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Wang YS, Zhou G, Tao HB, Gao L, Fang BZ, Yang XJ, Peng H, Wen X, Huang XM, Wang J, Li WJ, Shi QS, Xie XB. Acinetobacter corruptisaponis sp. nov., Isolated from a Spoiled Bath Lotion. Curr Microbiol 2024; 81:396. [PMID: 39375231 DOI: 10.1007/s00284-024-03921-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2024] [Accepted: 09/26/2024] [Indexed: 10/09/2024]
Abstract
Strain DM2021935T representing a novel Acinetobacter species was isolated from a spoiled bath lotion in Guangdong, China. Based on 16S rRNA gene phylogenetic analysis, strain DM2021935T was closely related to 'Acinetobacter thutiue' VNH17T, Acinetobacter junii CIP 64.5 T, and Acinetobacter tibetensis Y-23 T. Cells of strain DM2021935T were Gram-stain-negative, non-spore-forming, strictly aerobic, catalase-positive, oxidase-negative, α-hemolytic, and non-motile. Strain DM2021935T exhibited growth in 1-3% (w/v) NaCl at temperatures ranging from 4 to 37 °C and tolerated pH levels from 6.0 to 8.0. The predominant fatty acids in strain DM2021935T are C12:0, C16:0, C18:1 ω9c, and summed feature 3. Polar lipid profiles included glycolipids, phospholipids, phosphatidylethanolamine, and phosphatidyl-N-methylethanolamine. The identified respiratory quinones were ubiquinone Q-8 and Q-9. The genomic size of DM2021935T comprised 4.15 Mb, consisting of one chromosome (3,827,633 bp) and two plasmids (241,357 and 83,010 bp). The G + C content was 41.8%. The average nucleotide identity, average amino acid identity, and digital DNA-DNA hybridization values between strain DM2021935T and phylogenetically related type strains were below the species delineation thresholds (72.2-95.4, 53.1-87.0, and 20.4-66.4%, respectively). AntiSMASH analysis identified four gene clusters: non-ribosomal peptide synthetase, non-alpha poly-amino group acids, YcaO cyclodehydratase, and aryl polyene biosynthesis. Based on genotypic data, strain DM2021935T represents a novel species within the genus Acinetobacter. The proposed name for the novel species is Acinetobacter corruptisaponis sp. nov. (type strain DM2021935T = KCTC 92772 T = GDMCC 1.3703 T).
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Affiliation(s)
- Ying-Si Wang
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, 510070, People's Republic of China
- Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou, 510642, People's Republic of China
| | - Gang Zhou
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, 510070, People's Republic of China
| | - Hong-Bing Tao
- Guangdong De-May New Materials Technology Co., Ltd., Zhaoqing, Guangdong, 526238, People's Republic of China
| | - Lei Gao
- State Key Laboratory of Desert and Oasis Ecology, Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, People's Republic of China
| | - Bao-Zhu Fang
- State Key Laboratory of Desert and Oasis Ecology, Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, People's Republic of China
| | - Xiu-Jiang Yang
- Guangdong De-May New Materials Technology Co., Ltd., Zhaoqing, Guangdong, 526238, People's Republic of China
| | - Hong Peng
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, 510070, People's Republic of China
| | - Xia Wen
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, 510070, People's Republic of China
| | - Xiao-Mo Huang
- Guangdong De-May New Materials Technology Co., Ltd., Zhaoqing, Guangdong, 526238, People's Republic of China
| | - Jie Wang
- Guangdong Provincial Key Laboratory of Nutraceuticals and Functional Foods, College of Food Science, South China Agricultural University, Guangzhou, 510642, People's Republic of China
| | - Wen-Jun Li
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, Guangdong, People's Republic of China.
| | - Qing-Shan Shi
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, 510070, People's Republic of China.
| | - Xiao-Bao Xie
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, 510070, People's Republic of China.
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Hanson BS, Hailemariam A, Yang Y, Mohamed F, Donati GL, Baker D, Sacchettini J, Cai JJ, Subashchandrabose S. Identification of a copper-responsive small molecule inhibitor of uropathogenic Escherichia coli. J Bacteriol 2024; 206:e0011224. [PMID: 38856220 PMCID: PMC11270900 DOI: 10.1128/jb.00112-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Accepted: 05/10/2024] [Indexed: 06/11/2024] Open
Abstract
Urinary tract infections (UTIs) are a major global health problem and are caused predominantly by uropathogenic Escherichia coli (UPEC). UTIs are a leading cause of prescription antimicrobial use. Incessant increase in antimicrobial resistance in UPEC and other uropathogens poses a serious threat to the current treatment practices. Copper is an effector of nutritional immunity that impedes the growth of pathogens during infection. We hypothesized that copper would augment the toxicity of select small molecules against bacterial pathogens. We conducted a small molecule screening campaign with a library of 51,098 molecules to detect hits that inhibit a UPEC ΔtolC mutant in a copper-dependent manner. A molecule, denoted as E. coli inhibitor or ECIN, was identified as a copper-responsive inhibitor of wild-type UPEC strains. Our gene expression and metal content analysis results demonstrate that ECIN works in concert with copper to exacerbate Cu toxicity in UPEC. ECIN has a broad spectrum of activity against pathogens of medical and veterinary significance including Acinetobacter baumannii, Pseudomonas aeruginosa, and methicillin-resistant Staphylococcus aureus. Subinhibitory levels of ECIN eliminate UPEC biofilm formation. Transcriptome analysis of UPEC treated with ECIN reveals induction of multiple stress response systems. Furthermore, we demonstrate that L-cysteine rescues the growth of UPEC exposed to ECIN. In summary, we report the identification and characterization of a novel copper-responsive small molecule inhibitor of UPEC.IMPORTANCEUrinary tract infection (UTI) is a ubiquitous infectious condition affecting millions of people annually. Uropathogenic Escherichia coli (UPEC) is the predominant etiological agent of UTI. However, UTIs are becoming increasingly difficult to resolve with antimicrobials due to increased antimicrobial resistance in UPEC and other uropathogens. Here, we report the identification and characterization of a novel copper-responsive small molecule inhibitor of UPEC. In addition to E. coli, this small molecule also inhibits pathogens of medical and veterinary significance including Acinetobacter baumannii, Pseudomonas aeruginosa, and methicillin-resistant Staphylococcus aureus.
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Affiliation(s)
- Braden S Hanson
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Amanuel Hailemariam
- Department of Biochemistry and Biophysics, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas, USA
| | - Yongjian Yang
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Faras Mohamed
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - George L Donati
- Department of Chemistry, Wake Forest University, Winston-Salem, North Carolina, USA
| | - Dwight Baker
- Department of Biochemistry and Biophysics, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas, USA
| | - James Sacchettini
- Department of Biochemistry and Biophysics, College of Agriculture and Life Sciences, Texas A&M University, College Station, Texas, USA
| | - James J Cai
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Sargurunathan Subashchandrabose
- Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
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Bing C, Mengjuan A, Xinyu M, Chixin Z, Xinyao T, Yan S, Zhi L. Efflux pump inhibitor chlorpromazine effectively increases the susceptibility of Escherichia coli to antimicrobial peptide Brevinin-2CE. Future Microbiol 2024; 19:771-782. [PMID: 38683168 PMCID: PMC11290751 DOI: 10.2217/fmb-2023-0272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Accepted: 02/21/2024] [Indexed: 05/01/2024] Open
Abstract
Aim: The response of E. coli ATCC8739 to Brevinin-2CE (B2CE) was evaluated as a strategy to prevent the development of antimicrobial peptide (AMP)-resistant bacteria. Methods: Gene expression levels were detected by transcriptome sequencing and RT-PCR. Target genes were knocked out using CRISPR-Cas9. MIC was measured to evaluate strain resistance. Results: Expression of acrZ and sugE were increased with B2CE stimulation. ATCC8739ΔacrZ and ATCC8739ΔsugE showed twofold and fourfold increased sensitivity, respectively. The survival rate of ATCC8739 was reduced in the presence of B2CE/chlorpromazine (CPZ). Combinations of other AMPs with CPZ also showed antibacterial effects. Conclusion: The results indicate that combinations of AMPs/efflux pump inhibitors (EPIs) may be a potential approach to combat resistant bacteria.
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Affiliation(s)
- Cao Bing
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, PR China
| | - An Mengjuan
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, PR China
| | - Ma Xinyu
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, PR China
| | - Zhu Chixin
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, PR China
| | - Tan Xinyao
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, PR China
| | - Sun Yan
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, PR China
| | - Li Zhi
- College of Life Sciences, Shaanxi Normal University, Xi'an, 710119, PR China
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Zhou G, Gao L, Fang BZ, Wang YS, Tao HB, Wen X, Wang Q, Huang XM, Shi QS, Li WJ, Xie XB. Fundicoccus culcitae sp. nov., a novel potential bacteriocin producing bacterium isolated from a spoiled eye mask. Antonie Van Leeuwenhoek 2023; 116:1185-1195. [PMID: 37704902 DOI: 10.1007/s10482-023-01866-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 08/05/2023] [Indexed: 09/15/2023]
Abstract
A Gram-positive, facultatively anaerobic, oval beaded-shape, oxidase-negative, and non-motile bacterium designated DM20194951T was isolated from a spoiled eye mask obtained from Guangdong, China. Based on the 16S rRNA gene sequence, phylogenetic analysis indicated that strain DM20194951T showed the highest sequence similarity (95.8%) to Fundicoccus ignavus WS4937T. Meanwhile, strain DM20194951T could be distinguished from the type strains in the genus Fundicoccus by distinct phenotypic and genotypic traits. Strain DM20194951T grew variably with 1-2% (w/v) NaCl and tolerated pH 6.0-10.0. Growth was observed from 28 to 37 °C. The diagnostic diamino acids in the cell-wall peptidoglycan consisted of aspartic and glutamic acids as well as alanine. The predominant fatty acids were C18:1 ω9c, C16:0, and C16:1 ω9c. In the polar lipid profile, two glycolipids, three phospholipids, one phosphatidylglycerol, and one diphosphatidylglycerol were found. No respiratory quinones were detected. The DM20194951T genome is 3.2 Mb in size and contains a G + C content of 38.1%. A gene cluster for lactococcin 972 family bacteriocin production was found in the DM20194951T genome. Based on morphological, genotypic, and phylogenetic data, strain DM20194951T should be considered to represent a novel species in the genus Fundicoccus, for which the name Fundicoccus culcitae sp. nov. is proposed with the type strain DM20194951T (= KCTC 43472T = GDMCC 1.3614T).
