26 results on '"Yifan, Rao"'
Search Results
2. Optimizing a high‐sensitivity NanoLuc‐based bioluminescence system for in vivo evaluation of antimicrobial treatment
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Weilong Shang, Zhen Hu, Mengyang Li, Yuting Wang, Yifan Rao, Li Tan, Juan Chen, Xiaonan Huang, Lu Liu, He Liu, Zuwen Guo, Huagang Peng, Yi Yang, Qiwen Hu, Shu Li, Xiaomei Hu, Jiao Zou, and Xiancai Rao
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antimicrobial evaluation ,bioluminescence imaging ,Nluc‐based luciferases ,Staphylococcus aureus ,therapeutic efficacy ,Microbiology ,QR1-502 - Abstract
Abstract Focal and systemic infections are serious threats to human health. Preclinical models enable the development of new drugs and therapeutic regimens. In vivo, animal bioluminescence (BL) imaging has been used with bacterial reporter strains to evaluate antimicrobial treatment effects. However, high‐sensitivity bioluminescent systems are required because of the limited tissue penetration and low brightness of the BL signals of existing approaches. Here, we report that NanoLuc (Nluc) showed better performance than LuxCDABE in bacteria. However, the retention rate of plasmid constructs in bacteria was low. To construct stable Staphylococcus aureus reporter strains, a partner protein enolase (Eno) was identified by screening of S. aureus strain USA300 for fusion expression of Nluc‐based luciferases, including Nluc, Teluc, and Antares2. Different substrates, such as hydrofurimazine (HFZ), furimazine (FUR), and diphenylterazine (DTZ), were used to optimize a stable reporter strain/substrate pair for BL imaging. S. aureus USA300/Eno‐Antares2/HFZ produced the highest number of photons of orange‐red light in vitro and enabled sensitive BL tracking of S. aureus in vivo, with sensitivities of approximately 10 CFU from mouse skin and 750 CFU from mouse kidneys. USA300/Eno‐Antares2/HFZ was a powerful combination based on the longitudinal evaluation of the therapeutic efficacy of antibiotics. The optimized S. aureus Eno‐Antares2/HFZ pair provides a technological advancement for the in vivo evaluation of antimicrobial treatment.
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- 2023
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3. Graphene e-tattoos for unobstructive ambulatory electrodermal activity sensing on the palm enabled by heterogeneous serpentine ribbons
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Hongwoo Jang, Kaan Sel, Eunbin Kim, Sangjun Kim, Xiangxing Yang, Seungmin Kang, Kyoung-Ho Ha, Rebecca Wang, Yifan Rao, Roozbeh Jafari, and Nanshu Lu
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Science - Abstract
Designing efficient sensing devices for ambulatory use remains a challenge. Here, the authors demonstrate heterogeneous serpentine ribbons enable a stretchable and robust interface between sub-micron thin graphene e-tattoos and thick and rigid printed circuit boards, which allows ambulatory electrodermal activity monitoring on the palm.
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- 2022
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4. A vancomycin resistance-associated WalK(S221P) mutation attenuates the virulence of vancomycin-intermediate Staphylococcus aureus
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Yifan Rao, Huagang Peng, Weilong Shang, Zhen Hu, Yi Yang, Li Tan, Ming Li, Renjie Zhou, and Xiancai Rao
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Staphylococcus aureus ,Vancomycin resistance ,WalKR ,WalK(S221P) ,Virulence ,Agr system ,Medicine (General) ,R5-920 ,Science (General) ,Q1-390 - Abstract
Introduction: Vancomycin-intermediate Staphylococcus aureus (VISA) is typically associated with a decline in virulence. We previously reported a WalK(S221P) mutation that plays an important role in mediating vancomycin resistance in VISA XN108. Whether this mutation is implicated in bacterial virulence remains unknown. Objectives: This study aimed to investigate the effect of WalK(S221P) mutation on the virulence of VISA and the underlying mechanism of this effect. Methods: The influence of WalK(S221P) mutation on VISA virulence and its underlying mechanism were explored using animal models, RNA-seq analysis, RT-qPCR, hemolytic assay, slide coagulase test, Western blot, β-galactosidase assay, and electrophoresis mobility shift assay (EMSA). Results: Compared with XN108, WalK(S221P)-reverted strain XN108-R exacerbated cutaneous infections with increased lesion size and extensive inflammatory infiltration in mouse models. The bacterial loads of S. aureus XN108-R in murine kidney increased compared with those of XN108. RNA-seq analysis showed upregulation of a set of virulence genes in XN108-R, which exhibited greater hemolytic and stronger coagulase activities compared with XN108. Introduction of WalK(S221P) to methicillin-resistant S. aureus USA300 and methicillin-susceptible strain Newman increased the vancomycin resistance of the mutants, which exhibited reduced hemolytic activities and decreased expression levels of many virulence factors compared with their progenitors. WalK(S221P) mutation weakened agr promoter-controlled β-galactosidase activity. EMSA results showed that WalK-phosphorylated WalR could directly bind to the agr promoter region, whereas WalK(S221P)-activated WalR reduced binding to the target promoter. Inactivation of agr in S. aureus did not affect their vancomycin susceptibility but mitigated the virulence alterations caused by WalK(S221P) mutation. Conclusion: The results of our study indicate that WalK(S221P) mutation can enhance vancomycin resistance in S. aureus of diverse genetic backgrounds. WalK(S221P)- bearing S. aureus strains exhibit reduced virulence. WalK(S221P) mutation may directly impair the activation of the agr system by WalR, thereby decreasing the expression of virulence factors in VISA.
