1
|
Zou Z, Robinson JI, Steinberg LK, Henderson JP. Uropathogenic Escherichia coli wield enterobactin-derived catabolites as siderophores. J Biol Chem 2024; 300:105554. [PMID: 38072063 PMCID: PMC10788543 DOI: 10.1016/j.jbc.2023.105554] [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: 07/28/2023] [Revised: 11/20/2023] [Accepted: 12/05/2023] [Indexed: 12/19/2023] Open
Abstract
Uropathogenic Escherichia coli (UPEC) secrete multiple siderophore types to scavenge extracellular iron(III) ions during clinical urinary tract infections, despite the metabolic costs of biosynthesis. Here, we find the siderophore enterobactin (Ent) and its related products to be prominent components of the iron-responsive extracellular metabolome of a model UPEC strain. Using defined Ent biosynthesis and import mutants, we identify lower molecular weight dimeric exometabolites as products of incomplete siderophore catabolism, rather than prematurely released biosynthetic intermediates. In E. coli, iron acquisition from iron(III)-Ent complexes requires intracellular esterases that hydrolyze the siderophore. Although UPEC are equipped to consume the products of completely hydrolyzed Ent, we find that Ent and its derivatives may be incompletely hydrolyzed to yield products with retained siderophore activity. These results are consistent with catabolic inefficiency as means to obtain more than one iron ion per siderophore molecule. This is compatible with an evolved UPEC strategy to maximize the nutritional returns from metabolic investments in siderophore biosynthesis.
Collapse
Affiliation(s)
- Zongsen Zou
- Center for Women's Infectious Diseases Research, Washington University School of Medicine, St Louis, Missouri, USA; Division of Infectious Diseases, Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - John I Robinson
- Center for Women's Infectious Diseases Research, Washington University School of Medicine, St Louis, Missouri, USA; Division of Infectious Diseases, Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Lindsey K Steinberg
- Center for Women's Infectious Diseases Research, Washington University School of Medicine, St Louis, Missouri, USA; Division of Infectious Diseases, Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri, USA
| | - Jeffrey P Henderson
- Center for Women's Infectious Diseases Research, Washington University School of Medicine, St Louis, Missouri, USA; Division of Infectious Diseases, Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri, USA.
| |
Collapse
|
2
|
Zeng X, Vidlund J, Gillespie B, Cao L, Agga GE, Lin J, Dego OK. Evaluation of immunogenicity of enterobactin conjugate vaccine for the control of Escherichia coli mastitis in dairy cows. J Dairy Sci 2023; 106:7147-7163. [PMID: 37210351 DOI: 10.3168/jds.2022-23219] [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: 12/30/2022] [Accepted: 04/09/2023] [Indexed: 05/22/2023]
Abstract
Mastitis is the most common disease of dairy cows that incurs severe economic losses to the dairy industry. Currently, environmental mastitis pathogens are a major problem for most dairy farms. A current commercially available Escherichia coli vaccine does not prevent clinical mastitis and production losses, likely due to antibody accessibility and antigenic variation issues. Therefore, a novel vaccine that prevents clinical disease and production losses is critically needed. Recently a nutritional immunity approach, which restricts bacterial iron uptake by immunologically sequestering conserved iron-binding enterobactin (Ent), has been developed. The objective of this study was to evaluate the immunogenicity of the keyhole limpet hemocyanin-enterobactin (KLH-Ent) conjugate vaccine in dairy cows. Twelve pregnant Holstein dairy cows in their first through third lactations were randomized to the control or vaccine group, with 6 cows per group. The vaccine group received 3 subcutaneous vaccinations of KLH-Ent with adjuvants at drying off (D0), 20 (D21), and 40 (D42) days after drying off. The control group was injected with phosphate-buffered saline (pH 7.4) mixed with the same adjuvants at the same time points. Vaccination effects were assessed over the study period until the end of the first month of lactation. The KLH-Ent vaccine did not cause any systemic adverse reactions or reduction in milk production. Compared with the control group, the vaccine elicited significantly higher levels of serum Ent-specific IgG at calving (C0) and 30 d postcalving (C30), mainly its IgG2 fraction, which was significantly higher at D42, C0, C14, and C30 d, with no significant change in IgG1 levels. Milk Ent-specific IgG and IgG2 levels in the vaccine group were significantly higher on C30. Fecal microbial community structures were similar for both control and vaccine groups on the same day and shifted directionally along the sampling days. In conclusion, the KLH-Ent vaccine successfully triggered strong Ent-specific immune responses in dairy cows without significantly affecting the gut microbiota diversity and health. The results show that Ent conjugate vaccine is a promising nutritional immunity approach in control of E. coli mastitis in dairy cows.
Collapse
Affiliation(s)
- X Zeng
- Department of Animal Science, The University of Tennessee, Knoxville, TN 37996
| | - J Vidlund
- Department of Animal Science, The University of Tennessee, Knoxville, TN 37996
| | - B Gillespie
- Department of Animal Science, The University of Tennessee, Knoxville, TN 37996
| | - L Cao
- Department of Animal Science, The University of Tennessee, Knoxville, TN 37996
| | - G E Agga
- Food Animal Environmental Systems Research Unit, Agricultural Research Service, US Department of Agriculture, Bowling Green, KY 42101
| | - J Lin
- Department of Animal Science, The University of Tennessee, Knoxville, TN 37996
| | - O Kerro Dego
- Department of Animal Science, The University of Tennessee, Knoxville, TN 37996.
| |
Collapse
|
3
|
Zou Z, Robinson JI, Steinberg LK, Henderson JP. Uropathogenic Escherichia coli wield enterobactin-derived catabolites as siderophores. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.25.550588. [PMID: 37546885 PMCID: PMC10402112 DOI: 10.1101/2023.07.25.550588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
Uropathogenic E. coli (UPEC) secrete multiple siderophore types to scavenge extracellular iron(III) ions during clinical urinary tract infections, despite the metabolic costs of biosynthesis. Here we find the siderophore enterobactin and its related products to be prominent components of the iron-responsive extracellular metabolome of a model UPEC strain. Using defined enterobactin biosynthesis and import mutants, we identify lower molecular weight, dimeric exometabolites as products of incomplete siderophore catabolism, rather than prematurely released biosynthetic intermediates. In E. coli, iron acquisition from iron(III)-enterobactin complexes requires intracellular esterases that hydrolyze the siderophore. Although UPEC are equipped to consume the products of completely hydrolyzed enterobactin, we find that enterobactin and its derivatives may be incompletely hydrolyzed to yield products with retained siderophore activity. These results are consistent with catabolic inefficiency as means to obtain more than one iron ion per siderophore molecule. This is compatible with an evolved UPEC strategy to maximize the nutritional returns from metabolic investments in siderophore biosynthesis.
