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Li H, Zeng X, Yao T, Xu H. An antimicrobial film of silver/nanocellulose crystal/oxalic acid/polyvinyl alcohol with real-time bactericidal and prevention of biofilm formation properties. Colloids Surf B Biointerfaces 2024; 237:113868. [PMID: 38522282 DOI: 10.1016/j.colsurfb.2024.113868] [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: 01/06/2024] [Revised: 03/12/2024] [Accepted: 03/20/2024] [Indexed: 03/26/2024]
Abstract
Silver nanoparticles (AgNPs) is an excellent antibacterial agent, which is widely used in medical, food, environmental and other fields, but AgNPs are easy to accumulate in aqueous solution, so their application in various fields is limited. Therefore, it is particularly important to propose a new application method or to prepare a new composite material. In this study, OA/PVA was obtained by cross-linking oxalic acid (OA) with polyvinyl alcohol (PVA). Then Ag/NCC was obtained by in situ reduction of AgNPs on nanocellulose crystals (NCC). Finally, Ag/NCC/OA/PVA composite antimicrobial films with good waterproofing effect were prepared by mixing Ag/NCC with OA/PVA. Subsequently, the films were characterized using SEM, UV-vis, FTIR and XRD, as well as physicochemical properties such as mechanical strength and hydrophilic properties were determined. The results indicated that the Ag/NCC/OA/PVA films possess good light transmittance, mechanical properties, water resistance, antibacterial activity, and biodegradability. The results of the mechanism study showed that Ag/NCC/OA/PVA films can destroy cell integrity, inhibit succinate dehydrogenase (SDH) activity, thereby reducing intracellular ATP levels. And induce a large number of reactive oxygen species (ROS) production, eventually leading to the death of C. sakazakii. In summary, Ag/NCC/OA/PVA film has good physical and chemical properties, antibacterial activity and biocompatibility, and has promising applications in food and medical antibacterial fields.
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Affiliation(s)
- Hui Li
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, PR China
| | - Xianxiang Zeng
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, PR China
| | - Ting Yao
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, PR China
| | - Hengyi Xu
- State Key Laboratory of Food Science and Resources, Nanchang University, Nanchang 330047, PR China; International Institute of Food Innovation Co., Ltd., Nanchang University, Nanchang 330200, PR China.
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2
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Zheng R, Li W, Yin W, Qiao L, Song S, An Y, Ling Z, Bai L, Yang H, Shen J, Dong Y, Wang Y. PEtN-Modified O-Antigen Enhances Shigella Pathogenesis by Promoting Epithelial Cell Invasion and Inhibiting Complement Binding. ACS Infect Dis 2024; 10:377-383. [PMID: 38252850 DOI: 10.1021/acsinfecdis.3c00602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Shigellosis poses an ongoing global public health threat. The presence and length of the O-antigen in lipopolysaccharide play critical roles in Shigella pathogenesis. The plasmid-mediated opt gene encodes a phosphoethanolamine (PEtN) transferase that catalyzes the addition of PEtN to the O-antigen of Shigella flexneri serotype X and Y strains, converting them into serotype Xv and Yv strains, respectively. Since 2002, these modified strains have become prevalent in China. Here we demonstrate that PEtN-mediated O-antigen modification in S. flexneri increase the severity of corneal infection in guinea pigs without any adaptive cost. This heightened virulence is associated with epithelial cell adhesion and invasion, as well as an enhanced inflammatory response of macrophage. Notably, PEtN addition allow S. flexneri to attenuate the binding of complement C3 and better resist phagocytosis, potentially contributing to the retention of S. flexneri in the host environment.
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Affiliation(s)
- Ruicheng Zheng
- National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Wan Li
- School of Basic Medicine, Shenzhen University, Shenzhen, Guangdong 518055, China
| | - Wenjuan Yin
- School of Basic Medicine, Hebei University, Baoding, Hebei 071000, China
| | - Lu Qiao
- National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Shikai Song
- Poultry Institute, Shandong Academy of Agricultural Science, Jinan, Shandong 250100, China
| | - Yina An
- National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Zhuoren Ling
- National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Li Bai
- NHC Key Laboratory of Food Safety Risk Assessment, China National Center for Food Safety Risk Assessment, Beijing 100021, China
| | - Hui Yang
- NHC Key Laboratory of Food Safety Risk Assessment, China National Center for Food Safety Risk Assessment, Beijing 100021, China
| | - Jianzhong Shen
- National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Yanjun Dong
- National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
| | - Yang Wang
- National Key Laboratory of Veterinary Public Health and Safety, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China
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3
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Weikum J, van Dyck JF, Subramani S, Klebl DP, Storflor M, Muench SP, Abel S, Sobott F, Morth JP. The bacterial magnesium transporter MgtA reveals highly selective interaction with specific cardiolipin species. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119614. [PMID: 37879515 DOI: 10.1016/j.bbamcr.2023.119614] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 09/13/2023] [Accepted: 10/16/2023] [Indexed: 10/27/2023]
Abstract
The bacterial magnesium transporter A (MgtA) is a specialized P-type ATPase important for Mg2+ import into the cytoplasm; disrupted magnesium homeostasis is linked to intrinsic ribosome instability and antibacterial resistance in Salmonella strains. Here, we show that MgtA has functional specificity for cardiolipin 18:1. Still, it reaches maximum activity only in combination with cardiolipin 16:0, equivalent to the major components of native cardiolipin found in E. coli membranes. Native mass spectrometry indicates the presence of two binding sites for cardiolipin, agreeing with the kinetic studies revealing that a cooperative relationship likely exists between the two cardiolipin variants. This is the first experimental evidence of cooperative effects between lipids of the same class, with only minor variations in their acyl chain composition, acting on a membrane protein. In summary, our results reveal that MgtA exhibits a highly complex interaction with one cardiolipin 18:1 and one cardiolipin 16:0, affecting protein activity and stability, contributing to our understanding of the particular interactions between lipid environment and membrane proteins. Further, a better understanding of Mg2+ homeostasis in bacteria, due to its role as a virulence regulator, will provide further insights into the regulation and mechanism of bacterial infections.
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Affiliation(s)
- Julia Weikum
- Membrane Transport Group, Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, University of Oslo, P.O. Box 1137, Blindern, 0318 Oslo, Norway; Enzyme and Protein Chemistry, Section for Protein Chemistry and Enzyme Technology, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, 2800 Kgs. Lyngby, Denmark
| | - Jeroen F van Dyck
- Department of Chemistry, University of Antwerp, Campus Groenenborger, Groenenborgerlaan 171, G.V. 418, 2020 Antwerpen, Belgium
| | - Saranya Subramani
- Membrane Transport Group, Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, University of Oslo, P.O. Box 1137, Blindern, 0318 Oslo, Norway
| | - David P Klebl
- School of Biomedical Sciences & The Astbury Centre for Structural Molecular Biology, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
| | - Merete Storflor
- Infections Biology Lab, Department of Pharmacy, UiT-The Arctic University of Norway, 9037 Tromsø, Norway
| | - Stephen P Muench
- School of Biomedical Sciences & The Astbury Centre for Structural Molecular Biology, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
| | - Sören Abel
- Infections Biology Lab, Department of Pharmacy, UiT-The Arctic University of Norway, 9037 Tromsø, Norway
| | - Frank Sobott
- Department of Chemistry, University of Antwerp, Campus Groenenborger, Groenenborgerlaan 171, G.V. 418, 2020 Antwerpen, Belgium; School of Molecular and Cellular Biology & The Astbury Centre for Structural Molecular Biology, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom.
| | - J Preben Morth
- Membrane Transport Group, Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, University of Oslo, P.O. Box 1137, Blindern, 0318 Oslo, Norway; Enzyme and Protein Chemistry, Section for Protein Chemistry and Enzyme Technology, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, 2800 Kgs. Lyngby, Denmark; Institute for Experimental Medical Research (IEMR), Oslo University Hospital, Ullevål PB 4956 Nydalen, NO-0424 Oslo, Norway.
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4
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Song Y, Sun M, Mu G, Tuo Y. Exopolysaccharide produced by Lactiplantibacillus plantarum Y12 exhibits inhibitory effect on the Shigella flexneri genes expression related to biofilm formation. Int J Biol Macromol 2023; 253:127048. [PMID: 37748596 DOI: 10.1016/j.ijbiomac.2023.127048] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2023] [Revised: 09/20/2023] [Accepted: 09/21/2023] [Indexed: 09/27/2023]
Abstract
Shigella is a specific enteric pathogen in humans, causing symptoms of bacterial dysentery. The biofilm formation of S. flexneri contributes to the emergence of multidrug resistance and facilitates the establishment of persistent chronic infections. This study investigated the regulatory effects of Lactiplantibacillus plantarum Y12 exopolysaccharide (L-EPS) on gene expression and its spatial hindrance effects in inhibiting the biofilm formation of S. flexneri. The transcriptome analysis revealed a significant impact of L-EPS on the gene expression profile of S. flexneri, with a total of 968 genes showing significant changes (507 up-regulated and 461 down-regulated). The significantly down-regulated KEGG metabolic pathway enriched in phosphotransferase system, Embden-Meyerhf-Parnas, Citrate cycle, Lipopolysaccharide biosynthesis, Cationic antimicrobial peptide resistance, Two-component system. Moreover, L-EPS significantly down-regulated the gene expression levels of fimbriae synthesis (fimF), lipopolysaccharide synthesis (lptE, lptB), anchor protein repeat domain (arpA), virulence factor (lpp, yqgB), antibiotic resistance (marR, cusB, mdtL, mdlB), heavy metal resistance (zraP), and polysaccharide synthesis (mtgA, mdoB, mdoC). The expression of biofilm regulator factor (bssS) and two-component system suppressor factor (mgrB) were significantly up-regulated. The RT-qPCR results indicated that a major component of L-EPS (L-EPS 2-1) exhibited the gene regulatory effect on the S. flexneri biofilm formation. Furthermore, electrophoresis and isothermal microtitration calorimetry demonstrated that the interaction between L-EPS 2-1 and eDNA is electrostatic dependent on the change in environmental pH, disrupting the stable spatial structure of S. flexneri biofilm. In conclusion, L-EPS inhibited the biofilm formation of S. flexneri through gene regulation and spatial obstruction effects.