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- 2022
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5. Pyocyanin biosynthesis protects Pseudomonas aeruginosa from nonthermal plasma inactivation
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Huyue Zhou, Yi Yang, Weilong Shang, Yifan Rao, Juan Chen, Huagang Peng, Jingbin Huang, Zhen Hu, Rong Zhang, and Xiancai Rao
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Biotechnology ,TP248.13-248.65 - Abstract
Summary Pseudomonas aeruginosa is an important opportunistic human pathogen, which raises a worldwide concern for its increasing resistance. Nonthermal plasma, which is also called cold atmospheric plasma (CAP), is an alternative therapeutic approach for clinical infectious diseases. However, the bacterial factors that affect CAP treatment remain unclear. The sterilization effect of a portable CAP device on different P. aeruginosa strains was investigated in this study. Results revealed that CAP can directly or indirectly kill P. aeruginosa in a time‐dependent manner. Scanning electron microscopy and transmission electron microscope showed negligible surface changes between CAP‐treated and untreated P. aeruginosa cells. However, cell leakage occurred during the CAP process with increased bacterial lactate dehydrogenase release. More importantly, pigmentation of the P. aeruginosa culture was remarkably reduced after CAP treatment. Further mechanical exploration was performed by utilizing mutants with loss of functional genes involved in pyocyanin biosynthesis, including P. aeruginosa PAO1 strain‐derived phzA1::Tn, phzA2::Tn, ΔphzA1/ΔphzA2, phzM::Tn and phzS::Tn, as well as corresponding gene deletion mutants based on clinical PA1 isolate. The results indicated that pyocyanin and its intermediate 5‐methyl phenazine‐1‐carboxylic acid (5‐Me‐PCA) play important roles in P. aeruginosa resistance to CAP treatment. The unique enzymes, such as PhzM in the pyocyanin biosynthetic pathway, could be novel targets for the therapeutic strategy design to control the growing P. aeruginosa infections.
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- 2022
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6. Hcp1-loaded staphylococcal membrane vesicle vaccine protects against acute melioidosis
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Keting Zhu, Gang Li, Jia Li, Mingxia Zheng, Xiaohui Peng, Yifan Rao, Ming Li, Renjie Zhou, and Xiancai Rao
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Burkholderia pseudomallei ,vaccine ,membrane vesicles ,Hcp1 ,melioidosis ,protection ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Burkholderia pseudomallei is the causal agent of melioidosis, a deadly tropical infectious disease that lacks a vaccine. On the basis of the attenuated Staphylococcus aureus RN4220-Δagr (RN), we engineered the RN4220-Δagr/pdhB-hcp1 strain (RN-Hcp1) to generate B. pseudomallei hemolysin-coregulated protein 1 (Hcp1)-loaded membrane vesicles (hcp1MVs). The immunization of BALB/c mice with hcp1MVs mixed with adjuvant by a three-dose regimen increased the serum specific IgG production. The serum levels of inflammatory factors, including TNF-α and IL-6, in hcp1MV-vaccinated mice were comparable with those in PBS-challenged mice. The partial adjuvant effect of staphylococcal MVs was observed with the elevation of specific antibody titer in hcp1MV-vaccinated mice relative to those that received the recombinant Hcp1 protein (rHcp1) or MVs derived from RN strain (ΔagrMVs). The hcp1MVs/adjuvant vaccine protected 70% of mice from lethal B. pseudomallei challenge. Immunization with hcp1MVs only protected 60% of mice, whereas vaccination with rHcp1 or ΔagrMVs conferred no protection. Moreover, mice that received hcp1MVs/adjuvant and hcp1MVs immunization had low serum TNF-α and IL-6 levels and no inflammatory infiltration in comparison with other groups. In addition, all surviving mice in hcp1MVs/adjuvant and hcp1MVs groups exhibited no culturable bacteria in their lungs, livers, and spleens five days postinfection. Overall, our data highlighted a new strategy for developing B. pseudomallei vaccine and showed that Hcp1-incorporated staphylococcal MV is a promising candidate for the prevention of acute melioidosis.
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- 2022
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7. Accessory Gene Regulator (agr) Allelic Variants in Cognate Staphylococcus aureus Strain Display Similar Phenotypes
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Li Tan, Yuyang Huang, Weilong Shang, Yi Yang, Huagang Peng, Zhen Hu, Yuting Wang, Yifan Rao, Qiwen Hu, Xiancai Rao, Xiaomei Hu, Ming Li, Kaisen Chen, and Shu Li
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Staphylococcus aureus ,quorum sensing system ,accessory gene regulator (agr) alleles ,agr polymorphisms ,virulence factors ,Microbiology ,QR1-502 - Abstract
The accessory gene regulator (agr) quorum-sensing system is an important global regulatory system of Staphylococcus aureus and contributes to its pathogenicity. The S. aureus agr system is divided into four agr groups based on the amino acid polymorphisms of AgrB, AgrD, and AgrC. The agr activation is group-specific, resulting in variations in agr activity and pathogenicity among the four agr groups. Strains with divergent agr system always have different phenotypes. In the present report, we, respectively, exchanged the agr system of a certain S. aureus with other three agr alleles and assessed the corresponding phenotypes of these congenic strains. Replacement of the agr system led to significant variations in hemolytic activity, protein expression, and virulence gene expression comparing with that of the parental strain. Interestingly, we found that the biological characteristics of these agr congenic strains in the same strain background were highly similar to each other, and the allele-dependent differences of the agr systems were weakened. These findings indicate that the allele-dependent agr predilections of S. aureus are determined by some factors in addition to the polymorphisms of AgrB, AgrD, and AgrC. Future studies may reveal the novel mechanism to improve our understanding of the agr network.
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- 2022
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8. Fighting Mixed-Species Microbial Biofilms With Cold Atmospheric Plasma
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Yifan Rao, Weilong Shang, Yi Yang, Renjie Zhou, and Xiancai Rao
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mixed-species biofilms ,cold atmospheric plasma ,biofilm resistance ,biofilm infection ,biofilm eradication ,Microbiology ,QR1-502 - Abstract
Most biofilms in nature are formed by multiple microbial species, and such mixed-species biofilms represent the actual lifestyles of microbes, including bacteria, fungi, viruses (phages), and/or protozoa. Microorganisms cooperate and compete in mixed-species biofilms. Mixed-species biofilm formation and environmental resistance are major threats to water supply, food industry, and human health. The methods commonly used for microbial eradication, such as antibiotic or disinfectant treatments, are often ineffective for mixed-species biofilm consortia due to their physical matrix barrier and physiological interactions. For the last decade, an increasing number of investigations have been devoted to the usage of cold atmospheric plasma (CAP), which is produced by dielectric barrier discharges or plasma jets to prevent or eliminate microbial biofilms. Here, we summarized the production of CAP, the inactivation of microorganisms upon CAP treatment, and the microbial factors affecting the efficacy of CAP procedure. The applications of CAP as antibiotic alternative strategies for fighting mixed-species biofilms were also addressed.