Collapse
Affiliation(s)
- Zongsen Zou
- Center for Women’s Infectious Diseases Research, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, USA
| | - John I. Robinson
- Center for Women’s Infectious Diseases Research, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Lindsey K. Steinberg
- Center for Women’s Infectious Diseases Research, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Jeffrey P. Henderson
- Center for Women’s Infectious Diseases Research, Washington University School of Medicine, St. Louis, Missouri, USA
- Department of Internal Medicine, Division of Infectious Diseases, Washington University School of Medicine, St. Louis, Missouri, USA
| |
Collapse
|
4
|
Kocer K, Boudour-Halil D, Chanthalangsy Q, Sähr A, Heeg K, Boutin S, Nurjadi D. Genomic Modification of TonB and Emergence of Small-Colony Phenotype in VIM- and NDM-Producing Escherichia coli following Cefiderocol Exposure In Vitro. Antimicrob Agents Chemother 2023; 67:e0011823. [PMID: 37022155 PMCID: PMC10190670 DOI: 10.1128/aac.00118-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 03/07/2023] [Indexed: 04/07/2023] Open
Abstract
Knowledge on resistance mechanisms toward cefiderocol, a novel siderophore-conjugated cephalosporin antibiotic, is still limited. Although the presence of New-Delhi metallo-β-lactamase has been demonstrated to facilitate the resistance development toward cefiderocol via siderophore receptor mutations in Enterobacter cloacae and Klebsiella pneumoniae, the impact of metallo-β-lactamases on facilitating such mutations in Escherichia coli is not yet elucidated. Our study aimed to study the effect of the presence of various β-lactamases, such as NDM-5, VIM-1, KPC-2, and OXA-48, on the development of cefiderocol resistance in E. coli. To this end, we performed liquid mating to transfer these β-lactamases onto a defined K-12 E. coli background (J53) and exposed these transconjugants to increasing cefiderocol concentrations in a serial passage experiment. Cefiderocol-resistant isolates were genotyped by whole-genome sequencing to investigate the underlying resistance mechanism. Cefiderocol-resistant isolates emerged only in isolates producing VIM-1 and NDM-5 metallo-β-lactamase, but not in those producing the serine β-lactamases KPC-2 and OXA-48. We observed two distinct morphological changes of the J53 E. coli strain exhibiting reduced colony size after insertions of transposable elements in the tonB gene leading to alterations in the TonB binding site and morphological changes consistent with the small-colony variant (SCV) phenotype due to mutations in the hemB and hemH genes. Passaging experiments suggested that these phenotypes were highly plastic. The SCV phenotype is attributed to immune evasion and decreased susceptibility toward antibiotics. The emergence of SCV following cefiderocol exposure may have clinical implications for bacterial clearance and warrants further investigation.
Collapse
Affiliation(s)
- Kaan Kocer
- Department of Infectious Diseases, Medical Microbiology and Hospital Hygiene, University Hospital Heidelberg, Heidelberg, Germany
| | - Deniz Boudour-Halil
- Department of Infectious Diseases, Medical Microbiology and Hospital Hygiene, University Hospital Heidelberg, Heidelberg, Germany
| | - Quan Chanthalangsy
- Department of Infectious Diseases, Medical Microbiology and Hospital Hygiene, University Hospital Heidelberg, Heidelberg, Germany
| | - Aline Sähr
- Department of Infectious Diseases, Medical Microbiology and Hospital Hygiene, University Hospital Heidelberg, Heidelberg, Germany
| | - Klaus Heeg
- Department of Infectious Diseases, Medical Microbiology and Hospital Hygiene, University Hospital Heidelberg, Heidelberg, Germany
| | - Sébastien Boutin
- Translational Lung Research Center (TLRC), German Center for Lung Research (DZL), Heidelberg, Germany
- Department of Infectious Diseases and Microbiology, University of Lübeck, Lübeck, Germany
| | - Dennis Nurjadi
- Department of Infectious Diseases and Microbiology, University of Lübeck, Lübeck, Germany
- German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Hamburg-Lübeck-Borstel-Riems, Germany
| |
Collapse
|
5
|
Gao Q, Li X, Su S, Yang L, Gao S. Deletion of the c2515 and c2516 Genes Affects Iron Uptake and Virulence of APEC O1 Strain E516. Front Vet Sci 2021; 8:654721. [PMID: 33912608 PMCID: PMC8075096 DOI: 10.3389/fvets.2021.654721] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Accepted: 03/15/2021] [Indexed: 11/24/2022] Open
Abstract
Avian pathogenic Escherichia coli (APEC), widely spread among poultry, is well-known to cause colibacillosis in chickens, which results in significant losses in poultry industry. The ability to uptake iron in the extra-intestinal environment is prerequisite for APEC survival. For adaptation to the low-iron environments, the bacteria have evolved multiple iron acquisition systems to ensure optimal iron uptake. However, many components of these iron acquisition pathways are still not clearly known. An in silico analysis of the genome of a septicemic APEC O1 strain E516 identified two putative iron transport genes homologous to the c2515 and c2516 genes from uropathogenic E. coli CFT073. In this study, we constructed the single and double gene deletion mutants, and studied their biological characteristic and pathogenic traits through in vitro and in vivo assays. Reverse transcriptase PCR (RT-PCR) analyses demonstrated that the mutations destroying the reading frame of the target genes abolished their transcription. Deletion of the single or double genes of c2515 and c2516 in APEC E516 weakened its ability to produce siderophore. Consistently, the mutants exhibited growth defect under iron-depleted conditions and the intracellular iron levels in the mutants were decreased in comparison with that of the wild-type (WT). Cell infection assays showed that the iron uptake defective mutants were more easily eliminated by the macrophage. Inactivation of the c2515 and c2516 genes affected bacterial colonization of chicken tissues, as well as the 50% lethal dose levels compared with the WT strain. Moreover, the expression levels of several iron uptake-related genes were significantly decreased in the double-deletion mutant. In total, the c2515 and c2516 may involve in siderophore-mediated iron uptake and participate in the pathogenesis of APEC O1 strain E516.
