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Taki Y, Watanabe S, Sato'o Y, Tan XE, Ono HK, Kiga K, Aiba Y, Sasahara T, Azam AH, Thitiananpakorn K, Veeranarayanan S, Li FY, Zhang Y, Kawaguchi T, Hossain S, Maniruzzaman, Hu DL, Cui L. The Association Between Onset of Staphylococcal Non-menstrual Toxic Shock Syndrome With Inducibility of Toxic Shock Syndrome Toxin-1 Production. Front Microbiol 2022; 13:765317. [PMID: 35369432 PMCID: PMC8964310 DOI: 10.3389/fmicb.2022.765317] [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: 08/26/2021] [Accepted: 01/27/2022] [Indexed: 11/13/2022] Open
Abstract
Non-menstrual toxic shock syndrome (non-mTSS) is a life-threatening disease caused by Staphylococcus aureus strains producing superantigens, such as staphylococcal enterotoxins A, B, C, and toxic shock syndrome toxin-1 (TSST-1). However, little is known about why the TSS cases are rare, although S. aureus strains frequently carry a tst gene, which encodes TSST-1. To answer this question, the amount of TSST-1 produced by 541 clinical isolates was measured in both the presence and absence of serum supplementation to growth media. Then a set of S. aureus strains with similar genetic backgrounds isolated from patients presenting with non-mTSS and those with clinical manifestations other than non-mTSS was compared for their TSST-1 inducibility by human serum, and their whole-genome sequences were determined. Subsequently, the association of mutations identified in the tst promoter of non-mTSS strains with TSST-1 inducibility by human serum was evaluated by constructing promoter replacement mutants and green fluorescent protein (GFP) reporter recombinants. Results showed that 39 out of 541 clinical isolates (7.2%), including strains isolated from non-mTSS patients, had enhanced production of TSST-1 in the presence of serum. TSST-1 inducibility by human serum was more clearly seen in non-mTSS strains of clonal complex (CC)-5. Moreover, the whole-genome sequence analysis identified a set of sequence variations at a putative SarA-binding site of the tst promoter. This sequence variation was proven to be partially responsible for the induction of TSST-1 production by human serum. We conclude that the onset of staphylococcal toxic shock syndrome caused by TSST-1-producing CC-5 strains seem at least partially initiated by serum induction of TSST-1, which is regulated by the mutation of putative SarA-binding site at the tst promoter.
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Affiliation(s)
- Yusuke Taki
- Division of Bacteriology, Jichi Medical School, Tochigi, Japan.,Department of Gastroenterological Surgery, Shizuoka General Hospital, Shizuoka, Japan
| | - Shinya Watanabe
- Division of Bacteriology, Jichi Medical School, Tochigi, Japan
| | - Yusuke Sato'o
- Division of Bacteriology, Jichi Medical School, Tochigi, Japan
| | - Xin-Ee Tan
- Division of Bacteriology, Jichi Medical School, Tochigi, Japan
| | - Hisaya K Ono
- Department of Zoonoses, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Kotaro Kiga
- Division of Bacteriology, Jichi Medical School, Tochigi, Japan
| | - Yoshifumi Aiba
- Division of Bacteriology, Jichi Medical School, Tochigi, Japan
| | - Teppei Sasahara
- Division of Bacteriology, Jichi Medical School, Tochigi, Japan
| | | | | | | | - Feng-Yu Li
- Division of Bacteriology, Jichi Medical School, Tochigi, Japan
| | - Yuancheng Zhang
- Division of Bacteriology, Jichi Medical School, Tochigi, Japan
| | | | - Sarah Hossain
- Division of Bacteriology, Jichi Medical School, Tochigi, Japan
| | - Maniruzzaman
- Division of Bacteriology, Jichi Medical School, Tochigi, Japan
| | - Dong-Liang Hu
- Department of Zoonoses, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Longzhu Cui
- Division of Bacteriology, Jichi Medical School, Tochigi, Japan
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Identification and characterization of mutations responsible for the β-lactam resistance in oxacillin-susceptible mecA-positive Staphylococcus aureus. Sci Rep 2020; 10:16907. [PMID: 33037239 PMCID: PMC7547103 DOI: 10.1038/s41598-020-73796-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Accepted: 09/20/2020] [Indexed: 12/14/2022] Open
Abstract
Staphylococcus aureus strains that are susceptible to the β-lactam antibiotic oxacillin despite carrying mecA (OS-MRSA) cause serious clinical problems globally because of their ability to easily acquire β-lactam resistance. Understanding the genetic mechanism(s) of acquisition of the resistance is therefore crucial for infection control management. For this purpose, a whole-genome sequencing-based analysis was performed using 43 clinical OS-MRSA strains and 100 mutants with reduced susceptibility to oxacillin (MICs 1.0–256 µg/mL) generated from 26 representative OS-MRSA strains. Genome comparison between the mutants and their respective parent strains identified a total of 141 mutations in 46 genes and 8 intergenic regions. Among them, the mutations are frequently found in genes related to RNA polymerase (rpoBC), purine biosynthesis (guaA, prs, hprT), (p)ppGpp synthesis (relSau), glycolysis (pykA, fbaA, fruB), protein quality control (clpXP, ftsH), and tRNA synthase (lysS, gltX), whereas no mutations existed in mec and bla operons. Whole-genome transcriptional profile of the resistant mutants demonstrated that expression of genes associated with purine biosynthesis, protein quality control, and tRNA synthesis were significantly inhibited similar to the massive transcription downregulation seen in S. aureus during the stringent response, while the levels of mecA expression and PBP2a production were varied. We conclude that a combination effect of mecA upregulation and stringent-like response may play an important role in acquisition of β-lactam resistance in OS-MRSA.
