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Guzmán-Moreno J, García-Ortega LF, Torres-Saucedo L, Rivas-Noriega P, Ramírez-Santoyo RM, Sánchez-Calderón L, Quiroz-Serrano IN, Vidales-Rodríguez LE. Bacillus megaterium HgT21: a Promising Metal Multiresistant Plant Growth-Promoting Bacteria for Soil Biorestoration. Microbiol Spectr 2022; 10:e0065622. [PMID: 35980185 PMCID: PMC9604106 DOI: 10.1128/spectrum.00656-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 07/26/2022] [Indexed: 12/30/2022] Open
Abstract
The environmental deterioration produced by heavy metals derived from anthropogenic activities has gradually increased. The worldwide dissemination of toxic metals in crop soils represents a threat for sustainability and biosafety in agriculture and requires strategies for the recovery of metal-polluted crop soils. The biorestoration of metal-polluted soils using technologies that combine plants and microorganisms has gained attention in recent decades due to the beneficial and synergistic effects produced by its biotic interactions. In this context, native and heavy metal-resistant plant growth-promoting bacteria (PGPB) play a crucial role in the development of strategies for sustainable biorestoration of metal-contaminated soils. In this study, we present a genomic analysis and characterization of the rhizospheric bacterium Bacillus megaterium HgT21 isolated from metal-polluted soil from Zacatecas, Mexico. The results reveal that this autochthonous bacterium contains an important set of genes related to a variety of operons associated with mercury, arsenic, copper, cobalt, cadmium, zinc and aluminum resistance. Additionally, halotolerance-, beta-lactam resistance-, phosphate solubilization-, and plant growth-promotion-related genes were identified. The analysis of resistance to metal ions revealed resistance to mercury (HgII+), arsenate [AsO4]³-, cobalt (Co2+), zinc (Zn2+), and copper (Cu2+). Moreover, the ability of the HgT21 strain to produce indole acetic acid (a phytohormone) and promote the growth of Arabidopsis thaliana seedlings in vitro was also demonstrated. The genotype and phenotype of Bacillus megaterium HgT21 reveal its potential to be used as a model of both plant growth-promoting and metal multiresistant bacteria. IMPORTANCE Metal-polluted environments are natural sources of a wide variety of PGPB adapted to cope with toxic metal concentrations. In this work, the bacterial strain Bacillus megaterium HgT21 was isolated from metal-contaminated soil and is proposed as a model for the study of metal multiresistance in spore-forming Gram-positive bacteria due to the presence of a variety of metal resistance-associated genes similar to those encountered in the metal multiresistant Gram-negative Cupriavidus metallidurans CH34. The ability of B. megaterium HgT21 to promote the growth of plants also makes it suitable for the study of plant-bacteria interactions in metal-polluted environments, which is key for the development of techniques for the biorestoration of metal-contaminated soils used for agriculture.
