure-activity relationship for its antibiotic activity. Based on the preliminary data showing that modifications of armeniaspirol's N-methyl group increased antibiotic potency, we probed the structure-activity relationship of N-alkyl armeniaspirol derivatives. A series of focused derivatives were synthesized and evaluated for antibiotic activity against clinically relevant pathogens including methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus. Replacement of the N-methyl with N-hexyl, various N-benzyl, and N-phenethyl substituents led to substantial increases in antibiotic activity and potency for inhibition of both ClpYQ and ClpXP. Docking studies identified binding models for ClpXP and ClpYQ that were consistent with the inhibition data. This work confirms the role of ClpXP and ClpYQ in the mechanism of action of armeniaspirol and provides important lead compounds for further antibiotic development.
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Affiliation(s)
- Michael G. Darnowski
- Department of Chemistry and Biomolecular Sciences, University of OttawaOttawaONK1N 6N5 Canadacboddy!uottawa.ca
| | - Taylor D. Lanosky
- Department of Chemistry and Biomolecular Sciences, University of OttawaOttawaONK1N 6N5 Canadacboddy!uottawa.ca
| | - Puneet Labana
- Department of Chemistry and Biomolecular Sciences, University of OttawaOttawaONK1N 6N5 Canadacboddy!uottawa.ca
| | - Jordan T. Brazeau-Henrie
- Department of Chemistry and Biomolecular Sciences, University of OttawaOttawaONK1N 6N5 Canadacboddy!uottawa.ca
| | - Nicholas D. Calvert
- Department of Chemistry and Biomolecular Sciences, University of OttawaOttawaONK1N 6N5 Canadacboddy!uottawa.ca
| | - Mark H. Dornan
- Department of Chemistry and Biomolecular Sciences, University of OttawaOttawaONK1N 6N5 Canadacboddy!uottawa.ca
| | - Claudia Natola
- Department of Chemistry and Biomolecular Sciences, University of OttawaOttawaONK1N 6N5 Canadacboddy!uottawa.ca
| | - André R. Paquette
- Department of Chemistry and Biomolecular Sciences, University of OttawaOttawaONK1N 6N5 Canadacboddy!uottawa.ca
| | - Adam J. Shuhendler
- Department of Chemistry and Biomolecular Sciences, University of OttawaOttawaONK1N 6N5 Canadacboddy!uottawa.ca
| | - Christopher N. Boddy
- Department of Chemistry and Biomolecular Sciences, University of OttawaOttawaONK1N 6N5 Canadacboddy!uottawa.ca
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Superantigens promote Staphylococcus aureus bloodstream infection by eliciting pathogenic interferon-gamma production. Proc Natl Acad Sci U S A 2022; 119:2115987119. [PMID: 35165181 PMCID: PMC8872782 DOI: 10.1073/pnas.2115987119] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2022] [Indexed: 12/29/2022] Open
Abstract
Since their discovery over 30 y ago, it has become clear that the superantigens (SAgs) are important virulence factors produced during severe Staphylococcus aureus–mediated disease including bacteremia. However, until the current study, it was unclear how these toxins manipulated the immune system to promote infection. Here, we have demonstrated that the SAgs can target a critical immune signaling molecule (interferon gamma), inducing overproduction that promotes bacterial survival by subverting the ability of macrophages to be able to kill the pathogen. This highlights SAg activity as a critical target for antistaphylococcal therapy to mitigate the impact of severe S. aureus disease. Staphylococcus aureus is a foremost bacterial pathogen responsible for a vast array of human diseases. Staphylococcal superantigens (SAgs) constitute a family of exotoxins from S. aureus that bind directly to major histocompatibility complex (MHC) class II and T cell receptors to drive extensive T cell activation and cytokine release. Although these toxins have been implicated in serious disease, including toxic shock syndrome, the specific pathological mechanisms remain unclear. Herein, we aimed to elucidate how SAgs contribute to pathogenesis during bloodstream infections and utilized transgenic mice encoding human MHC class II to render mice susceptible to SAg activity. We demonstrate that SAgs contribute to S. aureus bacteremia by massively increasing bacterial burden in the liver, and this was mediated by CD4+ T cells that produced interferon gamma (IFN-γ) to high levels in a SAg-dependent manner. Bacterial burdens were reduced by blocking IFN-γ, phenocopying SAg-deletion mutant strains, and inhibiting a proinflammatory response. Infection kinetics and flow cytometry analyses suggested that this was a macrophage-driven mechanism, which was confirmed through macrophage-depletion experiments. Experiments in human cells demonstrated that excessive IFN-γ allowed S. aureus to replicate efficiently within macrophages. This indicates that SAgs promote bacterial survival by manipulating the immune response to inhibit effective clearing of S. aureus. Altogether, this work implicates SAg toxins as critical therapeutic targets for preventing persistent or severe S. aureus disease.
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Tran PM, Tang SS, Salgado-Pabón W. Staphylococcus aureus β-Toxin Exerts Anti-angiogenic Effects by Inhibiting Re-endothelialization and Neovessel Formation. Front Microbiol 2022; 13:840236. [PMID: 35185854 PMCID: PMC8851161 DOI: 10.3389/fmicb.2022.840236] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 01/11/2022] [Indexed: 12/25/2022] Open
Abstract
Staphylococcus aureus causes severe, life-threatening infections that often are complicated by severe local and systemic pathologies with non-healing lesions. A classic example is S. aureus infective endocarditis (IE), where the secreted hemolysin β-toxin potentiates the disease via its sphingomyelinase and biofilm ligase activities. Although these activities dysregulate human aortic endothelial cell activation, β-toxin effect on endothelial cell function in wound healing has not been addressed. With the use of the ex vivo rabbit aortic ring model, we provide evidence that β-toxin prevents branching microvessel formation, highlighting its ability to interfere with tissue re-vascularization and vascular repair. We show that β-toxin specifically targets both human aortic endothelial cell proliferation and cell migration and inhibits human umbilical vein endothelial cell rearrangement into capillary-like networks in vitro. Proteome arrays specific for angiogenesis-related molecules provided evidence that β-toxin promotes an inhibitory profile in endothelial cell monolayers, specifically targeting production of TIMP-1, TIMP-4, and IGFBP-3 to counter the effect of a pro-angiogenic environment. Dysregulation in the production of these molecules is known to result in sprouting defects (including deficient cell proliferation, migration, and survival), vessel instability and/or vascular regression. When endothelial cells are grown under re-endothelialization/wound healing conditions, β-toxin decreases the pro-angiogenic molecule MMP-8 and increases the anti-angiogenic molecule endostatin. Altogether, the data indicate that β-toxin is an anti-angiogenic virulence factor and highlight a mechanism where β-toxin exacerbates S. aureus invasive infections by interfering with tissue re-vascularization and vascular repair.