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- 2020
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9. Conformability of flexible sheets on spherical surfaces
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Siyi Liu, Jinlong He, Yifan Rao, Zhaohe Dai, Huilin Ye, John C. Tanir, Ying Li, and Nanshu Lu
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Multidisciplinary - Abstract
Three-dimensional surface-conformable electronics is a burgeoning technology with potential applications in curved displays, bioelectronics, and biomimetics. Flexible electronics are notoriously difficult to fully conform to nondevelopable surfaces such as spheres. Although stretchable electronics can well conform to nondevelopable surfaces, they need to sacrifice pixel density for stretchability. Various empirical designs have been explored to improve the conformability of flexible electronics on spherical surfaces. However, no rational design guidelines exist. This study uses a combination of experimental, analytical, and numerical approaches to systematically investigate the conformability of both intact and partially cut circular sheets on spherical surfaces. Through the analysis of thin film buckling on curved surfaces, we identify a scaling law that predicts the conformability of flexible sheets on spherical surfaces. We also quantify the effects of radial slits on enhancing conformability and provide a practical guideline for using these slits to improve conformability from 40% to more than 90%.
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- 2023
10. Strategies for body-conformable electronics
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Siyi Liu, Yifan Rao, Hongwoo Jang, Philip Tan, and Nanshu Lu
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General Materials Science - Published
- 2022
11. β-Lactam Antibiotics Enhance the Pathogenicity of Methicillin-Resistant Staphylococcus aureus via SarA-Controlled Lipoprotein-Like Cluster Expression
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Weilong Shang, Yifan Rao, Ying Zheng, Yi Yang, Qiwen Hu, Zhen Hu, Jizhen Yuan, Huagang Peng, Kun Xiong, Li Tan, Shu Li, Junmin Zhu, Ming Li, Xiaomei Hu, Xuhu Mao, and Xiancai Rao
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β-lactam antibiotics ,methicillin-resistant Staphylococcus aureus ,SarA ,TLR2 ,lipoprotein-like genes ,pathogenicity ,Microbiology ,QR1-502 - Abstract
ABSTRACT Methicillin-resistant Staphylococcus aureus (MRSA) resists nearly all β-lactam antibiotics that have a bactericidal activity. However, whether the empirically used β-lactams enhance MRSA pathogenicity in vivo remains unclear. In this study, we showed that a cluster of lipoprotein-like genes (lpl, sa2275 to sa2273 [sa2275–sa2273]) was upregulated in MRSA in response to subinhibitory concentrations of β-lactam induction. The increasing expression of lpl by β-lactams was directly controlled by the global regulator SarA. The β-lactam-induced Lpls stimulated the production of interleukin-6 and tumor necrosis factor alpha in RAW 264.7 macrophages. The lpl deletion mutants (N315Δlpl and USA300Δlpl) decreased the proinflammatory cytokine levels in vitro and in vivo. Purified lipidated SA2275-his proteins could trigger a Toll-like-receptor-2 (TLR2)-dependent immune response in primary mouse bone marrow-derived macrophages and C57BL/6 mice. The bacterial loads of N315Δlpl in the mouse kidney were lower than those of the wild-type N315. The β-lactam-treated MRSA exacerbated cutaneous infections in both BALB/c and C57BL/6 mice, presenting increased lesion size; destroyed skin structure; and easily promoted abscess formation compared with those of the untreated MRSA. However, the size of abscesses caused by the β-lactam-treated N315 was negligibly different from those caused by the untreated N315Δlpl in C57BL/6 TLR2−/− mice. Our findings suggest that β-lactams must be used carefully because they might aggravate the outcome of MRSA infection compared to inaction in treatment. IMPORTANCE β-Lactam antibiotics are widely applied to treat infectious diseases. However, certain poor disease outcomes caused by β-lactams remain poorly understood. In this study, we have identified a cluster of lipoprotein-like genes (lpl, sa2275–sa2273) that is upregulated in the major clinically prevalent MRSA clones in response to subinhibitory concentrations of β-lactam induction. The major highlight of this work is that β-lactams stimulate the expression of SarA, which directly binds to the lpl cluster promoter region and upregulates lpl expression in MRSA. Deletion of lpl significantly decreases proinflammatory cytokine levels in vitro and in vivo. The β-lactam-induced Lpls enhance host inflammatory responses by triggering the Toll-like-receptor-2-mediated expressions of interleukin-6 and tumor necrosis factor alpha. The β-lactam-induced Lpls are important virulence factors that enhance MRSA pathogenicity. These data elucidate that subinhibitory concentrations of β-lactams can exacerbate the outcomes of MRSA infection through induction of lpl controlled by the global regulator SarA.
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- 2019
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12. Virulence Determinants Are Required for Brain Abscess Formation Through Staphylococcus aureus Infection and Are Potential Targets of Antivirulence Factor Therapy
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Ying Zheng, Weilong Shang, Huagang Peng, Yifan Rao, Xia Zhao, Zhen Hu, Yi Yang, Qiwen Hu, Li Tan, Kun Xiong, Shu Li, Junmin Zhu, Xiaomei Hu, Renjie Zhou, Ming Li, and Xiancai Rao
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Staphylococcus aureus ,virulence determinant ,brain abscess ,ear colonization ,bacteremia ,antivirulence factor therapy ,Microbiology ,QR1-502 - Abstract
Bacterial brain abscesses (BAs) are difficult to treat with conventional antibiotics. Thus, the development of alternative therapeutic strategies for BAs is of high priority. Identifying the virulence determinants that contribute to BA formation induced by Staphylococcus aureus would improve the effectiveness of interventions for this disease. In this study, RT-qPCR was performed to compare the expression levels of 42 putative virulence determinants of S. aureus strains Newman and XQ during murine BA formation, ear colonization, and bacteremia. The alterations in the expression levels of 23 genes were further confirmed through specific TaqMan RT-qPCR. Eleven S. aureus genes that persistently upregulated expression levels during BA infection were identified, and their functions in BA formation were confirmed through isogenic mutant experiments. Bacterial loads and BA volumes in mice infected with isdA, isdC, lgt, hla, or spa deletion mutants and the hla/spa double mutant strain were lower than those in mice infected with the wild-type Newman strain. The therapeutic application of monoclonal antibodies against Hla and SpA decreased bacterial loads and BA volume in mice infected with Newman. This study provides insights into the virulence determinants that contribute to staphylococcal BA formation and a paradigm for antivirulence factor therapy against S. aureus infections.