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Affiliation(s)
- Yinglong Song
- School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, PR China
| | - Mengying Sun
- School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, PR China
| | - Guangqing Mu
- School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, PR China; Dalian Probiotics Function Research Key Laboratory, Dalian Polytechnic University, Dalian 116034, PR China.
| | - Yanfeng Tuo
- School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, PR China.
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5
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Haidar-Ahmad N, Manigat FO, Silué N, Pontier SM, Campbell-Valois FX. A Tale about Shigella: Evolution, Plasmid, and Virulence. Microorganisms 2023; 11:1709. [PMID: 37512882 PMCID: PMC10383432 DOI: 10.3390/microorganisms11071709] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 06/23/2023] [Accepted: 06/26/2023] [Indexed: 07/30/2023] Open
Abstract
Shigella spp. cause hundreds of millions of intestinal infections each year. They target the mucosa of the human colon and are an important model of intracellular bacterial pathogenesis. Shigella is a pathovar of Escherichia coli that is characterized by the presence of a large invasion plasmid, pINV, which encodes the characteristic type III secretion system and icsA used for cytosol invasion and cell-to-cell spread, respectively. First, we review recent advances in the genetic aspects of Shigella, shedding light on its evolutionary history within the E. coli lineage and its relationship to the acquisition of pINV. We then discuss recent insights into the processes that allow for the maintenance of pINV. Finally, we describe the role of the transcription activators VirF, VirB, and MxiE in the major virulence gene regulatory cascades that control the expression of the type III secretion system and icsA. This provides an opportunity to examine the interplay between these pINV-encoded transcriptional activators and numerous chromosome-encoded factors that modulate their activity. Finally, we discuss novel chromosomal genes icaR, icaT, and yccE that are regulated by MxiE. This review emphasizes the notion that Shigella and E. coli have walked the fine line between commensalism and pathogenesis for much of their history.
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Affiliation(s)
- Nathaline Haidar-Ahmad
- Host-Microbe Interactions Laboratory, Centre for Chemical and Synthetic Biology, Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - France Ourida Manigat
- Host-Microbe Interactions Laboratory, Centre for Chemical and Synthetic Biology, Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Navoun Silué
- Host-Microbe Interactions Laboratory, Centre for Chemical and Synthetic Biology, Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
| | - Stéphanie M Pontier
- Centre de Recherche Santé Environnementale et Biodiversité de l'Outaouais (SEBO), CEGEP de l'Outaouais, Gatineau, QC J8Y 6M4, Canada
| | - François-Xavier Campbell-Valois
- Host-Microbe Interactions Laboratory, Centre for Chemical and Synthetic Biology, Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada
- Centre for Infection, Immunity and Inflammation, Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1N 6N5, Canada
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6
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Hu M, Zhang Y, Huang X, He M, Zhu J, Zhang Z, Cui Y, He S, Shi X. PhoPQ Regulates Quinolone and Cephalosporin Resistance Formation in Salmonella Enteritidis at the Transcriptional Level. mBio 2023:e0339522. [PMID: 37184399 DOI: 10.1128/mbio.03395-22] [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: 05/16/2023] Open
Abstract
The two-component system (TCS) PhoPQ has been demonstrated to be crucial for the formation of resistance to quinolones and cephalosporins in Salmonella Enteritidis (S. Enteritidis). However, the mechanism underlying PhoPQ-mediated antibiotic resistance formation remains poorly understood. Here, it was shown that PhoP transcriptionally regulated an assortment of genes associated with envelope homeostasis, the osmotic stress response, and the redox balance to confer resistance to quinolones and cephalosporins in S. Enteritidis. Specifically, cells lacking the PhoP regulator, under nalidixic acid and ceftazidime stress, bore a severely compromised membrane on the aspects of integrity, fluidity, and permeability, with deficiency to withstand osmolarity stress, an increased accumulation of intracellular reactive oxygen species, and dysregulated redox homeostasis, which are unfavorable for bacterial survival. The phosphorylated PhoP elicited transcriptional alterations of resistance-associated genes, including the outer membrane porin ompF and the aconitate hydratase acnA, by directly binding to their promoters, leading to a limited influx of antibiotics and a well-maintained intracellular metabolism. Importantly, it was demonstrated that the cavity of the PhoQ sensor domain bound to and sensed quinolones/cephalosporins via the crucial surrounding residues, as their mutations abrogated the binding and PhoQ autophosphorylation. This recognition mode promoted signal transduction that activated PhoP, thereby modulating the transcription of downstream genes to accommodate cells to antibiotic stress. These findings have revealed how bacteria employ a specific TCS to sense antibiotics and combat them, suggesting PhoPQ as a potential drug target with which to surmount S. Enteritidis. IMPORTANCE The prevalence of quinolone and cephalosporin-resistant S. Enteritidis is of increasing clinical concern. Thus, it is imperative to identify novel therapeutic targets with which to treat S. Enteritidis-associated infections. The PhoPQ two-component system is conserved across a variety of Gram-negative pathogens, by which bacteria adapt to a range of environmental stimuli. Our earlier work has demonstrated the importance of PhoPQ in the resistance formation in S. Enteritidis to quinolones and cephalosporins. In the current work, we identified a global profile of genes that are regulated by PhoP under antibiotic stresses, with a focus on how PhoP regulated downstream genes, either positively or negatively. Additionally, we established that PhoQ sensed quinolones and cephalosporins in a manner of directly binding to them. These identified genes and pathways that are mediated by PhoPQ represent promising targets for the development of a drug potentiator with which to neutralize antibiotic resistance in S. Enteritidis.
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Affiliation(s)
- Mengjun Hu
- Department of Food Science & Technology, School of Agriculture & Biology, and State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
| | - Yuyan Zhang
- Department of Food Science & Technology, School of Agriculture & Biology, and State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
| | - Xiaozhen Huang
- Department of Food Science & Technology, School of Agriculture & Biology, and State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
| | - Mu He
- Department of Food Science & Technology, School of Agriculture & Biology, and State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
| | - Jinyu Zhu
- Department of Food Science & Technology, School of Agriculture & Biology, and State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
| | - Zengfeng Zhang
- Department of Food Science & Technology, School of Agriculture & Biology, and State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
| | - Yan Cui
- Department of Food Science & Technology, School of Agriculture & Biology, and State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
| | - Shoukui He
- Department of Food Science & Technology, School of Agriculture & Biology, and State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
| | - Xianming Shi
- Department of Food Science & Technology, School of Agriculture & Biology, and State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
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7
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Peng J, Xu Z, Li L, Zhao B, Guo Y. Disruption of the sensor kinase phoQ gene decreases acid resistance in plant growth-promoting rhizobacterium Rahnella aquatilis HX2. J Appl Microbiol 2023; 134:6991427. [PMID: 36748653 DOI: 10.1093/jambio/lxad009] [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: 10/26/2022] [Revised: 12/24/2022] [Accepted: 01/17/2023] [Indexed: 01/20/2023]
Abstract
AIMS Rahnella aquatilis HX2, a promising plant growth-promoting rhizobacterium (PGPR) in the field, contains genes homologous to the PhoP/PhoQ two-component regulatory system. Although this system regulates stress response in numerous pathogens, PhoP/PhoQ characterization in a PGPR has not received in-depth exploration. METHODS AND RESULTS The phoQ gene was mutated in strain HX2 using an in-frame deletion strategy. Compared to the wild type, the phoQ mutant exhibited increased sensitivity to acidic conditions (pH 4.0) in a chemically defined medium and in mild acidic natural soil (pH 5.7). The phoQ mutant also exhibited increased swimming motility under acidic conditions. Acid resistance was restored in the mutant by introducing the phoQ gene on a plasmid. Three acid resistance genes, add, cfa, and fur were downregulated significantly, whereas the chaperone encoding gene, dnak, was upregulated when the phoQ mutant was exposed to acid stress. CONCLUSIONS This study suggested that the PhoP/PhoQ system positively regulates the acid resistance of R. aquatilis HX2.