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Affiliation(s)
- Jesús Guzmán-Moreno
- Laboratorio de Biología de Bacterias y Hongos Filamentosos, Unidad Académica de Ciencias Biológicas, Universidad Autónoma de Zacatecas, Zacatecas, Zacatecas, Mexico
| | - Luis Fernando García-Ortega
- Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Irapuato, Guanajuato, Mexico
| | - Lilia Torres-Saucedo
- Laboratorio de Biología de Bacterias y Hongos Filamentosos, Unidad Académica de Ciencias Biológicas, Universidad Autónoma de Zacatecas, Zacatecas, Zacatecas, Mexico
| | - Paulina Rivas-Noriega
- Laboratorio de Biología de Bacterias y Hongos Filamentosos, Unidad Académica de Ciencias Biológicas, Universidad Autónoma de Zacatecas, Zacatecas, Zacatecas, Mexico
| | - Rosa María Ramírez-Santoyo
- Laboratorio de Biología de Bacterias y Hongos Filamentosos, Unidad Académica de Ciencias Biológicas, Universidad Autónoma de Zacatecas, Zacatecas, Zacatecas, Mexico
| | - Lenin Sánchez-Calderón
- Laboratorio de Genómica Evolutiva, Unidad Académica de Ciencias Biológicas, Universidad Autónoma de Zacatecas, Zacatecas, Zacatecas, Mexico
| | - Iliana Noemi Quiroz-Serrano
- Laboratorio de Biología de Bacterias y Hongos Filamentosos, Unidad Académica de Ciencias Biológicas, Universidad Autónoma de Zacatecas, Zacatecas, Zacatecas, Mexico
| | - Luz Elena Vidales-Rodríguez
- Laboratorio de Biología de Bacterias y Hongos Filamentosos, Unidad Académica de Ciencias Biológicas, Universidad Autónoma de Zacatecas, Zacatecas, Zacatecas, Mexico
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Wu X, Zhan F, Zhang J, Chen S, Yang B. Identification of hypervirulent Klebsiella pneumoniae carrying terW gene by MacConkey-potassium tellurite medium in the general population. Front Public Health 2022; 10:946370. [PMID: 36091562 PMCID: PMC9448990 DOI: 10.3389/fpubh.2022.946370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 08/05/2022] [Indexed: 01/21/2023] Open
Abstract
Objectives To establish a MacConkey-potassium tellurium medium-based method for selectively culturing terW gene-positive Klebsiella pneumoniae (KP), to evaluate its performance and apply it to identifying particular clonal hypervirulent KP (hvKP) strains in epidemiological surveillance. Methods The virulence genes, rmpA, iutA, and terW, were detected by PCR. The minimum inhibitory concentration of potassium tellurite of hvKP (rmpA +/ iutA +) and classical KP (rmpA - and iutA -) was determined using the agar dilution method. The MacConkey medium containing 4 μg/ml potassium tellurite was prepared and the performance in detecting terW + KP was evaluated, including an agreement with PCR and positive/negative predictive value. Fecal samples from healthy volunteers in Fujian were collected and cultured in the medium, then positive strains were identified using MALDI-TOF MS, antimicrobial susceptibility was tested by Kirby-Bauer assays, and virulence genes and capsular serotype genes were tested by PCR. Results In KP isolated from clinical specimens (N = 198), the positive rate of terW was 37.9%, and the detection rate of terW in hvKP was significantly higher than that in classical KP (70.6% vs 13.3%). The potassium tellurite resistance levels of terW + (N = 75) and terW - (N = 55) KP were 8-128 μg/ml and <1-8 μg/ml, respectively, with significant differences. KP was selectively cultured on a MacConkey medium with 4 μg/ml potassium tellurite, and its agreement with PCR was good (Kappa=0.936), and the positive and negative percent agreement and positive and negative predictive values were 100% (75/75), 92.7% (51/55), 94.9% (75/79), and 100% (51/51), respectively. The prevalence of tellurite-resistant KP was 16.7% (86/516) in fecal samples from healthy volunteers, among which the positive rate of terW was 100% (86/86). The antimicrobial resistance characteristics of terW + KP showed no difference between healthy volunteers and inpatients. The most common capsular serotypes associated with high virulence were K1, K2, and K57. Conclusions The MacConkey medium containing 4 μg/ml potassium tellurite could easily select and culture terW + KP in fecal samples with high sensitivity and specificity, which is a practical method for the epidemic surveillance of hvKP in the general population.