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- 2019
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13. Reconstruction of the Vancomycin-Susceptible Staphylococcus aureus Phenotype From a Vancomycin-Intermediate S. aureus XN108
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Huagang Peng, Yifan Rao, Wenchang Yuan, Ying Zheng, Weilong Shang, Zhen Hu, Yi Yang, Li Tan, Kun Xiong, Shu Li, Junmin Zhu, Xiaomei Hu, Qiwen Hu, and Xiancai Rao
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Vancomycin-intermediate Staphylococcus aureus ,vancomycin resistance ,WalKR ,GraSR ,RpoB ,Microbiology ,QR1-502 - Abstract
The emergence of vancomycin-intermediate Staphylococcus aureus (VISA) has raised healthcare concerns worldwide. VISA is often associated with multiple genetic changes. However, the relative contributions of these changes to VISA phenotypes are incompletely defined. We have characterized VISA XN108 with vancomycin MIC of 12 μg/ml. Genome comparison revealed that WalK(S221P), GraS(T136I), and RpoB(H481N) mutations possibly contributed to the VISA phenotype of XN108. In this study, the above mutations were stepwise cured, and the phenotypes between XN108 and its derivates were compared. We constructed four isogenic mutant strains, XN108-WalK(P221S) (termed as K65), XN108-GraS(I136T) (termed as S65), XN108-RpoB(N481H) (termed as B65), and XN108-WalK(P221S)/GraS(I136T) (termed as KS65), using the allelic replacement experiments with the native alleles derived from a vancomycin-susceptible S. aureus isolate DP65. Antimicrobial susceptibility test revealed K65 and S65 exhibited decreased vancomycin resistance, whereas B65 revealed negligibly differed when compared with the wild-type XN108. Sequentially introducing WalK(P221S) and GraS(I136T) completely converted XN108 into a VSSA phenotype. Transmission electronic microscopy and autolysis determination demonstrated that cell wall thickening and decreasing autolysis were associated with the change of vancomycin resistance levels. Compared with XN108, K65 exhibited 577 differentially expressed genes (DEGs), whereas KS65 presented 555 DEGs. Of those DEGs, 390 were common in K65 and KS65, including those upregulated genes responsible for citrate cycle and bacterial autolysis, and the downregulated genes involved in peptidoglycan biosynthesis and teichoic acid modification. In conclusion, a VSSA phenotype could be completely reconstituted from a VISA strain XN108. WalK(S221P) and GraS(T136I) mutations may work synergistically in conferring vancomycin resistance in XN108.
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- 2018
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14. A vancomycin resistance-associated WalK(S221P) mutation attenuates the virulence of vancomycin-intermediate Staphylococcus aureus
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Li Tan, Weilong Shang, Zhen Hu, Renjie Zhou, Xiancai Rao, Ming Li, Yifan Rao, Huagang Peng, and Yi Yang
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Coagulase ,Methicillin-Resistant Staphylococcus aureus ,Staphylococcus aureus ,Virulence Factors ,Mutant ,Virulence ,Microbial Sensitivity Tests ,Biology ,medicine.disease_cause ,Microbiology ,Mice ,Bacterial Proteins ,medicine ,Animals ,Electrophoretic mobility shift assay ,Mutation ,Multidisciplinary ,Promoter ,Vancomycin Resistance ,beta-Galactosidase ,Anti-Bacterial Agents ,Vancomycin-Resistant Staphylococcus aureus ,Vancomycin ,medicine.drug - Abstract
Introduction Vancomycin-intermediate Staphylococcus aureus (VISA) is typically associated with a decline in virulence. We previously reported a WalK(S221P) mutation that plays an important role in mediating vancomycin resistance in VISA XN108. Whether this mutation is implicated in bacterial virulence remains unknown. Objectives This study aimed to investigate the effect of WalK(S221P) mutation on the virulence of VISA and the underlying mechanism of this effect. Methods The influence of WalK(S221P) mutation on VISA virulence and its underlying mechanism were explored using animal models, RNA-seq analysis, RT-qPCR, hemolytic assay, slide coagulase test, Western blot, β-galactosidase assay, and electrophoresis mobility shift assay (EMSA). Results Compared with XN108, WalK(S221P)-reverted strain XN108-R exacerbated cutaneous infections with increased lesion size and extensive inflammatory infiltration in mouse models. The bacterial loads of S. aureus XN108-R in murine kidney increased compared with those of XN108. RNA-seq analysis showed upregulation of a set of virulence genes in XN108-R, which exhibited greater hemolytic and stronger coagulase activities compared with XN108. Introduction of WalK(S221P) to methicillin-resistant S. aureus USA300 and methicillin-susceptible strain Newman increased the vancomycin resistance of the mutants, which exhibited reduced hemolytic activities and decreased expression levels of many virulence factors compared with their progenitors. WalK(S221P) mutation weakened agr promoter-controlled β-galactosidase activity. EMSA results showed that WalK-phosphorylated WalR could directly bind to the agr promoter region, whereas WalK(S221P)-activated WalR reduced binding to the target promoter. Inactivation of agr in S. aureus did not affect their vancomycin susceptibility but mitigated the virulence alterations caused by WalK(S221P) mutation. Conclusion The results of our study indicate that WalK(S221P) mutation can enhance vancomycin resistance in S. aureus of diverse genetic backgrounds. WalK(S221P)- bearing S. aureus strains exhibit reduced virulence. WalK(S221P) mutation may directly impair the activation of the agr system by WalR, thereby decreasing the expression of virulence factors in VISA.
- Published
- 2021
15. Laser In-Situ synthesis of metallic cobalt decorated porous graphene for flexible In-Plane microsupercapacitors
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Xianping Chen, Yifan Rao, Min Yuan, Feng Luo, Jiabing Yu, and Hui Li
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Nanocomposite ,Materials science ,Graphene ,chemistry.chemical_element ,Nanoparticle ,Electrolyte ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,law.invention ,Biomaterials ,Colloid and Surface Chemistry ,Transition metal ,Chemical engineering ,chemistry ,law ,Electrode ,Cobalt ,Polyimide - Abstract
Transition metal nanoparticles-graphene nanocomposites incorporate the advantages of graphene and metal nanoparticles, which arouse extensive attention. Here, we design a novel, facile and versatile method for in-situ synthesis of laser-induced porous graphene (LIG) decorated with cobalt particles (Co). The LIG/Co nanocomposites are fabricated through one-step laser direct scribing on a customized film composed of polyimide (PI) powder, polyvinyl alcohol (PVA), and cobalt chloride (CoCl2·6H2O) precursors. Benefiting from the unique properties of Co nanoparticles embedded LIG, the obtained optimal in-plane micro-supercapacitors (IMSC) based on LIG/Co-1.5 possesses an excellent areal capacitance of 110.11 mF cm-2 and a superior energy density of 9.79 μWh cm-2, which are about 79 times that of pure LIG-based IMSCs. Simultaneously, the LIG/Co-1.5 MSCs also present good cycling stability, remarkable modular integration capability, and outstanding mechanical flexibility, showing potential for practical applications. Additionally, the density functional theory (DFT) calculations indicate that the decorating of cobalt particles elevates electron transfer. Moreover, the interaction between electrolyte and electrodes is also improved with the introduction of cobalt particles. Therefore, this strategy offers a new avenue for facile and large-scale manufacturing of various metallic atoms in-situ decorating in porous graphene.