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Affiliation(s)
- Jing Peng
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.,Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China
| | - Zhongnan Xu
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.,Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China
| | - Lei Li
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.,Institute of Vegetables and Flowers, Chinese Academy of Agricultural Science, Beijing 100081, China
| | - Bingjie Zhao
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.,Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China
| | - Yanbin Guo
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.,Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing 100193, China
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8
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Abstract
Duck infectious serositis, also known as Riemerella anatipestifer disease, infects domestic ducks, geese, and turkeys and wild birds. However, the regulatory mechanism of its pathogenicity remains unclear. The PhoPR two-component system (TCS) was first reported in Gram-negative bacteria in our previous research and was demonstrated to be involved in virulence and gene expression. Here, DNA affinity purification sequencing (DAP-seq) was applied to further explore the regulation of PhoPR in relation to pathogenicity in R. anatipestifer. A conserved motif was identified upstream of 583 candidate target genes which were directly regulated by PhoP. To further confirm the genes which are regulated by PhoR and PhoP, single-gene-deletion strains were constructed. The results of transcriptome analysis using next-generation RNA sequencing showed 136 differentially expressed genes (DEGs) between the ΔphoP strain and the wild type (WT) and 183 DEGs between the ΔphoR strain and the WT. The candidate target genes of PhoP were further identified by combining transcriptome analysis and DAP-seq, which revealed that the main direct regulons of PhoP are located on the membrane and PhoP is involved in regulating aerotolerance. Using the in vivo duck model, the pathogenicity of ΔphoP and ΔphoR mutants was found to be significantly lower than that of the WT. Together, our findings provide insight into the direct regulation of PhoP and suggest that phoPR is essential for the pathogenicity of R. anatipestifer. The gene deletion strains are expected to be candidate live vaccine strains of R. anatipestifer which can be used as ideal genetic engineering vector strains for the expression of foreign antigens. IMPORTANCE Riemerella anatipestifer is a significant pathogen with high mortality in the poultry industry that causes acute septicemia and infectious polyserositis in ducks, chickens, geese, and other avian species. Previously, we characterized the two-component system encoded by phoPR and found that R. anatipestifer almost completely lost its pathogenicity for ducklings when phoPR was deleted. However, the mechanism of PhoPR regulation of virulence in R. anatipestifer had not been deeply explored. In this study, we utilized DAP-seq to explore the DNA-binding sites of PhoP as a response regulator in the global genome. Furthermore, phoP and phoR were deleted separately, and transcriptomics analysis of the corresponding gene deletion strains was performed. We identified a series of directly regulated genes of the PhoPR two-component system. The duckling model showed that both PhoP and PhoR are essential virulence-related factors in R. anatipestifer.
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9
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Xerri NL, Payne SM. Bacteroides thetaiotaomicron Outer Membrane Vesicles Modulate Virulence of Shigella flexneri. mBio 2022; 13:e0236022. [PMID: 36102517 PMCID: PMC9600379 DOI: 10.1128/mbio.02360-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 08/24/2022] [Indexed: 11/20/2022] Open
Abstract
The role of the gut microbiota in the pathogenesis of Shigella flexneri remains largely unknown. To understand the impact of the gut microbiota on S. flexneri virulence, we examined the effect of interspecies interactions with Bacteroides thetaiotaomicron, a prominent member of the gut microbiota, on S. flexneri invasion. When grown in B. thetaiotaomicron-conditioned medium, S. flexneri showed reduced invasion of human epithelial cells. This decrease in invasiveness of S. flexneri resulted from a reduction in the level of the S. flexneri master virulence regulator VirF. Reduction of VirF corresponded with a decrease in expression of a secondary virulence regulator, virB, as well as expression of S. flexneri virulence genes required for invasion, intracellular motility, and spread. Repression of S. flexneri virulence factors by B. thetaiotaomicron-conditioned medium was not caused by either a secreted metabolite or secreted protein but rather was due to the presence of B. thetaiotaomicron outer membrane vesicles (OMVs) in the conditioned medium. The addition of purified B. thetaiotaomicron OMVs to S. flexneri growth medium recapitulated the inhibitory effects of B. thetaiotaomicron-conditioned medium on invasion, virulence gene expression, and virulence protein levels. Total lipids extracted from either B. thetaiotaomicron cells or B. thetaiotaomicron OMVs also recapitulated the effects of B. thetaiotaomicron-conditioned medium on expression of the S. flexneri virulence factor IpaC, indicating that B. thetaiotaomicron OMV lipids, rather than a cargo contained in the vesicles, are the active factor responsible for the inhibition of S. flexneri virulence. IMPORTANCE Shigella flexneri is the causative agent of bacillary dysentery in humans. Shigella spp. are one of the leading causes of diarrheal morbidity and mortality, especially among children in low- and middle-income countries. The rise of antimicrobial resistance combined with the lack of an effective vaccine for Shigella heightens the importance of studies aimed at better understanding previously uncharacterized aspects of Shigella pathogenesis. Here, we show that conditioned growth medium from the commensal bacterium Bacteroides thetaiotaomicron represses the invasion of S. flexneri. This repression is due to the presence of B. thetaiotaomicron outer membrane vesicles. These findings establish a role for interspecies interactions with a prominent member of the gut microbiota in modulating the virulence of S. flexneri and identify a novel function of outer membrane vesicles in interbacterial signaling between members of the gut microbiota and an enteric pathogen.
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Affiliation(s)
- Nicholas L. Xerri
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
| | - Shelley M. Payne
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
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10
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Naha A, Ramaiah S. Structural chemistry and molecular-level interactome reveals histidine kinase EvgS to subvert both antimicrobial resistance and virulence in Shigella flexneri 2a str. 301. 3 Biotech 2022; 12:258. [PMID: 36068841 PMCID: PMC9440972 DOI: 10.1007/s13205-022-03325-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 08/22/2022] [Indexed: 11/25/2022] Open
Abstract
Multi-drug resistant (MDR) Shigella flexneri 2a, one of the leading bacterial agents of diarrhoeal mortality, has posed challenges in treatment strategies. The present study was conducted to identify potential therapeutic biomarkers using gene interaction network (GIN) in order to understand the cellular and molecular level interactions of both antimicrobial resistance (AMR) and virulence genes through topological and clustering metrics. Statistically significant differential gene expression (DGE), structural chemistry and dynamics were incorporated to elucidate biomarker for sustainable therapeutic regimen against MDR S. flexneri. Functional enrichments and topological metrics revealed evgS, ybjZ, tolC, gyrA, parC and their direct interactors to be associated with diverse AMR mechanisms. Histidine kinase EvgS was considered as the hub protein due to its highest prevalence in the molecular interactome profiles of both the AMR (71.6%) and virulence (45.8%) clusters interconnecting several genes concerning two-component system (TCS). DGE profiles of ΔPhoPQ (deleted regulatory PhoP and sensor PhoQ) led to the upregulation of TCS comprising EvgSA thereby validating EvgS as a promising therapeutic biomarker. Druggability and structural stability of EvgS was assessed through thermal shifts, backbone stability and coarse dynamics refinement. Structure-function relationship was established revealing the C-terminal extracellular domain as the drug-binding site which was further validated through molecular dynamics simulation. Structure elucidation of identified biomarker followed by secondary and tertiary structural validation would prove pivotal for future therapeutic interventions against subverting both AMR and virulence posed by this strain. Supplementary Information The online version contains supplementary material available at 10.1007/s13205-022-03325-w.
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Affiliation(s)
- Aniket Naha
- Medical and Biological Computing Laboratory, School of Bio-Sciences and Technology, Vellore Institute of Technology (VIT), Vellore, 632014 Tamil Nadu India
- Department of Bio-Medical Sciences, School of Bio-Sciences and Technology, Vellore Institute of Technology (VIT), Vellore, 632014 Tamil Nadu India
| | - Sudha Ramaiah
- Medical and Biological Computing Laboratory, School of Bio-Sciences and Technology, Vellore Institute of Technology (VIT), Vellore, 632014 Tamil Nadu India
- Department of Bio-Sciences, School of Bio-Sciences and Technology, Vellore Institute of Technology (VIT), Vellore, 632014 Tamil Nadu India
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11
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Roles of Two-Component Signal Transduction Systems in Shigella Virulence. Biomolecules 2022; 12:biom12091321. [PMID: 36139160 PMCID: PMC9496106 DOI: 10.3390/biom12091321] [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: 08/08/2022] [Revised: 09/12/2022] [Accepted: 09/13/2022] [Indexed: 11/17/2022] Open
Abstract
Two-component signal transduction systems (TCSs) are widespread types of protein machinery, typically consisting of a histidine kinase membrane sensor and a cytoplasmic transcriptional regulator that can sense and respond to environmental signals. TCSs are responsible for modulating genes involved in a multitude of bacterial functions, including cell division, motility, differentiation, biofilm formation, antibiotic resistance, and virulence. Pathogenic bacteria exploit the capabilities of TCSs to reprogram gene expression according to the different niches they encounter during host infection. This review focuses on the role of TCSs in regulating the virulence phenotype of Shigella, an intracellular pathogen responsible for severe human enteric syndrome. The pathogenicity of Shigella is the result of the complex action of a wide number of virulence determinants located on the chromosome and on a large virulence plasmid. In particular, we will discuss how five TCSs, EnvZ/OmpR, CpxA/CpxR, ArcB/ArcA, PhoQ/PhoP, and EvgS/EvgA, contribute to linking environmental stimuli to the expression of genes related to virulence and fitness within the host. Considering the relevance of TCSs in the expression of virulence in pathogenic bacteria, the identification of drugs that inhibit TCS function may represent a promising approach to combat bacterial infections.
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12
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Li H, Zhao Y, Zhang J, Li W, You Q, Zeng X, Xu H. Silver nanoparticles reduce the tolerance of Cronobacter sakazakii to environmental stress by inhibiting expression of related genes. J Dairy Sci 2022; 105:6469-6482. [PMID: 35840406 DOI: 10.3168/jds.2022-21833] [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: 01/17/2022] [Accepted: 04/25/2022] [Indexed: 11/19/2022]
Abstract
Cronobacter sakazakii is a food-borne pathogen that is resistant to a variety of environmental stress conditions. It can survive in harsh environments. We studied the effects of silver nanoparticles (AgNP) on the environmental tolerance and biofilm formation of C. sakazakii. First, we determined the minimum inhibitory concentration (MIC) of AgNP to C. sakazakii and determined the growth curve of C. sakazakii treated with different concentrations of AgNP by using the plate counting method. After determining the sub-inhibition concentrations (SIC) of AgNP on C. sakazakii, we studied the effects of AgNP on the resistance of C. sakazakii to heat, desiccation, osmotic pressure, and acid. The antibiofilm activity of AgNP was also studied. Finally, real-time quantitative PCR was used to analyze the transcription levels of 16 genes related to the environmental tolerance of C. sakazakii. The SIC of AgNP significantly reduced the survival rate of C. sakazakii under various environmental stress conditions. The results showed that AgNP at 0.625 and 1.25 μg/mL significantly inhibited the formation of C. sakazakii biofilms. The expression levels of most genes were significantly downregulated in C. sakazakii cells treated with 0.625 and 1.25 μg/mL AgNP. Therefore, AgNP may reduce the environmental tolerance of C. sakazakii by inhibiting the expression of genes related to stress tolerance. Moreover, AgNP inhibited the production of ATP in C. sakazakii cells and the formation of C. sakazakii biofilms. Our research provides a theoretical basis for the application of AgNP in food packaging, bactericidal coatings, and other fields.