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Affiliation(s)
- Xiufeng Wu
- Department of Laboratory Medicine, Fujian Medical University Union Hospital, Fuzhou, China
| | - Fuguo Zhan
- Department of Laboratory Medicine, Gene Diagnosis Research Center, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China,Fujian Key Laboratory of Laboratory Medicine, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China,First Clinical College, Fujian Medical University, Fuzhou, China
| | - Jiawei Zhang
- Department of Laboratory Medicine, Gene Diagnosis Research Center, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China,Fujian Key Laboratory of Laboratory Medicine, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China,First Clinical College, Fujian Medical University, Fuzhou, China
| | - Shanjian Chen
- Department of Laboratory Medicine, Gene Diagnosis Research Center, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China,Fujian Key Laboratory of Laboratory Medicine, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China,First Clinical College, Fujian Medical University, Fuzhou, China
| | - Bin Yang
- Department of Laboratory Medicine, Gene Diagnosis Research Center, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China,Fujian Key Laboratory of Laboratory Medicine, The First Affiliated Hospital, Fujian Medical University, Fuzhou, China,First Clinical College, Fujian Medical University, Fuzhou, China,*Correspondence: Bin Yang
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Sohrabi M, Alizade Naini M, Rasekhi A, Oloomi M, Moradhaseli F, Ayoub A, Bazargani A, Hashemizadeh Z, Shahcheraghi F, Badmasti F. Emergence of K1 ST23 and K2 ST65 hypervirulent klebsiella pneumoniae as true pathogens with specific virulence genes in cryptogenic pyogenic liver abscesses Shiraz Iran. Front Cell Infect Microbiol 2022; 12:964290. [PMID: 36017366 PMCID: PMC9396702 DOI: 10.3389/fcimb.2022.964290] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 07/18/2022] [Indexed: 11/17/2022] Open
Abstract
Hypervirulent Klebsiella pneumoniae (hvKp) pathotype is emerging worldwide in pyogenic liver abscesses (PLAs). However, the role of virulence factors in pathogenicity remains unclear. On the other hand, the epidemiology of PLAs in Iran is unknown. From July 2020 to April 2022, bacterial species were isolated and identified from the drainage samples of 54 patients with PLAs. K. pneumoniae as the most common pathogen of pyogenic liver abscesses was identified in 20 (37%) of the 54 patients. We analyzed the clinical and microbiological characteristics of K. pneumoniae-related pyogenic liver abscesses. Antibiotic susceptibility testes and string test were performed. 16S rRNA, antibiotic resistance, and virulence genes were determined by polymerase chain reaction amplification. Clonal relatedness of isolates was identified by multilocus sequence typing. Virulence levels were assessed in the Galleria mellonella larval infection model. Four hvKp isolates (K1/K2) were found to be responsible for cryptogenic PLAs, and 16 classical K. pneumoniae isolates (non-K1/K2) were associated with non-cryptogenic PLAs. Three capsular serotype K1 strains belonged to sequence type 23 (ST23) and one K2 strain to ST65. Meanwhile, the non-K1/K2 strains belonged to other STs. ST231 was the most common strain among the classical K. pneumoniae strains. Compared with the non-K1/K2 strains, capsular serotypes K1/K2 strains were less resistant to antibiotics, had positive string test results, and had more virulence genes. In Galleria mellonella, a concentration of 106 colony-forming units of the K1 hvKp strain resulted in 100% death at 24 hours, confirming the higher virulence of the hvKp strain compared with cKp. K. pneumoniae isolates represented that the acquisition of any plasmid or chromosomal virulence genes contributes to pathogenicity and high prevalence in PLAs. Meanwhile, hvKp isolates with a specific genetic background were detected in cryptogenic PLAs.