- Published
- 2021
16. Two-dimensional crystals on adhesive substrates subjected to uniform transverse pressure
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Zhaohe Dai, Yifan Rao, and Nanshu Lu
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Physics::Fluid Dynamics ,Mechanics of Materials ,Applied Mathematics ,Mechanical Engineering ,Modeling and Simulation ,Soft Condensed Matter (cond-mat.soft) ,FOS: Physical sciences ,General Materials Science ,Condensed Matter - Soft Condensed Matter ,Condensed Matter Physics - Abstract
In this work we consider bubbles that can form spontaneously when a two-dimensional (2D) crystal is transferred to a substrate with gases or liquids trapped at the crystal-substrate interface. The underlying mechanics may be described by a thin sheet on an adhesive substrate with the trapped fluid applying uniform transverse pressure. What makes this apparently simple problem complex is the rich interplay among geometry, interface, elasticity and instability. Particularly, extensive small-scale experiments have shown that the 2D crystal surrounding a bubble can adhere to and, meanwhile, slide on the substrate. The radially inward sliding causes hoop compression to the 2D crystal which may exploit wrinkling instabilities to relax or partially relax the compression. We present a theoretical model to understand the complex behaviors of even a linearly elastic 2D crystal due to the combination of nonlinear geometry, adhesion, sliding, and wrinkling in bubble systems. We show that this understanding not only successfully predicts the geometry of a spontaneous bubble but also reveals the strain-coupled physics of 2D crystals, e.g., the pseudomagnetic fields in graphene bubbles.
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- 2022
17. Staphylococcus aureus small-colony variants: Formation, infection, and treatment
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Shengzhe, Zhou, Yifan, Rao, Jia, Li, Qiaoyi, Huang, and Xiancai, Rao
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Staphylococcus aureus ,Virulence Factors ,Mutation ,Humans ,Staphylococcal Infections ,Microbiology - Abstract
Staphylococcus aureus (Sau) plays an important role in human infections occurring in both the community and hospital settings. Sau-related chronic and relapsing infections are mainly attributed to small-colony variants (SCVs), a type of subpopulation that has a size one-tenth that of normal colonies and is accompanied by several unique characteristics, including a lack of or reduced pigmentation, decreased hemolytic activity, increased biofilm formation, enhanced resistance to antimicrobials, upregulated genes encoding adhesion molecules, and downregulated genes for virulence factors. This review summarizes the significance of genetic mutations involved in diverse biosynthesis pathways that contribute to Sau-SCV promotion. Sau-SCV-caused persistent infections and the prospects and challenges faced in the treatment of Sau-SCV infections are addressed. Progress in the management of Sau-SCVs may provide guidance for addressing the long-term and recurrent infections caused by other bacterial SCVs.
- Published
- 2022
18. Accessory Gene Regulator (
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Li, Tan, Yuyang, Huang, Weilong, Shang, Yi, Yang, Huagang, Peng, Zhen, Hu, Yuting, Wang, Yifan, Rao, Qiwen, Hu, Xiancai, Rao, Xiaomei, Hu, Ming, Li, Kaisen, Chen, and Shu, Li
- Abstract
The accessory gene regulator (
- Published
- 2021
19. Fighting Mixed-Species Microbial Biofilms With Cold Atmospheric Plasma
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Renjie Zhou, Xiancai Rao, Yifan Rao, Yi Yang, and Weilong Shang
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Microbiology (medical) ,Disinfectant ,Microorganism ,lcsh:QR1-502 ,Review ,cold atmospheric plasma ,biofilm infection ,Microbiology ,biofilm eradication ,lcsh:Microbiology ,03 medical and health sciences ,Human health ,Mixed species ,030304 developmental biology ,Microbial Biofilms ,0303 health sciences ,biology ,030306 microbiology ,Chemistry ,Biofilm ,biochemical phenomena, metabolism, and nutrition ,biology.organism_classification ,biofilm resistance ,Environmental resistance ,mixed-species biofilms ,Bacteria - Abstract
Most biofilms in nature are formed by multiple microbial species, and such mixed-species biofilms represent the actual lifestyles of microbes, including bacteria, fungi, viruses (phages), and/or protozoa. Microorganisms cooperate and compete in mixed-species biofilms. Mixed-species biofilm formation and environmental resistance are major threats to water supply, food industry, and human health. The methods commonly used for microbial eradication, such as antibiotic or disinfectant treatments, are often ineffective for mixed-species biofilm consortia due to their physical matrix barrier and physiological interactions. For the last decade, an increasing number of investigations have been devoted to the usage of cold atmospheric plasma (CAP), which is produced by dielectric barrier discharges or plasma jets to prevent or eliminate microbial biofilms. Here, we summarized the production of CAP, the inactivation of microorganisms upon CAP treatment, and the microbial factors affecting the efficacy of CAP procedure. The applications of CAP as antibiotic alternative strategies for fighting mixed-species biofilms were also addressed.