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Affiliation(s)
- Hui Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Yi Zhao
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Jingjing Zhang
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Wen Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Qixiu You
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Xianxiang Zeng
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - Hengyi Xu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China.
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13
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Chen H, Yu C, Wu H, Li G, Li C, Hong W, Yang X, Wang H, You X. Recent Advances in Histidine Kinase-Targeted Antimicrobial Agents. Front Chem 2022; 10:866392. [PMID: 35860627 PMCID: PMC9289397 DOI: 10.3389/fchem.2022.866392] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 05/16/2022] [Indexed: 11/15/2022] Open
Abstract
The prevalence of antimicrobial-resistant pathogens significantly limited the number of effective antibiotics available clinically, which urgently requires new drug targets to screen, design, and develop novel antibacterial drugs. Two-component system (TCS), which is comprised of a histidine kinase (HK) and a response regulator (RR), is a common mechanism whereby bacteria can sense a range of stimuli and make an appropriate adaptive response. HKs as the sensor part of the bacterial TCS can regulate various processes such as growth, vitality, antibiotic resistance, and virulence, and have been considered as a promising target for antibacterial drugs. In the current review, we highlighted the structural basis and functional importance of bacterial TCS especially HKs as a target in the discovery of new antimicrobials, and summarize the latest research progress of small-molecule HK-inhibitors as potential novel antimicrobial drugs reported in the past decade.
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Affiliation(s)
- Hongtong Chen
- Laboratory of Pharmacology/Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Chengqi Yu
- School of Basic Medical Science, Capital Medical University, Beijing, China
| | - Han Wu
- School of Pharmacy, Minzu University of China, Beijing, China
- Key Laboratory of Ethnomedicine (Minzu University of China), Ministry of Education, Beijing, China
| | - Guoqing Li
- Laboratory of Pharmacology/Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Congran Li
- Laboratory of Pharmacology/Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Wei Hong
- Beijing Institute of Collaborative Innovation, Beijing, China
| | - Xinyi Yang
- Laboratory of Pharmacology/Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- *Correspondence: Xinyi Yang, ; Hao Wang, ; Xuefu You,
| | - Hao Wang
- School of Pharmacy, Minzu University of China, Beijing, China
- Key Laboratory of Ethnomedicine (Minzu University of China), Ministry of Education, Beijing, China
- Institute of National Security, Minzu University of China, Beijing, China
- *Correspondence: Xinyi Yang, ; Hao Wang, ; Xuefu You,
| | - Xuefu You
- Laboratory of Pharmacology/Beijing Key Laboratory of Antimicrobial Agents, Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
- *Correspondence: Xinyi Yang, ; Hao Wang, ; Xuefu You,
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14
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Ma Y, Zhang Y, Shan Z, Wang X, Xia X. Involvement of PhoP/PhoQ two-component system in biofilm formation in Cronobacter sakazakii. Food Control 2022. [DOI: 10.1016/j.foodcont.2021.108621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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Sadredinamin M, Shabani M, Karimi A, Sohrabi MR, Karimi-Yazdi M, Ghalavand Z, Alebouyeh M. Virulence genes expression profiling of different Shigella flexneri serotypes in response to sub-inhibitory concentrations of azithromycin and ciprofloxacin. Gut Pathog 2022; 14:10. [PMID: 35193669 PMCID: PMC8864791 DOI: 10.1186/s13099-022-00483-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 02/07/2022] [Indexed: 11/25/2022] Open
Abstract
Background Shigellosis is a self-limiting disease that antibiotic therapy could decrease its complications and duration. However, sublethal levels of antibiotics, may lead to alteration in disease state, besides its role in the emergence of resistant variants. To understand this link, we investigated diversity of Shigella serogroups in children with diarrhea, diversity of S. flexneri serotypes, cytotoxic potential, resistance patterns to antibiotics, and alteration in transcriptional expression of main virulence genes in response to sub-inhibitory concentrations of azithromycin and ciprofloxacin. Results The most frequently isolated serogroups were S. sonnei (70.3%), followed by S. flexneri (29.1%) and S. boydii (0.6%). Ten serotypes were characterized among the S. flexneri isolates, including 2b, 1b, 2a, 1c, 4a, 3a, 3b, 6 and X and/or Xv. Antimicrobial susceptibility testing showed low frequency of multi-drug resistance phenotype among S. flexneri isolates with minimum inhibitory concentrations (MIC) of 0.5–64 and 0.25–8 µg/mL for azithromycin and ciprofloxacin, respectively. Gene expression analysis showed upregulation of icsA in serotype 4a after exposure with azithromycin, whereas other genes in the VirF pathway were downregulated, and downregulation of virB in serotypes 2a and 3a after exposure with ciprofloxacin, while upregulation of noted genes was detected. Conclusions Alteration in transcription of key virulence genes of S. flexneri serotypes was shown in response to sublethal concentration of antibiotics. The detected incongruency in the extent of gene transcription proposed that diverse regulatory pathways are possibly mediating response to sub-MIC concentrations of antibiotics in S. flexneri.
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Affiliation(s)
- Mehrzad Sadredinamin
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahdi Shabani
- Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Abdollah Karimi
- Pediatric Infections Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad-Reza Sohrabi
- Social Determinants of Health Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Zohreh Ghalavand
- Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Masoud Alebouyeh
- Pediatric Infections Research Center, Research Institute for Children's Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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16
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Guo H, Zhao T, Huang C, Chen J. The Role of the Two-Component System PhoP/PhoQ in Intrinsic Resistance of Yersinia enterocolitica to Polymyxin. Front Microbiol 2022; 13:758571. [PMID: 35222323 PMCID: PMC8867023 DOI: 10.3389/fmicb.2022.758571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Accepted: 01/06/2022] [Indexed: 12/02/2022] Open
Abstract
Polymyxin is the “last resort” of antibiotics. The self-induced resistance to polymyxin in Gram-negative bacteria could be mediated by lipopolysaccharide (LPS) modification, which is regulated by the two-component system, PhoP/PhoQ. Yersinia enterocolitica is a common foodborne pathogen. However, PhoP/PhoQ has not been thoroughly studied in Y. enterocolitica. In this study, the functions of PhoP/PhoQ in Y. enterocolitica intrinsic resistance were investigated. The resistance of Y. enterocolitica was found to decrease with the deletion of PhoP/PhoQ. Further, PhoP/PhoQ was found to play an important role in maintaining membrane permeability, intercellular metabolism, and reducing membrane depolarization. Based on subsequent studies, the binding ability of polymyxin to Y. enterocolitica was decreased by the modification of LPS with structures, such as L-Ara4N and palmitate. Analysis of the gene transcription levels revealed that the LPS modification genes, pagP and arn operon, were downregulated with the deletion of PhoP/PhoQ in Y. enterocolitica during exposure to polymyxin. In addition, pmrA, pmrB, and eptA were downregulated in the mutants compared with the wild-type strain. Such findings demonstrate that PhoP/PhoQ contributes to the intrinsic resistance of Y. enterocolitica toward polymyxins. LPS modification with L-Ara4N or palmitate is mainly responsible for the resistance of Y. enterocolitica to polymyxins. The transcription of genes related to LPS modification and PmrA/PmrB can be both affected by PhoP/PhoQ in Y. enterocolitica. This study adds to current knowledge regarding the role of PhoP/PhoQ in intrinsic resistance of Y. enterocolitica to polymyxin.
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17
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Liu X, Wu Y, Zhu Y, Jia P, Li X, Jia X, Yu W, Cui Y, Yang R, Xia W, Xu Y, Yang Q. Emergence of colistin-resistant hypervirulent Klebsiella pneumoniae (CoR-HvKp) in China. Emerg Microbes Infect 2022; 11:648-661. [PMID: 35086435 PMCID: PMC8896207 DOI: 10.1080/22221751.2022.2036078] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Colistin is regarded as a last-resort agent to combat infections caused by multidrug-resistant (MDR) Gram-negative bacteria, especially carbapenem-resistant isolates. In recent years, reports of colistin-resistant Klebsiella pneumoniae (CoRKp) are increasing. However, the molecular mechanism and relevance of colistin resistance and virulence remain unclear. Fourteen CoRKp strains were retrospectively screened from 1884 clinical K. pneumoniae isolates during 2017–2018 in China. Six CoRKp strains belonging to ST11 were MDR strains. Plasmid-mediated mobile colistin-resistance genes had a low prevalence in CoRKp. Our results revealed that up-regulated expression of two-component systems, especially phoPQ, contributed more to colistin resistance. mgrB mutation was the most common molecular mechanism of colistin resistance, caused by either nonsense mutations or insertion sequences, which drove the overexpression of phoPQ system. This study also identified three novel point mutations in pmrAB system, in which D313N mutation in pmrB was proved to increase the MIC to colistin by 16-fold. In addition, 6 out of 14 CoRKP strains independently carried hypervirulence genes. All six strains showed medium-to-high virulence phenotype compared with NTUH-K2044 strain in mice intraperitoneal challenge models. We found that 4 strains were biofilm strong producers and transcriptome analysis revealed that three of them significantly up-regulated expression of type III fimbrial shaft gene mrkA. In conclusion, our result revealed the emergence of colistin-resistant and hypervirulent MDR K. pneumoniae, which is a noticeable superbug and could cause a severe challenge to public health.