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Affiliation(s)
- Gang Zhou
- Key Laboratory of Agricultural Microbiomics and Precision Application (MARA), Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Key Laboratory of Agricultural Microbiome (MARA), State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, 510070, People's Republic of China
| | - Lei Gao
- State Key Laboratory of Desert and Oasis Ecology, Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, People's Republic of China
| | - Bao-Zhu Fang
- State Key Laboratory of Desert and Oasis Ecology, Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, People's Republic of China
| | - Ying-Si Wang
- Key Laboratory of Agricultural Microbiomics and Precision Application (MARA), Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Key Laboratory of Agricultural Microbiome (MARA), State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, 510070, People's Republic of China
| | - Hong-Bing Tao
- Guangdong Dimei Biotechnology Co, Ltd, Guangzhou, 510070, People's Republic of China
| | - Xia Wen
- Key Laboratory of Agricultural Microbiomics and Precision Application (MARA), Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Key Laboratory of Agricultural Microbiome (MARA), State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, 510070, People's Republic of China
| | - Qian Wang
- Key Laboratory of Agricultural Microbiomics and Precision Application (MARA), Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Key Laboratory of Agricultural Microbiome (MARA), State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, 510070, People's Republic of China
| | - Xiao-Mo Huang
- Guangdong Dimei Biotechnology Co, Ltd, Guangzhou, 510070, People's Republic of China
| | - Qing-Shan Shi
- Key Laboratory of Agricultural Microbiomics and Precision Application (MARA), Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Key Laboratory of Agricultural Microbiome (MARA), State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, 510070, People's Republic of China
| | - Wen-Jun Li
- State Key Laboratory of Biocontrol, Guangdong Provincial Key Laboratory of Plant Resources and Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), School of Life Sciences, Sun Yat-Sen University, Guangzhou, 510275, People's Republic of China.
| | - Xiao-Bao Xie
- Key Laboratory of Agricultural Microbiomics and Precision Application (MARA), Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Key Laboratory of Agricultural Microbiome (MARA), State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, 510070, People's Republic of China.
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Riediger M, Hoffmann K, Isberner R, Dreyer A, Tersteegen A, Marquardt P, Kaasch AJ, Zautner AE. Chimaeribacter arupi a new member of the Yersineacea family has the characteristics of a human pathogen. Front Cell Infect Microbiol 2023; 13:1277522. [PMID: 37868348 PMCID: PMC10587679 DOI: 10.3389/fcimb.2023.1277522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 09/14/2023] [Indexed: 10/24/2023] Open
Abstract
Chimaeribacter arupi (heterotypic synonym: "Nissabacter archeti") is a facultative anaerobic, newly described Gram-negative rod and belongs to the Yersineacea family. Here, we report the case of a 19-month-old female infant patient who presented to the emergency unit with somnolence and fever. C. arupi was isolated from a positive blood culture, taken via an implanted Broviac catheter, proving a bloodstream infection by the pathogen. The objective of this study was to utilize whole genome sequencing to assess the genes encoding potential virulence associated factors, which may play a role in host tropism, tissue invasion and the subsequent stages in the pathogenesis of a bloodstream infection with C. arupi. The genome of the isolate was completely sequenced employing Illumina MiSeq and Nanopore MinION sequencing and the presumptive virulence associated factors and antimicrobial resistance genes were investigated in more detail. Additionally, we performed metabolic profiling and susceptibility testing by microdilution. The presence of predicted TcfC-like α-Pili suggests that C. arupi is highly adapted to humans as a host. It utilizes flagellar and type IV pili-mediated motility, as well as a number of γ1-pili and a σ-pilus, which may be used to facilitate biofilm formation and adherence to host epithelia. Additionally, long polar fimbriae may aid in tissue invasion. The bacterium possesses antioxidant factors, which may enable temporary survival in phagolysosomes, and a capsule that potentially provides protection from phagocytosis. It may acquire iron ions from erythrocytes through the type 6 secretion system and hemolysins. Furthermore, the isolate exhibits beta-lactamase-mediated penicillin and aminopenicillin resistance. Based on the analysis of the whole genome, we conclude that C. arupi possesses virulence factors associated with tissue invasion and may thus be a potential opportunistic pathogen of bloodstream infections.
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Affiliation(s)
- Matthias Riediger
- Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Medizinische Fakultät der Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
| | - Katharina Hoffmann
- Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Medizinische Fakultät der Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
| | - Riekje Isberner
- Universitätskinderklinik, Medizinische Fakultät der Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
| | - Annika Dreyer
- Institut für Medizinische Mikrobiologie und Virologie, Universitätsmedizin Göttingen, Göttingen, Germany
| | - Aljoscha Tersteegen
- Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Medizinische Fakultät der Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
| | - Pauline Marquardt
- Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Medizinische Fakultät der Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
| | - Achim J. Kaasch
- Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Medizinische Fakultät der Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
- Center for Health and Medical Prevention (CHaMP), Center for Health and Medical Prevention, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
| | - Andreas E. Zautner
- Institut für Medizinische Mikrobiologie und Krankenhaushygiene, Medizinische Fakultät der Otto-von-Guericke Universität Magdeburg, Magdeburg, Germany
- Center for Health and Medical Prevention (CHaMP), Center for Health and Medical Prevention, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
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Yin L, Wang X, Xu H, Yin B, Wang X, Zhang Y, Li X, Luo Y, Chen Z. Unrecognized risk of perfluorooctane sulfonate in promoting conjugative transfers of bacterial antibiotic resistance genes. Appl Environ Microbiol 2023; 89:e0053323. [PMID: 37565764 PMCID: PMC10537727 DOI: 10.1128/aem.00533-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 06/28/2023] [Indexed: 08/12/2023] Open
Abstract
Antibiotic resistance is a major global health crisis facing humanity, with horizontal gene transfer (HGT) as a principal dissemination mechanism in the natural and clinical environments. Perfluoroalkyl substances (PFASs) are emerging contaminants of global concern due to their high persistence in the environment and adverse effects on humans. However, it is unknown whether PFASs affect the HGT of bacterial antibiotic resistance. Using a genetically engineered Escherichia coli MG1655 as the donor of plasmid-encoded antibiotic resistance genes (ARGs), E. coli J53 and soil bacterial community as two different recipients, this study demonstrated that the conjugation frequency of ARGs between two E. coli strains was (1.45 ± 0.17) × 10-5 and perfluorooctane sulfonate (PFOS) at environmentally relevant concentrations (2-50 μg L-1) increased conjugation transfer between E. coli strains by up to 3.25-fold. Increases in reactive oxygen species production, cell membrane permeability, biofilm formation capacity, and cell contact in two E. coli strains were proposed as major promotion mechanisms from PFOS exposure. Weighted gene co-expression network analysis of transcriptome data identified a series of candidate genes whose expression changes could contribute to the increase in conjugation transfer induced by PFOS. Furthermore, PFOS also generally increased the ARG transfer into the studied soil bacterial community, although the uptake ability of different community members of the plasmid either increased or decreased upon PFOS exposure depending on specific bacterial taxa. Overall, this study reveals an unrecognized risk of PFOS in accelerating the dissemination of antibiotic resistance. IMPORTANCE Perfluoroalkyl substances (PFASs) are emerging contaminants of global concern due to their high persistence in the environment and adverse health effects. Although the influence of environmental pollutants on the spread of antibiotic resistance, one of the biggest threats to global health, has attracted increasing attention in recent years, it is unknown whether environmental residues of PFASs affect the dissemination of bacterial antibiotic resistance. Considering PFASs, often called "forever" compounds, have significantly higher environmental persistence than most emerging organic contaminants, exploring the effect of PFASs on the spread of antibiotic resistance is more environmentally relevant and has essential ecological and health significance. By systematically examining the influence of perfluorooctane sulfonate on the antibiotic resistance gene conjugative transfer, not only at the single-strain level but also at the community level, this study has uncovered an unrecognized risk of PFASs in promoting conjugative transfers of bacterial antibiotic resistance genes, which could be incorporated into the risk assessment framework of PFASs.