Collapse
Affiliation(s)
- Qingqing Gao
- Animal Infectious Disease Laboratory, Ministry of Agriculture, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
| | - Xi Li
- Animal Infectious Disease Laboratory, Ministry of Agriculture, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
| | - Senyan Su
- Animal Infectious Disease Laboratory, Ministry of Agriculture, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
| | - Lei Yang
- Animal Infectious Disease Laboratory, Ministry of Agriculture, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
| | - Song Gao
- Animal Infectious Disease Laboratory, Ministry of Agriculture, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
| |
Collapse
|
6
|
Kim SH, Chelliah R, Ramakrishnan SR, Perumal AS, Bang WS, Rubab M, Daliri EBM, Barathikannan K, Elahi F, Park E, Jo HY, Hwang SB, Oh DH. Review on Stress Tolerance in Campylobacter jejuni. Front Cell Infect Microbiol 2021; 10:596570. [PMID: 33614524 PMCID: PMC7890702 DOI: 10.3389/fcimb.2020.596570] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Accepted: 12/03/2020] [Indexed: 01/17/2023] Open
Abstract
Campylobacter spp. are the leading global cause of bacterial colon infections in humans. Enteropathogens are subjected to several stress conditions in the host colon, food complexes, and the environment. Species of the genus Campylobacter, in collective interactions with certain enteropathogens, can manage and survive such stress conditions. The stress-adaptation mechanisms of Campylobacter spp. diverge from other enteropathogenic bacteria, such as Escherichia coli, Salmonella enterica serovar Typhi, S. enterica ser. Paratyphi, S. enterica ser. Typhimurium, and species of the genera Klebsiella and Shigella. This review summarizes the different mechanisms of various stress-adaptive factors on the basis of species diversity in Campylobacter, including their response to various stress conditions that enhance their ability to survive on different types of food and in adverse environmental conditions. Understanding how these stress adaptation mechanisms in Campylobacter, and other enteric bacteria, are used to overcome various challenging environments facilitates the fight against resistance mechanisms in Campylobacter spp., and aids the development of novel therapeutics to control Campylobacter in both veterinary and human populations.
Collapse
Affiliation(s)
- Se-Hun Kim
- Food Microbiology Division, Food Safety Evaluation Department, National Institute of Food and Drug Safety Evaluation, Cheongju, South Korea.,College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, South Korea
| | - Ramachandran Chelliah
- College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, South Korea
| | - Sudha Rani Ramakrishnan
- School of Food Science, Department of Food Science and Biotechnology, College of Agriculture and Life Sciences, Kyungpook National University, Daegu, South Korea
| | | | - Woo-Suk Bang
- Department of Food and Nutrition, College of Human Ecology and Kinesiology, Yeungnam University, Gyeongsan, South Korea
| | - Momna Rubab
- College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, South Korea
| | - Eric Banan-Mwine Daliri
- College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, South Korea
| | - Kaliyan Barathikannan
- College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, South Korea
| | - Fazle Elahi
- College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, South Korea
| | - Eunji Park
- College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, South Korea
| | - Hyeon Yeong Jo
- College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, South Korea
| | - Su-Bin Hwang
- College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, South Korea
| | - Deog Hwan Oh
- College of Agriculture and Life Sciences, Kangwon National University, Chuncheon, South Korea
| |
Collapse
|
7
|
Liu M, Lyte M. Pyruvate is required for catecholamine-stimulated growth of different strains of Campylobacter jejuni. PeerJ 2020; 8:e10011. [PMID: 33062434 PMCID: PMC7528810 DOI: 10.7717/peerj.10011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 08/31/2020] [Indexed: 01/10/2023] Open
Abstract
Humans and food-producing animals are constantly exposed to and affected by stress. As a consequence of stress, the release of stress-related catecholamines, such as norepinephrine (NE) and dopamine (DA), from nerve terminals in the gastrointestinal tract potentiates both the growth and the virulence of pathogenic bacteria. This may lead to the enhancement of gastrointestinal infections in humans or food-producing animals. Compared with foodborne bacterial pathogens such as Escherichia coli and Salmonella spp., less is known about the effect of stress catecholamines on Campylobacter jejuni subsp. jejuni. The present study focuses on the effect(s) of stress catecholamines DA and NE in iron-restricted media and how they affect the growth of different C. jejuni strains NCTC 11168, 81–176, and ML2126. Results demonstrated that DA- and NE-enhanced growth of C. jejuni in iron-restricted media may involve different mechanisms that cannot be explained by current understanding which relies on catecholamine-mediated iron delivery. Specifically, we found that DA-enhanced growth requires pyruvate, whereas NE-enhanced growth does not. We further report significant strain-specific dependence of C. jejuni growth on various catecholamines in the presence or absence of pyruvate. These data provide novel insights into the effect(s) of stress catecholamines on the in vitro growth of C. jejuni in iron-restricted environments, such as the intestinal tract. They suggest a mechanism by which stress-related catecholamines affect the growth of C. jejuni in the intestinal tract of food-producing animals, which in turn may influence colonization and transmission to humans.