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Affiliation(s)
- Xiaoyu Liu
- Medical Technology Academy, Beihua University, Jilin, Jilin Province, China; Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Beijing, China; Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yarong Wu
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Ying Zhu
- Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Peiyao Jia
- Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Xue Li
- Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Department of Clinical Laboratory, Beijing Anzhen Hospital, Capital Medical University, Beijing, China
| | - Xinmiao Jia
- Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Medical Research Center, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Central Research Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, People's Republic of China
| | - Wei Yu
- Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.,Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China
| | - Yujun Cui
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Ruifu Yang
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing, 100071, China
| | - Wei Xia
- Medical Technology Academy, Beihua University, Jilin, Jilin Province, China; Department of Clinical Laboratory, Peking Union Medical College Hospital, Peking Union Medical College, Beijing, China; Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yingchun Xu
- Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Qiwen Yang
- Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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18
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Queiroz PA, Meneguello JE, Silva BR, Caleffi-Ferracioli KR, Scodro RB, Cardoso RF, Marchiosi R, Siqueira VL. Proteomic profiling of Klebsiella pneumoniae carbapenemase (KPC)-producer Klebsiella pneumoniae after induced polymyxin resistance. Future Microbiol 2021; 16:1195-1207. [PMID: 34590903 DOI: 10.2217/fmb-2021-0005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aim: To elucidate the changes in protein expression associated with polymyxin resistance in Klebsiella pneumoniae, we profiled a comparative proteomic analysis of polymyxin B-resistant mutants KPC-2-producing K. pneumoniae, and of its susceptible counterparts. Material & methods: Two-dimensional reversed phase nano ultra-performance liquid chromatography mass spectrometry was used for proteomic analysis. Results: Our results showed that the proteomic profile involved several biological processes, and we highlight the downregulation of outer membrane protein A (OmpA) and the upregulation of SlyB outer membrane lipoprotein (conserved protein member of the PhoPQ regulon) and AcrA multidrug efflux pump in polymyxin B-resistant strains. Conclusion: Our results highlight the possible participation of the SlyB, AcrA and OmpA proteins in the determination of polymyxin B heteroresistance in KPC-2-producing K. pneumoniae.
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Affiliation(s)
- Paula A Queiroz
- Postgraduate Program in Bioscience & Physiopathology, State University of Maringa, Parana, 87020-900, Brazil
| | - Jean E Meneguello
- Postgraduate Program in Bioscience & Physiopathology, State University of Maringa, Parana, 87020-900, Brazil
| | - Bruna R Silva
- Postgraduate Program in Bioscience & Physiopathology, State University of Maringa, Parana, 87020-900, Brazil
| | - Katiany R Caleffi-Ferracioli
- Postgraduate Program in Bioscience & Physiopathology, State University of Maringa, Parana, 87020-900, Brazil.,Laboratory of Medical Bacteriology, Department of Clinical Analysis & Biomedicine, State University of Maringa, Parana, 87020-900, Brazil
| | - Regiane Bl Scodro
- Laboratory of Medical Bacteriology, Department of Clinical Analysis & Biomedicine, State University of Maringa, Parana, 87020-900, Brazil
| | - Rosilene F Cardoso
- Postgraduate Program in Bioscience & Physiopathology, State University of Maringa, Parana, 87020-900, Brazil.,Laboratory of Medical Bacteriology, Department of Clinical Analysis & Biomedicine, State University of Maringa, Parana, 87020-900, Brazil
| | - Rogério Marchiosi
- Department of Biochemistry, State University of Maringa, Maringa, Parana, Brazil
| | - Vera Ld Siqueira
- Postgraduate Program in Bioscience & Physiopathology, State University of Maringa, Parana, 87020-900, Brazil.,Laboratory of Medical Bacteriology, Department of Clinical Analysis & Biomedicine, State University of Maringa, Parana, 87020-900, Brazil
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19
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Planas A. Peptidoglycan Deacetylases in Bacterial Cell Wall Remodeling and Pathogenesis. Curr Med Chem 2021; 29:1293-1312. [PMID: 34525907 DOI: 10.2174/0929867328666210915113723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 07/24/2021] [Accepted: 07/26/2021] [Indexed: 11/22/2022]
Abstract
The bacterial cell wall peptidoglycan (PG) is a dynamic structure that is constantly synthesized, re-modeled and degraded during bacterial division and growth. Post-synthetic modifications modulate the action of endogenous autolysis during PG lysis and remodeling for growth and sporulation, but also they are a mechanism used by pathogenic bacteria to evade the host innate immune system. Modifica-tions of the glycan backbone are limited to the C-2 amine and the C-6 hydroxyl moieties of either Glc-NAc or MurNAc residues. This paper reviews the functional roles and properties of peptidoglycan de-N-acetylases (distinct PG GlcNAc and MurNAc deacetylases) and recent progress through genetic stud-ies and biochemical characterization to elucidate their mechanism of action, 3D structures, substrate specificities and biological functions. Since they are virulence factors in pathogenic bacteria, peptidogly-can deacetylases are potential targets for the design of novel antimicrobial agents.
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Affiliation(s)
- Antoni Planas
- Laboratory of Biochemistry, Institut Químic de Sarrià. University Ramon Llull, 08017 Barcelona. Spain
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20
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Sayed M, Ozdemir O, Essa M, Olivier A, Karsi A, Lawrence ML, Abdelhamed H. Virulence and live vaccine potential of Edwardsiella piscicida phoP and phoQ mutants in catfish against edwardsiellosis. JOURNAL OF FISH DISEASES 2021; 44:1463-1474. [PMID: 34037985 DOI: 10.1111/jfd.13453] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/10/2021] [Accepted: 05/11/2021] [Indexed: 06/12/2023]
Abstract
Edwardsiella piscicida is a Gram-negative facultative intracellular bacterium causing edwardsiellosis in catfish, the largest aquaculture industry in the United States. A safe and effective vaccine is an urgent need to avoid economic losses associated with E. piscicida outbreaks. PhoP/PhoQ is a two-component signal transduction system (TCS) that plays an important role in bacterial pathogenesis through sense and response to environmental and host stress signals. This study aimed to explore the contribution of PhoQ/PhoP in E. piscicida virulence and develop live attenuated vaccines against E. piscicida infection in channel catfish (Ictalurus punctatus) and hybrid catfish (channel catfish ♀ × blue catfish (I. furcatus) ♂). In the current study, two in-frame deletion mutants were constructed by deleting phoP (ETAC_09785) and phoQ (ETAC_09790) genes in E. piscicida strain C07-087, and the virulence and protection efficacy of the constructed strains were evaluated in catfish following intraperitoneal injection. Both EpΔphoP and EpΔphoQ strains had a delayed adaptation to oxidative stress (0.2% H2 O2 ) compared to E. piscicida wild type. The EpΔphoP and EpΔphoQ mutants produced significantly less biofilm compared to wild-type E. piscicida. Notably, EpΔphoP and EpΔphoQ mutants were significantly attenuated in channel catfish compared with wild-type E. piscicida (6.63% and 4.17% versus 49.16% mortalities), and channel catfish vaccinated with EpΔphoP and EpΔphoQ were significantly protected (95.65% and 97.92% survival) against E. piscicida infection at 21 days post-vaccination. In hybrid catfish, EpΔphoP was significantly more attenuated than EpΔphoQ, but EpΔphoQ provided significantly better protection than EpΔphoP. EpΔphoP and EpΔphoQ strains both induced specific antibodies in channel catfish against E. piscicida at 14 and 21 days post-vaccination. This result indicated that EpΔphoP and EpΔphoQ mutants were safe and protective in channel catfish fingerlings, while EpΔphoP was safe in hybrid catfish. Our findings show that PhoP and PhoQ are required for adaptation to oxidative stress and biofilm formation and may help E. piscicida face tough environmental challenges; thus, functional PhoP and PhoQ are critical for a successful infection.
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Affiliation(s)
- Mohamed Sayed
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
- Department of Fish Diseases and Management, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef, Egypt
| | - Ozan Ozdemir
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
| | - Manal Essa
- Department of Fish Diseases and Management, Faculty of Veterinary Medicine, Beni-Suef University, Beni-Suef, Egypt
| | - Alicia Olivier
- Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
| | - Attila Karsi
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
| | - Mark L Lawrence
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
| | - Hossam Abdelhamed
- Department of Comparative Biomedical Sciences, College of Veterinary Medicine, Mississippi State University, Mississippi State, MS, USA
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21
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Ma Y, Zhang Y, Chen K, Zhang L, Zhang Y, Wang X, Xia X. The role of PhoP/PhoQ two component system in regulating stress adaptation in Cronobacter sakazakii. Food Microbiol 2021; 100:103851. [PMID: 34416955 DOI: 10.1016/j.fm.2021.103851] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Revised: 05/30/2021] [Accepted: 06/03/2021] [Indexed: 01/06/2023]
Abstract
Cronobacter sakazakii is an opportunistic foodborne bacterial pathogen that shows resistance to multiple stress conditions. The PhoP/PhoQ two component system is a key regulatory mechanism of stress response and virulence in various bacteria, but its role in C. sakazakii has not been thoroughly studied. In this study, we found the PhoP/PhoQ system in C. sakazakii ATCC BAA-894 enhanced bacterial growth in conditions with low Mg2+, acid pH, and the presence of polymyxin B. Moreover, the ΔphoPQ strain significantly reduced survival following exposure to heat, high osmotic pressure, oxidative or bile salts compared with WT strain. Furthermore, the RNA-seq analysis indicated that 1029 genes were upregulated and 979 genes were downregulated in ΔphoPQ strain. The bacterial secretion system, flagella assembly, beta-Lactam resistance and two-component system pathways were significantly downregulated, while the ABC transporters and microbial metabolism in diverse environments pathways were upregulated. qRT-PCR analysis further confirmed that twelve genes associated with stress tolerance were positively regulated by the PhoP/PhoQ system. Therefore, these findings suggest that the PhoP/PhoQ system is an important regulatory mechanism for C. sakazakii to resist various environmental stress.