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Affiliation(s)
- Lichun Yin
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, China
| | - Xiaolong Wang
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, China
| | - Han Xu
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, China
| | - Bo Yin
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, China
| | - Xingshuo Wang
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, China
| | - Yulin Zhang
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, China
| | - Xinyao Li
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, China
| | - Yi Luo
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, China
| | - Zeyou Chen
- Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin, China
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Serratia marcescens DUF1471-Containing Protein SrfN Is Needed for Adaptation to Acid and Oxidative Stresses. mSphere 2022; 7:e0021222. [PMID: 36218346 PMCID: PMC9769812 DOI: 10.1128/msphere.00212-22] [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
Bacteria can quickly adapt to constantly changing environments through a number of mechanisms, including secretion of secondary metabolites, peptides, and proteins. Serratia marcescens, an emerging pathogen with growing clinical importance due to its intrinsic resistance to several classes of antibiotics, can cause an array of infections in immunocompromised individuals. To better control the spread of S. marcescens infections, it is critical to identify additional targets for bacterial growth inhibition. We found that extracellular metabolites produced by the wild-type organism in response to peroxide exposure had a protective effect on an otherwise-H2O2-sensitive ΔmacAB indicator strain. Detailed analysis of the conditioned medium demonstrated that the protective effect was associated with a low-molecular-weight heat-sensitive and proteinase K-sensitive metabolite. Furthermore, liquid chromatography-tandem mass spectrometry analysis of the low-molecular-weight proteins present in the conditioned medium led to identification of the previously uncharacterized DUF1471-containing protein TBU67220 (SrfN). We found that loss of the srfN gene did not have an impact on the production of extracellular enzymes. However, the S. marcescens mutant lacking SrfN was significantly more sensitive to growth in medium with a low pH and to exposure to oxidative stress. Both defects were fully rescued by complementation. Thus, our results indicate that SrfN, a low-molecular-weight DUF1471-containing protein, is involved in S. marcescens SM6 adaptation to adverse environmental conditions. IMPORTANCE Serratia marcescens is ubiquitous in the environment and can survive in water, soil, plants, insects, and animals, and it can also cause infections in humans. In the face of disturbances such as oxidative or low-pH stress, bacteria adapt, survive, and recover through several mechanisms, including changes in their secretome. We show that a hydrogen peroxide-exposed S. marcescens milieu contains a small previously uncharacterized DUF1471-containing protein similar to the SrfN protein in Salmonella enterica serovar Typhimurium, and we illustrate the role of this protein in bacterial survival during acid and oxidative stresses.
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Song N, De Greve H, Wang Q, Hernalsteens JP, Li Z. Plasmid parB contributes to uropathogenic Escherichia coli colonization in vivo by acting on biofilm formation and global gene regulation. Front Mol Biosci 2022; 9:1053888. [PMID: 36589237 PMCID: PMC9800825 DOI: 10.3389/fmolb.2022.1053888] [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: 09/26/2022] [Accepted: 11/28/2022] [Indexed: 12/23/2022] Open
Abstract
The endogenous plasmid pUTI89 harbored by the uropathogenic Escherichia coli (UPEC) strain UTI89 plays an important role in the acute stage of infection. The partitioning gene parB is important for stable inheritance of pUTI89. However, the function of partitioning genes located on the plasmid in pathogenesis of UPEC still needs to be further investigated. In the present study, we observed that disruption of the parB gene leads to a deficiency in biofilm formation in vitro. Moreover, in a mixed infection with the wild type strain and the parB mutant, in an ascending UTI mouse model, the mutant displayed a lower bacterial burden in the bladder and kidneys, not only at the acute infection stage but also extending to 72 hours post infection. However, in the single infection test, the reduced colonization ability of the parB mutant was only observed at six hpi in the bladder, but not in the kidneys. The colonization capacity in vivo of the parB-complemented strain was recovered. qRT-PCR assay suggested that ParB could be a global regulator, influencing the expression of genes located on both the endogenous plasmid and chromosome, while the gene parA or the operon parAB could not. Our study demonstrates that parB contributes to the virulence of UPEC by influencing biofilm formation and proposes that the parB gene of the endogenous plasmid could regulate gene expression globally.
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Affiliation(s)
- Ningning Song
- School of Life Science and Technology, Weifang Medical University, Weifang, China,Department of Biology, Vrije Universiteit Brussel, Brussels, Belgium
| | - Henri De Greve
- VIB-VUB Center for Structural Biology, Vrije Universiteit Brussel, Brussels, Belgium,Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Quanjun Wang
- SAFE Pharmaceutical Technology Co, Ltd., Beijing, China
| | - Jean-Pierre Hernalsteens
- Department of Biology, Vrije Universiteit Brussel, Brussels, Belgium,*Correspondence: Jean-Pierre Hernalsteens, , Zhaoli Li,
| | - Zhaoli Li
- Department of Biology, Vrije Universiteit Brussel, Brussels, Belgium,SAFE Pharmaceutical Technology Co, Ltd., Beijing, China,*Correspondence: Jean-Pierre Hernalsteens, , Zhaoli Li,
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Mechanism of nitrite transporter NirC in motility, biofilm formation, and adhesion of avian pathogenic Escherichia coli. Arch Microbiol 2021; 203:4221-4231. [PMID: 34091701 DOI: 10.1007/s00203-021-02412-5] [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: 03/27/2021] [Revised: 05/25/2021] [Accepted: 05/27/2021] [Indexed: 10/21/2022]
Abstract
The Escherichia coli (E. coli) nirC gene encodes a nitrite transporter, which involved in transporting toxic nitrite (NO2-) from the environment into the bacteria. Although the deletion of nirC gene could cause changes in motility, adhesion in the previous study, and the virulence involved in the specified mechanism for pathogenic E. coli remains to be known. In the present work, we aimed to evaluate the role of NirC in a serotype O2:K1:H7 avian pathogenic Escherichia coli (APEC) strain. For this purpose, we generated a NirC-deficient mutant of APEC XM strain and examined its biological characteristics. The nirC gene deletion mutant enhanced ability of motility, decreased in biofilm formation, and it markedly reduced ability to adhere mouse brain microvascular endothelial cell b.End3 cells. For understanding its mechanism, sequentially we detected and found the stress regulator rpoS and its downstream genes csrA were up-regulated in NirC-deficient mutant while diguanylate cyclase gene dgcT was down-regulated. By high-performance liquid chromatography (HPLC) experiment, we demonstrated the concentration of intracellular 3',5'-cyclic diguanosine monophosphate (c-di-GMP) significantly decrease in nirC gene deletion mutant. Taken data together, we may make a conclusion with a possible signal pathway clue, due to NirC mutation, environmental NO2- accumulation leads to nitrite stress and inactivates c-di-GMP synthesis by stimulating the stress regulator RpoS, resulting in changes of biological characteristics.
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10
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Zhou G, Wang YS, Peng H, Li SJ, Sun TL, Shen PF, Xie XB, Shi QS. Roles of ompA of Citrobacter werkmanii in bacterial growth, biocide resistance, biofilm formation and swimming motility. Appl Microbiol Biotechnol 2021; 105:2841-2854. [PMID: 33763710 DOI: 10.1007/s00253-020-11057-1] [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: 08/02/2020] [Revised: 11/30/2020] [Accepted: 12/09/2020] [Indexed: 10/21/2022]
Abstract
The genus Citrobacter is commonly found in environmental and industrial settings, some members of which have been used for bioremediation of heavy metals owing to the absorption ability of their biofilms. Although our previous studies have found that the outer membrane protein A (OmpA) contributes to the process of Citrobacter werkmanii biofilm formation, the underlying mechanisms remain elusive. Therefore, we deleted ompA from the genome of C. werkmanii and investigated its phenotypes in comparison to the wild type strain (WT) and the complementary strain using biochemical and molecular techniques including RNA-Seq. Our results demonstrated that the deletion of ompA led to an increase in biofilm formation on both polystyrene and glass surfaces due to upregulation of some biofilm formation related genes. Meanwhile, swimming ability, which is mediated by activation of flagellar assembly genes, was increased on semi-solid plates in the ∆ompA strain when compared with WT. Additionally, inactivation of ompA also caused increased 1,2-benzisothiazolin-3-one (BIT) resistance, differential responses to Ca2+ stress, curli protein expression and cellulose production. Finally, ∆ompA caused differential expression of a total of 1470 genes when compared with WT, of which 146 were upregulated and 1324 were downregulated. These genes were classified into different Gene Ontology (GO) and KEGG pathways. In summary, ompA in C. werkmanii contributes to a variety of biological functions and may act as a target site to modulate biofilm formation. KEY POINTS: • ompA is a negative regulator for biofilm formation by C. werkmanii. • ompA inhibits swimming motility of C. werkmanii. • ompA deletion causes different expression profiles in C. werkmanii.
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Affiliation(s)
- Gang Zhou
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, Guangdong, 510070, People's Republic of China
| | - Ying-Si Wang
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, Guangdong, 510070, People's Republic of China
| | - Hong Peng
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, Guangdong, 510070, People's Republic of China
| | - Su-Juan Li
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, Guangdong, 510070, People's Republic of China
| | - Ting-Li Sun
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, Guangdong, 510070, People's Republic of China
| | - Peng-Fei Shen
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, Guangdong, 510070, People's Republic of China
| | - Xiao-Bao Xie
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, Guangdong, 510070, People's Republic of China.
| | - Qing-Shan Shi
- Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, State Key Laboratory of Applied Microbiology Southern China, Institute of Microbiology, Guangdong Academy of Sciences, Guangzhou, Guangdong, 510070, People's Republic of China.
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11
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Vatansever C, Turetgen I. Investigation of the effects of various stress factors on biofilms and planktonic bacteria in cooling tower model system. Arch Microbiol 2021; 203:1411-1425. [PMID: 33388788 DOI: 10.1007/s00203-020-02116-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 09/09/2020] [Accepted: 11/08/2020] [Indexed: 11/27/2022]
Abstract
Biofilm is a microbial population which live in a self-produced extracellular polymeric matrix by attaching to surfaces. Biofilms consist of different different types of organisms such as bacteria, fungi, protozoa, etc. Many biofilms that develop in nature consist of more than one type of organism. Biofilms protect bacteria from adverse conditions such as temperature fluctuation and disinfectants. The aim of this study was to determine the effective elimination strategies for combating biofilm and planktonic bacteria in cooling tower model system using different decontamination / disinfection techniques. In this study, 14 week-old biofilms were treated with temperatures of 4 °C, 65 °C; pH of 3, 11; 2 and 10 mg/l chlorine, 2 and 10 mg/l monochloramine; hypotonic salt (0.01% NaCl) and hypertonic salt (3% NaCl) solution. For enumeration, number of aerobic heterotrophic bacteria was determined by conventional culture method, number of live bacteria was determined by LIVE/DEAD viability kit, CTC-DAPI and Alamar blue staining methods. Temperature of 65 °C, pH of 3, 10 mg/l monochloramine and hypertonic salt solution were the most effective parameters for decontamination of biofilm and planktonic bacteria. Biofilm bacteria in the circulating water system were significantly more resistant than planktonic bacteria against stress factors. When the numbers of epifluorescence microscopy and conventional culture technique were compared, significantly higher number of live bacteria were detected using epifluorescence microscopy. Bacteria enter the viable but non-culturable phase by loosing their culturability under stress conditions. For this reason, the conventional culture method should be supported by different techniques to get more realistic numbers.