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Affiliation(s)
- Maryam Sohrabi
- Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran
| | - Mahvash Alizade Naini
- Department of Internal Medicine, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Alireza Rasekhi
- Department of Radiology, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mana Oloomi
- Department of Molecular Biology, Pasteur Institute of Iran, Tehran, Iran
| | - Farzad Moradhaseli
- Department of Radiology, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Abbas Ayoub
- Department of Radiology, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Abdollah Bazargani
- Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Zahra Hashemizadeh
- Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Fereshteh Shahcheraghi
- Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran
- *Correspondence: Farzad Badmasti, ; Fereshteh Shahcheraghi,
| | - Farzad Badmasti
- Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran
- *Correspondence: Farzad Badmasti, ; Fereshteh Shahcheraghi,
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Farias P, Francisco R, Morais PV. Potential of tellurite resistance in heterotrophic bacteria from mining environments. iScience 2022; 25:104566. [PMID: 35784792 PMCID: PMC9240799 DOI: 10.1016/j.isci.2022.104566] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 03/24/2022] [Accepted: 06/06/2022] [Indexed: 11/22/2022] Open
Abstract
Untreated mining wastes and improper disposal of high-tech devices generate an environmental increase of bioavailable metalloids, exerting stress on autochthonous microbial populations. Tellurium is a metalloid, an element with raising economic importance; nevertheless, its interaction with living organisms is not yet fully understood. Here we characterized aerobic heterotrophic bacteria, isolated from high metal-content mining residues, able to resist/reduce tellurite into tellurium structures and to determine the presence of confirmed tellurite resistance genetic determinants in resistant strains. We identified over 50 tellurite-resistant strains, among 144 isolates, eight strains reduced tellurite to tellurium at different rates, with the concomitant production of tellurium deposits. Most tellurite resistance genes were found in strains from Bacillales, with the prevalence of genes of the ter operon. This work demonstrated that bacterial isolates, from environments with a persistent selective pressure, are potential candidates for uncovering strategies for tellurite resistance and/or production of valuable Te-containing materials. Sites with continuous high metal pressure as a source of Te-resistant bacteria diversity Organism-specific Te (IV) reduction produces unique Te (0) insoluble structures Unveiled Te resistance genetic determinants and arrangements in Bacillales
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Affiliation(s)
- Pedro Farias
- University of Coimbra, Centre for Mechanical Engineering, Materials and Processes, Department of Life Sciences, 3000-456 Coimbra, Portugal
| | - Romeu Francisco
- University of Coimbra, Centre for Mechanical Engineering, Materials and Processes, Department of Life Sciences, 3000-456 Coimbra, Portugal
| | - Paula V. Morais
- University of Coimbra, Centre for Mechanical Engineering, Materials and Processes, Department of Life Sciences, 3000-456 Coimbra, Portugal
- Corresponding author
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Ott L, Möller J, Burkovski A. Interactions between the Re-Emerging Pathogen Corynebacterium diphtheriae and Host Cells. Int J Mol Sci 2022; 23:3298. [PMID: 35328715 PMCID: PMC8952647 DOI: 10.3390/ijms23063298] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 03/16/2022] [Accepted: 03/17/2022] [Indexed: 02/07/2023] Open
Abstract
Corynebacterium diphtheriae, the etiological agent of diphtheria, is a re-emerging pathogen, responsible for several thousand deaths per year. In addition to diphtheria, systemic infections, often by non-toxigenic strains, are increasingly observed. This indicates that besides the well-studied and highly potent diphtheria toxin, various other virulence factors may influence the progression of the infection. This review focuses on the known components of C. diphtheriae responsible for adhesion, invasion, inflammation, and cell death, as well as on the cellular signaling pathways activated upon infection.
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Affiliation(s)
- Lisa Ott
- Department of Biology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 5, 91058 Erlangen, Germany
| | - Jens Möller
- Microbiology Division, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 5, 91058 Erlangen, Germany
| | - Andreas Burkovski
- Microbiology Division, Friedrich-Alexander-Universität Erlangen-Nürnberg, Staudtstr. 5, 91058 Erlangen, Germany
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6