Collapse
Affiliation(s)
- Meicen Liu
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States of America
| | - Mark Lyte
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA, United States of America
| |
Collapse
|
8
|
Zhang Y, Edmonds KA, Raines DJ, Murphy BA, Wu H, Guo C, Nolan EM, VanNieuwenhze MS, Duhme-Klair AK, Giedroc DP. The Pneumococcal Iron Uptake Protein A (PiuA) Specifically Recognizes Tetradentate Fe IIIbis- and Mono-Catechol Complexes. J Mol Biol 2020; 432:5390-5410. [PMID: 32795535 DOI: 10.1016/j.jmb.2020.08.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/02/2020] [Accepted: 08/05/2020] [Indexed: 12/15/2022]
Abstract
Streptococcus pneumoniae (Spn) is an important Gram-positive human pathogen that causes millions of infections worldwide with an increasing occurrence of antibiotic resistance. Fe acquisition is a crucial virulence determinant in Spn; further, Spn relies on exogenous FeIII-siderophore scavenging to meet nutritional Fe needs. Recent studies suggest that the human catecholamine stress hormone, norepinephrine (NE), facilitates Fe acquisition in Spn under conditions of transferrin-mediated Fe starvation. Here we show that the solute binding lipoprotein PiuA from the piu Fe acquisition ABC transporter PiuBCDA, previously described as an Fe-hemin binding protein, binds tetradentate catechol FeIII complexes, including NE and the hydrolysis products of enterobactin. Two protein-derived ligands (H238, Y300) create a coordinately saturated FeIII complex, which parallel recent studies in the Gram-negative intestinal pathogen Campylobacter jejuni. Our in vitro studies using NMR spectroscopy and 54Fe LC-ICP-MS confirm the FeIII can move from transferrin to apo-PiuA in an NE-dependent manner. Structural analysis of PiuA FeIII-bis-catechol and GaIII-bis-catechol and GaIII-(NE)2 complexes by NMR spectroscopy reveals only localized structural perturbations in PiuA upon ligand binding, largely consistent with recent descriptions of other solute binding proteins of type II ABC transporters. We speculate that tetradentate FeIII complexes formed by mono- and bis-catechol species are important Fe sources in Gram-positive human pathogens, since PiuA functions in the same way as SstD from Staphylococcus aureus.
Collapse
Affiliation(s)
- Yifan Zhang
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA; Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA
| | - Katherine A Edmonds
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
| | - Daniel J Raines
- Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - Brennan A Murphy
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
| | - Hongwei Wu
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
| | - Chuchu Guo
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Elizabeth M Nolan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | - Anne-K Duhme-Klair
- Department of Chemistry, University of York, Heslington, York YO10 5DD, United Kingdom
| | - David P Giedroc
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA; Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, USA.
| |
Collapse
|
9
|
Zhang Y, Sen S, Giedroc DP. Iron Acquisition by Bacterial Pathogens: Beyond Tris-Catecholate Complexes. Chembiochem 2020; 21:1955-1967. [PMID: 32180318 PMCID: PMC7367709 DOI: 10.1002/cbic.201900778] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/06/2020] [Indexed: 12/11/2022]
Abstract
Sequestration of the essential nutrient iron from bacterial invaders that colonize the vertebrate host is a central feature of nutritional immunity and the "fight over transition metals" at the host-pathogen interface. The iron quota for many bacterial pathogens is large, as iron enzymes often make up a significant share of the metalloproteome. Iron enzymes play critical roles in respiration, energy metabolism, and other cellular processes by catalyzing a wide range of oxidation-reduction, electron transfer, and oxygen activation reactions. In this Concept article, we discuss recent insights into the diverse ways that bacterial pathogens acquire this essential nutrient, beyond the well-characterized tris-catecholate FeIII complexes, in competition and cooperation with significant host efforts to cripple these processes. We also discuss pathogen strategies to adapt their metabolism to less-than-optimal iron concentrations, and briefly speculate on what might be an integrated adaptive response to the concurrent limitation of both iron and zinc in the infected host.
Collapse
Affiliation(s)
- Yifan Zhang
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405-7102, USA
| | - Sambuddha Sen
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
| | - David P Giedroc
- Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405-7102, USA
| |
Collapse
|
10
|
A Cotransformation Method To Identify a Restriction-Modification Enzyme That Reduces Conjugation Efficiency in Campylobacter jejuni. Appl Environ Microbiol 2018; 84:AEM.02004-18. [PMID: 30242003 DOI: 10.1128/aem.02004-18] [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: 08/16/2018] [Accepted: 09/14/2018] [Indexed: 01/07/2023] Open
Abstract
Conjugation is an important mechanism for horizontal gene transfer in Campylobacter jejuni, the leading cause of human bacterial gastroenteritis in developed countries. However, to date, the factors that significantly influence conjugation efficiency in Campylobacter spp. are still largely unknown. Given that multiple recombinant loci could independently occur within one recipient cell during natural transformation, the genetic materials from a high-frequency conjugation (HFC) C. jejuni strain may be cotransformed with a selection marker into a low-frequency conjugation (LFC) recipient strain, creating new HFC transformants suitable for the identification of conjugation factors using a comparative genomics approach. To test this, an erythromycin resistance selection marker was created in an HFC C. jejuni strain; subsequently, the DNA of this strain was naturally transformed into NCTC 11168, an LFC C. jejuni strain, leading to the isolation of NCTC 11168-derived HFC transformants. Whole-genome sequencing analysis and subsequent site-directed mutagenesis identified Cj1051c, a putative restriction-modification enzyme (aka CjeI) that could drastically reduce the conjugation efficiency of NCTC 11168 (>5,000-fold). Chromosomal complementation of three diverse HFC C. jejuni strains with CjeI also led to a dramatic reduction in conjugation efficiency (∼1,000-fold). The purified recombinant CjeI could effectively digest the Escherichia coli-derived shuttle vector pRY107. The endonuclease activity of CjeI was abolished upon short heat shock treatment at 50°C, which is consistent with our previous observation that heat shock enhanced conjugation efficiency in C. jejuni Together, in this study, we successfully developed and utilized a unique cotransformation strategy to identify a restriction-modification enzyme that significantly influences conjugation efficiency in C. jejuni IMPORTANCE Conjugation is an important horizontal gene transfer mechanism contributing to the evolution of bacterial pathogenesis and antimicrobial resistance. Campylobacter jejuni, the leading foodborne bacterial organism, displays significant strain diversity due to horizontal gene transfer; however, the molecular components influencing conjugation efficiency in C. jejuni are still largely unknown. In this study, we developed a cotransformation strategy for comparative genomics analysis and successfully identified a restriction-modification enzyme that significantly influences conjugation efficiency in C. jejuni The new cotransformation strategy developed in this study is also expected to be broadly applied in other naturally competent bacteria for functional comparative genomics research.