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Affiliation(s)
- Cansu Vatansever
- Faculty of Pharmacy, Department of Pharmaceutical Microbiology, Altinbas University, Istanbul, Turkey.
| | - Irfan Turetgen
- Faculty of Science, Department of Biology, Istanbul University, Istanbul, Turkey
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Expression of a Shiga-Like Toxin during Plastic Colonization by Two Multidrug-Resistant Bacteria, Aeromonas hydrophila RIT668 and Citrobacter freundii RIT669, Isolated from Endangered Turtles ( Clemmys guttata). Microorganisms 2020; 8:microorganisms8081172. [PMID: 32752245 PMCID: PMC7465454 DOI: 10.3390/microorganisms8081172] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 07/23/2020] [Accepted: 07/30/2020] [Indexed: 12/12/2022] Open
Abstract
Aeromonas hydrophila RIT668 and Citrobacter freundii RIT669 were isolated from endangered spotted turtles (Clemmys guttata). Whole-genome sequencing, annotation and phylogenetic analyses of the genomes revealed that the closest relative of RIT668 is A. hydrophila ATCC 7966 and Citrobacter portucalensis A60 for RIT669. Resistome analysis showed that A. hydrophila and C. freundii harbor six and 19 different antibiotic resistance genes, respectively. Both bacteria colonize polyethylene and polypropylene, which are common plastics, found in the environment and are used to fabricate medical devices. The expression of six biofilm-related genes—biofilm peroxide resistance protein (bsmA), biofilm formation regulatory protein subunit R (bssR), biofilm formation regulatory protein subunit S (bssS), biofilm formation regulator (hmsP), toxin-antitoxin biofilm protein (tabA) and transcriptional activator of curli operon (csgD)—and two virulence factors—Vi antigen-related gene (viaB) and Shiga-like toxin (slt-II)—was investigated by RT-PCR. A. hydrophila displayed a > 2-fold increase in slt-II expression in cells adhering to both polymers, C. freundii adhering on polyethylene displayed a > 2-fold, and on polypropylene a > 6-fold upregulation of slt-II. Thus, the two new isolates are potential pathogens owing to their drug resistance, surface colonization and upregulation of a slt-II-type diarrheal toxin on polymer surfaces.
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Escherichia coli CFT073 Fitness Factors during Urinary Tract Infection: Identification Using an Ordered Transposon Library. Appl Environ Microbiol 2020; 86:AEM.00691-20. [PMID: 32358013 DOI: 10.1128/aem.00691-20] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Accepted: 04/24/2020] [Indexed: 12/15/2022] Open
Abstract
Urinary tract infections (UTI), the second most diagnosed infectious disease worldwide, are caused primarily by uropathogenic Escherichia coli (UPEC), placing a significant financial burden on the health care system. High-throughput transposon mutagenesis combined with genome-targeted sequencing is a powerful technique to interrogate genomes for fitness genes. Genome-wide analysis of E. coli requires random libraries of at least 50,000 mutants to achieve 99.99% saturation; however, the traditional murine model of ascending UTI does not permit testing of large mutant pools due to a bottleneck during infection. To address this, an E. coli CFT073 transposon mutant ordered library of 9,216 mutants was created and insertion sites were identified. A single transposon mutant was selected for each gene to assemble a condensed library consisting of 2,913 unique nonessential mutants. Using a modified UTI model in BALB/c mice, we identified 36 genes important for colonizing the bladder, including purB, yihE, and carB Screening of the condensed library in vitro identified yigP and ubiG to be essential for growth in human urine. Additionally, we developed a novel quantitative PCR (qPCR) technique to identify genes with fitness defects within defined subgroups of related genes (e.g., genes encoding fimbriae, toxins, etc.) following UTI. The number of mutants within these subgroups circumvents bottleneck restriction and facilitates validation of multiple mutants to generate individual competitive indices. Collectively, this study investigates the bottleneck effects during UTI, provides two techniques for evading those effects that can be applied to other disease models, and contributes a genetic tool in prototype strain CFT073 to the field.IMPORTANCE Uropathogenic Escherichia coli strains cause most uncomplicated urinary tract infections (UTI), one of the most common infectious diseases worldwide. Random transposon mutagenesis techniques have been utilized to identify essential bacterial genes during infection; however, this has been met with limitations when applied to the murine UTI model. Conventional high-throughput transposon mutagenesis screens are not feasible because of inoculum size restrictions due to a bottleneck during infection. Our study utilizes a condensed ordered transposon library, limiting the number of mutants while maintaining the largest possible genome coverage. Screening of this library in vivo, and in human urine in vitro, identified numerous candidate fitness factors. Additionally, we have developed a novel technique using qPCR to quantify bacterial outputs following infection with small subgroups of transposon mutants. Molecular approaches developed in this study will serve as useful tools to probe in vivo models that are restricted by anatomical, physiological, or genetic bottleneck limitations.
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Christensen DG, Meyer JG, Baumgartner JT, D'Souza AK, Nelson WC, Payne SH, Kuhn ML, Schilling B, Wolfe AJ. Identification of Novel Protein Lysine Acetyltransferases in Escherichia coli. mBio 2018; 9:e01905-18. [PMID: 30352934 PMCID: PMC6199490 DOI: 10.1128/mbio.01905-18] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 09/18/2018] [Indexed: 12/31/2022] Open
Abstract
Posttranslational modifications, such as Nε-lysine acetylation, regulate protein function. Nε-lysine acetylation can occur either nonenzymatically or enzymatically. The nonenzymatic mechanism uses acetyl phosphate (AcP) or acetyl coenzyme A (AcCoA) as acetyl donor to modify an Nε-lysine residue of a protein. The enzymatic mechanism uses Nε-lysine acetyltransferases (KATs) to specifically transfer an acetyl group from AcCoA to Nε-lysine residues on proteins. To date, only one KAT (YfiQ, also known as Pka and PatZ) has been identified in Escherichia coli Here, we demonstrate the existence of 4 additional E. coli KATs: RimI, YiaC, YjaB, and PhnO. In a genetic background devoid of all known acetylation mechanisms (most notably AcP and YfiQ) and one deacetylase (CobB), overexpression of these putative KATs elicited unique patterns of protein acetylation. We mutated key active site residues and found that most of them eliminated enzymatic acetylation activity. We used mass spectrometry to identify and quantify the specificity of YfiQ and the four novel KATs. Surprisingly, our analysis revealed a high degree of substrate specificity. The overlap between KAT-dependent and AcP-dependent acetylation was extremely limited, supporting the hypothesis that these two acetylation mechanisms play distinct roles in the posttranslational modification of bacterial proteins. We further showed that these novel KATs are conserved across broad swaths of bacterial phylogeny. Finally, we determined that one of the novel KATs (YiaC) and the known KAT (YfiQ) can negatively regulate bacterial migration. Together, these results emphasize distinct and specific nonenzymatic and enzymatic protein acetylation mechanisms present in bacteria.IMPORTANCENε-Lysine acetylation is one of the most abundant and important posttranslational modifications across all domains of life. One of the best-studied effects of acetylation occurs in eukaryotes, where acetylation of histone tails activates gene transcription. Although bacteria do not have true histones, Nε-lysine acetylation is prevalent; however, the role of these modifications is mostly unknown. We constructed an E. coli strain that lacked both known acetylation mechanisms to identify four new Nε-lysine acetyltransferases (RimI, YiaC, YjaB, and PhnO). We used mass spectrometry to determine the substrate specificity of these acetyltransferases. Structural analysis of selected substrate proteins revealed site-specific preferences for enzymatic acetylation that had little overlap with the preferences of the previously reported acetyl-phosphate nonenzymatic acetylation mechanism. Finally, YiaC and YfiQ appear to regulate flagellum-based motility, a phenotype critical for pathogenesis of many organisms. These acetyltransferases are highly conserved and reveal deeper and more complex roles for bacterial posttranslational modification.