- Published
- 2020
20. Laser synthesis of superhydrophilic O/S co-doped porous graphene derived from sodium lignosulfonate for enhanced microsupercapacitors
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Feng Luo, Xianping Chen, Ying Wang, Min Yuan, Hui Li, Yifan Rao, and Jiabing Yu
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Supercapacitor ,Materials science ,Renewable Energy, Sustainability and the Environment ,Graphene ,Sodium lignosulfonate ,Energy Engineering and Power Technology ,Nanotechnology ,Electrolyte ,Capacitance ,Pseudocapacitance ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,Superhydrophilicity ,Electrode ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry - Abstract
Porous graphene with rational heteroatoms doping has been widely researched as one of the most prominent materials for application in supercapacitors. Herein, we implement a green and facile laser engraving strategy to synthesize three-dimensional (3D) superhydrophilic and oxygen (O)-sulfur (S) co-doped porous graphene electrodes. Specifically, the mixed sodium lignosulfonate slurry is evenly coated on the laser-induced graphene (LIG) interdigital electrodes, and followed by a duplicated laser scribing process. The as-prepared materials can synchronously possess hierarchical porous graphene architectures, superior hydrophilicity, and O/S co-doped chemistry properties, which can significantly promote the penetration and transport of electrolyte ions and provide extra pseudocapacitance. Benefiting from these advantages, satisfactory capacitive performance of the assembled MSCs is obtained, such as an outstanding areal capacitance of 53.2 mF cm−2@0.08 mA cm−2, which is about 39 times larger than of undoped MSC. Moreover, remarkable mechanical flexibility, excellent modular integration capability as well as good cycling stability (81.3% capacitance retention after 8000 cycles) have been also achieved. As such, this study offers a novel and efficient strategy for valuable utilization of biomass lignosulfonate, and the as-prepared heteroatom-doped superhydrophilic porous graphene holds enormous promise for high-performance energy storage devices.
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- 2021
21. Protective Effect of the Golden Staphyloxanthin Biosynthesis Pathway on Staphylococcus aureus under Cold Atmospheric Plasma Treatment
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Hao Wang, Huagang Peng, Yang Yi, Haiyun Luo, Rong Zhang, Yifan Rao, Qiwen Hu, Weilong Shang, Ying Zheng, Zhen Hu, Xiancai Rao, and Huyue Zhou
- Subjects
Staphylococcus aureus ,Time Factors ,Plasma Gases ,Physiology ,Xanthophylls ,medicine.disease_cause ,Applied Microbiology and Biotechnology ,Tryptic soy broth ,Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,Antibiotic resistance ,Biosynthesis ,medicine ,Pathogen ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,Microbial Viability ,Ecology ,biology ,030306 microbiology ,Chemistry ,Staphyloxanthin ,biology.organism_classification ,Anti-Bacterial Agents ,Biosynthetic Pathways ,Enzyme ,Bacteria ,Food Science ,Biotechnology - Abstract
Staphylococcus aureus infection poses a serious threat to public health, and antibiotic resistance has complicated the clinical treatment and limited the solutions available to solve this problem. Cold atmospheric plasma (CAP) is a promising strategy for microorganism inactivation. However, the mechanisms of microbial inactivation or resistance remain unclear. In this study, we treated S. aureus strains with a self-assembled CAP device and found that CAP can kill S. aureus in an exposure time-dependent manner. In addition, the liquid environment can influence the survival rate of S. aureus post-CAP treatment. The S. aureus cells can be completely inactivated in normal saline and phosphate-buffered saline but not in tryptic soy broth culture medium. Scanning and transmission electron microscopy revealed that the CAP-treated S. aureus cells maintained integrated morphological structures, similar to the wild-type strain. Importantly, the CAP-treated S. aureus cells exhibited a reduced pigment phenotype. Deletion of the staphyloxanthin biosynthetic genes crtM and crtN deprived the pigmentation ability of S. aureus Newman. Both the Newman-ΔcrtM and Newman-ΔcrtN mutants presented high sensitivity to CAP treatment, whereas Newman-ΔcrtO exhibited a survival rate comparable to wild-type Newman after CAP treatment. Our data demonstrated that the yellow pigment intermediates of the staphyloxanthin biosynthetic pathway are responsible for the protection of S. aureus from CAP inactivation. The key enzymes, such as CrtM and CrtN, of the golden staphyloxanthin biosynthetic pathway could be important targets for the design of novel sterilization strategies against S. aureus infections. IMPORTANCE Staphylococcus aureus is an important pathogen that can be widely distributed in the community and clinical settings. The emergence of S. aureus with multiple-antibiotic resistance has complicated staphylococcal infection control. The development of alternative strategies with powerful bactericidal effects is urgently needed. Cold atmospheric plasma (CAP) is a promising strategy for microorganism inactivation. Nevertheless, the underlying mechanisms of microbial inactivation or resistance are not completely illustrated. In this study, we validated the bactericidal effects of CAP on S. aureus, including antibiotic-resistant strains. We also found that the golden staphyloxanthin, as well as its yellow pigment intermediates, protected S. aureus against CAP, and blocking the staphyloxanthin synthesis pathway at the early steps could strengthen the sensitivity of S. aureus to CAP treatment. These data provide insights into the germicidal mechanism of CAP from the aspect of bacteria and suggest new targets against S. aureus infections.
