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Li H, Yang Y, Li L, Zheng H, Xiong Z, Hou J, Wang L. Genome-Based Identification and Characterization of Bacteriocins Selectively Inhibiting Staphylococcus aureus in Fermented Sausages. Probiotics Antimicrob Proteins 2024:10.1007/s12602-024-10240-4. [PMID: 38451405 DOI: 10.1007/s12602-024-10240-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/27/2024] [Indexed: 03/08/2024]
Abstract
The bacteriocin-producing Lactiplantibacillus plantarum SL47 was isolated from conventional fermented sausages, and the bacteriocin SL47 was purified using ethyl acetate, Sephadex G-25 gel chromatography, and reversed-phase high-performance liquid chromatography (RP-HPLC). Bacteriocin SL47 was identified by HPLC-MS/MS combined with whole-genome sequencing, and the results showed it consisted of plantaricin A, J, K, and N. Further characterization analysis showed that the bacteriocin SL47 was highly thermostable (30 min, 121 °C), pH stable (2-10), sensitive to protease and exhibited broad-spectrum antibacterial ability against Gram-positive and Gram-negative bacteria. The mechanism of action showed that the bacteriocin SL47 increased cell membrane permeability, and 2 × minimum inhibitory concentration (MIC) treatment for 40 min caused apoptosis of Staphylococcus aureus F2. The count of S. aureus in the sausage that was inoculated with L. plantarum SL47 and bacteriocin SL47 decreased by about 64% and 53% of that in the initial stage, respectively. These results indicated the potential of L. plantarum SL47 and bacteriocin SL47 as a bio-preservative in meat products.
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Affiliation(s)
- Hongbiao Li
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, 201306, China
| | - Yongqi Yang
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, 201306, China
| | - Lanxin Li
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, 201306, China
| | - Huojian Zheng
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, 201306, China
| | - Zhiguo Xiong
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, 201306, China
| | - Junjie Hou
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, 201306, China
| | - Liping Wang
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, 201306, China.
- Engineering Research Center of Food Thermal-Processing Technology, Shanghai Ocean University, Shanghai, 201306, China.
- Laboratory of Quality and Safety Risk Assessment for Aquatic Products On Storage and Preservation, Shanghai, 201306, China.
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Ren J, Wang M, Zhou W, Liu Z. Efflux pumps as potential targets for biofilm inhibition. Front Microbiol 2024; 15:1315238. [PMID: 38596384 PMCID: PMC11002903 DOI: 10.3389/fmicb.2024.1315238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 01/26/2024] [Indexed: 04/11/2024] Open
Abstract
Biofilms account for a great deal of infectious diseases and contribute significantly to antimicrobial resistance. Efflux pumps confer antimicrobial resistance to microorganisms and involve multiple processes of biofilm formation. Efflux pump inhibitors (EPIs) are attracting considerable attention as a biofilm inhibition strategy. The regulatory functions of efflux pumps in biofilm formation such as mediating adherence, quorum sensing (QS) systems, and the expression of biofilm-associated genes have been increasingly identified. The versatile properties confer efflux pumps both positive and negative effects on biofilm formation. Furthermore, the expression and function of efflux pumps in biofilm formation are species-specific. Therefore, this review aims to detail the double-edged sword role of efflux pumps in biofilm formation to provide potential inhibition targets and give an overview of the effects of EPIs on biofilm formation.