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Affiliation(s)
- David G Christensen
- Department of Microbiology and Immunology, Stritch School of Medicine, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, USA
| | - Jesse G Meyer
- Buck Institute for Research on Aging, Novato, California, USA
| | - Jackson T Baumgartner
- Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California, USA
| | | | - William C Nelson
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Samuel H Payne
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, Washington, USA
| | - Misty L Kuhn
- Department of Chemistry and Biochemistry, San Francisco State University, San Francisco, California, USA
| | | | - Alan J Wolfe
- Department of Microbiology and Immunology, Stritch School of Medicine, Health Sciences Division, Loyola University Chicago, Maywood, Illinois, USA
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15
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Ju X, Li J, Zhu M, Lu Z, Lv F, Zhu X, Bie X. Effect of the luxS gene on biofilm formation and antibiotic resistance by Salmonella serovar Dublin. Food Res Int 2018; 107:385-393. [PMID: 29580499 DOI: 10.1016/j.foodres.2018.02.039] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 02/10/2018] [Accepted: 02/13/2018] [Indexed: 12/26/2022]
Abstract
Biofilms are communities of bacterial cells that serve to protect them from external adverse influences and enhance bacterial resistance to antibiotics and sanitizers. Here, we studied the regulatory effects of glucose and sodium chloride on biofilm formation in Salmonella serovar Dublin (S. Dublin). To analyze expression levels of the quorum sensing gene luxS, we created a luxS knockout mutant. Also, antimicrobial resistance, hydrophobicity and autoinducer-2 (AI-2) activity of both the wild-type (WT) and the mutant strain were investigated. Our results revealed that glucose was not essential for S. Dublin biofilm formation but had an inhibitory effect on biofilm formation when the concentration was over 0.1%. NaCl was found to be indispensable in forming biofilm, and it also exerted an inhibitory effect at high concentrations (>1.0%). Both the WT and the mutant strains displayed significant MIC growth after biofilm formation. An increase of up to 32,768 times in the resistance of S. Dublin in biofilm phonotype against antibiotic (ampicillin) compared to its planktonic phonotype was observed. However, S. Dublin luxS knockout mutant only showed slight differences compared to the WT strain in the antimicrobial tests although it displayed better biofilm-forming capacity than the WT strain. The mutant strain also exhibited higher hydrophobicity than the WT strain, which was a feature related to biofilm formation. The production of the quorum sensing autoinducer-2 (AI-2) was significantly lower in the mutant strain than in the WT strain since the LuxS enzyme, encoded by the luxS gene, plays an essential role in AI-2 synthesis. However, the limited biofilm-forming ability in the WT strain indicated AI-2 was not directly related to S. Dublin biofilm formation. Furthermore, gene expression analysis of the WT and mutant strains revealed upregulation of genes related to biofilm stress response and enhanced resistance in the luxS mutant strain, which may provide evidence for the regulatory role of the luxS gene in biofilm formation.
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Affiliation(s)
- Xiangyu Ju
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, People's Republic of China
| | - Junjie Li
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, People's Republic of China
| | - Mengjiao Zhu
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, People's Republic of China
| | - Zhaoxin Lu
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, People's Republic of China
| | - Fengxia Lv
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, People's Republic of China
| | - Xiaoyu Zhu
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, People's Republic of China
| | - Xiaomei Bie
- College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, People's Republic of China.
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16
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17
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Chin KCJ, Taylor TD, Hebrard M, Anbalagan K, Dashti MG, Phua KK. Transcriptomic study of Salmonella enterica subspecies enterica serovar Typhi biofilm. BMC Genomics 2017; 18:836. [PMID: 29089020 PMCID: PMC5664820 DOI: 10.1186/s12864-017-4212-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 10/12/2017] [Indexed: 11/29/2022] Open
Abstract
Background Typhoid fever is an acute systemic infection of humans caused by Salmonella enterica subspecies enterica serovar Typhi (S. Typhi). In chronic carriers, the bacteria survive the harsh environment of the gallbladder by producing biofilm. The phenotype of S. Typhi biofilm cells is significantly different from the free-swimming planktonic cells, and studies have shown that they are associated with antibiotic resistance, immune system evasion, and bacterial persistence. However, the mechanism of this transition and the events leading to biofilm formation are unknown. High throughput sequencing was performed to identify the genes involved in biofilm formation and to postulate the mechanism of action. Results Planktonic S. Typhi cells were cultured using standard nutrient broth whereas biofilm cells were cultured in a stressful environment using high shearing-force and bile to mimic the gallbladder. Sequencing libraries were prepared from S. Typhi planktonic cells and mature biofilm cells using the Illumina HiSeq 2500 platform, and the transcriptome data obtained were processed using Cufflinks bioinformatics suite of programs to investigate differential gene expression between the two phenotypes. A total of 35 up-regulated and 29 down-regulated genes were identified. The identities of the differentially expressed genes were confirmed using NCBI BLAST and their functions were analyzed. The results showed that the genes associated with metabolic processes and biofilm regulations were down-regulated while those associated with the membrane matrix and antibiotic resistance were highly up-regulated. Conclusions It is proposed that the biofilm phenotype of S. Typhi allows the bacteria to increase production of the membrane matrix in order to serve as a physical shield and to adhere to surfaces, and enter an energy conservation state in response to the stressful environment. Conversely, the planktonic phenotype allows the bacteria to produce flagella and increase metabolic activity to enable the bacteria to migrate and form new colonies of infection. This data provide a basis for further studies to uncover the mechanism of biofilm formation in S. Typhi and to discover novel genes or pathways associated with the development of the typhoid carrier state. Electronic supplementary material The online version of this article (10.1186/s12864-017-4212-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Khee Chian Jason Chin
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, 11800, Penang, USM, Malaysia.,USM-RIKEN Centre for Aging Science (URICAS), Universiti Sains Malaysia, 11800, Penang, USM, Malaysia
| | - Todd Duane Taylor
- Laboratory for Integrated Bioinformatics, Core for Precise Measuring and Modeling, RIKEN Center for Integrative Medical Sciences, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, Japan.,USM-RIKEN Centre for Aging Science (URICAS), Universiti Sains Malaysia, 11800, Penang, USM, Malaysia
| | - Maxime Hebrard
- Laboratory for Integrated Bioinformatics, Core for Precise Measuring and Modeling, RIKEN Center for Integrative Medical Sciences, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, Japan
| | - Kogaan Anbalagan
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, 11800, Penang, USM, Malaysia
| | - Marjan Ganjali Dashti
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, 11800, Penang, USM, Malaysia
| | - Kia Kien Phua
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, 11800, Penang, USM, Malaysia. .,USM-RIKEN Centre for Aging Science (URICAS), Universiti Sains Malaysia, 11800, Penang, USM, Malaysia.
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Zhou G, Peng H, Wang YS, Huang XM, Xie XB, Shi QS. Complete genome sequence of Citrobacter werkmanii strain BF-6 isolated from industrial putrefaction. BMC Genomics 2017; 18:765. [PMID: 29017450 PMCID: PMC5635574 DOI: 10.1186/s12864-017-4157-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 10/04/2017] [Indexed: 11/10/2022] Open
Abstract
Background In our previous study, Citrobacter werkmanii BF-6 was isolated from an industrial spoilage sample and demonstrated an excellent ability to form biofilms, which could be affected by various environmental factors. However, the genome sequence of this organism has not been reported so far. Results We report the complete genome sequence of C. werkmanii BF-6 together with the description of the genome features and its annotation. The size of the complete chromosome is 4,929,789 bp with an average coverage of 137×. The chromosome exhibits an average G + C content of 52.0%, and encodes 4570 protein coding genes, 84 tRNA genes, 25 rRNA operons, 3 microsatellite sequences and 34 minisatellite sequences. A previously unknown circular plasmid designated as pCW001 was also found with a length of 212,549 bp and a G + C content of 48.2%. 73.5%, 75.6% and 92.6% of the protein coding genes could be assigned to GO Ontology, KEGG Pathway, and COG (Clusters of Orthologous Groups) categories respectively. C. werkmanii BF-6 and C. werkmanii NRBC 105721 exhibited the closest evolutionary relationships based on 16S ribosomal RNA and core-pan genome assay. Furthermore, C. werkmanii BF-6 exhibits typical bacterial biofilm formation and development. In the RT-PCR experiments, we found that a great number of biofilm related genes, such as bsmA, bssR, bssS, hmsP, tabA, csgA, csgB, csgC, csgD, csgE, and csgG, were involved in C. werkmanii BF-6 biofilm formation. Conclusions This is the first complete genome of C. werkmanii. Our work highlights the potential genetic mechanisms involved in biofilm formation and paves a way for further application of C. werkmanii in biofilms research. Electronic supplementary material The online version of this article (10.1186/s12864-017-4157-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Gang Zhou
- Guangdong Institute of Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China.,State Key Laboratory of Applied Microbiology Southern China, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Open Laboratory of Applied Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China
| | - Hong Peng
- Guangdong Institute of Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China.,State Key Laboratory of Applied Microbiology Southern China, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Open Laboratory of Applied Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China
| | - Ying-Si Wang
- Guangdong Institute of Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China.,State Key Laboratory of Applied Microbiology Southern China, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Open Laboratory of Applied Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China
| | - Xiao-Mo Huang
- Guangdong Institute of Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China.,State Key Laboratory of Applied Microbiology Southern China, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Open Laboratory of Applied Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China
| | - Xiao-Bao Xie
- Guangdong Institute of Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China.,State Key Laboratory of Applied Microbiology Southern China, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangzhou, Guangdong, 510070, People's Republic of China.,Guangdong Open Laboratory of Applied Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China
| | - Qing-Shan Shi
- Guangdong Institute of Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China. .,State Key Laboratory of Applied Microbiology Southern China, Guangzhou, Guangdong, 510070, People's Republic of China. .,Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application, Guangzhou, Guangdong, 510070, People's Republic of China. .,Guangdong Open Laboratory of Applied Microbiology, Guangzhou, Guangdong, 510070, People's Republic of China.