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Affiliation(s)
- Phuong M. Tran
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, United States
- Department of Microbiology and Immunology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Sharon S. Tang
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, United States
| | - Wilmara Salgado-Pabón
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, United States
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Investigation of Virulence Genes of Staphylococcus aureus Isolated from Sterile Body Fluid Samples and Their Correlation with Clinical Symptoms and Outcomes. THE CANADIAN JOURNAL OF INFECTIOUS DISEASES & MEDICAL MICROBIOLOGY = JOURNAL CANADIEN DES MALADIES INFECTIEUSES ET DE LA MICROBIOLOGIE MEDICALE 2022; 2021:5354747. [PMID: 34987680 PMCID: PMC8720599 DOI: 10.1155/2021/5354747] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Accepted: 12/15/2021] [Indexed: 12/31/2022]
Abstract
Staphylococcus aureus is the major pathogen causing nosocomial human infections and produces a variety of virulence factors that contribute to its ability to colonize and cause diseases. This study was conducted to investigate the virulence genes in S. aureus isolated from sterile body fluid samples and their correlation with clinical symptoms and outcomes. The VITEK 2® Compact system was used to perform biochemical identification and antimicrobial susceptibility tests on 33 S. aureus isolates. Virulence genes were amplified using multiplex PCR. The virulence gene patterns were analyzed by systematic cluster analysis. The frequency of methicillin-resistant S. aureus was 45.45%, and 17 virulence genes were identified. Genes encoding hemolysins showed high frequencies. The frequencies of hla, hlb, hld, and hlgB were 93.94% and that of the luk-F/S-PV was 21.21%. Except for the frequency of splB (51.52%), the remaining genes encoding invasive proteases showed frequencies greater than 81.82%. Among the patients, 100.00% had undergone invasive medical procedures and 24.00% had been treated with more than three types of antibiotic drugs. Invasive medical procedures are the main causes of infection. Resistance to antibiotic drugs and the status of carrying virulence genes were highly related to clinical symptoms and outcomes.
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Rom JS, Beenken KE, Ramirez AM, Walker CM, Echols EJ, Smeltzer MS. Limiting protease production plays a key role in the pathogenesis of the divergent clinical isolates of Staphylococcus aureus LAC and UAMS-1. Virulence 2021; 12:584-600. [PMID: 33538230 PMCID: PMC7872036 DOI: 10.1080/21505594.2021.1879550] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 11/17/2020] [Accepted: 01/10/2021] [Indexed: 01/13/2023] Open
Abstract
Using the USA300, methicillin-resistant Staphylococcus aureus strain LAC, we previously examined the impact of regulatory mutations implicated in biofilm formation on protease production and virulence in a murine sepsis model. Here we examined the impact of these mutations in the USA200, methicillin-sensitive strain UAMS-1. Mutation of agr, mgrA, rot, sarA and sigB attenuated the virulence of UAMS-1. A common characteristic of codY, rot, sigB, and sarA mutants was increased protease production, with mutation of rot having the least impact followed by mutation of codY, sigB and sarA, respectively. Protein A was undetectable in conditioned medium from all four mutants, while extracellular nuclease was only present in the proteolytically cleaved NucA form. The abundance of high molecular weight proteins was reduced in all four mutants. Biofilm formation was reduced in codY, sarA and sigB mutants, but not in the rot mutant. Eliminating protease production partially reversed these phenotypes and enhanced biofilm formation. This was also true in LAC codY, rot, sarA and sigB mutants. Eliminating protease production enhanced the virulence of LAC and UAMS-1 sarA, sigB and rot mutants in a murine sepsis model but did not significantly impact the virulence of the codY mutant in either strain. Nevertheless, these results demonstrate that repressing protease production plays an important role in defining critical phenotypes in diverse clinical isolates of S. aureus and that Rot, SigB and SarA play critical roles in this regard.
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Affiliation(s)
- Joseph S. Rom
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Karen E. Beenken
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Aura M. Ramirez
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Christopher M. Walker
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Ethan J. Echols
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Mark S. Smeltzer
- Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
- Department of Orthopaedic Surgery, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
- Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
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Clinical Features and Molecular Characteristics of Methicillin-Susceptible Staphylococcus aureus Ocular Infection in Taiwan. Antibiotics (Basel) 2021; 10:antibiotics10121445. [PMID: 34943657 PMCID: PMC8698105 DOI: 10.3390/antibiotics10121445] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/18/2021] [Accepted: 11/21/2021] [Indexed: 11/17/2022] Open
Abstract
This study analyzed the clinical features and molecular characteristics of methicillin-susceptible Staphylococcus aureus (MSSA) ocular infections in Taiwan and compared them between community-associated (CA) and health-care-associated (HA) infections. We collected S. aureus ocular isolates from patients at Chang Gung Memorial Hospital between 2010 and 2017. The infections were classified as CA or HA using epidemiological criteria, and the isolates were molecularly characterized using pulsed-field gel electrophoresis, multilocus sequence typing, and Panton-Valentine leukocidin (PVL) gene detection. Antibiotic susceptibility was evaluated using disk diffusion and an E test. A total of 104 MSSA ocular isolates were identified; 46 (44.2%) were CA-MSSA and 58 (55.8%) were HA-MSSA. Compared with HA-MSSA strains, CA-MSSA strains caused a significantly higher rate of keratitis, but a lower rate of conjunctivitis. We identified 14 pulsotypes. ST 7/pulsotype BA was frequently identified in both CA-MSSA (28.3%) and HA-MSSA (37.9%) cases. PVL genes were identified in seven isolates (6.7%). Both CA-MSSA and HA-MSSA isolates were highly susceptible to vancomycin, teicoplanin, tigecycline, sulfamethoxazole–trimethoprim, and fluoroquinolones. The most common ocular manifestations were keratitis and conjunctivitis for CA-MSSA and HA-MSSA, respectively. The MSSA ocular isolates had diverse molecular characteristics; no specific genotype differentiated CA-MSSA from HA-MSSA. Both strains exhibited similar antibiotic susceptibility.