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Affiliation(s)
| | | | - Wenjuan Zhou
- Department of Implantology, Yantai Stomatological Hospital Affiliated to Binzhou Medical University, Yantai, China
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Jin T, Zhan X, Pang L, Peng B, Zhang X, Zhu W, Yang B, Xia X. CpxAR two-component system contributes to virulence properties of Cronobacter sakazakii. Food Microbiol 2024; 117:104393. [PMID: 37919015 DOI: 10.1016/j.fm.2023.104393] [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: 07/29/2023] [Revised: 09/24/2023] [Accepted: 10/01/2023] [Indexed: 11/04/2023]
Abstract
Cronobacter sakazakii (C. sakazakii) is a foodborne pathogen which threaten susceptible hosts including infants. CpxA/CpxR, a regulatory two-component system (TSC), contributes to stress response and virulence in various Gram-negative pathogens, but its role in C. sakazakii has not been thoroughly studied. In this study, we constructed CpxA, CpxR, CpxAR deletion and complementation strains. The mutants showed weakened bacterial adhesion to and invasion of HBMEC and Caco-2, reduced intracellular survival and replication of C. sakazakii within RAW264.7 macrophages, and decreased translocation of HBMEC and Caco-2 monolayers. Mutants demonstrated lower levels of tight junction proteins disruption and reduced apoptosis and cytotoxicity in Caco-2 monolayer compared to wild type strain. CpxAR TCS deletion mutants demonstrate attenuated virulence in newborn mice, which was evidenced by fewer bacterial cells loads in tissues and organs, lower levels of intestinal epithelial barrier dysfuction and milder damages in intestinal tissues. All these phenotypes were recovered in complemented strains. In addition, qRT-PCR results showed that CpxAR TCS of C. sakazakii played roles in regulating the expression of several genes associated with bacterial virulence and cellular invasion. These findings indicate that CpxAR TCS is an important regulatory mechanism for virulence of C. sakazakii, which enrich our understanding of genetic determinants of pathogenicity of the pathogen.
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Affiliation(s)
- Tong Jin
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Xiangjun Zhan
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Liuxin Pang
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Bo Peng
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China; Food Science and Technology Department, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Xinpeng Zhang
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China; Food Science and Technology Department, University of Nebraska-Lincoln, Lincoln, NE, 68588, USA
| | - Wenxiu Zhu
- State Key Laboratory of Marine Food Processing and Safety Control, National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian, Liaoning, 116034, China
| | - Baowei Yang
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China.
| | - Xiaodong Xia
- College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China; State Key Laboratory of Marine Food Processing and Safety Control, National Engineering Research Center of Seafood, School of Food Science and Technology, Dalian Polytechnic University, Dalian, Liaoning, 116034, China.
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4
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Dinda V, Kimang’a AN, Kariuki D, Sifuna AW, O’Brien TJ, Welch M, Reva ON. Whole genome sequencing and genotyping Klebsiella pneumoniae multi-drug resistant hospital isolates from Western Kenya. Access Microbiol 2024; 6:000667.v4. [PMID: 38361654 PMCID: PMC10866029 DOI: 10.1099/acmi.0.000667.v4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 01/08/2024] [Indexed: 02/17/2024] Open
Abstract
Objectives Klebsiella pneumoniae are a frequent cause of nosocomial infections worldwide. Sequence type 147 (ST147) has been reported as a major circulating high-risk lineage in many countries, and appears to be a formidable platform for the dissemination of antimicrobial resistance (AMR) determinants. However, the distribution of this pathogen in Western African hospitals has been scarcely studied. The main objective of this work was to perform whole genome sequencing of K. pneumoniae isolates from a referral hospital in Kakamega (Kenya) for genotyping and identification of AMR and virulence determinants. Methods In total, 15 K. pneumoniae isolates showing a broad spectrum antimicrobial resistance were selected for whole genome sequencing by Illumina HiSeq 2500 platform. Results ST147 was the dominant lineage among the highly-resistant K. pneumoniae isolates that we sequenced. ST147 was associated with both community- and the hospital-acquired infections, and with different infection sites, whereas other STs were predominantly uropathogens. Multiple antibiotic resistance and virulence determinants were detected in the genomes including extended-spectrum β-lactamases (ESBL) and carbapenemases. Many of these genes were plasmid-borne. Conclusions Our data suggest that the evolutionary success of ST147 may be linked with the acquisition of broad host-range plasmids, and their propensity to accrue AMR and virulence determinants. Although ST147 is a dominant lineage in many countries worldwide, it has not been previously reported as prevalent in Africa. Our data suggest an influx of new nosocomial pathogens with new virulence genes into African hospitals from other continents.