Collapse
|
11
|
Guo Y, Hu D, Guo J, Li X, Guo J, Wang X, Xiao Y, Jin H, Liu M, Li Z, Bi D, Zhou Z. The Role of the Regulator Fur in Gene Regulation and Virulence of Riemerella anatipestifer Assessed Using an Unmarked Gene Deletion System. Front Cell Infect Microbiol 2017; 7:382. [PMID: 28971067 PMCID: PMC5609570 DOI: 10.3389/fcimb.2017.00382] [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: 05/15/2017] [Accepted: 08/09/2017] [Indexed: 11/29/2022] Open
Abstract
Riemerella anatipestifer, an avian pathogen, has resulted in enormous economic losses to the duck industry globally. Notwithstanding, little is known regarding the physiological, pathogenic and virulence mechanisms of Riemerella anatipestifer (RA) infection. However, the role of Ferric uptake regulator (Fur) in the virulence of R. anatipestifer has not, to date, been demonstrated. Using a genetic approach, unmarked gene deletion system, we evaluated the function of fur gene in the virulence of R. anatipestifer. For this purpose, we constructed a suicide vector containing pheS as a counter selectable marker for unmarked deletion of fur gene to investigate its role in the virulence. After successful transformation of the newly constructed vector, a mutant strain was characterized for genes regulated by iron and Fur using RNA-sequencing and a comparison was made between wild type and mutant strains in both iron restricted and enriched conditions. RNA-seq analysis of the mutant strain in a restricted iron environment showed the downregulation and upregulation of genes which were involved in either important metabolic pathways, transport processes, growth or cell membrane synthesis. Electrophoretic mobility shift assay was performed to identify the putative sequences recognized by Fur. The putative Fur-box sequence was 5′-GATAATGATAATCATTATC-3′. Lastly, the median lethal dose and histopathological investigations of animal tissues also illustrated mild pathological lesions produced by the mutant strain as compared to the wild type RA strain, hence showing declined virulence. Conclusively, an unmarked gene deletion system was successfully developed for RA and the role of the fur gene in virulence was explored comprehensively.
Collapse
Affiliation(s)
- Yunqing Guo
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Di Hu
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Jie Guo
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Xiaowen Li
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Jinyue Guo
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Xiliang Wang
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Yuncai Xiao
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Hui Jin
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural UniversityWuhan, China
| | - Mei Liu
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Zili Li
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| | - Dingren Bi
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China.,State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural UniversityWuhan, China
| | - Zutao Zhou
- College of Veterinary Medicine, Huazhong Agricultural UniversityWuhan, China.,Key Lab of Preventive Veterinary Medicine of Hubei Province, Huazhong Agricultural UniversityWuhan, China
| |
Collapse
|
12
|
Xia K, Li Y, Sun J, Liang X. Comparative Genomics of Acetobacterpasteurianus Ab3, an Acetic Acid Producing Strain Isolated from Chinese Traditional Rice Vinegar Meiguichu. PLoS One 2016; 11:e0162172. [PMID: 27611790 PMCID: PMC5017713 DOI: 10.1371/journal.pone.0162172] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Accepted: 08/18/2016] [Indexed: 11/21/2022] Open
Abstract
Acetobacter pasteurianus, an acetic acid resistant bacterium belonging to alpha-proteobacteria, has been widely used to produce vinegar in the food industry. To understand the mechanism of its high tolerance to acetic acid and robust ability of oxidizing ethanol to acetic acid (> 12%, w/v), we described the 3.1 Mb complete genome sequence (including 0.28 M plasmid sequence) with a G+C content of 52.4% of A. pasteurianus Ab3, which was isolated from the traditional Chinese rice vinegar (Meiguichu) fermentation process. Automatic annotation of the complete genome revealed 2,786 protein-coding genes and 73 RNA genes. The comparative genome analysis among A. pasteurianus strains revealed that A. pasteurianus Ab3 possesses many unique genes potentially involved in acetic acid resistance mechanisms. In particular, two-component systems or toxin-antitoxin systems may be the signal pathway and modulatory network in A. pasteurianus to cope with acid stress. In addition, the large numbers of unique transport systems may also be related to its acid resistance capacity and cell fitness. Our results provide new clues to understanding the underlying mechanisms of acetic acid resistance in Acetobacter species and guiding industrial strain breeding for vinegar fermentation processes.
Collapse
Affiliation(s)
- Kai Xia
- College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, China
| | - Yudong Li
- College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, China
| | - Jing Sun
- College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, China
| | - Xinle Liang
- College of Food Science and Biotechnology, Zhejiang Gongshang University, Hangzhou, 310018, China
- * E-mail:
| |
Collapse
|
13
|
Bronnec V, Turoňová H, Bouju A, Cruveiller S, Rodrigues R, Demnerova K, Tresse O, Haddad N, Zagorec M. Adhesion, Biofilm Formation, and Genomic Features of Campylobacter jejuni Bf, an Atypical Strain Able to Grow under Aerobic Conditions. Front Microbiol 2016; 7:1002. [PMID: 27446042 PMCID: PMC4927563 DOI: 10.3389/fmicb.2016.01002] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 06/13/2016] [Indexed: 12/29/2022] Open
Abstract
Campylobacter jejuni is the leading cause of bacterial enteritis in Europe. Human campylobacteriosis cases are frequently associated to the consumption of contaminated poultry meat. To survive under environmental conditions encountered along the food chain, i.e., from poultry digestive tract its natural reservoir to the consumer's plate, this pathogen has developed adaptation mechanisms. Among those, biofilm lifestyle has been suggested as a strategy to survive in the food environment and under atmospheric conditions. Recently, the clinical isolate C. jejuni Bf has been shown to survive and grow under aerobic conditions, a property that may help this strain to better survive along the food chain. The aim of this study was to evaluate the adhesion capacity of C. jejuni Bf and its ability to develop a biofilm. C. jejuni Bf can adhere to abiotic surfaces and to human epithelial cells, and can develop biofilm under both microaerobiosis and aerobiosis. These two conditions have no influence on this strain, unlike results obtained with the reference strain C. jejuni 81-176, which harbors only planktonic cells under aerobic conditions. Compared to 81-176, the biofilm of C. jejuni Bf is more homogenous and cell motility at the bottom of biofilm was not modified whatever the atmosphere used. C. jejuni Bf whole genome sequence did not reveal any gene unique to this strain, suggesting that its unusual property does not result from acquisition of new genetic material. Nevertheless some genetic particularities seem to be shared only between Bf and few others strains. Among the main features of C. jejuni Bf genome we noticed (i) a complete type VI secretion system important in pathogenicity and environmental adaptation; (ii) a mutation in the oorD gene involved in oxygen metabolism; and (iii) the presence of an uncommon insertion of a 72 amino acid coding sequence upstream from dnaK, which is involved in stress resistance. Therefore, the atypical behavior of this strain under aerobic atmosphere may result from the combination of insertions and mutations. In addition, the comparison of mRNA transcript levels of several genes targeted through genome analysis suggests the modification of regulatory processes in this strain.