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Thitiananpakorn K, Aiba Y, Tan XE, Watanabe S, Kiga K, Sato'o Y, Boonsiri T, Li FY, Sasahara T, Taki Y, Azam AH, Zhang Y, Cui L. Association of mprF mutations with cross-resistance to daptomycin and vancomycin in methicillin-resistant Staphylococcus aureus (MRSA). Sci Rep 2020; 10:16107. [PMID: 32999359 PMCID: PMC7527455 DOI: 10.1038/s41598-020-73108-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 08/24/2020] [Indexed: 12/11/2022] Open
Abstract
We first reported a phenomenon of cross-resistance to vancomycin (VCM) and daptomycin (DAP) in methicillin-resistant Staphylococcus aureus (MRSA) in 2006, but mechanisms underlying the cross-resistance remain incompletely understood. Here, we present a follow-up study aimed to investigate genetic determinants associated with the cross-resistance. Using 12 sets of paired DAP susceptible (DAPS) and DAP non-susceptible (DAPR) MRSA isolates from 12 patients who had DAP therapy, we (i) assessed susceptibility to DAP and VCM, (ii) compared whole-genome sequences, (iii) identified mutations associated with cross-resistance to DAP and VCM, and (iv) investigated the impact of altered gene expression and metabolic pathway relevant to the cross-resistance. We found that all 12 DAPR strains exhibiting cross-resistance to DAP and VCM carried mutations in mprF, while one DAPR strain with reduced susceptibility to only DAP carried a lacF mutation. On the other hand, among the 32 vancomycin-intermediate S. aureus (VISA) strains isolated from patients treated with VCM, five out of the 18 strains showing cross-resistance to DAP and VCM carried a mprF mutation, while 14 strains resistant to only VCM had no mprF mutation. Moreover, substitution of mprF in a DAPS strain with mutated mprF resulted in cross-resistance and vice versa. The elevated lysyl-phosphatidylglycerol (L-PG) production, increased positive bacterial surface charges and activated cell wall (CW) synthetic pathways were commonly found in both clinical isolates and laboratory-developed mutants that carry mprF mutations. We conclude that mprF mutation is responsible for the cross-resistance of MRSA to DAP and VCM, and treatment with DAP is more likely to select for mprF-mediated cross-resistance than is with VCM.
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Affiliation(s)
- Kanate Thitiananpakorn
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Yoshifumi Aiba
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Xin-Ee Tan
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Shinya Watanabe
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Kotaro Kiga
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Yusuke Sato'o
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Tanit Boonsiri
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Feng-Yu Li
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Teppei Sasahara
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Yusuke Taki
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Aa Haeruman Azam
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Yuancheng Zhang
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan
| | - Longzhu Cui
- Division of Bacteriology, Department of Infection and Immunity, Faculty of Medicine, Jichi Medical University, 3311-1, Yakushiji, Shimotsuke-shi, Tochigi, 329-0498, Japan.
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Leech JM, Dhariwala MO, Lowe MM, Chu K, Merana GR, Cornuot C, Weckel A, Ma JM, Leitner EG, Gonzalez JR, Vasquez KS, Diep BA, Scharschmidt TC. Toxin-Triggered Interleukin-1 Receptor Signaling Enables Early-Life Discrimination of Pathogenic versus Commensal Skin Bacteria. Cell Host Microbe 2019; 26:795-809.e5. [PMID: 31784259 DOI: 10.1016/j.chom.2019.10.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 08/27/2019] [Accepted: 10/09/2019] [Indexed: 12/12/2022]
Abstract
The host must develop tolerance to commensal microbes and protective responses to infectious pathogens, yet the mechanisms enabling a privileged relationship with commensals remain largely unknown. Skin colonization by commensal Staphylococcus epidermidis facilitates immune tolerance preferentially in neonates via induction of antigen-specific regulatory T cells (Tregs). Here, we demonstrate that this tolerance is not indiscriminately extended to all bacteria encountered in this early window. Rather, neonatal colonization by Staphylococcus aureus minimally enriches for antigen-specific Tregs and does not prevent skin inflammation upon later-life exposure. S. aureus α-toxin contributes to this response by stimulating myeloid cell production of IL-1β, which limits S. aureus-specific Tregs. Loss of α-toxin or the IL-1 receptor increases Treg enrichment, whereas topical application of IL-1β or α-toxin diminishes tolerogenic responses to S. epidermidis. Thus, the preferential activation of a key alarmin pathway facilitates early discrimination of microbial "foe" from "friend," thereby preventing tolerance to a common skin pathogen.