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Affiliation(s)
- Victor Dinda
- Department of Medical Laboratory Science, Masinde Muliro University of Science and Technology, Kakamega, Kenya
| | - Andrew Nyerere Kimang’a
- Department of Medical Microbiology, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Daniel Kariuki
- Department of Biochemistry, Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya
| | - Anthony Wawire Sifuna
- Department of Medical Biochemistry, Masinde Muliro University of Science and Technology, Kakamega, Kenya
| | - Thomas James O’Brien
- Department of Biochemistry, University of Cambridge, Hopkins Building, Cambridge, UK
| | - Martin Welch
- Department of Biochemistry, University of Cambridge, Hopkins Building, Cambridge, UK
| | - Oleg N. Reva
- Centre for Bioinformatics and Computational Biology, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Pretoria, South Africa
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Sheoran P, Yadav MK, Kumari I, Tiwari SK. Enterocin LD3 from Enterococcus hirae LD3 Inhibits the Growth of Salmonella enterica subsp. enterica serovar Typhimurium ATCC 13311 in Fruit Juice. Probiotics Antimicrob Proteins 2023:10.1007/s12602-023-10108-z. [PMID: 37330452 DOI: 10.1007/s12602-023-10108-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/06/2023] [Indexed: 06/19/2023]
Abstract
In order to prevent the growth of pathogens in food, bacteriocins produced by various probiotic lactic acid bacteria have been recognized as potential substitutes of chemical preservatives. In this study, enterocin LD3 was purified from the cell-free supernatant of a food isolate, Enterococcus hirae LD3 using multistep chromatography. In the fruit juice, lethal concentration (LC50) of enterocin LD3 was found to be 260 µg/mL against Salmonella enterica subsp. enterica serovar Typhimurium ATCC 13311. The cells treated with enterocin LD3 were red colour indicating dead cells after propidium iodide staining, while untreated cells were found blue after staining with 4', 6-diamidino-2-phenylindole. The mechanism of cell killing was analyzed using infrared spectrum of cells treated with enterocin LD3 which was found altered in the range of 1,094.30 and 1,451.82 cm-1 corresponding to nucleic acids and phospholipids, respectively. The morphology of target cells were severely ruptured and lysed as observed under electron microscopy. Thus, the present study suggested that enterocin LD3 showed bactericidal activity against Salm. enterica subsp. enterica serovar Typhimurium ATCC 13311 and may be applied as a bio-preservative for the safety of fruit juices.
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Affiliation(s)
- Poonam Sheoran
- Department of Genetics, Maharshi Dayanand University, Rohtak, 124001, Haryana, India
| | - Manoj Kumar Yadav
- Department of Genetics, Maharshi Dayanand University, Rohtak, 124001, Haryana, India
| | - Indu Kumari
- Department of Genetics, Maharshi Dayanand University, Rohtak, 124001, Haryana, India
| | - Santosh Kumar Tiwari
- Department of Genetics, Maharshi Dayanand University, Rohtak, 124001, Haryana, India.