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Indole production provides limited benefit to Escherichia coli during co-culture with Enterococcus faecalis. Arch Microbiol 2016; 199:145-153. [PMID: 27638396 DOI: 10.1007/s00203-016-1289-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 06/28/2016] [Accepted: 09/07/2016] [Indexed: 01/15/2023]
Abstract
Escherichia coli lives in the gastrointestinal tract and elsewhere, where it coexists within a mixed population. Indole production enables E. coli to grow with other gram-negative bacteria as indole inhibits N-acyl-homoserine lactone (AHL) quorum regulation. We investigated whether E. coli indole production enhanced competition with gram-positive Enterococcus faecalis, wherein quorum signaling is mediated by small peptides. During planktonic co-culture with E. faecalis, the fitness and population density of E. coli tnaA mutants (unable to produce indole) equaled or surpassed that of E. coli wt. During biofilm growth, the fitness of both populations of E. coli stabilized around 100 %, whereas the fitness of E. faecalis declined over time to 85-90 %, suggesting that biofilm and planktonic populations have different competition strategies. Media supplementation with indole removed the competitive advantage of E. coli tnaA in planktonic populations but enhanced it in biofilm populations. E. coli wt and tnaA showed similar growth in Luria-Bertani (LB) broth. However, E. coli growth was inhibited in the presence of filter-sterilized spent LB from E. faecalis, with inhibition being enhanced by indole. Similarly, there was also an inhibition of E. faecalis growth by proteinaceous components (likely bacteriocins) from spent culture media from both E. coli strains. We conclude that E. coli indole production is not a universal competition strategy, but rather works against gram-negative, AHL-producing bacteria.
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Wasfi R, Elkhatib WF, Khairalla AS. Effects of Selected Egyptian Honeys on the Cellular Ultrastructure and the Gene Expression Profile of Escherichia coli. PLoS One 2016; 11:e0150984. [PMID: 26954570 PMCID: PMC4783026 DOI: 10.1371/journal.pone.0150984] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 02/21/2016] [Indexed: 01/22/2023] Open
Abstract
The purpose of this study was to: (i) evaluate the antibacterial activities of three Egyptian honeys collected from different floral sources (namely, citrus, clover, and marjoram) against Escherichia coli; (ii) investigate the effects of these honeys on bacterial ultrastructure; and (iii) assess the anti-virulence potential of these honeys, by examining their impacts on the expression of eight selected genes (involved in biofilm formation, quorum sensing, and stress survival) in the test organism. The minimum inhibitory concentration (MIC) of the honey samples against E. coli ATCC 8739 were assessed by the broth microdilution assay in the presence and absence of catalase enzyme. Impacts of the honeys on the cellular ultrastructure and the expression profiles of the selected genes of E. coli were examined using transmission electron microscopy (TEM) and quantitative real-time polymerase chain reaction (qPCR) analysis, respectively. The susceptibility tests showed promising antibacterial activities of all the tested honeys against E. coli. This was supported by the TEM observations, which revealed “ghost” cells lacking DNA, in addition to cells with increased vacuoles, and/or with irregular shrunken cytoplasm. Among the tested honeys, marjoram exhibited the highest total antibacterial activity and the highest levels of peroxide-dependent activity. The qPCR analysis showed that all honey-treated cells share a similar overall pattern of gene expression, with a trend toward reduced expression of the virulence genes of interest. Our results indicate that some varieties of the Egyptian honey have the potential to be effective inhibitor and virulence modulator of E. coli via multiple molecular targets.
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Affiliation(s)
- Reham Wasfi
- Department of Microbiology & Immunology, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA), Giza, Egypt
| | - Walid F. Elkhatib
- Department of Microbiology & Immunology, Faculty of Pharmacy, Ain Shams University, Cairo, Egypt
| | - Ahmed S. Khairalla
- Department of Microbiology & Immunology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef, Egypt
- * E-mail:
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21
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Peano C, Wolf J, Demol J, Rossi E, Petiti L, De Bellis G, Geiselmann J, Egli T, Lacour S, Landini P. Characterization of the Escherichia coli σ(S) core regulon by Chromatin Immunoprecipitation-sequencing (ChIP-seq) analysis. Sci Rep 2015; 5:10469. [PMID: 26020590 PMCID: PMC4447067 DOI: 10.1038/srep10469] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 04/15/2015] [Indexed: 11/29/2022] Open
Abstract
In bacteria, selective promoter recognition by RNA polymerase is achieved by its association with σ factors, accessory subunits able to direct RNA polymerase “core enzyme” (E) to different promoter sequences. Using Chromatin Immunoprecipitation-sequencing (ChIP-seq), we searched for promoters bound by the σS-associated RNA polymerase form (EσS) during transition from exponential to stationary phase. We identified 63 binding sites for EσS overlapping known or putative promoters, often located upstream of genes (encoding either ORFs or non-coding RNAs) showing at least some degree of dependence on the σS-encoding rpoS gene. EσS binding did not always correlate with an increase in transcription level, suggesting that, at some σS-dependent promoters, EσS might remain poised in a pre-initiation state upon binding. A large fraction of EσS-binding sites corresponded to promoters recognized by RNA polymerase associated with σ70 or other σ factors, suggesting a considerable overlap in promoter recognition between different forms of RNA polymerase. In particular, EσS appears to contribute significantly to transcription of genes encoding proteins involved in LPS biosynthesis and in cell surface composition. Finally, our results highlight a direct role of EσS in the regulation of non coding RNAs, such as OmrA/B, RyeA/B and SibC.
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Affiliation(s)
- Clelia Peano
- Institute of Biomedical Technologies, National Research Council (ITB-CNR), Segrate (MI), Italy
| | - Johannes Wolf
- EAWAG, Swiss Federal Institute for Environmental Science and Technology, Dübendorf, Switzerland
| | - Julien Demol
- Lab. Adaptation et Pathogénie des Micro-organismes (LAPM), Univ. Grenoble Alpes, F-38000 Grenoble, France.,UMR 5163, Centre National de Recherche Scientifique (CNRS), Grenoble, France
| | - Elio Rossi
- Department of Biosciences, Università degli Studi di Milano, Milan, Italy
| | - Luca Petiti
- Institute of Biomedical Technologies, National Research Council (ITB-CNR), Segrate (MI), Italy
| | - Gianluca De Bellis
- Institute of Biomedical Technologies, National Research Council (ITB-CNR), Segrate (MI), Italy
| | - Johannes Geiselmann
- Lab. Adaptation et Pathogénie des Micro-organismes (LAPM), Univ. Grenoble Alpes, F-38000 Grenoble, France.,UMR 5163, Centre National de Recherche Scientifique (CNRS), Grenoble, France
| | - Thomas Egli
- EAWAG, Swiss Federal Institute for Environmental Science and Technology, Dübendorf, Switzerland
| | - Stephan Lacour
- Lab. Adaptation et Pathogénie des Micro-organismes (LAPM), Univ. Grenoble Alpes, F-38000 Grenoble, France.,UMR 5163, Centre National de Recherche Scientifique (CNRS), Grenoble, France
| | - Paolo Landini
- Department of Biosciences, Università degli Studi di Milano, Milan, Italy
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22
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Vadyvaloo V, Viall AK, Jarrett CO, Hinz AK, Sturdevant DE, Joseph Hinnebusch B. Role of the PhoP-PhoQ gene regulatory system in adaptation of Yersinia pestis to environmental stress in the flea digestive tract. MICROBIOLOGY-SGM 2015; 161:1198-1210. [PMID: 25804213 PMCID: PMC4635514 DOI: 10.1099/mic.0.000082] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The Yersinia pestis PhoPQ gene regulatory system is induced during infection of the flea digestive tract and is required to produce adherent biofilm in the foregut, which greatly enhances bacterial transmission during a flea bite. To understand the in vivo context of PhoPQ induction and to determine PhoP-regulated targets in the flea, we undertook whole-genome comparative transcriptional profiling of Y. pestis WT and ΔphoP strains isolated from infected fleas and from temperature-matched in vitro planktonic and flow-cell biofilm cultures. In the absence of PhoP regulation, the gene expression program indicated that the bacteria experienced diverse physiological stresses and were in a metabolically less active state. Multiple stress response genes, including several toxin–antitoxin loci and YhcN family genes responsible for increased acid tolerance, were upregulated in the phoP mutant during flea infection. The data implied that PhoPQ was induced by low pH in the flea gut, and that PhoP modulated physiological adaptation to acid and other stresses encountered during infection of the flea. This adaptive response, together with PhoP-dependent modification of the bacterial outer surface that includes repression of pH 6 antigen fimbriae, supports stable biofilm development in the flea foregut.
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Affiliation(s)
- Viveka Vadyvaloo
- 1Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA, 99164, USA
| | - Austin K Viall
- 2Plague Section, Laboratory of Zoonotic Pathogens, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, 59840, USA
| | - Clayton O Jarrett
- 2Plague Section, Laboratory of Zoonotic Pathogens, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, 59840, USA
| | - Angela K Hinz
- 1Paul G. Allen School for Global Animal Health, Washington State University, Pullman, WA, 99164, USA
| | - Daniel E Sturdevant
- 3Genomics Unit, Research Technologies Section, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, 59840, USA
| | - B Joseph Hinnebusch
- 2Plague Section, Laboratory of Zoonotic Pathogens, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, 59840, USA
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Wang P, Yu Z, Li B, Cai X, Zeng Z, Chen X, Wang X. Development of an efficient conjugation-based genetic manipulation system for Pseudoalteromonas. Microb Cell Fact 2015; 14:11. [PMID: 25612661 PMCID: PMC4318363 DOI: 10.1186/s12934-015-0194-8] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 01/10/2015] [Indexed: 11/10/2022] Open
Abstract
Pseudoalteromonas is commonly found throughout the world's oceans, and has gained increased attention due to the ecological and biological significance. Although over fifty Pseudoalteromonas genomes have been sequenced with an aim to explore the adaptive strategies in different habitats, in vivo studies are hampered by the lack of effective genetic manipulation systems for most strains in this genus. Here, nine Pseudoalteromonas strains isolated from different habitats were selected and used as representative strains to develop a universal genetic manipulation system. Erythromycin and chloramphenicol resistance were chosen as selection markers based on antibiotics resistance test of the nine strains. A conjugation protocol based on the RP4 conjugative machinery in E. coli WM3064 was developed to overcome current limitations of genetic manipulation in Pseudoalteromonas. Two mobilizable gene expression shuttle vectors (pWD2-oriT and pWD2Ery-oriT) were constructed, and conjugation efficiency of pWD2-oriT from E. coli to the nine Pseudoalteromonas strains ranged from 10(-6) to 10(-3) transconjugants per recipient cells. Two suicide vectors, pK18mobsacB-Cm and pK18mobsacB-Ery (with sacB for counter-selection), were constructed for gene knockout. To verify the feasibility of this system, we selected gene or operon that may lead to phenotypic change once disrupted as targets to facilitate in vivo functional confirmation. Successful deletions of two genes related to prodigiosin biosynthesis (pigMK) in P. rubra DSM 6842, one biofilm related gene (bsmA) in P. sp. SM9913, one gene related to melanin hyperproduction (hmgA) in P. lipolytica SCSIO 04301 and two flagella-related genes (fliF and fliG) in P. sp. SCSIO 11900 were verified, respectively. In addition, complementation of hmgA using shuttle vector pWD2-oriT was rescued the phenotype caused by deletion of chromosomal copy of hmgA in P. lipolytica SCSIO 04301. Taken together, we demonstrate that the vectors and the conjugative protocol developed here have potential to use in various Pseudoalteromonas strains.