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Messingham KN, Cahill MP, Kilgore SH, Munjal A, Schlievert PM, Fairley JA. TSST-1 +Staphylococcus aureus in Bullous Pemphigoid. J Invest Dermatol 2021; 142:1032-1039.e6. [PMID: 34606884 DOI: 10.1016/j.jid.2021.08.438] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 08/23/2021] [Accepted: 08/30/2021] [Indexed: 01/31/2023]
Abstract
A potential role of Staphylococcus aureus in bullous pemphigoid was explored by examining the colonization rate in patients with new-onset disease compared with that in age- and sex-matched controls. S. aureus colonization was observed in 85% of bullous pemphigoid lesions, 3-6-fold higher than the nares or unaffected skin from the same patients (P ≤ 0.003) and 6-fold higher than the nares or skin of controls (P ≤ 0.0015). Furthermore, 96% of the lesional isolates produced the toxic shock syndrome toxin-1 superantigen, and most of these additionally exhibited homogeneous expression of the enterotoxin gene cluster toxins. Toxic shock syndrome toxin-1‒neutralizing antibodies were not protective against colonization. However, S. aureus colonization was not observed in patients who had recently received antibiotics, and the addition of antibiotics with staphylococcal coverage eliminated S. aureus and resulted in clinical improvement. This study shows that toxic shock syndrome toxin-1‒positive S. aureus is prevalent in bullous pemphigoid lesions and suggests that early implementation of antibiotics may be of benefit. Furthermore, our results suggest that S. aureus colonization could provide a source of infection in patients with bullous pemphigoid, particularly in the setting of high-dose immunosuppression.
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Affiliation(s)
- Kelly N Messingham
- Department of Dermatology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA.
| | - Michael P Cahill
- Department of Microbiology and Immunology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Samuel H Kilgore
- Department of Microbiology and Immunology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Ananya Munjal
- Department of Dermatology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Patrick M Schlievert
- Department of Microbiology and Immunology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Janet A Fairley
- Department of Dermatology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
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Analysis of Virulence and Antimicrobial Resistance Gene Carriage in Staphylococcus aureus Infections in Equids Using Whole-Genome Sequencing. mSphere 2021; 6:e0019620. [PMID: 34346711 PMCID: PMC8386420 DOI: 10.1128/msphere.00196-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
While Staphylococcus aureus is associated with significant morbidity and mortality in equids (horses, donkeys, and mules), few studies have performed whole-genome sequencing to fully categorize large collections of equine isolates. Such sequencing allows for a comprehensive analysis of the genetic lineage and relationships of isolates, as well as the virulence genes present in each, which can be important for understanding the epidemiology of strains and their range of infections. Seventy-two clinical Staphylococcus aureus isolates from equids were collected at the Texas A&M University Veterinary Medical Teaching Hospital between 2007 and 2017. Whole-genome sequencing was performed to characterize the isolates according to sequence typing, biofilm association, antimicrobial resistance, and toxin gene carriage. Of the 72 isolates, 19% were methicillin resistant, of which the majority belonged to clonal complex 8. Eighteen distinct sequence types (STs) were represented, with the most common being ST1, ST133, ST8, and ST97. Most isolates had weak or negative overall biofilm production. Toxin and antimicrobial resistance gene carriage was varied; of note, this study revealed that a large proportion of North American equine isolates carry the leucocidin PQ toxin (66% of isolates). One isolate (17-021) carried genes imparting lincosamide and high-level mupirocin resistance, a combination not previously reported in equine-derived S. aureus isolates. IMPORTANCE This is one of the first studies to perform whole-genome sequencing (WGS) of a large collection of Staphylococcus aureus isolates, both methicillin resistant and susceptible, collected from horses. A large proportion of the isolates carry leucocidin PQ (LukPQ), making this one of the first reports of such carriage in the United States. The presence of lincosamide and high-level mupirocin resistance in a methicillin-susceptible S. aureus (MSSA) isolate highlights the importance of MSSA as a reservoir of important antimicrobial resistance genes. As microbial resistance genes on mobile genetic elements can pass between S. aureus strains and livestock-associated strains can be transferred to humans, these findings have important public health implications.