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Affiliation(s)
- John M Leech
- Department of Dermatology, University of California, San Francisco, San Francisco, CA, USA
| | - Miqdad O Dhariwala
- Department of Dermatology, University of California, San Francisco, San Francisco, CA, USA
| | - Margaret M Lowe
- Department of Dermatology, University of California, San Francisco, San Francisco, CA, USA
| | - Kevin Chu
- Department of Dermatology, University of California, San Francisco, San Francisco, CA, USA
| | - Geil R Merana
- Department of Dermatology, University of California, San Francisco, San Francisco, CA, USA
| | - Clémence Cornuot
- Department of Dermatology, University of California, San Francisco, San Francisco, CA, USA
| | - Antonin Weckel
- Department of Dermatology, University of California, San Francisco, San Francisco, CA, USA
| | - Jessica M Ma
- Department of Dermatology, University of California, San Francisco, San Francisco, CA, USA
| | - Elizabeth G Leitner
- Department of Dermatology, University of California, San Francisco, San Francisco, CA, USA
| | - Jeanmarie R Gonzalez
- Department of Dermatology, University of California, San Francisco, San Francisco, CA, USA
| | - Kimberly S Vasquez
- Department of Dermatology, University of California, San Francisco, San Francisco, CA, USA; Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA, USA
| | - Binh An Diep
- Division of HIV, Infectious Diseases and Global Medicine, Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Tiffany C Scharschmidt
- Department of Dermatology, University of California, San Francisco, San Francisco, CA, USA.
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Welker DL, Coburn BM, McClatchy JH, Broadbent JR. Multiple pulse electroporation of lactic acid bacteria Lactococcus lactis and Lactobacillus casei. J Microbiol Methods 2019; 166:105741. [PMID: 31634499 DOI: 10.1016/j.mimet.2019.105741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 10/11/2019] [Accepted: 10/11/2019] [Indexed: 11/18/2022]
Abstract
Genetic manipulation of lactic acid bacteria is often difficult due to the inability to transform them with high efficiency. Multi-pulse electroporation offers a simple approach to increase transformation efficiencies. Using cells grown with 1% glycine and pretreated with lithium acetate and dithiothreitol, multi-pulse electroporation (five pulses of 12.5 kV cm-1) of Lactococcus lactis JB704 cells resulted in a transformation efficiency of up to 1.2 × 106 colony forming units (CFU) μg-1 pGK13, an 8-fold increase in the transformation efficiency compared to single pulse electroporation. Other cell growth and pretreatment conditions with JB704 resulted in lower transformation efficiencies but had 4-fold to 27-fold higher transformation efficiencies with the five pulse electroporations. With similarly grown and pretreated Lactobacillus casei 32G cells, multi-pulse electroporation (five pulses of 7.5 kV cm-1) resulted in a mean transformation efficiency of 7.3 × 103 CFU μg-1 pTRKH2, a 4-fold increase in the transformation efficiency compared to single pulse electroporation.
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Affiliation(s)
- Dennis L Welker
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, United States.
| | - Bryan M Coburn
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, United States
| | - John H McClatchy
- Department of Biology, Utah State University, 5305 Old Main Hill, Logan, UT 84322-5305, United States
| | - Jeff R Broadbent
- Department of Nutrition, Dietetics and Food Science, Utah State University, 8700 Old Main Hill, Logan, UT 84322-8700, United States
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Abstract
Although the pan and the core genome of Acinetobacter baumannii and its essential genes are relatively well characterized, functional characterization of these genes has not paralleled the genome-level studies. However, recently developed genetic tools and optimized protocols are poised to accelerate genetic manipulation of A. baumannii. Transferring exogenous DNA into the cytosol of bacteria cells is a critical step in genetic characterizations. Conjugation is restricted to the transfer of DNA from one bacterial cell to another, and only a portion of A. baumannii clinical isolates are naturally competent. Electroporation, which is thought to transiently create aqueous pores in the membrane, is a preferred method in transferring exogenous DNA as it does not have such limitations. Several factors contribute to efficiency of electroporation and often need to be empirically optimized to maximize efficiency of this procedure. Here we provide an optimized electroporation protocol and guidance for electroporation of clinical MDR isolates of A. baumannii.
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Affiliation(s)
- Mitchell G Thompson
- Department of Plant and Microbial Biology, University of California Berkeley, Berkeley, CA, USA
| | - Süleyman Yildirim
- Department of Medical Microbiology, International School of Medicine, Istanbul Medipol University, Istanbul, Turkey.
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