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Affiliation(s)
- Yan Ma
- College of Food Science and Engineering, Sino-US Joint Research Center, Northwest A&F University, Shaanxi, 712100, China
| | - Yingying Zhang
- College of Food Science and Engineering, Sino-US Joint Research Center, Northwest A&F University, Shaanxi, 712100, China
| | - Ke Chen
- College of Food Science and Engineering, Sino-US Joint Research Center, Northwest A&F University, Shaanxi, 712100, China
| | - Lingzhu Zhang
- College of Food Science and Engineering, Sino-US Joint Research Center, Northwest A&F University, Shaanxi, 712100, China
| | - Yibei Zhang
- College of Food Science and Engineering, Sino-US Joint Research Center, Northwest A&F University, Shaanxi, 712100, China
| | - Xin Wang
- College of Food Science and Engineering, Sino-US Joint Research Center, Northwest A&F University, Shaanxi, 712100, China
| | - Xiaodong Xia
- College of Food Science and Engineering, Sino-US Joint Research Center, Northwest A&F University, Shaanxi, 712100, China; School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, 1 Qinggongyuan, Ganjingzi District, Dalian, Liaoning, 116034, China.
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Groisman EA, Duprey A, Choi J. How the PhoP/PhoQ System Controls Virulence and Mg 2+ Homeostasis: Lessons in Signal Transduction, Pathogenesis, Physiology, and Evolution. Microbiol Mol Biol Rev 2021; 85:e0017620. [PMID: 34191587 PMCID: PMC8483708 DOI: 10.1128/mmbr.00176-20] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The PhoP/PhoQ two-component system governs virulence, Mg2+ homeostasis, and resistance to a variety of antimicrobial agents, including acidic pH and cationic antimicrobial peptides, in several Gram-negative bacterial species. Best understood in Salmonella enterica serovar Typhimurium, the PhoP/PhoQ system consists o-regulated gene products alter PhoP-P amounts, even under constant inducing conditions. PhoP-P controls the abundance of hundreds of proteins both directly, by having transcriptional effects on the corresponding genes, and indirectly, by modifying the abundance, activity, or stability of other transcription factors, regulatory RNAs, protease regulators, and metabolites. The investigation of PhoP/PhoQ has uncovered novel forms of signal transduction and the physiological consequences of regulon evolution.
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Affiliation(s)
- Eduardo A. Groisman
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
- Yale Microbial Sciences Institute, West Haven, Connecticut, USA
| | - Alexandre Duprey
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
| | - Jeongjoon Choi
- Department of Microbial Pathogenesis, Yale School of Medicine, New Haven, Connecticut, USA
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23
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Serratia marcescens RamA Expression Is under PhoP-Dependent Control and Modulates Lipid A-Related Gene Transcription and Antibiotic Resistance Phenotypes. J Bacteriol 2021; 203:e0052320. [PMID: 33927048 DOI: 10.1128/jb.00523-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Serratia marcescens is an enteric bacterium that can function as an opportunistic pathogen with increasing incidence in clinical settings. This is mainly due to the ability to express a wide range of virulence factors and the acquisition of antibiotic resistance mechanisms. For these reasons, S. marcescens has been declared by the World Health Organization (WHO) as a research priority to develop alternative antimicrobial strategies. In this study, we found a PhoP-binding motif in the promoter region of transcriptional regulator RamA of S. marcescens RM66262. We demonstrated that the expression of ramA is autoregulated and that ramA is also part of the PhoP/PhoQ regulon. We have also shown that PhoP binds directly and specifically to ramA, mgtE1, mgtE2, lpxO1, and lpxO2 promoter regions and that RamA binds to ramA and lpxO1 but not to mgtE1 and lpxO2, suggesting an indirect control for the latter genes. Finally, we have demonstrated that in S. marcescens, RamA overexpression induces the AcrAB-TolC efflux pump, required to reduce the susceptibility of the bacteria to tetracycline and nalidixic acid. In sum, we here provide the first report describing the regulation of ramA under the control of the PhoP/PhoQ regulon and the regulatory role of RamA in S. marcescens. IMPORTANCE We demonstrate that in S. marcescens, the transcriptional regulator RamA is autoregulated and also controlled by the PhoP/PhoQ signal transduction system. We show that PhoP is able to directly and specifically bind to ramA, mgtE1, mgtE2, lpxO1, and lpxO2 promoter regions. In addition, RamA is able to directly interact with the promoter regions of ramA and lpxO1 but indirectly regulates mgtE1 and lpxO2. Finally, we found that in S. marcescens, RamA overexpression induces the AcrAB-TolC efflux pump, required to reduce susceptibility to tetracycline and nalidixic acid. Collectively, these results further our understanding of the PhoP/PhoQ regulon in S. marcescens and demonstrate the involvement of RamA in the protection against antibiotic challenges.
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24
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The expanding world of protein kinase-like families in bacteria: forty families and counting. Biochem Soc Trans 2021; 48:1337-1352. [PMID: 32677675 DOI: 10.1042/bst20190712] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 06/24/2020] [Accepted: 06/29/2020] [Indexed: 12/14/2022]
Abstract
The protein kinase-like clan/superfamily is a large group of regulatory, signaling and biosynthetic enzymes that were historically regarded as typically eukaryotic proteins, although bacterial members have also been known for a long time. In this review, we explore the diversity of bacterial protein kinase like families, and discuss functional versatility of these enzymes, both the ones acting within the bacterial cell, and those acting within eukaryotic cells as effectors during infection. We focus on novel bacterial kinase-like families discovered in the last five years. A bioinformatics perspective is held here, hence sequence and structure comparison overview is presented, and also a comparison of genomic neighbourhoods of the families. We perform a phylum-level census of the families. Also, we discuss apparent pseudokinases that turned out to perform alternative catalytic functions by repurposing their atypical kinase-like active sites. We also highlight some 'unpopular' kinase-like families that await characterisation.
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25
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Gu D, Xue H, Yuan X, Yu J, Xu X, Huang Y, Li M, Zhai X, Pan Z, Zhang Y, Jiao X. Genome-Wide Identification of Genes Involved in Acid Stress Resistance of Salmonella Derby. Genes (Basel) 2021; 12:genes12040476. [PMID: 33806186 PMCID: PMC8065570 DOI: 10.3390/genes12040476] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Revised: 03/23/2021] [Accepted: 03/23/2021] [Indexed: 02/05/2023] Open
Abstract
Resistance to and survival under acidic conditions are critical for Salmonella to infect the host. As one of the most prevalent serotypes identified in pigs and humans, how S. Derby overcomes acid stress remains unclear. Here, we de novo sequenced the genome of a representative S. Derby strain 14T from our S. Derby strain stock and identified its acid resistance-associated genes using Tn-seq analysis. A total of 35 genes, including those belonging to two-component systems (TCS) (cpxAR), the CRISPR-Cas system (casCE), and other systems, were identified as essential for 14T to survive under acid stress. The results demonstrated that the growth curve and survival ability of ΔcpxA and ΔcpxR were decreased under acid stress, and the adhesion and invasion abilities to the mouse colon cancer epithelial cells (MC38) of ΔcpxR were also decreased compared with the wild type strain, suggesting that the TCS CpxAR plays an essential role in the acid resistance and virulence of S. Derby. Also, CasC and CasE were found to be responsible for acid resistance in S. Derby. Our results indicate that acid stress induces multiple genes’ expression to mediate the acid resistance of S. Derby and enhance its pathogenesis during an infection.
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Affiliation(s)
- Dan Gu
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Han Xue
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Xiaohui Yuan
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Jinyan Yu
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Xiaomeng Xu
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Yu Huang
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Mingzhu Li
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Xianyue Zhai
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Zhiming Pan
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Yunzeng Zhang
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
- Correspondence:
| | - Xinan Jiao
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; (D.G.); (H.X.); (X.Y.); (J.Y.); (X.X.); (Y.H.); (M.L.); (X.Z.); (Z.P.); (X.J.)
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou 225009, China
- Joint International Research Laboratory of Agriculture and Agri-Product Safety of the Ministry of Education, Yangzhou University, Yangzhou 225009, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
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Bruchmann S, Feltwell T, Parkhill J, Short FL. Identifying virulence determinants of multidrug-resistant Klebsiella pneumoniae in Galleria mellonella. Pathog Dis 2021; 79:6123718. [PMID: 33512418 PMCID: PMC7981267 DOI: 10.1093/femspd/ftab009] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 01/26/2021] [Indexed: 12/30/2022] Open
Abstract
Infections caused by Klebsiella pneumoniae are a major public health threat. Extensively drug-resistant and even pan-resistant strains have been reported. Understanding K. pneumoniae pathogenesis is hampered by the fact that murine models of infection offer limited resolution for non-hypervirulent strains which cause the majority of infections. The insect Galleria mellonella larva is a widely used alternative model organism for bacterial pathogens. We have performed genome-scale fitness profiling of a multidrug-resistant K. pneumoniae ST258 strain during infection of G. mellonella, to determine if this model is suitable for large-scale virulence factor discovery in this pathogen. Our results demonstrated a dominant role for surface polysaccharides in infection, with contributions from siderophores, cell envelope proteins, purine biosynthesis genes and additional genes of unknown function. Comparison with a hypervirulent strain, ATCC 43816, revealed substantial overlap in important infection-related genes, as well as additional putative virulence factors specific to ST258, reflecting strain-dependent fitness effects. Our analysis also identified a role for the metalloregulatory protein NfeR (YqjI) in virulence. Overall, this study offers new insight into the infection fitness landscape of K. pneumoniae, and provides a framework for using the highly flexible and easily scalable G. mellonella infection model to dissect molecular virulence mechanisms of bacterial pathogens.