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Abstract
Atopic dermatitis (AD) is a condition affecting 30 million persons in the United States. AD patients are heavily infected with Staphylococcus aureus on the skin. A particularly severe form of AD is eczema herpeticum (ADEH), where the patients' AD is complicated by S. aureus and herpes simplex virus (HSV) infection. This study examined the S. aureus strains from 15 ADEH patients, provided blinded, and showed a high association of ADEH with strains that produce toxic shock syndrome toxin-1 (TSST-1; 73%) compared to 10% production by typical AD isolates from patients without EH and those from another unrelated condition, cystic fibrosis. The ADEH isolates produced the superantigens associated with TSS (TSST-1 and staphylococcal enterotoxins A, B, and C). This association may in part explain the potential severity of ADEH. We also examined the effect of TSST-1 and HSV-1 on human epithelial cells and keratinocytes. TSST-1 used CD40 as its receptor on epithelial cells, and HSV-1 either directly or indirectly interacted with CD40. The consequence of these interactions was chemokine production, which is capable of causing harmful inflammation, with epidermal/keratinocyte barrier disruption. Human epithelial cells treated first with TSST-1 and then HSV-1 resulted in enhanced chemokine production. Finally, we showed that TSST-1 modestly increased HSV-1 replication but did not increase viral plaque size. Our data suggest that ADEH is associated with production of the major TSS-associated superantigens, together with HSV reactivation. The superantigens plus HSV may damage the skin barrier by causing harmful inflammation, thereby leading to increased symptoms. IMPORTANCE Atopic dermatitis (eczema, AD) with concurrent herpes simplex virus infection (eczema herpeticum, ADEH) is a severe form of AD. We show that ADEH patients are colonized with Staphylococcus aureus that primarily produces the superantigen toxic shock syndrome toxin-1 (TSST-1); however, significantly but to a lesser extent the superantigens staphylococcal enterotoxins A, B, and C are also represented in ADEH. Our studies showed that TSST-1 uses the immune costimulatory molecule CD40 as its epithelial cell receptor. Herpes simplex virus (HSV) also interacted directly or indirectly with CD40 on epithelial cells. Treatment of epithelial cells with TSST-1 and then HSV-1 resulted in enhanced chemokine production. We propose that this combination of exposures (TSST-1 and then HSV) leads to opening of epithelial and skin barriers to facilitate potentially serious ADEH.
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38
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Labana P, Dornan MH, Lafrenière M, Czarny TL, Brown ED, Pezacki JP, Boddy CN. Armeniaspirols inhibit the AAA+ proteases ClpXP and ClpYQ leading to cell division arrest in Gram-positive bacteria. Cell Chem Biol 2021; 28:1703-1715.e11. [PMID: 34293284 DOI: 10.1016/j.chembiol.2021.07.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 04/22/2021] [Accepted: 06/29/2021] [Indexed: 01/16/2023]
Abstract
Multi-drug-resistant bacteria present an urgent threat to modern medicine, creating a desperate need for antibiotics with new modes of action. As natural products remain an unsurpassed source for clinically viable antibiotic compounds, we investigate the mechanism of action of armeniaspirol. The armeniaspirols are a structurally unique class of Gram-positive antibiotic discovered from Streptomyces armeniacus for which resistance cannot be readily obtained. We show that armeniaspirol inhibits the ATP-dependent proteases ClpXP and ClpYQ in vitro and in the model Gram-positive Bacillus subtilis. This inhibition dysregulates the divisome and elongasome supported by an upregulation of key proteins FtsZ, DivIVA, and MreB inducing cell division arrest. The inhibition of ClpXP and ClpYQ to dysregulate cell division represents a unique antibiotic mechanism of action and armeniaspirol is the only known natural product inhibitor of the coveted anti-virulence target ClpP. Thus, armeniaspirol possesses a promising lead scaffold for antibiotic development with unique pharmacology.
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Affiliation(s)
- Puneet Labana
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Mark H Dornan
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Matthew Lafrenière
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Tomasz L Czarny
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Eric D Brown
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - John P Pezacki
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Christopher N Boddy
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada.
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Su M, Davis MH, Peterson J, Solis-Lemus C, Satola SW, Read TD. Effect of genetic background on the evolution of Vancomycin-Intermediate Staphylococcus aureus (VISA). PeerJ 2021; 9:e11764. [PMID: 34306830 PMCID: PMC8284308 DOI: 10.7717/peerj.11764] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 06/22/2021] [Indexed: 11/20/2022] Open
Abstract
Vancomycin-intermediate Staphylococcus aureus (VISA) typically arises through accumulation of chromosomal mutations that alter cell-wall thickness and global regulatory pathways. Genome-based prediction of VISA requires understanding whether strain background influences patterns of mutation that lead to resistance. We used an iterative method to experimentally evolve three important methicillin-resistant S. aureus (MRSA) strain backgrounds-(CC1, CC5 and CC8 (USA300)) to generate a library of 120 laboratory selected VISA isolates. At the endpoint, isolates had vancomycin MICs ranging from 4 to 10 μg/mL. We detected mutations in more than 150 genes, but only six genes (already known to be associated with VISA from prior studies) were mutated in all three background strains (walK, prs, rpoB, rpoC, vraS, yvqF). We found evidence of interactions between loci (e.g., vraS and yvqF mutants were significantly negatively correlated) and rpoB, rpoC, vraS and yvqF were more frequently mutated in one of the backgrounds. Increasing vancomycin resistance was correlated with lower maximal growth rates (a proxy for fitness) regardless of background. However, CC5 VISA isolates had higher MICs with fewer rounds of selection and had lower fitness costs than the CC8 VISA isolates. Using multivariable regression, we found that genes differed in their contribution to overall MIC depending on the background. Overall, these results demonstrated that VISA evolved through mutations in a similar set of loci in all backgrounds, but the effect of mutation in common genes differed with regard to fitness and contribution to resistance in different strains.