- Published
- 2019
22. β-Lactam Antibiotics Enhance the Pathogenicity of Methicillin-Resistant <named-content content-type='genus-species'>Staphylococcus aureus</named-content> via SarA-Controlled Lipoprotein-Like Cluster Expression
- Author
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Ying Zheng, Junmin Zhu, Huagang Peng, Weilong Shang, Ming Li, Kun Xiong, Qiwen Hu, Li Tan, Yifan Rao, Shu Li, Zhen Hu, Jizhen Yuan, Xuhu Mao, Xiancai Rao, Xiaomei Hu, and Yi Yang
- Subjects
medicine.drug_class ,Lipoproteins ,Antibiotics ,Microbial Sensitivity Tests ,Biology ,methicillin-resistant Staphylococcus aureus ,medicine.disease_cause ,beta-Lactams ,Microbiology ,Proinflammatory cytokine ,Host-Microbe Biology ,lipoprotein-like genes ,Mice ,Immune system ,Bacterial Proteins ,In vivo ,Virology ,β-lactam antibiotics ,medicine ,polycyclic compounds ,Animals ,TLR2 ,pathogenicity ,Mice, Knockout ,Mice, Inbred BALB C ,Virulence ,biochemical phenomena, metabolism, and nutrition ,Methicillin-resistant Staphylococcus aureus ,Toll-Like Receptor 2 ,QR1-502 ,Anti-Bacterial Agents ,Up-Regulation ,Mice, Inbred C57BL ,Staphylococcus aureus ,Multigene Family ,Trans-Activators ,Tumor necrosis factor alpha ,Female ,Research Article ,SarA - Abstract
β-Lactam antibiotics are widely applied to treat infectious diseases. However, certain poor disease outcomes caused by β-lactams remain poorly understood. In this study, we have identified a cluster of lipoprotein-like genes (lpl, sa2275–sa2273) that is upregulated in the major clinically prevalent MRSA clones in response to subinhibitory concentrations of β-lactam induction. The major highlight of this work is that β-lactams stimulate the expression of SarA, which directly binds to the lpl cluster promoter region and upregulates lpl expression in MRSA. Deletion of lpl significantly decreases proinflammatory cytokine levels in vitro and in vivo. The β-lactam-induced Lpls enhance host inflammatory responses by triggering the Toll-like-receptor-2-mediated expressions of interleukin-6 and tumor necrosis factor alpha. The β-lactam-induced Lpls are important virulence factors that enhance MRSA pathogenicity. These data elucidate that subinhibitory concentrations of β-lactams can exacerbate the outcomes of MRSA infection through induction of lpl controlled by the global regulator SarA., Methicillin-resistant Staphylococcus aureus (MRSA) resists nearly all β-lactam antibiotics that have a bactericidal activity. However, whether the empirically used β-lactams enhance MRSA pathogenicity in vivo remains unclear. In this study, we showed that a cluster of lipoprotein-like genes (lpl, sa2275 to sa2273 [sa2275–sa2273]) was upregulated in MRSA in response to subinhibitory concentrations of β-lactam induction. The increasing expression of lpl by β-lactams was directly controlled by the global regulator SarA. The β-lactam-induced Lpls stimulated the production of interleukin-6 and tumor necrosis factor alpha in RAW 264.7 macrophages. The lpl deletion mutants (N315Δlpl and USA300Δlpl) decreased the proinflammatory cytokine levels in vitro and in vivo. Purified lipidated SA2275-his proteins could trigger a Toll-like-receptor-2 (TLR2)-dependent immune response in primary mouse bone marrow-derived macrophages and C57BL/6 mice. The bacterial loads of N315Δlpl in the mouse kidney were lower than those of the wild-type N315. The β-lactam-treated MRSA exacerbated cutaneous infections in both BALB/c and C57BL/6 mice, presenting increased lesion size; destroyed skin structure; and easily promoted abscess formation compared with those of the untreated MRSA. However, the size of abscesses caused by the β-lactam-treated N315 was negligibly different from those caused by the untreated N315Δlpl in C57BL/6 TLR2−/− mice. Our findings suggest that β-lactams must be used carefully because they might aggravate the outcome of MRSA infection compared to inaction in treatment.
- Published
- 2019
23. Virulence Determinants Are Required for Brain Abscess Formation Through Staphylococcus aureus Infection and Are Potential Targets of Antivirulence Factor Therapy
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Xiancai Rao, Huagang Peng, Weilong Shang, Yifan Rao, Kun Xiong, Qiwen Hu, Ying Zheng, Li Tan, Yi Yang, Shu Li, Renjie Zhou, Junmin Zhu, Xiaomei Hu, Zhen Hu, Xia Zhao, and Ming Li
- Subjects
Microbiology (medical) ,Staphylococcus aureus ,medicine.drug_class ,Antibiotics ,lcsh:QR1-502 ,Virulence ,Human leukocyte antigen ,Biology ,Monoclonal antibody ,medicine.disease_cause ,Microbiology ,lcsh:Microbiology ,03 medical and health sciences ,medicine ,bacteremia ,Brain abscess ,Gene ,Original Research ,030304 developmental biology ,0303 health sciences ,ear colonization ,030306 microbiology ,virulence determinant ,medicine.disease ,brain abscess ,Bacteremia ,antivirulence factor therapy - Abstract
Bacterial brain abscesses (BAs) are difficult to treat with conventional antibiotics. Thus, the development of alternative therapeutic strategies for BAs is of high priority. Identifying the virulence determinants that contribute to BA formation induced by Staphylococcus aureus would improve the effectiveness of interventions for this disease. In this study, RT-qPCR was performed to compare the expression levels of 42 putative virulence determinants of S. aureus strains Newman and XQ during murine BA formation, ear colonization, and bacteremia. The alterations in the expression levels of 23 genes were further confirmed through specific TaqMan RT-qPCR. Eleven S. aureus genes that persistently upregulated expression levels during BA infection were identified, and their functions in BA formation were confirmed through isogenic mutant experiments. Bacterial loads and BA volumes in mice infected with isdA, isdC, lgt, hla, or spa deletion mutants and the hla/spa double mutant strain were lower than those in mice infected with the wild-type Newman strain. The therapeutic application of monoclonal antibodies against Hla and SpA decreased bacterial loads and BA volume in mice infected with Newman. This study provides insights into the virulence determinants that contribute to staphylococcal BA formation and a paradigm for antivirulence factor therapy against S. aureus infections.
- Published
- 2019
24. Reconstruction of the Vancomycin-Susceptible Staphylococcus aureus Phenotype From a Vancomycin-Intermediate S. aureus XN108
- Author
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Ying Zheng, Li Tan, Kun Xiong, Yi Yang, Shu Li, Weilong Shang, Yifan Rao, Huagang Peng, Xiancai Rao, Wenchang Yuan, Qiwen Hu, Zhen Hu, Xiaomei Hu, and Junmin Zhu
- Subjects
0301 basic medicine ,Microbiology (medical) ,Autolysis (biology) ,030106 microbiology ,lcsh:QR1-502 ,Biology ,medicine.disease_cause ,Microbiology ,lcsh:Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,medicine ,Gene ,Teichoic acid ,RpoB ,WalKR ,Vancomycin-intermediate Staphylococcus aureus ,GraSR ,rpoB ,Phenotype ,chemistry ,vancomycin resistance ,Staphylococcus aureus ,Vancomycin ,Cell wall thickening ,medicine.drug - Abstract
The emergence of vancomycin-intermediate Staphylococcus aureus (VISA) has raised healthcare concerns worldwide. VISA is often associated with multiple genetic changes. However, the relative contributions of these changes to VISA phenotypes are incompletely defined. We have characterized VISA XN108 with vancomycin MIC of 12 μg/ml. Genome comparison revealed that WalK(S221P), GraS(T136I), and RpoB(H481N) mutations possibly contributed to the VISA phenotype of XN108. In this study, the above mutations were stepwise cured, and the phenotypes between XN108 and its derivates were compared. We constructed four isogenic mutant strains, XN108-WalK(P221S) (termed as K65), XN108-GraS(I136T) (termed as S65), XN108-RpoB(N481H) (termed as B65), and XN108-WalK(P221S)/GraS(I136T) (termed as KS65), using the allelic replacement experiments with the native alleles derived from a vancomycin-susceptible S. aureus isolate DP65. Antimicrobial susceptibility test revealed K65 and S65 exhibited decreased vancomycin resistance, whereas B65 revealed negligibly differed when compared with the wild-type XN108. Sequentially introducing WalK(P221S) and GraS(I136T) completely converted XN108 into a VSSA phenotype. Transmission electronic microscopy and autolysis determination demonstrated that cell wall thickening and decreasing autolysis were associated with the change of vancomycin resistance levels. Compared with XN108, K65 exhibited 577 differentially expressed genes (DEGs), whereas KS65 presented 555 DEGs. Of those DEGs, 390 were common in K65 and KS65, including those upregulated genes responsible for citrate cycle and bacterial autolysis, and the downregulated genes involved in peptidoglycan biosynthesis and teichoic acid modification. In conclusion, a VSSA phenotype could be completely reconstituted from a VISA strain XN108. WalK(S221P) and GraS(T136I) mutations may work synergistically in conferring vancomycin resistance in XN108.