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Affiliation(s)
- Sebastian Bruchmann
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK.,Pathogen Genomics, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, UK
| | - Theresa Feltwell
- Pathogen Genomics, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, UK.,Department of Medicine, University of Cambridge, The Old Schools, Cambridge, CB2 3PU, UK
| | - Julian Parkhill
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, CB3 0ES, UK
| | - Francesca L Short
- Pathogen Genomics, Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, UK.,Department of Medicine, University of Cambridge, The Old Schools, Cambridge, CB2 3PU, UK.,Department of Molecular Sciences, Macquarie University, North Ryde, NSW 2113, Australia
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27
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Song Y, Sun M, Feng L, Liang X, Song X, Mu G, Tuo Y, Jiang S, Qian F. Antibiofilm Activity of Lactobacillus plantarum 12 Exopolysaccharides against Shigella flexneri. Appl Environ Microbiol 2020; 86:e00694-20. [PMID: 32444475 PMCID: PMC7376565 DOI: 10.1128/aem.00694-20] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 05/14/2020] [Indexed: 12/13/2022] Open
Abstract
In developing countries, Shigella flexneri is the most common enteric pathogen causing bacillary dysentery. Biofilm formation by S. flexneri can cause the emergence of antibiotic-resistant strains, which poses serious threats to food safety and human health. In this study, the effects of Lactobacillus plantarum 12 exopolysaccharides (L-EPSs) and S. flexneri exopolysaccharides (S-EPSs) on S. flexneri CMCC51574 biofilm formation were investigated. The results showed that L-EPS could decrease polysaccharide production in the extracellular polymeric matrix of S. flexneri and inhibit biofilm formation by S. flexneri L-EPS could decrease the minimum biofilm elimination concentration (MBEC) of antibiotics against S. flexneri biofilm and inhibit S. flexneri adhesion to and invasion into HT-29 cell monolayers, which might be ascribed to S. flexneri biofilm disturbance by L-EPS. In contrast, S-EPS exhibited the opposite effects compared to L-EPS. The monosaccharide composition analysis showed that L-EPS was composed of mannose, glucuronic acid, galactosamine, glucose, galactose, and xylose, with the molar ratio of 32.26:0.99:1.79:5.63:0.05:4.07, while S-EPS was composed of mannose, glucuronic acid, galactosamine, glucose, and galactose, with the molar ratio of 25.43:2.28:7.13:5.35. L-EPS was separated into the neutral polysaccharide L-EPS 1-1 and the acidic polysaccharide L-EPS 2-1 by ion-exchange chromatography and gel chromatography. L-EPS 2-1 exerted higher antibiofilm activity than L-EPS 1-1. The antibiofilm activity of L-EPS might be associated with its structure.IMPORTANCES. flexneri is a widespread foodborne pathogen causing food contamination and responsible for food poisoning outbreaks related to various foods in developing countries. Not only has biofilm formation by S. flexneri been difficult to eliminate, but it has also increased the drug resistance of the strain. In the present study, it was demonstrated that L-EPSs secreted by Lactobacillus plantrum 12 could inhibit S. flexneri biofilm formation on, adhesion to, and invasion into HT-29 cells. Also, L-EPSs could decrease the minimum biofilm elimination concentration (MBEC) of the antibiotics used against S. flexneri biofilm. Therefore, L-EPSs were shown to be bioactive macromolecules with the potential ability to act against S. flexneri infections.
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Affiliation(s)
- Yinglong Song
- School of Food Science and Technology, Dalian Polytechnic University, Dalian, People's Republic of China
| | - Mengying Sun
- School of Food Science and Technology, Dalian Polytechnic University, Dalian, People's Republic of China
| | - Lu Feng
- School of Food Science and Technology, Dalian Polytechnic University, Dalian, People's Republic of China
| | - Xue Liang
- School of Food Science and Technology, Dalian Polytechnic University, Dalian, People's Republic of China
| | - Xing Song
- School of Food Science and Technology, Dalian Polytechnic University, Dalian, People's Republic of China
| | - Guangqing Mu
- School of Food Science and Technology, Dalian Polytechnic University, Dalian, People's Republic of China
- Dalian Probiotics Function Research Key Laboratory, Dalian Polytechnic University, Dalian, People's Republic of China
| | - Yanfeng Tuo
- School of Food Science and Technology, Dalian Polytechnic University, Dalian, People's Republic of China
| | - Shujuan Jiang
- School of Food Science and Technology, Dalian Polytechnic University, Dalian, People's Republic of China
| | - Fang Qian
- School of Food Science and Technology, Dalian Polytechnic University, Dalian, People's Republic of China
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28
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Inactivation of the sfgtr4 Gene of Shigella flexneri Induces Biofilm Formation and Affects Bacterial Pathogenicity. Microorganisms 2020; 8:microorganisms8060841. [PMID: 32512756 PMCID: PMC7355660 DOI: 10.3390/microorganisms8060841] [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: 04/07/2020] [Revised: 05/08/2020] [Accepted: 05/21/2020] [Indexed: 01/08/2023] Open
Abstract
Biofilm formation is a significant cause for the environmental persistence of foodborne pathogens. This phenomenon remains misunderstood in Shigellaflexneri whose pathogenicity is mainly associated with the virulence plasmid pWR100. Sequence analysis of the latter predicts a putative lipopolysaccharides (LPS) glycosyltransferase (Gtr) encoded by Sfgtr4, which is the second gene of the SfpgdA-orf186-virK-msbB2 locus. We demonstrated here that purified SfGtr4 exhibited a Gtr activity in vitro by transferring glucose to lipid A. To establish the role of SfGtr4 in virulence, we generated a Sfgtr4 mutant and assessed its phenotype in vitro. Sfgtr4 mutant significantly reduced HeLa cells invasion without impairing type III effectors secretion, increased susceptibility to lysozyme degradation, and enhanced bacterial killing by polymorphonuclear neutrophils (PMNs). SfGtr4 is related to proteins required in biofilm formation. We established conditions whereby wild-type Shigella formed biofilm and revealed that its appearance was accelerated by the Sfgtr4 mutant. Additional phenotypical analysis revealed that single SfpdgA and double SfpgdA-Sfgtr4 mutants behaved similarly to Sfgtr4 mutant. Furthermore, a molecular interaction between SfGtr4 and SfPgdA was identified. In summary, the dual contribution of SfGtr4 and SfPgdA to the pathogenicity and the regulation biofilm formation by S. flexneri was demonstrated here.
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Role of yoaE Gene Regulated by CpxR in the Survival of Salmonella enterica Serovar Enteritidis in Antibacterial Egg White. mSphere 2020; 5:5/1/e00638-19. [PMID: 31915212 PMCID: PMC6952189 DOI: 10.1128/msphere.00638-19] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Salmonella enterica serovar Enteritidis is the predominant Salmonella serotype that causes human salmonellosis mainly through contaminated chicken eggs or egg products and has been a global public health threat. The spread and frequent outbreaks of this serotype through eggs correlate significantly with its exceptional survival in eggs, despite the antibacterial properties of egg white. Research on the survival mechanisms of S. Enteritidis in egg white will help develop effective strategies to control the contamination of eggs by this Salmonella serotype and help further elucidate the complex antibacterial mechanisms of egg white. This study revealed the importance of yoaE, a gene with unknown function, on the survival of S. Enteritidis in egg white, as well as its transcriptional regulation by CpxR. Our work provides the basis to reveal the mechanisms of survival of S. Enteritidis in egg white and the specific function of the yoaE gene. The survival ability of Salmonella enterica serovar Enteritidis in antibacterial egg white is an important factor leading to Salmonella outbreaks through eggs and egg products. In this study, the role of the gene yoaE, encoding an inner membrane protein, in the survival of Salmonella Enteritidis in egg white, and its transcriptional regulation by CpxR were investigated. Quantitative reverse transcription-PCR (RT-qPCR) results showed that the yoaE gene expression was upregulated 35-fold after exposure to egg white for 4 h compared to that in M9FeS medium, and the deletion of yoaE (ΔyoaE) dramatically decreased the survival rate of bacteria in egg white to less than 1% of the wild type (WT) and the complementary strain at both 37 and 20°C, indicating that yoaE was essential for bacteria to survive in egg white. Furthermore, the ΔyoaE strain was sensitive to a 3-kDa ultrafiltration matrix of egg white because of its high pH and antimicrobial peptide components. Putative conserved binding sites for the envelope stress response regulator CpxR were found in the yoaE promoter region. In vivo, the RT-qPCR assay results showed that the upregulation of yoaE in a ΔcpxR strain in egg white was 1/5 that of the WT. In vitro, results from DNase I footprinting and electrophoretic mobility shift assays further demonstrated that CpxR could directly bind to the yoaE promoter region, and a specific CpxR binding sequence was identified. In conclusion, it was shown for the first time that CpxR positively regulated the transcription of yoaE, which was indispensable for survival of Salmonella Enteritidis in egg white. IMPORTANCESalmonella enterica serovar Enteritidis is the predominant Salmonella serotype that causes human salmonellosis mainly through contaminated chicken eggs or egg products and has been a global public health threat. The spread and frequent outbreaks of this serotype through eggs correlate significantly with its exceptional survival in eggs, despite the antibacterial properties of egg white. Research on the survival mechanisms of S. Enteritidis in egg white will help develop effective strategies to control the contamination of eggs by this Salmonella serotype and help further elucidate the complex antibacterial mechanisms of egg white. This study revealed the importance of yoaE, a gene with unknown function, on the survival of S. Enteritidis in egg white, as well as its transcriptional regulation by CpxR. Our work provides the basis to reveal the mechanisms of survival of S. Enteritidis in egg white and the specific function of the yoaE gene.