Collapse
Affiliation(s)
| | - Hana Turoňová
- Institute of Chemical Technology, Faculty of Food and Biochemical Technology, Department of Biochemistry and MicrobiologyPrague, Czech Republic
| | | | - Stéphane Cruveiller
- CNRS-UMR 8030 and Commissariat à l’Energie Atomique et aux Energies Alternatives CEA/DRF/IG/Genoscope LABGeMEvry, France
| | | | - Katerina Demnerova
- Institute of Chemical Technology, Faculty of Food and Biochemical Technology, Department of Biochemistry and MicrobiologyPrague, Czech Republic
| | | | | | | |
Collapse
|
14
|
Zeng X, Gillespie B, Lin J. Important Role of a Putative Lytic Transglycosylase Cj0843c in β-Lactam Resistance in Campylobacter jejuni. Front Microbiol 2015; 6:1292. [PMID: 26635760 PMCID: PMC4647113 DOI: 10.3389/fmicb.2015.01292] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 11/04/2015] [Indexed: 01/26/2023] Open
Abstract
Beta-lactam antibiotics are an important class of antibiotics for treating bacterial infections. Despite prevalent β-lactam resistance in Campylobacter jejuni, the leading bacterial cause of human diarrhea in developed countries, molecular mechanism of β-lactam resistance in C. jejuni is still largely unknown. In this study, C. jejuni 81–176 was used for random transposon mutagenesis. Screening of a 2,800-mutant library identified 22 mutants with increased susceptibility to ampicillin. Of these mutants, two mutants contains mutations in Cj0843c (a putative lytic transglycosylase gene) and in its upstream gene Cj0844c, respectively. Complementation experiment demonstrated that the Cj0843 contributes to β-lactam resistance. The Cj0843c insertional mutation was subsequently introduced to diverse C. jejuni clinical strains for MIC test, showing that Cj0843c contributes to both intrinsic and acquired β-lactam resistance of C. jejuni. Consistent with this finding, inactivation of Cj0843c also dramatically reduced β-lactamase activity. Genomic examination and PCR analysis showed Cj0843c is widely distributed in C. jejuni. High purity recombinant Cj0843c was produced for generation of specific antiserum. The Cj0843 was localized in the periplasm, as demonstrated by immunoblotting using specific antibodies. Turbidimetric assay further demonstrated the capability of the purified Cj0843c to hydrolyze cell walls. Inactivation of Cj0843c also significantly reduced C. jejuni colonization in the intestine. Together, this study identifies a mechanism of β-lactam resistance in C. jejuni and provides insights into the role of cell wall metabolism in regulating β-lactamase activity.
Collapse
Affiliation(s)
- Ximin Zeng
- Department of Animal Science, The University of Tennessee, Knoxville TN, USA
| | - Barbara Gillespie
- Department of Animal Science, The University of Tennessee, Knoxville TN, USA
| | - Jun Lin
- Department of Animal Science, The University of Tennessee, Knoxville TN, USA
| |
Collapse
|
15
|
Liao H, Cheng X, Zhu D, Wang M, Jia R, Chen S, Chen X, Biville F, Liu M, Cheng A. TonB Energy Transduction Systems of Riemerella anatipestifer Are Required for Iron and Hemin Utilization. PLoS One 2015; 10:e0127506. [PMID: 26017672 PMCID: PMC4446302 DOI: 10.1371/journal.pone.0127506] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 04/16/2015] [Indexed: 12/13/2022] Open
Abstract
Riemerella anatipestifer (R. anatipestifer) is one of the most important pathogens in ducks. The bacteria causes acute or chronic septicemia characterized by fibrinous pericarditis and meningitis. The R. anatipestifer genome encodes multiple iron/hemin-uptake systems that facilitate adaptation to iron-limited host environments. These systems include several TonB-dependent transporters and three TonB proteins responsible for energy transduction. These three tonB genes are present in all the R. anatipestifer genomes sequenced so far. Two of these genes are contained within the exbB-exbD-tonB1 and exbB-exbD-exbD-tonB2 operons. The third, tonB3, forms a monocistronic transcription unit. The inability to recover derivatives deleted for this gene suggests its product is essential for R. anatipestifer growth. Here, we show that deletion of tonB1 had no effect on hemin uptake of R. anatipestifer, though disruption of tonB2 strongly decreases hemin uptake, and disruption of both tonB1 and tonB2 abolishes the transport of exogenously added hemin. The ability of R. anatipestifer to grow on iron-depleted medium is decreased by tonB2 but not tonB1 disruption. When expressed in an E. coli model strain, the TonB1 complex, TonB2 complex, and TonB3 protein from R. anatipestifer cannot energize heterologous hemin transporters. Further, only the TonB1 complex can energize a R. anatipestifer hemin transporter when co-expressed in an E. coli model strain.