- Published
- 2018
25. β-lactam Antibiotics Stimulate the Pathogenicity of Methicillin-resistant Staphylococcus aureus Via SarA-controlled Tandem Lipoprotein Expression
- Author
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Qiwen Hu, Xiaomei Hu, Zhen Hu, Huagang Peng, Yifan Rao, Jizhen Yuan, Kun Xiong, Li Tan, Ming Li, Shu Li, Ying Zheng, Xiancai Rao, Yi Yang, Weilong Shang, Xuhu Mao, and Junmin Zhu
- Subjects
business.industry ,medicine.drug_class ,Antibiotics ,Wild type ,biochemical phenomena, metabolism, and nutrition ,medicine.disease_cause ,Methicillin-resistant Staphylococcus aureus ,Microbiology ,Proinflammatory cytokine ,Immune system ,In vivo ,Staphylococcus aureus ,Medicine ,Tumor necrosis factor alpha ,business - Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of nosocomial infections worldwide. MRSA resists nearly all β-lactam antibiotics that have a bactericidal activity and a signal inducer effect. However, studies have yet to clarify whether the inducer effect of empirically used β-lactams stimulates MRSA pathogenicity in vivo. Here, we showed that a new cluster of tandem lipoprotein genes (tlpps) was upregulated in MRSA in response to the subinhibitory concentrations of β-lactam induction. The increased Tlpps significantly altered immune responses by macrophages with high IL-6 and TNFα levels. The deletion of the tlpps mutant (N315Δtlpps) significantly decreased the proinflammatory cytokine levels in vitro and in vivo. The bacterial loads of N315Δtlpps in the mouse kidney were also reduced compared with those of the wild type N315. The β-lactam-treated MRSA exacerbated cutaneous infections with increased lesion size, extended illness, and flake-like abscess-formation compared with those of the nontreatment. The β-lactam antibiotics that promoted the MRSA pathogenicity were SarA dependent, and the increasing expression of tlpps after β-lactam treatment was directly controlled by the global regulator SarA. Overall, our findings suggested that β-lactams should be used carefully because it might lead to a worse outcome of MRSA infection than inaction in the treatment.Author summaryβ-lactams are widely used in practice to treat infectious diseases, however, β-lactams worsening the outcome of a certain disease is poorly understood. In this study, we have identified a new cluster of tandem lipoprotein genes (tlpps) that is upregulated in the major clinically prevalent MRSA clones in response to the subinhibitory concentrations of β-lactams induction. The major highlight in this work is that β-lactams induce SarA expression, and then SarA directly binds to the tlpp cluster promoter region and upregulates the tlpp expression in MRSA. Moreover, the β-lactam stimulated Tlpps are important virulence factors that enhance MRSA pathogenicity. The deletion of the tlpps mutant significantly decreases the proinflammatory cytokine levels in vitro and in vivo. The β-lactam induced Tlpps enhance the host inflammatory responses by triggering the expression of IL-6 and TNFα, thereby promoting bacterial colonization and abscess formation. These data elucidate that β-lactams can worsen the outcome of MRSA infection through the induction of tlpps that are controlled by the global regulator SarA.
- Published
- 2018
- Full Text
- View/download PDF
26. Protective Effect of the Golden Staphyloxanthin Biosynthesis Pathway on Staphylococcus aureus under Cold Atmospheric Plasma Treatment.
- Author
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Yi Yang, Hao Wang, Huyue Zhou, Zhen Hu, Weilong Shang, Yifan Rao, Huagang Peng, Ying Zheng, Qiwen Hu, Rong Zhang, Haiyun Luo, and Xiancai Rao
- Subjects
- *
LOW temperature plasmas , *SCANNING transmission electron microscopy , *STAPHYLOCOCCUS aureus infections , *DRUG resistance in bacteria , *MICROBIAL inactivation , *STAPHYLOCOCCUS aureus , *MICROCOCCACEAE - Abstract
Staphylococcus aureus infection poses a serious threat to public health, and antibiotic resistance has complicated the clinical treatment and limited the solutions available to solve this problem. Cold atmospheric plasma (CAP) is a promising strategy for microorganism inactivation. However, the mechanisms of microbial inactivation or resistance remain unclear. In this study, we treated S. aureus strains with a self-assembled CAP device and found that CAP can kill S. aureus in an exposure time-dependent manner. In addition, the liquid environment can influence the survival rate of S. aureus post-CAP treatment. The S. aureus cells can be completely inactivated in normal saline and phosphate-buffered saline but not in tryptic soy broth culture medium. Scanning and transmission electron microscopy revealed that the CAP-treated S. aureus cells maintained integrated morphological structures, similar to the wild-type strain. Importantly, the CAP-treated S. aureus cells exhibited a reduced pigment phenotype. Deletion of the staphyloxanthin biosynthetic genes crtM and crtN deprived the pigmentation ability of S. aureus Newman. Both the Newman- ΔcrtM and Newman-ΔcrtN mutants presented high sensitivity to CAP treatment, whereas Newman-ΔcrtO exhibited a survival rate comparable to wild-type Newman after CAP treatment. Our data demonstrated that the yellow pigment intermediates of the staphyloxanthin biosynthetic pathway are responsible for the protection of S. aureus from CAP inactivation. The key enzymes, such as CrtM and CrtN, of the golden staphyloxanthin biosynthetic pathway could be important targets for the design of novel sterilization strategies against S. aureus infections. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
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