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Affiliation(s)
- Pengxia Wang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, the South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.
| | - Zichao Yu
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan, 250100, China.
| | - Baiyuan Li
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, the South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Xingsheng Cai
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, the South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.
| | - Zhenshun Zeng
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, the South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Xiulan Chen
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan, 250100, China.
| | - Xiaoxue Wang
- Key Laboratory of Tropical Marine Bio-resources and Ecology, Guangdong Key Laboratory of Marine Materia Medica, RNAM Center for Marine Microbiology, the South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.
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24
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NAD captureSeq indicates NAD as a bacterial cap for a subset of regulatory RNAs. Nature 2014; 519:374-7. [PMID: 25533955 DOI: 10.1038/nature14020] [Citation(s) in RCA: 188] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 10/27/2014] [Indexed: 11/08/2022]
Abstract
A distinctive feature of prokaryotic gene expression is the absence of 5'-capped RNA. In eukaryotes, 5',5'-triphosphate-linked 7-methylguanosine protects messenger RNA from degradation and modulates maturation, localization and translation. Recently, the cofactor nicotinamide adenine dinucleotide (NAD) was reported as a covalent modification of bacterial RNA. Given the central role of NAD in redox biochemistry, posttranslational protein modification and signalling, its attachment to RNA indicates that there are unknown functions of RNA in these processes and undiscovered pathways in RNA metabolism and regulation. The unknown identity of NAD-modified RNAs has so far precluded functional analyses. Here we identify NAD-linked RNAs from bacteria by chemo-enzymatic capture and next-generation sequencing (NAD captureSeq). Among those identified, specific regulatory small RNAs (sRNAs) and sRNA-like 5'-terminal fragments of certain mRNAs are particularly abundant. Analogous to a eukaryotic cap, 5'-NAD modification is shown in vitro to stabilize RNA against 5'-processing by the RNA-pyrophosphohydrolase RppH and against endonucleolytic cleavage by ribonuclease (RNase) E. The nudix phosphohydrolase NudC decaps NAD-RNA and thereby triggers RNase-E-mediated RNA decay, while being inactive against triphosphate-RNA. In vivo, ∼13% of the abundant sRNA RNAI is NAD-capped in the presence, and ∼26% in the absence, of functional NudC. To our knowledge, this is the first description of a cap-like structure and a decapping machinery in bacteria.
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Hidalgo-Romano B, Gollihar J, Brown SA, Whiteley M, Valenzuela E, Kaplan HB, Wood TK, McLean RJC. Indole inhibition of N-acylated homoserine lactone-mediated quorum signalling is widespread in Gram-negative bacteria. MICROBIOLOGY-SGM 2014; 160:2464-2473. [PMID: 25165125 DOI: 10.1099/mic.0.081729-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The LuxI/R quorum-sensing system and its associated N-acylated homoserine lactone (AHL) signal is widespread among Gram-negative bacteria. Although inhibition by indole of AHL quorum signalling in Pseudomonas aeruginosa and Acinetobacter oleivorans has been reported previously, it has not been documented among other species. Here, we show that co-culture with wild-type Escherichia coli, but not with E. coli tnaA mutants that lack tryptophanase and as a result do not produce indole, inhibits AHL-regulated pigmentation in Chromobacterium violaceum (violacein), Pseudomonas chlororaphis (phenazine) and Serratia marcescens (prodigiosin). Loss of pigmentation also occurred during pure culture growth of Chro. violaceum, P. chlororaphis and S. marcescens in the presence of physiologically relevant indole concentrations (0.5-1.0 mM). Inhibition of violacein production by indole was counteracted by the addition of the Chro. violaceum cognate autoinducer, N-decanoyl homoserine lactone (C10-HSL), in a dose-dependent manner. The addition of exogenous indole or co-culture with E. coli also affected Chro. violaceum transcription of vioA (violacein pigment production) and chiA (chitinase production), but had no effect on pykF (pyruvate kinase), which is not quorum regulated. Chro. violaceum AHL-regulated elastase and chitinase activity were inhibited by indole, as was motility. Growth of Chro. violaceum was not affected by indole or C10-HSL supplementation. Using a nematode-feeding virulence assay, we observed that survival of Caenorhabditis elegans exposed to Chro. violaceum, P. chlororaphis and S. marcescens was enhanced during indole supplementation. Overall, these studies suggest that indole represents a general inhibitor of AHL-based quorum signalling in Gram-negative bacteria.
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Affiliation(s)
- Benjamin Hidalgo-Romano
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX 78666, USA
| | - Jimmy Gollihar
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Stacie A Brown
- Department of Biology, Southwestern University, Georgetown, TX 78626, USA
| | - Marvin Whiteley
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX 78712, USA
| | - Ernesto Valenzuela
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Heidi B Kaplan
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center at Houston, Houston, TX 77030, USA
| | - Thomas K Wood
- Department of Chemical Engineering, Pennsylvania State University, University Park, PA 16802-4400, USA
| | - Robert J C McLean
- Department of Biology, Texas State University, 601 University Drive, San Marcos, TX 78666, USA
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26
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Structural and functional characterization of DUF1471 domains of Salmonella proteins SrfN, YdgH/SssB, and YahO. PLoS One 2014; 9:e101787. [PMID: 25010333 PMCID: PMC4092069 DOI: 10.1371/journal.pone.0101787] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 04/07/2014] [Indexed: 11/20/2022] Open
Abstract
Bacterial species in the Enterobacteriaceae typically contain multiple paralogues of a small domain of unknown function (DUF1471) from a family of conserved proteins also known as YhcN or BhsA/McbA. Proteins containing DUF1471 may have a single or three copies of this domain. Representatives of this family have been demonstrated to play roles in several cellular processes including stress response, biofilm formation, and pathogenesis. We have conducted NMR and X-ray crystallographic studies of four DUF1471 domains from Salmonella representing three different paralogous DUF1471 subfamilies: SrfN, YahO, and SssB/YdgH (two of its three DUF1471 domains: the N-terminal domain I (residues 21–91), and the C-terminal domain III (residues 244–314)). Notably, SrfN has been shown to have a role in intracellular infection by Salmonella Typhimurium. These domains share less than 35% pairwise sequence identity. Structures of all four domains show a mixed α+β fold that is most similar to that of bacterial lipoprotein RcsF. However, all four DUF1471 sequences lack the redox sensitive cysteine residues essential for RcsF activity in a phospho-relay pathway, suggesting that DUF1471 domains perform a different function(s). SrfN forms a dimer in contrast to YahO and SssB domains I and III, which are monomers in solution. A putative binding site for oxyanions such as phosphate and sulfate was identified in SrfN, and an interaction between the SrfN dimer and sulfated polysaccharides was demonstrated, suggesting a direct role for this DUF1471 domain at the host-pathogen interface.
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27
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Vega LM, Alvarez PJ, McLean RJC. Bacterial signaling ecology and potential applications during aquatic biofilm construction. MICROBIAL ECOLOGY 2014; 68:24-34. [PMID: 24276538 DOI: 10.1007/s00248-013-0321-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 10/24/2013] [Indexed: 06/02/2023]
Abstract
In their natural environment, bacteria and other microorganisms typically grow as surface-adherent biofilm communities. Cell signal processes, including quorum signaling, are now recognized as being intimately involved in the development and function of biofilms. In contrast to their planktonic (unattached) counterparts, bacteria within biofilms are notoriously resistant to many traditional antimicrobial agents and so represent a major challenge in industry and medicine. Although biofilms impact many human activities, they actually represent an ancient mode of bacterial growth as shown in the fossil record. Consequently, many aquatic organisms have evolved strategies involving signal manipulation to control or co-exist with biofilms. Here, we review the chemical ecology of biofilms and propose mechanisms whereby signal manipulation can be used to promote or control biofilms.