Collapse
Affiliation(s)
- HeBin Liao
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Ya’an, Sichuan, People’s Republic of China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, People’s Republic of China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, People’s Republic of China
| | - XingJun Cheng
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Ya’an, Sichuan, People’s Republic of China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, People’s Republic of China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, People’s Republic of China
| | - DeKang Zhu
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Ya’an, Sichuan, People’s Republic of China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, People’s Republic of China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, People’s Republic of China
| | - MingShu Wang
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Ya’an, Sichuan, People’s Republic of China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, People’s Republic of China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, People’s Republic of China
| | - RenYong Jia
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Ya’an, Sichuan, People’s Republic of China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, People’s Republic of China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, People’s Republic of China
| | - Shun Chen
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Ya’an, Sichuan, People’s Republic of China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, People’s Republic of China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, People’s Republic of China
| | - XiaoYue Chen
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Ya’an, Sichuan, People’s Republic of China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, People’s Republic of China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, People’s Republic of China
| | - Francis Biville
- Unité des Infections Bactériennes Invasives, Institut Pasteur, Paris, France
| | - MaFeng Liu
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Ya’an, Sichuan, People’s Republic of China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, People’s Republic of China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, People’s Republic of China
- * E-mail: (ML); (AC)
| | - AnChun Cheng
- Avian Disease Research Center, College of Veterinary Medicine of Sichuan Agricultural University, Ya’an, Sichuan, People’s Republic of China
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, Sichuan, People’s Republic of China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, Sichuan, People’s Republic of China
- * E-mail: (ML); (AC)
| |
Collapse
|
16
|
Heat Shock-Enhanced Conjugation Efficiency in Standard Campylobacter jejuni Strains. Appl Environ Microbiol 2015; 81:4546-52. [PMID: 25911489 DOI: 10.1128/aem.00346-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 04/21/2015] [Indexed: 12/12/2022] Open
Abstract
Campylobacter jejuni, the leading bacterial cause of human gastroenteritis in the United States, displays significant strain diversity due to horizontal gene transfer. Conjugation is an important horizontal gene transfer mechanism contributing to the evolution of bacterial pathogenesis and antimicrobial resistance. It has been observed that heat shock could increase transformation efficiency in some bacteria. In this study, the effect of heat shock on C. jejuni conjugation efficiency and the underlying mechanisms were examined. With a modified Escherichia coli donor strain, different C. jejuni recipient strains displayed significant variation in conjugation efficiency ranging from 6.2 × 10(-8) to 6.0 × 10(-3) CFU per recipient cell. Despite reduced viability, heat shock of standard C. jejuni NCTC 11168 and 81-176 strains (e.g., 48 to 54°C for 30 to 60 min) could dramatically enhance C. jejuni conjugation efficiency up to 1,000-fold. The phenotype of the heat shock-enhanced conjugation in C. jejuni recipient cells could be sustained for at least 9 h. Filtered supernatant from the heat shock-treated C. jejuni cells could not enhance conjugation efficiency, which suggests that the enhanced conjugation efficiency is independent of secreted substances. Mutagenesis analysis indicated that the clustered regularly interspaced short palindromic repeats system and the selected restriction-modification systems (Cj0030/Cj0031, Cj0139/Cj0140, Cj0690c, and HsdR) were dispensable for heat shock-enhanced conjugation in C. jejuni. Taking all results together, this study demonstrated a heat shock-enhanced conjugation efficiency in standard C. jejuni strains, leading to an optimized conjugation protocol for molecular manipulation of this organism. The findings from this study also represent a significant step toward elucidation of the molecular mechanism of conjugative gene transfer in C. jejuni.
Collapse
|
17
|
Analysis of the activity and regulon of the two-component regulatory system composed by Cjj81176_1484 and Cjj81176_1483 of Campylobacter jejuni. J Bacteriol 2015; 197:1592-605. [PMID: 25691530 DOI: 10.1128/jb.02564-14] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 02/11/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Campylobacter jejuni is a leading cause of bacterial diarrheal disease and a frequent commensal of the intestinal tract in poultry and other animals. For optimal growth and colonization of hosts, C. jejuni employs two-component regulatory systems (TCSs) to monitor environmental conditions and promote proper expression of specific genes. We analyzed the potential of C. jejuni Cjj81176_1484 (Cjj1484) and Cjj81176_1483 (Cjj1483) to encode proteins of a cognate TCS that influences expression of genes possibly important for C. jejuni growth and colonization. Transcriptome analysis revealed that the regulons of the Cjj81176_1484 (Cjj1484) histidine kinase and the Cjj81176_1483 (Cjj1483) response regulator contain many common genes, suggesting that these proteins likely form a cognate TCS. We found that this TCS generally functions to repress expression of specific proteins with roles in metabolism, iron/heme acquisition, and respiration. Furthermore, the TCS repressed expression of Cjj81176_0438 and Cjj81176_0439, which had previously been found to encode a gluconate dehydrogenase complex required for commensal colonization of the chick intestinal tract. However, the TCS and other specific genes whose expression is repressed by the TCS were not required for colonization of chicks. We observed that the Cjj1483 response regulator binds target promoters in both unphosphorylated and phosphorylated forms and influences expression of some specific genes independently of the Cjj1484 histidine kinase. This work further expands the signaling mechanisms of C. jejuni and provides additional insights regarding the complex and multifactorial regulation of many genes involved in basic metabolism, respiration, and nutrient acquisition that the bacterium requires for optimal growth in different environments. IMPORTANCE Bacterial two-component regulatory systems (TCSs) link environmental cues to expression of specific genes that enable optimal bacterial growth or colonization of hosts. We found that the Campylobacter jejuni Cjj1484 histidine kinase and Cjj1483 response regulator function as a cognate TCS to largely repress expression of target genes encoding a gluconate dehydrogenase complex required for commensal colonization of the chick intestinal tract, as well as other genes encoding proteins for heme or iron acquisition, metabolism, and respiration. We also discovered different modes by which Cjj1483 may mediate repression with and without Cjj1484. This work provides insight into the signal transduction mechanisms of a leading cause of bacterial diarrheal disease and emphasizes the multifactorial and complex regulation of specific biological processes in C. jejuni.