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Characterization of the Role of Two-Component Systems in Antibiotic Resistance Formation in Salmonella enterica Serovar Enteritidis. mSphere 2022; 7:e0038322. [PMID: 36286534 PMCID: PMC9769886 DOI: 10.1128/msphere.00383-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The two-component system (TCS) is one of the primary pathways by which bacteria adapt to environmental stresses such as antibiotics. This study aimed to systematically explore the role of TCSs in the development of multidrug resistance (MDR) in Salmonella enterica serovar Enteritidis. Twenty-six in-frame deletion mutants of TCSs were generated from S. Enteritidis SJTUF12367 (the wild type [WT]). Antimicrobial susceptibility tests with these mutants revealed that 10 TCSs were involved in the development of antibiotic resistance in S. Enteritidis. In these 10 pairs of TCSs, functional defects in CpxAR, PhoPQ, and GlnGL in various S. Enteritidis isolates led to a frequent decrease in MIC values against at least three classes of clinically important antibiotics, including cephalosporins and quinolones, which indicated the importance of these TCSs to the formation of MDR. Interaction network analysis via STRING revealed that the genes cpxA, cpxR, phoP, and phoQ played important roles in the direct interaction with global regulatory genes and the relevant genes of efflux pumps and outer membrane porins. Quantitative reverse transcription-PCR analysis further demonstrated that the increased susceptibility to cephalosporins and quinolones in ΔphoP and ΔcpxR mutant cells was accompanied by increased expression of membrane porin genes (ompC, ompD, and ompF) and reduced expression of efflux pump genes (acrA, macB, and mdtK), as well as an adverse transcription of the global regulatory genes (ramA and crp). These results indicated that CpxAR and PhoPQ played an important role in the development of MDR in S. Enteritidis through regulation of cell membrane permeability and efflux pump activity. IMPORTANCE S. Enteritidis is a predominant Salmonella serotype that causes human salmonellosis and frequently exhibits high-level resistance to commonly used antibiotics, including cephalosporins and quinolones. Although TCSs are known as regulators for bacterial adaptation to stressful conditions, which modulates β-lactam resistance in Vibrio parahaemolyticus and colistin resistance in Salmonella enterica serovar Typhimurium, there is little knowledge of their functional mechanisms underlying the development of antibiotic resistance in S. Enteritidis. Here, we systematically identified the TCS elements in S. Enteritidis SJTUF12367, revealed that the three TCSs CpxAR, PhoPQ, and GlnGL were crucial for the MDR formation in S. Enteritidis, and preliminarily illustrated the regulatory functions of CpxAR and PhoPQ for antimicrobial resistance genes. Our work provides the basis to understand the important TCSs that regulate formation of antibiotic resistance in S. Enteritidis.
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Abitayeva GK, Urazova MS, Abilkhadirov AS, Sarmurzina ZS, Shaikhin SM. Characterization of a new bacteriocin-like inhibitory peptide produced by Lactobacillus sakei B-RKM 0559. Biotechnol Lett 2021; 43:2243-2257. [PMID: 34652635 DOI: 10.1007/s10529-021-03193-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 10/02/2021] [Indexed: 10/20/2022]
Abstract
The biopreservation strategy allows extending the shelf life and food safety through the use of indigenous or controlled microbiota and their antimicrobial compounds. The aim of this work was to characterize an inhibitory substance with bacteriocin-like activity (Sak-59) produced by the potentially probiotic L. sakei strain from artisanal traditional Kazakh horse meat product Kazy. The maximum production of Sak-59 occurred at the stationary phase of the L. sakei growth. Sak-59 showed inhibitory activity against gram-positive meat spoilage bacteria strains of Listeria monocytogenes, Staphylococcus aureus, and pathogenic gram-negative bacteria strains of Serratia marcescens and Escherichia coli, but not against the tested Lactobacilli strains. Sak-59 activity, as measured by diffusion assay in agar wells, was completely suppressed after treatment with proteolytic enzymes and remained stable after treatment with α-amylase and lipase, indicating that Sak-59 is a peptide and most likely not glycosylated or lipidated. It was concluded that Sak-59 is a potential new bacteriocin with a characteristic activity spectrum, which can be useful in the food and feed industries.