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Affiliation(s)
- Michelle Su
- Division of Infectious Diseases, Department of Medicine, School of Medicine, Emory University, Atlanta, Georgia, USA
| | - Michelle H Davis
- Division of Infectious Diseases, Department of Medicine, School of Medicine, Emory University, Atlanta, Georgia, USA
| | - Jessica Peterson
- Division of Infectious Diseases, Department of Medicine, School of Medicine, Emory University, Atlanta, Georgia, USA
| | - Claudia Solis-Lemus
- Wisconsin Institute for Discovery and Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Sarah W Satola
- Division of Infectious Diseases, Department of Medicine, School of Medicine, Emory University, Atlanta, Georgia, USA
| | - Timothy D Read
- Division of Infectious Diseases, Department of Medicine, School of Medicine, Emory University, Atlanta, Georgia, USA.,Department of Dermatology, School of Medicine, Emory University, Atlanta, Georgia, USA
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Tomlinson BR, Malof ME, Shaw LN. A global transcriptomic analysis of Staphylococcus aureus biofilm formation across diverse clonal lineages. Microb Genom 2021; 7. [PMID: 34227933 PMCID: PMC8477394 DOI: 10.1099/mgen.0.000598] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
A key characteristic of Staphylococcus aureus infections, and one that also varies phenotypically between clones, is that of biofilm formation, which aids in bacterial persistence through increased adherence and immune evasion. Though there is a general understanding of the process of biofilm formation - adhesion, proliferation, maturation and dispersal - the tightly orchestrated molecular events behind each stage, and what drives variation between S. aureus strains, has yet to be unravelled. Herein we measure biofilm progression and dispersal in real-time across the five major S. aureus CDC-types (USA100-USA500) revealing adherence patterns that differ markedly amongst strains. To gain insight into this, we performed transcriptomic profiling on these isolates at multiple timepoints, compared to planktonically growing counterparts. Our findings support a model in which eDNA release, followed by increased positive surface charge, perhaps drives initial abiotic attachment. This is seemingly followed by cooperative repression of autolysis and activation of poly-N-acetylglucosamine (PNAG) production, which may indicate a developmental shift in structuring the biofilm matrix. As biofilms mature, diminished translational capacity was apparent, with 53 % of all ribosomal proteins downregulated, followed by upregulation of anaerobic respiration enzymes. These findings are noteworthy because reduced cellular activity and an altered metabolic state have been previously shown to contribute to higher antibiotic tolerance and bacterial persistence. In sum, this work is, to our knowledge, the first study to investigate transcriptional regulation during the early, establishing phase of biofilm formation, and to compare global transcriptional regulation both temporally and across multiple clonal lineages.
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Affiliation(s)
- Brooke R Tomlinson
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, 4202 East Fowler Avenue, ISA 2015, Tampa, FL, USA
| | - Morgan E Malof
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, 4202 East Fowler Avenue, ISA 2015, Tampa, FL, USA
| | - Lindsey N Shaw
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, 4202 East Fowler Avenue, ISA 2015, Tampa, FL, USA
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41
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Tomlinson BR, Malof ME, Shaw LN. A global transcriptomic analysis of Staphylococcus aureus biofilm formation across diverse clonal lineages. Microb Genom 2021. [PMID: 34227933 DOI: 10.1099/mgen0000598] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
A key characteristic of Staphylococcus aureus infections, and one that also varies phenotypically between clones, is that of biofilm formation, which aids in bacterial persistence through increased adherence and immune evasion. Though there is a general understanding of the process of biofilm formation - adhesion, proliferation, maturation and dispersal - the tightly orchestrated molecular events behind each stage, and what drives variation between S. aureus strains, has yet to be unravelled. Herein we measure biofilm progression and dispersal in real-time across the five major S. aureus CDC-types (USA100-USA500) revealing adherence patterns that differ markedly amongst strains. To gain insight into this, we performed transcriptomic profiling on these isolates at multiple timepoints, compared to planktonically growing counterparts. Our findings support a model in which eDNA release, followed by increased positive surface charge, perhaps drives initial abiotic attachment. This is seemingly followed by cooperative repression of autolysis and activation of poly-N-acetylglucosamine (PNAG) production, which may indicate a developmental shift in structuring the biofilm matrix. As biofilms mature, diminished translational capacity was apparent, with 53 % of all ribosomal proteins downregulated, followed by upregulation of anaerobic respiration enzymes. These findings are noteworthy because reduced cellular activity and an altered metabolic state have been previously shown to contribute to higher antibiotic tolerance and bacterial persistence. In sum, this work is, to our knowledge, the first study to investigate transcriptional regulation during the early, establishing phase of biofilm formation, and to compare global transcriptional regulation both temporally and across multiple clonal lineages.
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Affiliation(s)
- Brooke R Tomlinson
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, 4202 East Fowler Avenue, ISA 2015, Tampa, FL, USA
| | - Morgan E Malof
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, 4202 East Fowler Avenue, ISA 2015, Tampa, FL, USA
| | - Lindsey N Shaw
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, 4202 East Fowler Avenue, ISA 2015, Tampa, FL, USA
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Lerche CJ, Schwartz F, Theut M, Fosbøl EL, Iversen K, Bundgaard H, Høiby N, Moser C. Anti-biofilm Approach in Infective Endocarditis Exposes New Treatment Strategies for Improved Outcome. Front Cell Dev Biol 2021; 9:643335. [PMID: 34222225 PMCID: PMC8249808 DOI: 10.3389/fcell.2021.643335] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 05/04/2021] [Indexed: 12/13/2022] Open
Abstract
Infective endocarditis (IE) is a life-threatening infective disease with increasing incidence worldwide. From early on, in the antibiotic era, it was recognized that high-dose and long-term antibiotic therapy was correlated to improved outcome. In addition, for several of the common microbial IE etiologies, the use of combination antibiotic therapy further improves outcome. IE vegetations on affected heart valves from patients and experimental animal models resemble biofilm infections. Besides the recalcitrant nature of IE, the microorganisms often present in an aggregated form, and gradients of bacterial activity in the vegetations can be observed. Even after appropriate antibiotic therapy, such microbial formations can often be identified in surgically removed, infected heart valves. Therefore, persistent or recurrent cases of IE, after apparent initial infection control, can be related to biofilm formation in the heart valve vegetations. On this background, the present review will describe potentially novel non-antibiotic, antimicrobial approaches in IE, with special focus on anti-thrombotic strategies and hyperbaric oxygen therapy targeting the biofilm formation of the infected heart valves caused by Staphylococcus aureus. The format is translational from preclinical models to actual clinical treatment strategies.