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Bai B, Lin Z, Pu Z, Xu G, Zhang F, Chen Z, Sun X, Zheng J, Li P, Deng Q, Yu Z. In vitro Activity and Heteroresistance of Omadacycline Against Clinical Staphylococcus aureus Isolates From China Reveal the Impact of Omadacycline Susceptibility by Branched-Chain Amino Acid Transport System II Carrier Protein, Na/Pi Cotransporter Family Protein, and Fibronectin-Binding Protein. Front Microbiol 2019; 10:2546. [PMID: 31787948 PMCID: PMC6856048 DOI: 10.3389/fmicb.2019.02546] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 10/22/2019] [Indexed: 12/11/2022] Open
Abstract
Omadacycline (Omad), a new tetracycline (Tet)-class broad-spectrum aminomethylcycline, has been reported to exhibit excellent potency against Gram-positive bacteria, including Staphylococcus aureus and Enterococci. The aim of this study was to evaluate the in vitro activity and heteroresistance characteristics of Omad in clinical S. aureus isolates from China and investigate Omad resistance mechanisms. A sample of 263 non-duplicate clinical S. aureus isolates [127 methicillin-resistant (MRSA) and 136 methicillin-sensitive (MSSA)] were collected retrospectively. Our data indicated that Omad exhibited excellent in vitro activity against both MRSA and MSSA. Omad heteroresistance frequencies were 3.17% (4/126) in MRSA and 12.78% (17/133) in MSSA. No mutations in Tet target sites, (five 16SrRNA copies and 30S ribosomal protein S10) were present in heteroresistance-derived clones, whereas Tet target site mutations contribute to induced Omad resistance in S. aureus in vitro. RNA sequencing (RNA-Seq) revealed that overexpression of branched-chain amino acid transport system II carrier protein and Na/Pi cotransporter family protein contributes to Omad heteroresistance emergence. Whole-genome sequencing demonstrated that the genetic mutation of fibronectin-binding protein (FnBP) could increase the Omad MIC. In conclusion, Omad heteroresistance risk should be considered in clinical isolates with MICs ≥ 0.5 mg/L and Omad susceptibility in S. aureus may be affected by efflux pump proteins (i.e., a branched-chain amino acid transport system II carrier protein and an Na/Pi cotransporter family protein), and FnBP.
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Affiliation(s)
- Bing Bai
- Department of Infectious Diseases and Shenzhen Key Lab of Endogenous Infections, Shenzhen Nanshan People's Hospital and the 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China.,Quality Control Center of Hospital Infection Management of Shenzhen, Shenzhen Nanshan People's Hospital, Guangdong Medical University, Shenzhen, China
| | - Zhiwei Lin
- Department of Infectious Diseases and Shenzhen Key Lab of Endogenous Infections, Shenzhen Nanshan People's Hospital and the 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China.,Quality Control Center of Hospital Infection Management of Shenzhen, Shenzhen Nanshan People's Hospital, Guangdong Medical University, Shenzhen, China
| | - Zhangya Pu
- Key Laboratory of Viral Hepatitis of Hunan Province, Department of Infectious Diseases, Xiangya Hospital, Central South University, Changsha, China
| | - Guangjian Xu
- Department of Infectious Diseases and Shenzhen Key Lab of Endogenous Infections, Shenzhen Nanshan People's Hospital and the 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China.,Quality Control Center of Hospital Infection Management of Shenzhen, Shenzhen Nanshan People's Hospital, Guangdong Medical University, Shenzhen, China
| | - Fan Zhang
- Department of Infectious Diseases and Shenzhen Key Lab of Endogenous Infections, Shenzhen Nanshan People's Hospital and the 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China.,Quality Control Center of Hospital Infection Management of Shenzhen, Shenzhen Nanshan People's Hospital, Guangdong Medical University, Shenzhen, China
| | - Zhong Chen
- Department of Infectious Diseases and Shenzhen Key Lab of Endogenous Infections, Shenzhen Nanshan People's Hospital and the 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China.,Quality Control Center of Hospital Infection Management of Shenzhen, Shenzhen Nanshan People's Hospital, Guangdong Medical University, Shenzhen, China
| | - Xiang Sun
- Department of Infectious Diseases and Shenzhen Key Lab of Endogenous Infections, Shenzhen Nanshan People's Hospital and the 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China
| | - Jinxin Zheng
- Department of Infectious Diseases and Shenzhen Key Lab of Endogenous Infections, Shenzhen Nanshan People's Hospital and the 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China
| | - Peiyu Li
- Department of Infectious Diseases and Shenzhen Key Lab of Endogenous Infections, Shenzhen Nanshan People's Hospital and the 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China.,Quality Control Center of Hospital Infection Management of Shenzhen, Shenzhen Nanshan People's Hospital, Guangdong Medical University, Shenzhen, China
| | - Qiwen Deng
- Department of Infectious Diseases and Shenzhen Key Lab of Endogenous Infections, Shenzhen Nanshan People's Hospital and the 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China.,Quality Control Center of Hospital Infection Management of Shenzhen, Shenzhen Nanshan People's Hospital, Guangdong Medical University, Shenzhen, China
| | - Zhijian Yu
- Department of Infectious Diseases and Shenzhen Key Lab of Endogenous Infections, Shenzhen Nanshan People's Hospital and the 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China.,Quality Control Center of Hospital Infection Management of Shenzhen, Shenzhen Nanshan People's Hospital, Guangdong Medical University, Shenzhen, China
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Metabolic adaptability shifts of cell membrane fatty acids of Komagataeibacter hansenii HDM1-3 improve acid stress resistance and survival in acidic environments. J Ind Microbiol Biotechnol 2019; 46:1491-1503. [PMID: 31512094 DOI: 10.1007/s10295-019-02225-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 08/07/2019] [Indexed: 12/17/2022]
Abstract
Komagataeibacter hansenii HDM1-3 (K. hansenii HDM1-3) has been widely applied for producing bacterial cellulose (BC). The yield of BC has been frequently limited by the acidification during sugar metabolism, due to the generation of organic acids such as acetic acid. In this study, the acid resistance mechanism of K. hansenii HDM1-3 has been investigated from the aspect of metabolic adaptability of cell membrane fatty acids. Firstly, we observed that the survival rate of K. hansenii HDM1-3 was decreased with lowered pH values (adjusted with acetic acids), accompanied by increased leakage rate. Secondly, the cell membrane adaptability in response to acid stress was evaluated, including the variations of cell membrane fluidity and fatty acid composition. The proportion of unsaturated fatty acids was increased (especially, C18-1w9c and C19-Cyc), unsaturation degree and chain length of fatty acids were also increased. Thirdly, the potential molecular regulation mechanism was further elucidated. Under acid stress, the fatty acid synthesis pathway was involved in the structure and composition variations of fatty acids, which was proved by the activation of both fatty acid dehydrogenase (des) and cyclopropane fatty acid synthase (cfa) genes, as well as the addition of exogenous fatty acids. The fatty acid synthesis of K. hansenii HDM1-3 may be mediated by the activation of two-component sensor signaling pathways in response to the acid stress. The acid resistance mechanism of K. hansenii HDM1-3 adds to our knowledge of the acid stress adaptation, which may facilitate the development of new strategies for improving the industrial performance of this species under acid stress.
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Song X, Hou M, Tu J, Xue M, Shao Y, Jiang H, Liu H, Xue T, Wang G, Qi K. Outer membrane proteins YbjX and PagP co-regulate motility in Escherichia coli via the bacterial chemotaxis pathway. Res Vet Sci 2019; 125:279-284. [PMID: 31326704 DOI: 10.1016/j.rvsc.2019.07.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 05/25/2019] [Accepted: 07/10/2019] [Indexed: 02/08/2023]
Abstract
Mutation of the PhoP/Q two-component system decreases the expression of ybjX and pagP encoding outer membrane proteins, and mutation of ybjX or pagP attenuates avian pathogenic Escherichia coli (APEC) pathogenicity. However, whether ybjX/pagP mutation (double-deletion mutant) has a synergistic effect on pathogenicity remains unknown. Herein, electrophoresis mobility shift assay (EMSA) experiments showed that the PhoP/Q system regulated ybjX and pagP transcription indirectly. The APECΔybjX/pagP mutant strain, constructed using the Red recombination method, exhibited reduced invasion of chicken embryo fibroblast (DF-1) cells, but had no effect on virulence in a chicken model. Using RNA sequencing to identify differential mRNAs in APECΔybjXΔpagP and native strains, we revealed up-regulation of genes involved in the bacterial chemotaxis pathway. The ybjX/pagP mutant strain displayed significantly increased motility, suggesting that double deletion of ybjX and pagP enhances motility via the bacterial chemotaxis pathway.
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Affiliation(s)
- Xiangjun Song
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, PR China
| | - Manman Hou
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, PR China
| | - Jian Tu
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, PR China
| | - Mei Xue
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, PR China
| | - Ying Shao
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, PR China
| | - Huyan Jiang
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, PR China
| | - Hongmei Liu
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, PR China
| | - Ting Xue
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, PR China
| | - Guijun Wang
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, PR China
| | - Kezong Qi
- Anhui Province Key Laboratory of Veterinary Pathobiology and Disease Control, College of Animal Science and Technology, Anhui Agricultural University, Hefei 230036, PR China.
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