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Affiliation(s)
- Gulyaim K Abitayeva
- Laboratory of Genetics and Biochemistry of Microorganisms, Republican Collection of Microorganisms of the Committee of Science of the Ministry of Education and Science of the Republic of Kazakhstan, 13/1 Valikhanov Str., 010000, Nur-Sultan, Republic of Kazakhstan
| | - Maira S Urazova
- Laboratory of Biotechnology, Republican Collection of Microorganisms of the Committee of Science of the Ministry of Education and Science of the Republic of Kazakhstan, 13/1 Valikhanov Str., Nur-Sultan, 010000, Republic of Kazakhstan
| | - Arman S Abilkhadirov
- Laboratory of Genetics and Biochemistry of Microorganisms, Republican Collection of Microorganisms of the Committee of Science of the Ministry of Education and Science of the Republic of Kazakhstan, 13/1 Valikhanov Str., 010000, Nur-Sultan, Republic of Kazakhstan
| | - Zinigul S Sarmurzina
- Laboratory of Microbiology, Republican Collection of Microorganisms of the Committee of Science of the Ministry of Education and Science of the Republic of Kazakhstan, 13/1 Valikhanov Str., 010000, Nur-Sultan, Republic of Kazakhstan
| | - Serik M Shaikhin
- Laboratory of Genetics and Biochemistry of Microorganisms, Republican Collection of Microorganisms of the Committee of Science of the Ministry of Education and Science of the Republic of Kazakhstan, 13/1 Valikhanov Str., 010000, Nur-Sultan, Republic of Kazakhstan.
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Zhang MK, Zhang MY, Liu SB, Yang YY, Zhai YJ, He DD, Wu H, Pan YS, Liu JH, Yuan L, Hu GZ. Double deletion of cpxR and tolC significantly increases the susceptibility of Salmonella enterica serovar Typhimurium to colistin. J Antimicrob Chemother 2021; 76:3168-3174. [PMID: 34499729 DOI: 10.1093/jac/dkab332] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 08/16/2021] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND The increasing use of colistin causes a serious breach in our last line of defence against MDR Gram-negative pathogens. Our previous study showed that CpxR overexpression increases the susceptibility of acrB and cpxR double-deleted Salmonella enterica serovar Typhimurium to colistin. OBJECTIVES To identify the mechanism of CpxAR and efflux pumps that synergistically enhance the susceptibility of S. Typhimurium to colistin. METHODS A series of cpxR- and tolC-deleted mutants and a cpxR-complemented strain from a multidrug-susceptible standard strain of S. Typhimurium (JS) were generated in our previous study. Herein, we investigated the susceptibility of these strains to colistin through the broth microdilution method, time-kill curves and survival assays. Growth curves were measured by OD600 in LB broth, tryptone-soy broth (TSB) and M9-glucose (0.2%) minimal media. Finally, molecular mechanisms underlying the mode of action were elucidated by transcriptomic analysis. RESULTS We found that in contrast to JS (0.8 mg/L), the MIC of colistin for JSΔtolC::kan showed a 16-fold decrease (0.05 mg/L). Notably, JSΔcpxRΔtolC and JSΔcpxRΔtolC/pcpxR were associated with a 256-fold decrease (0.0031 mg/L) compared with JS. Growth curves identified that JSΔcpxRΔtolC and JSΔcpxRΔtolC/pcpxR displayed a markedly lower growth rate and poorer adaptability. In addition, time-kill curves and survival assays showed that JSΔcpxRΔtolC and JSΔcpxRΔtolC/pcpxR were more susceptible to colistin. Lastly, double deletion of cpxR and tolC enhanced oxidative damage through promoting oxidative phosphorylation, the tricarboxylic acid (TCA) cycle and trimethylamine N-oxide (TMAO) respiration. CONCLUSIONS Our findings revealed that double deletion of cpxR and tolC significantly increases the susceptibility of S. Typhimurium to colistin.