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Affiliation(s)
- Christian Johann Lerche
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Franziska Schwartz
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Marie Theut
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Emil Loldrup Fosbøl
- Department of Cardiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Kasper Iversen
- Department of Cardiology, Herlev and Gentofte Hospital, University of Copenhagen, Herlev, Denmark
- Department of Emergency Medicine, Herlev and Gentofte Hospital, University of Copenhagen, Herlev, Denmark
| | - Henning Bundgaard
- Department of Cardiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
| | - Niels Høiby
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark
| | - Claus Moser
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark
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Saur JS, Wirtz SN, Schilling NA, Krismer B, Peschel A, Grond S. Distinct Lugdunins from a New Efficient Synthesis and Broad Exploitation of Its MRSA-Antimicrobial Structure. J Med Chem 2021; 64:4034-4058. [PMID: 33779184 DOI: 10.1021/acs.jmedchem.0c02170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
A new solid-phase peptide synthesis and bioprofiling of the antimicrobial activity of lugdunin, a fibupeptide, enable a comprehensive structure-activity relationship (SAR) study (MRSA Staphylococcus aureus). Distinct lugdunin analogues with variation of the three important amino acids Val2, Trp3, and Leu4 are readily available based on the established high-output synthesis. This efficient synthesis concept takes advantage of the presynthesized thiazolidine building block. To gain further knowledge of SAR, d-Val2, and d-Leu4 were replaced with aliphatic amino acids. For l-Trp3 derivatization, a set of non-natural aromatic amino acids with manifold substitution and annulation patterns precisely shows structural imperatives, starting from the exchange of d-Val6 → d-Trp6 with a 2-fold improved biological activity. d-Trp6-lugdunin analogues with additional variation of d-Val2 and d-Leu4 residues were designed and synthesized followed by antimicrobial profiling. For the first time, these SAR studies deliver valuable information on the tolerance of other amino acids to d-Val2, l-Trp3, and d-Leu4 in the sequence of lugdunin.
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Affiliation(s)
- Julian S Saur
- Institute of Organic Chemistry, Eberhard Karls University Tuebingen, Auf der Morgenstelle 18, 72076 Tuebingen, Germany
| | - Sebastian N Wirtz
- Institute of Organic Chemistry, Eberhard Karls University Tuebingen, Auf der Morgenstelle 18, 72076 Tuebingen, Germany
| | - Nadine A Schilling
- Institute of Organic Chemistry, Eberhard Karls University Tuebingen, Auf der Morgenstelle 18, 72076 Tuebingen, Germany
| | - Bernhard Krismer
- Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infections, Eberhard Karls University Tuebingen, Auf der Morgenstelle 28, 72076 Tuebingen, Germany.,Interfaculty Institute of Microbiology and Infection Medicine, German Center for Infection Research (DZIF), Eberhard Karls University Tuebingen, Auf der Morgenstelle 28, 72076 Tuebingen, Germany.,German Center for Infection Research (DZIF), Eberhard Karls University Tuebingen, Auf der Morgenstelle 28, 72076 Tuebingen, Germany
| | - Andreas Peschel
- Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infections, Eberhard Karls University Tuebingen, Auf der Morgenstelle 28, 72076 Tuebingen, Germany.,Interfaculty Institute of Microbiology and Infection Medicine, German Center for Infection Research (DZIF), Eberhard Karls University Tuebingen, Auf der Morgenstelle 28, 72076 Tuebingen, Germany.,German Center for Infection Research (DZIF), Eberhard Karls University Tuebingen, Auf der Morgenstelle 28, 72076 Tuebingen, Germany
| | - Stephanie Grond
- Institute of Organic Chemistry, Eberhard Karls University Tuebingen, Auf der Morgenstelle 18, 72076 Tuebingen, Germany.,Cluster of Excellence EXC 2124 Controlling Microbes to Fight Infections, Eberhard Karls University Tuebingen, Auf der Morgenstelle 28, 72076 Tuebingen, Germany
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44
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Park S, Ronholm J. Staphylococcus aureus in Agriculture: Lessons in Evolution from a Multispecies Pathogen. Clin Microbiol Rev 2021; 34:e00182-20. [PMID: 33568553 PMCID: PMC7950364 DOI: 10.1128/cmr.00182-20] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Staphylococcus aureus is a formidable bacterial pathogen that is responsible for infections in humans and various species of wild, companion, and agricultural animals. The ability of S. aureus to move between humans and livestock is due to specific characteristics of this bacterium as well as modern agricultural practices. Pathoadaptive clonal lineages of S. aureus have emerged and caused significant economic losses in the agricultural sector. While humans appear to be a primary reservoir for S. aureus, the continued expansion of the livestock industry, globalization, and ubiquitous use of antibiotics has increased the dissemination of pathoadaptive S. aureus in this environment. This review comprehensively summarizes the available literature on the epidemiology, pathophysiology, genomics, antibiotic resistance (ABR), and clinical manifestations of S. aureus infections in domesticated livestock. The availability of S. aureus whole-genome sequence data has provided insight into the mechanisms of host adaptation and host specificity. Several lineages of S. aureus are specifically adapted to a narrow host range on a short evolutionary time scale. However, on a longer evolutionary time scale, host-specific S. aureus has jumped the species barrier between livestock and humans in both directions several times. S. aureus illustrates how close contact between humans and animals in high-density environments can drive evolution. The use of antibiotics in agriculture also drives the emergence of antibiotic-resistant strains, making the possible emergence of human-adapted ABR strains from agricultural practices concerning. Addressing the concerns of ABR S. aureus, without negatively affecting agricultural productivity, is a challenging priority.