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Affiliation(s)
- Leticia M Vega
- Department of Civil and Environmental Engineering, Rice University, Houston, TX, 77005, USA
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28
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Landstorfer R, Simon S, Schober S, Keim D, Scherer S, Neuhaus K. Comparison of strand-specific transcriptomes of enterohemorrhagic Escherichia coli O157:H7 EDL933 (EHEC) under eleven different environmental conditions including radish sprouts and cattle feces. BMC Genomics 2014; 15:353. [PMID: 24885796 PMCID: PMC4048457 DOI: 10.1186/1471-2164-15-353] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 03/31/2014] [Indexed: 12/26/2022] Open
Abstract
Background Multiple infection sources for enterohemorrhagic Escherichia coli O157:H7 (EHEC) are known, including animal products, fruit and vegetables. The ecology of this pathogen outside its human host is largely unknown and one third of its annotated genes are still hypothetical. To identify genetic determinants expressed under a variety of environmental factors, we applied strand-specific RNA-sequencing, comparing the SOLiD and Illumina systems. Results Transcriptomes of EHEC were sequenced under 11 different biotic and abiotic conditions: LB medium at pH4, pH7, pH9, or at 15°C; LB with nitrite or trimethoprim-sulfamethoxazole; LB-agar surface, M9 minimal medium, spinach leaf juice, surface of living radish sprouts, and cattle feces. Of 5379 annotated genes in strain EDL933 (genome and plasmid), a surprising minority of only 144 had null sequencing reads under all conditions. We therefore developed a statistical method to distinguish weakly transcribed genes from background transcription. We find that 96% of all genes and 91.5% of the hypothetical genes exhibit a significant transcriptional signal under at least one condition. Comparing SOLiD and Illumina systems, we find a high correlation between both approaches for fold-changes of the induced or repressed genes. The pathogenicity island LEE showed highest transcriptional activity in LB medium, minimal medium, and after treatment with antibiotics. Unique sets of genes, including many hypothetical genes, are highly up-regulated on radish sprouts, cattle feces, or in the presence of antibiotics. Furthermore, we observed induction of the shiga-toxin carrying phages by antibiotics and confirmed active biofilm related genes on radish sprouts, in cattle feces, and on agar plates. Conclusions Since only a minority of genes (2.7%) were not active under any condition tested (null reads), we suggest that the assumption of significant genome over-annotations is wrong. Environmental transcriptomics uncovered hitherto unknown gene functions and unique regulatory patterns in EHEC. For instance, the environmental function of azoR had been elusive, but this gene is highly active on radish sprouts. Thus, NGS-transcriptomics is an appropriate technique to propose new roles of hypothetical genes and to guide future research. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-353) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | | | - Klaus Neuhaus
- Lehrstuhl für Mikrobielle Ökologie, Wissenschaftszentrum Weihenstephan, Technische Universität München, Weihenstephaner Berg 3, D-85350 Freising, Germany.
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29
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Smirnov SV, Sokolov PM, Kotlyarova VA, Samsonova NN, Kodera T, Sugiyama M, Torii T, Hibi M, Shimizu S, Yokozeki K, Ogawa J. A novel l-isoleucine-4'-dioxygenase and l-isoleucine dihydroxylation cascade in Pantoea ananatis. Microbiologyopen 2013; 2:471-81. [PMID: 23554367 PMCID: PMC3684760 DOI: 10.1002/mbo3.87] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 02/24/2013] [Accepted: 03/06/2013] [Indexed: 01/18/2023] Open
Abstract
A unique operon structure has been identified in the genomes of several plant- and insect-associated bacteria. The distinguishing feature of this operon is the presence of tandem hilA and hilB genes encoding dioxygenases belonging to the PF13640 and PF10014 (BsmA) Pfam families, respectively. The genes encoding HilA and HilB from Pantoea ananatis AJ13355 were cloned and expressed in Escherichia coli. The culturing of E. coli cells expressing hilA (E. coli-HilA) or both hilA and hilB (E. coli-HilAB) in the presence of l-isoleucine resulted in the conversion of l-isoleucine into two novel biogenic compounds: l-4′-isoleucine and l-4,4′-dihydroxyisoleucine, respectively. In parallel, two novel enzymatic activities were detected in the crude cell lysates of the E. coli-HilA and E. coli-HilAB strains: l-isoleucine, 2-oxoglutarate: oxygen oxidoreductase (4′-hydroxylating) (HilA) and l-4′-hydroxyisoleucine, 2-oxoglutarate: oxygen oxidoreductase (4-hydroxylating) (HilB), respectively. Two hypotheses regarding the physiological significance of C-4(4′)-hydroxylation of l-isoleucine in bacteria are also discussed. According to first hypothesis, the l-isoleucine dihydroxylation cascade is involved in synthesis of dipeptide antibiotic in P. ananatis. Another unifying hypothesis is that the C-4(4′)-hydroxylation of l-isoleucine in bacteria could result in the synthesis of signal molecules belonging to two classes: 2(5H)-furanones and analogs of N-acyl homoserine lactone.
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Affiliation(s)
- Sergey V Smirnov
- Ajinomoto-Genetika Research Institute, 1st Dorozhny pr. 1, Moscow, 113545, Russia
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30
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Tavares AFN, Nobre LS, Saraiva LM. A role for reactive oxygen species in the antibacterial properties of carbon monoxide-releasing molecules. FEMS Microbiol Lett 2012; 336:1-10. [PMID: 22774863 DOI: 10.1111/j.1574-6968.2012.02633.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 07/02/2012] [Accepted: 07/03/2012] [Indexed: 12/24/2022] Open
Abstract
Carbon monoxide-releasing molecules (CO-RMs) are, in general, transition metal carbonyl complexes that liberate controlled amounts of CO. In animal models, CO-RMs have been shown to reduce myocardial ischaemia, inflammation and vascular dysfunction, and to provide a protective effect in organ transplantation. Moreover, CO-RMs are bactericides that kill both Gram-positive and Gram-negative bacteria such as Staphylococcus aureus and Pseudomonas aeruginosa. Herein are reviewed the microbial genetic and biochemical responses associated with CO-RM-mediated cell death. Particular emphasis is given to the data revealing that CO-RMs induce the generation of reactive oxygen species (ROS), which contribute to the antibacterial activity of these compounds.
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Affiliation(s)
- Ana Filipa N Tavares
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
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Indole production promotes Escherichia coli mixed-culture growth with Pseudomonas aeruginosa by inhibiting quorum signaling. Appl Environ Microbiol 2011; 78:411-9. [PMID: 22101045 DOI: 10.1128/aem.06396-11] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Indole production by Escherichia coli, discovered in the early 20th century, has been used as a diagnostic marker for distinguishing E. coli from other enteric bacteria. By using transcriptional profiling and competition studies with defined mutants, we show that cyclic AMP (cAMP)-regulated indole formation is a major factor that enables E. coli growth in mixed biofilm and planktonic populations with Pseudomonas aeruginosa. Mutants deficient in cAMP production (cyaA) or the cAMP receptor gene (crp), as well as indole production (tnaA), were not competitive in coculture with P. aeruginosa but could be restored to wild-type competitiveness by supplementation with a physiologically relevant indole concentration. E. coli sdiA mutants, which lacked the receptor for both indole and N-acyl-homoserine lactones (AHLs), showed no change in competitive fitness, suggesting that indole acted directly on P. aeruginosa. An E. coli tnaA mutant strain regained wild-type competiveness if grown with P. aeruginosa AHL synthase (rhlI and rhlI lasI) mutants. In contrast to the wild type, P. aeruginosa AHL synthase mutants were unable to degrade indole. Indole produced during mixed-culture growth inhibited pyocyanin production and other AHL-regulated virulence factors in P. aeruginosa. Mixed-culture growth with P. aeruginosa stimulated indole formation in E. coli cpdA, which is unable to regulate cAMP levels, suggesting the potential for mixed-culture gene activation via cAMP. These findings illustrate how indole, an early described feature of E. coli central metabolism, can play a significant role in mixed-culture survival by inhibiting quorum-regulated competition factors in P. aeruginosa.
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Machado I, Lopes SP, Sousa AM, Pereira MO. Adaptive response of single and binary Pseudomonas aeruginosa and Escherichia coli biofilms to benzalkonium chloride. J Basic Microbiol 2011; 52:43-52. [DOI: 10.1002/jobm.201100137] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2011] [Accepted: 05/01/2011] [Indexed: 11/09/2022]
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Bacteriophage ecology in Escherichia coli and Pseudomonas aeruginosa mixed-biofilm communities. Appl Environ Microbiol 2010; 77:821-9. [PMID: 21131510 DOI: 10.1128/aem.01797-10] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Phage therapy is being reexamined as a strategy for bacterial control in medical and other environments. As microorganisms often live in mixed populations, we examined the effect of Escherichia coli bacteriophage λW60 and Pseudomonas aeruginosa bacteriophage PB-1 infection on the viability of monoculture and mixed-species biofilm and planktonic cultures. In mixed-species biofilm communities, E. coli and P. aeruginosa maintained stable cell populations in the presence of one or both phages. In contrast, E. coli planktonic populations were severely depleted in coculture in the presence of λW60. Both E. coli and P. aeruginosa developed phage resistance in planktonic culture; however, reduced resistance was observed in biofilm communities. Increased phage titers and reduced resistance in biofilms suggest that phage can replicate on susceptible cells in biofilms. Infectious phage could be released from mixed-culture biofilms upon treatment with Tween 20 but not upon treatment with chloroform. Tween 20 and chloroform treatments had no effect on phage associated with planktonic cells, suggesting that planktonic phage were not cell or matrix associated. Transmission electron microscopy showed bacteriophage particles to be enmeshed in the extracellular polymeric substance component of biofilms and that this substance could be removed by Tween 20 treatment. Overall, this study demonstrates how mixed-culture biofilms can maintain a reservoir of viable phage and bacterial populations in the environment.
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Hancock V, Vejborg RM, Klemm P. Functional genomics of probiotic Escherichia coli Nissle 1917 and 83972, and UPEC strain CFT073: comparison of transcriptomes, growth and biofilm formation. Mol Genet Genomics 2010; 284:437-54. [DOI: 10.1007/s00438-010-0578-8] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2010] [Accepted: 09/10/2010] [Indexed: 12/25/2022]
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