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Affiliation(s)
- Meng-Ke Zhang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Meng-Yao Zhang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Shuo-Bo Liu
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Ying-Ying Yang
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Ya-Jun Zhai
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Dan-Dan He
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Hua Wu
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Yu-Shan Pan
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Jian-Hua Liu
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Li Yuan
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
| | - Gong-Zheng Hu
- College of Veterinary Medicine, Henan Agricultural University, Zhengzhou, China
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Chen X, Liu Y, Jin J, Liu H, Hao Y, Zhang H, Xie Y. YbfA Regulates the Sensitivity of Escherichia coli K12 to Plantaricin BM-1 via the BasS/BasR Two-Component Regulatory System. Front Microbiol 2021; 12:659198. [PMID: 34484135 PMCID: PMC8415914 DOI: 10.3389/fmicb.2021.659198] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 07/23/2021] [Indexed: 11/16/2022] Open
Abstract
Plantaricin BM-1, a class IIa bacteriocin produced by Lactobacillus plantarum BM-1, shows obvious antibacterial activity against Escherichia coli. However, the mechanism underlying the action of class IIa bacteriocins against gram-negative bacteria remains to be explored. The purpose of this study was to investigate the role of YbfA, a DUF2517 domain-containing protein, in the response of Escherichia coli K12 to plantaricin BM-1. The growth curve experiment and MIC experiment showed that the sensitivity of E. coli to plantaricin BM-1 was decreased by a ybfA null mutation. Electron microscopy showed that the ybfA null mutation reduced the surface rupture and contraction caused by plantaricin BM-1, and mitigated the effect of plantaricin BM-1 on the morphology of the E. coli cell membrane. Proteomics analysis showed that 323 proteins were differentially expressed in E. coli lacking the ybfA gene (P < 0.05); 118 proteins were downregulated, and 205 proteins were upregulated. The metabolic pathways containing the upregulated proteins mainly included outer membrane proteins, integral components of the plasma membrane, regulation of cell motility, and regulation of locomotion. The metabolic pathways involving the downregulated proteins mainly included outer membrane protein glycine betaine transport, amino-acid betaine transport, and transmembrane signaling receptor activity. The results of the proteomics analysis showed that the protein expression of the BasS/BasR two-component system was significantly increased (P < 0.05). Moreover, the expression levels of downstream proteins regulated by this two-component system were also significantly increased, including DgkA, FliC, and MlaE, which are involved in cell membrane structure and function, and RT-qPCR also confirmed this result. The growth curve showed that the sensitivity of E. coli to plantaricin BM-1 was significantly increased due to deletion of the BasS/BasR two-component system. Thus, deletion of ybfA in E. coli can increase the expression of the BasS/BasR two-component system and positively regulate the structure and function of the cell membrane to reduce the sensitivity to plantaricin BM-1. This will help to explore the mechanism of action of class IIa bacteriocins against gram-negative bacteria.
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Affiliation(s)
- Xinyue Chen
- Beijing Laboratory of Food Quality and Safety, Beijing Key Laboratory of Agricultural Product Detection and Control of Spoilage Organisms and Pesticide Residue, College of Food Science and Engineering, Beijing University of Agriculture, Beijing, China
| | - Yifei Liu
- Beijing Laboratory of Food Quality and Safety, Beijing Key Laboratory of Agricultural Product Detection and Control of Spoilage Organisms and Pesticide Residue, College of Food Science and Engineering, Beijing University of Agriculture, Beijing, China
| | - Junhua Jin
- Beijing Laboratory of Food Quality and Safety, Beijing Key Laboratory of Agricultural Product Detection and Control of Spoilage Organisms and Pesticide Residue, College of Food Science and Engineering, Beijing University of Agriculture, Beijing, China
| | - Hui Liu
- Beijing Laboratory of Food Quality and Safety, Beijing Key Laboratory of Agricultural Product Detection and Control of Spoilage Organisms and Pesticide Residue, College of Food Science and Engineering, Beijing University of Agriculture, Beijing, China
| | - Yanling Hao
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Hongxing Zhang
- Beijing Laboratory of Food Quality and Safety, Beijing Key Laboratory of Agricultural Product Detection and Control of Spoilage Organisms and Pesticide Residue, College of Food Science and Engineering, Beijing University of Agriculture, Beijing, China
| | - Yuanhong Xie
- Beijing Laboratory of Food Quality and Safety, Beijing Key Laboratory of Agricultural Product Detection and Control of Spoilage Organisms and Pesticide Residue, College of Food Science and Engineering, Beijing University of Agriculture, Beijing, China
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