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Affiliation(s)
- Soyoun Park
- Faculty of Agricultural and Environmental Sciences, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
| | - Jennifer Ronholm
- Faculty of Agricultural and Environmental Sciences, McGill University, Sainte-Anne-de-Bellevue, Quebec, Canada
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45
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Dong Q, Liu Y, Li W, Chen M, Li W, Wang X, Fu J, Ye X. Phenotypic and Molecular Characteristics of Community-Associated Staphylococcus aureus Infection in Neonates. Infect Drug Resist 2020; 13:4589-4600. [PMID: 33376365 PMCID: PMC7765684 DOI: 10.2147/idr.s284781] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 11/27/2020] [Indexed: 12/14/2022] Open
Abstract
Background Staphylococcus aureus is an important human pathogen causing a wide variety of diseases ranging from mild skin infections to life-threatening bacteremia. This study aimed to provide insight into the phenotype-genotype characteristics of S. aureus isolated from neonates. Methods A hospital-based retrospective study was conducted to recruit neonatal patients with community-associated S. aureus infection. All 92 S. aureus clinical isolates were tested for antimicrobial susceptibility, resistance genes, virulence genes, and multilocus sequence typing. Results A total of 92 S. aureus isolates were included in this study, including 29 (31.5%) MRSA isolates. Most S. aureus isolates were susceptible to gentamicin, and most methicillin-resistant S. aureus (MRSA) isolates were susceptible to vancomycin and linezolid. The predominant S. aureus genotypes were CC188 (ST188), CC59 (ST338), CC5 (ST5), CC88 (ST8), and CC6 (ST6), with CC59 (ST338) as the most prevalent MRSA. We observed a significantly corresponding relationship between clonal complexes and resistance patterns (such as CC45/CC59/CC121/CC630 associated with multidrug resistance) or the number of virulence genes (such as CC1/CC5/CC45/CC59/CC88 associated with harboring 5-7 virulence genes, and CC22/CC25/CC121 associated with carrying 8-13 genes). Moreover, both univariate and multivariate analyses indicated that invasive S. aureus isolates were significantly associated with resistance to several classes of antibiotics and carrying specific virulence factors. Conclusion Our findings provide insight into phenotype-genotype characteristics for S. aureus isolates so as to provide new ideas for differentiating potential genetic backgrounds and monitoring new epidemiologic trends.
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Affiliation(s)
- Qian Dong
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, People's Republic of China
| | - Yanling Liu
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, People's Republic of China
| | - Wenhui Li
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, People's Republic of China
| | - Minqi Chen
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, People's Republic of China
| | - Wenyu Li
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, People's Republic of China
| | - Xulin Wang
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, People's Republic of China
| | - Jinjian Fu
- Department of Prevention and Health Care, Liuzhou Maternity and Child Health Care Hospital, Liuzhou, People's Republic of China
| | - Xiaohua Ye
- School of Public Health, Guangdong Pharmaceutical University, Guangzhou, People's Republic of China
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Global Epidemiology and Evolutionary History of Staphylococcus aureus ST45. J Clin Microbiol 2020; 59:JCM.02198-20. [PMID: 33087430 DOI: 10.1128/jcm.02198-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 10/14/2020] [Indexed: 12/19/2022] Open
Abstract
Staphylococcus aureus ST45 is a major global MRSA lineage with huge strain diversity and a high clinical impact. It is one of the most prevalent carrier lineages but also frequently causes severe invasive disease, such as bacteremia. Little is known about its evolutionary history. In this study, we used whole-genome sequencing to analyze a large collection of 451 diverse ST45 isolates from 6 continents and 26 countries. De novo-assembled genomes were used to understand genomic plasticity and to perform coalescent analyses. The ST45 population contained two distinct sublineages, which correlated with the isolates' geographical origins. One sublineage primarily consisted of European/North American isolates, while the second sublineage primarily consisted of African and Australian isolates. Bayesian analysis predicted ST45 originated in northwestern Europe about 500 years ago. Isolation time, host, and clinical symptoms did not correlate with phylogenetic groups. Our phylogenetic analyses suggest multiple acquisitions of the SCCmec element and key virulence factors throughout the evolution of the ST45 lineage.
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Jaradat ZW, Ababneh QO, Sha’aban ST, Alkofahi AA, Assaleh D, Al Shara A. Methicillin Resistant Staphylococcus aureus and public fomites: a review. Pathog Glob Health 2020; 114:426-450. [PMID: 33115375 PMCID: PMC7759291 DOI: 10.1080/20477724.2020.1824112] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Staphylococcus genus is a Gram-positive coccus normally associated with skin and mucous membranes of warm-blooded animals. It is part of the commensal human microflora, or found in animals, or contaminating surfaces in the community and hospital settings. Staphylococcus aureus is the most pathogenic species belonging to this genus, as it possesses a collection of virulence factors that are expressed solely to evade the immune system. The increase in the misuse of antimicrobial agents predisposed S. aureus to develop antibiotic resistance, including the resistance to methicillin which led to the emergence of Methicillin-Resistant S. aureus (MRSA). MRSA is considered one of the most dangerous nosocomial pathogens causing many hard to treat infections in hospitals and was named as Hospital Associated MRSA (HA-MRSA). Over the past 20-25 years, MRSA was isolated from community settings and thus Community Associated MRSA (CA-MRSA) has emerged. Inside hospitals, MRSA has been isolated from fomites in contact with patients, as well as staff's protective and personal items. This review highlights the worldwide prevalence of MRSA on fomites within the contexts of hospital and community settings.