Collapse
|
18
|
Xu S, Pan X, Luo J, Wu J, Zhou Z, Liang X, He Y, Zhou M. Effects of phenazine-1-carboxylic acid on the biology of the plant-pathogenic bacterium Xanthomonas oryzae pv. oryzae. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2015; 117:39-46. [PMID: 25619910 DOI: 10.1016/j.pestbp.2014.10.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Revised: 09/10/2014] [Accepted: 10/06/2014] [Indexed: 05/21/2023]
Abstract
Xanthomonas oryzae pv. oryzae (Xoo) is the casual agent of bacterial blight, which is one of the most serious diseases of rice. The antibiotic phenazine-1-carboxylic acid (PCA), which is primarily produced by Pseudomonas spp., was found and previously reported very effective against Xoo. However, the biological effects of PCA on Xoo remain unclear. In this study, we found that PCA increased the accumulation of reactive oxygen species (ROS) and reduced the activities of catalase (CAT) and superoxide dismutase (SOD) in Xoo. Xoo was more sensitive to H2O2 than Xanthomonas oryzae pv. oryzicola (Xoc), and had a much lower expression of CAT genes. In addition, proteomic analysis indicated that PCA inhibited carbohydrate metabolism and nutrient uptake in Xoo, and analysis of carbon source utilization further confirmed that carbohydrate metabolism in Xoo was repressed by PCA. In conclusion, PCA acted as a redox-cycling agent that disturbed the redox balance in Xoo and reduced CAT and SOD activities, resulting in higher accumulation of ROS, altered carbohydrate metabolism, and lower energy production and nutrient uptake. Moreover, a deficient antioxidant system in Xoo made it very sensitive to PCA.
Collapse
Affiliation(s)
- Shu Xu
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Pesticide, Nanjing Agricultural University, Jiangsu Province, China
| | - Xiayan Pan
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Pesticide, Nanjing Agricultural University, Jiangsu Province, China
| | - Jianying Luo
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Pesticide, Nanjing Agricultural University, Jiangsu Province, China
| | - Jian Wu
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Pesticide, Nanjing Agricultural University, Jiangsu Province, China
| | - Zehua Zhou
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Pesticide, Nanjing Agricultural University, Jiangsu Province, China
| | - Xiaoyu Liang
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Pesticide, Nanjing Agricultural University, Jiangsu Province, China
| | - Yawen He
- State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
| | - Mingguo Zhou
- College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Pesticide, Nanjing Agricultural University, Jiangsu Province, China.
| |
Collapse
|
19
|
Baily JL, Méric G, Bayliss S, Foster G, Moss SE, Watson E, Pascoe B, Mikhail J, Pizzi R, Goldstone RJ, Smith DGE, Willoughby K, Hall AJ, Sheppard SK, Dagleish MP. Evidence of land-sea transfer of the zoonotic pathogen Campylobacter to a wildlife marine sentinel species. Mol Ecol 2014; 24:208-21. [PMID: 25401947 DOI: 10.1111/mec.13001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 11/11/2014] [Accepted: 11/13/2014] [Indexed: 01/14/2023]
Abstract
Environmental pollution often accompanies the expansion and urbanization of human populations where sewage and wastewaters commonly have an impact on the marine environments. Here, we explored the potential for faecal bacterial pathogens, of anthropic origin, to spread to marine wildlife in coastal areas. The common zoonotic bacterium Campylobacter was isolated from grey seals (Halichoerus grypus), an important sentinel species for environmental pollution, and compared to isolates from wild birds, agricultural sources and clinical samples to characterize possible transmission routes. Campylobacter jejuni was present in half of all grey seal pups sampled (24/50 dead and 46/90 live pups) in the breeding colony on the Isle of May (Scotland), where it was frequently associated with histological evidence of disease. Returning yearling animals (19/19) were negative for C. jejuni suggesting clearance of infection while away from the localized colony infection source. The genomes of 90 isolates from seals were sequenced and characterized using a whole-genome multilocus sequence typing (MLST) approach and compared to 192 published genomes from multiple sources using population genetic approaches and a probabilistic genetic attribution model to infer the source of infection from MLST data. The strong genotype-host association has enabled the application of source attribution models in epidemiological studies of human campylobacteriosis, and here assignment analyses consistently grouped seal isolates with those from human clinical samples. These findings are consistent with either a common infection source or direct transmission of human campylobacter to grey seals, raising concerns about the spread of human pathogens to wildlife marine sentinel species in coastal areas.
Collapse
Affiliation(s)
- Johanna L Baily
- Moredun Research Institute, Pentlands Science Park, Bush Loan, Penicuik, EH26 0PZ, UK; SeaMammal Research Unit, University of St Andrews, Fife, KY16 8LB, UK
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Hofreuter D. Defining the metabolic requirements for the growth and colonization capacity of Campylobacter jejuni. Front Cell Infect Microbiol 2014; 4:137. [PMID: 25325018 PMCID: PMC4178425 DOI: 10.3389/fcimb.2014.00137] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 09/11/2014] [Indexed: 01/27/2023] Open
Abstract
During the last decade Campylobacter jejuni has been recognized as the leading cause of bacterial gastroenteritis worldwide. This facultative intracellular pathogen is a member of the Epsilonproteobacteria and requires microaerobic atmosphere and nutrient rich media for efficient proliferation in vitro. Its catabolic capacity is highly restricted in contrast to Salmonella Typhimurium and other enteropathogenic bacteria because several common pathways for carbohydrate utilization are either missing or incomplete. Despite these metabolic limitations, C. jejuni efficiently colonizes various animal hosts as a commensal intestinal inhabitant. Moreover, C. jejuni is tremendously successful in competing with the human intestinal microbiota; an infectious dose of few hundreds bacteria is sufficient to overcome the colonization resistance of humans and can lead to campylobacteriosis. Besides the importance and clear clinical manifestation of this disease, the pathogenesis mechanisms of C. jejuni infections are still poorly understood. In recent years comparative genome sequence, transcriptome and metabolome analyses as well as mutagenesis studies combined with animal infection models have provided a new understanding of how the specific metabolic capacity of C. jejuni drives its persistence in the intestinal habitat of various hosts. Furthermore, new insights into the metabolic requirements that support the intracellular survival of C. jejuni were obtained. Because C. jejuni harbors distinct properties in establishing an infection in comparison to pathogenic Enterobacteriaceae, it represents an excellent organism for elucidating new aspects of the dynamic interaction and metabolic cross talk between a bacterial pathogen, the microbiota and the host.
Collapse
Affiliation(s)
- Dirk Hofreuter
- Hannover Medical School, Institute for Medical Microbiology and Hospital Epidemiology Hannover, Germany
| |
Collapse
|