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Affiliation(s)
- Ziad W Jaradat
- Jordan University of Science and Technology, Irbid, 22110, Jordan
| | | | - Sherin T Sha’aban
- Department of Applied Biological Sciences, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Ayesha A Alkofahi
- Department of Applied Biological Sciences, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Duaa Assaleh
- Department of Applied Biological Sciences, Jordan University of Science and Technology, Irbid, 22110, Jordan
| | - Anan Al Shara
- Department of Applied Biological Sciences, Jordan University of Science and Technology, Irbid, 22110, Jordan
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Genardi S, Visvabharathy L, Cao L, Morgun E, Cui Y, Qi C, Chen YH, Gapin L, Berdyshev E, Wang CR. Type II Natural Killer T Cells Contribute to Protection Against Systemic Methicillin-Resistant Staphylococcus aureus Infection. Front Immunol 2020; 11:610010. [PMID: 33312179 PMCID: PMC7708336 DOI: 10.3389/fimmu.2020.610010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 10/22/2020] [Indexed: 12/31/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (SA) bacteremia is responsible for over 10,000 deaths in the hospital setting each year. Both conventional CD4+ T cells and γδ T cells play protective roles in SA infection through secretion of IFN-γ and IL-17. However, the role of other unconventional T cells in SA infection is largely unknown. Natural killer T (NKT) cells, a subset of innate-like T cells, are activated rapidly in response to a wide range of self and microbial lipid antigens presented by MHC I-like molecule CD1d. NKT cells are divided into two groups, invariant NKT (iNKT) and type II NKT cells, based on TCR usage. Using mice lacking either iNKT cells or both types of NKT cells, we show that both NKT cell subsets are activated after systemic SA infection and produce IFN-γ in response to SA antigen, however type II NKT cells are sufficient to control bacterial burden and inflammatory infiltrate in infected organs. This protective capacity was specific for NKT cells, as mice lacking mucosal associated invariant T (MAIT) cells, another innate-like T cell subset, had no increased susceptibility to SA systemic infection. We identify polar lipid species from SA that induce IFN-γ production from type II NKT cells, which requires both CD1d-TCR engagement and IL-12 production by antigen presenting cells. We also demonstrate that a population of T cells enriched for type II NKT cells are increased in PBMC of SA bacteremic patients compared to healthy controls. Therefore, type II NKT cells perform effector functions that enhance control of SA infection prior to conventional T cell activation and recognize SA-derived lipid antigens. As CD1d is highly conserved in humans, these CD1d-restricted SA lipid antigens could be used in the design of next generation SA vaccines targeting cell-mediated immunity.
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Affiliation(s)
- Samantha Genardi
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Lavanya Visvabharathy
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Liang Cao
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Eva Morgun
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Yongyong Cui
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Chao Qi
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Yi-Hua Chen
- Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
| | - Laurent Gapin
- Department of Immunology and Microbiology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Evgeny Berdyshev
- Department of Medicine, National Jewish Health, Denver, CO, United States
| | - Chyung-Ru Wang
- Department of Microbiology and Immunology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States
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Strain Background, Species Frequency, and Environmental Conditions Are Important in Determining Pseudomonas aeruginosa and Staphylococcus aureus Population Dynamics and Species Coexistence. Appl Environ Microbiol 2020; 86:AEM.00962-20. [PMID: 32651205 DOI: 10.1128/aem.00962-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 07/04/2020] [Indexed: 01/09/2023] Open
Abstract
Bacterial communities in the environment and in infections are typically diverse, yet we know little about the factors that determine interspecies interactions. Here, we apply concepts from ecological theory to understand how biotic and abiotic factors affect interaction patterns between the two opportunistic human pathogens Pseudomonas aeruginosa and Staphylococcus aureus, which often cooccur in polymicrobial infections. Specifically, we conducted a series of short- and long-term competition experiments between P. aeruginosa PAO1 (as our reference strain) and three different S. aureus strains (Cowan I, 6850, and JE2) at three starting frequencies and under three environmental (culturing) conditions. We found that the competitive ability of P. aeruginosa strongly depended on the strain background of S. aureus, whereby P. aeruginosa dominated against Cowan I and 6850 but not against JE2. In the latter case, both species could end up as winners depending on conditions. Specifically, we observed strong frequency-dependent fitness patterns, including positive frequency dependence, where P. aeruginosa could dominate JE2 only when common (not when rare). Finally, changes in environmental (culturing) conditions fundamentally altered the competitive balance between the two species in a way that P. aeruginosa dominance increased when moving from shaken to static environments. Altogether, our results highlight that ecological details can have profound effects on the competitive dynamics between coinfecting pathogens and determine whether two species can coexist or invade each others' populations from a state of rare frequency. Moreover, our findings might parallel certain dynamics observed in chronic polymicrobial infections.IMPORTANCE Bacterial infections are frequently caused by more than one species, and such polymicrobial infections are often considered more virulent and more difficult to treat than the respective monospecies infections. Pseudomonas aeruginosa and Staphylococcus aureus are among the most important pathogens in polymicrobial infections, and their cooccurrence is linked to worse disease outcome. There is great interest in understanding how these two species interact and what the consequences for the host are. While previous studies have mainly looked at molecular mechanisms implicated in interactions between P. aeruginosa and S. aureus, here we show that ecological factors, such as strain background, species frequency, and environmental conditions, are important elements determining population dynamics and species coexistence patterns. We propose that the uncovered principles also play major roles in infections and, therefore, proclaim that an integrative approach combining molecular and ecological aspects is required to fully understand polymicrobial infections.
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Bennett MR, Thomsen IP. Epidemiological and Clinical Evidence for the Role of Toxins in S. aureus Human Disease. Toxins (Basel) 2020; 12:toxins12060408. [PMID: 32575633 PMCID: PMC7354447 DOI: 10.3390/toxins12060408] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/12/2020] [Accepted: 06/15/2020] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus asymptomatically colonizes approximately 30–50% of the population and is a leading cause of bacteremia, bone/joint infections, and skin infections in the US. S. aureus has become a major public health threat due to antibiotic resistance and an increasing number of failed vaccine attempts. To develop new anti-staphylococcal preventive therapies, it will take a more thorough understanding of the current role S. aureus virulence factors play in contributing to human disease. This review focuses on the clinical association of individual toxins with S. aureus infection as well as attempted treatment options. Further understanding of these associations will increase understanding of toxins and their importance to S. aureus pathogenesis.
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Affiliation(s)
- Monique R. Bennett
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA;
- Vanderbilt Vaccine Research Program, Nashville, TN 37232, USA
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Isaac P. Thomsen
- Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA;
- Vanderbilt Vaccine Research Program, Nashville, TN 37232, USA
- Vanderbilt Institute for Infection, Immunology and Inflammation, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Correspondence:
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