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Bacillus velezensis: A Treasure House of Bioactive Compounds of Medicinal, Biocontrol and Environmental Importance. FORESTS 2021. [DOI: 10.3390/f12121714] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Bacillus velezensis gram-positive bacterium, is frequently isolated from diverse niches mainly soil, water, plant roots, and fermented foods. B. velezensis is ubiquitous, non-pathogenic and endospore forming. Being frequently isolated from diverse plant holobionts it is considered host adapted microorganism and recognized of high economic importance given its ability to promote plant growth under diverse biotic and abiotic stress conditions. Additionally, the species suppress many plant diseases, including bacterial, oomycete, and fungal diseases. It is also able after plant host root colonization to induce unique physiological situation of host plant called primed state. Primed host plants are able to respond more rapidly and/or effectively to biotic or abiotic stress. Moreover, B. velezenis have the ability to resist diverse environmental stresses and help host plants to cope with, including metal and xenobiotic stresses. Within species B. velezensis strains have unique abilities allowing them to adopt different life styles. Strain level abilities knowledge is warranted and could be inferred using the ever-expanding new genomes list available in genomes databases. Pangenome analysis and subsequent identification of core, accessory and unique genomes is actually of paramount importance to decipher species full metabolic capacities and fitness across diverse environmental conditions shaping its life style. Despite the crucial importance of the pan genome, its assessment among large number of strains remains sparse and systematic studies still needed. Extensive knowledge of the pan genome is needed to translate genome sequencing efforts into developing more efficient biocontrol agents and bio-fertilizers. In this study, a genome survey of B. velezensis allowed us to (a) highlight B. velezensis species boundaries and show that Bacillus suffers taxonomic imprecision that blurs the debate over species pangenome; (b) identify drivers of their successful acquisition of specific life styles and colonization of new niches; (c) describe strategies they use to promote plant growth and development; (d) reveal the unlocked strain specific orphan secondary metabolite gene clusters (biosynthetic clusters with corresponding metabolites unknown) that product identification is still awaiting to amend our knowledge of their putative role in suppression of pathogens and plant growth promotion, and (e) to describe a dynamic pangenome with a secondary metabolite rich accessory genome.
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Turner MJ, Cox JK, Spellman AC, Stahl C, Bavari S. Avoidance behavior independent of innate-immune signaling seen in Caenorhabditis elegans challenged with Bacillus anthracis. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2020; 102:103453. [PMID: 31326564 DOI: 10.1016/j.dci.2019.103453] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 07/16/2019] [Accepted: 07/16/2019] [Indexed: 06/10/2023]
Abstract
Small organisms, like the nematode C. elegans, are emerging as insightful models in which to study host/pathogen interactions and the evolving interplay between host defenses and microbial offenses. In C. elegans the innate immune response has been shown to be connected to the DAF-2 insulin/insulin-like growth factor 1 (IGF-1) signal pathway, a critical transduction pathway that mediates stress response in the worms via the DAF-16 FOXO/forkhead transcription factor. Our studies of the C. elegans' phenotypes that are associated with behavioral innate immune response (avoidance behavior) and IGF-1 signaling perturbations (lifespan effects) led us to question the cause of the avoidance behavior observed when C. elegans are challenged with B. anthracis. While worms indeed avoid B. anthracis, and this behavior seems to be partly tied to IGF-1 signaling, the bacteria have neither nematocidal nor visible pathogenic effects on the worms. In fact, worms fed B. anthracis alone exhibit extended lifespans. We demonstrate that the extended lifespan phenotype seen in worms fed B. anthracis is likely the result of calorie restriction, and that worms do not eat B. anthracis even when avoidance behaviors have been suppressed. We further demonstrate a large time lag between the onset of avoidance behavior (which occurs upon contact with B. anthracis), and the induction of IGF-1 signaling (which occurs much later) in worms fed B. anthracis. Taken together, our data demonstrate behavioral avoidance that does not appear to be linked to a measurable immune response. We propose that, in some situations, avoidance behaviors categorized as immunological might be more accurately described as broad foraging behaviors induced in worms presented with a non-preferred food choice, or with a food choice that is either difficult or impossible for the worms to ingest.
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Affiliation(s)
- Michael J Turner
- School of Natural Sciences and Mathematics, Department of Science, Mount St. Mary's University, 16300 Old Emmitsburg Rd, Emmitsburg, MD, 21727, USA; Molecular and Translational Sciences, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), 1425 Porter Street, Fort Detrick, Frederick, MD, 21702, USA.
| | - Justin K Cox
- School of Natural Sciences and Mathematics, Department of Science, Mount St. Mary's University, 16300 Old Emmitsburg Rd, Emmitsburg, MD, 21727, USA.
| | - Anthony C Spellman
- School of Natural Sciences and Mathematics, Department of Science, Mount St. Mary's University, 16300 Old Emmitsburg Rd, Emmitsburg, MD, 21727, USA.
| | - Craig Stahl
- Molecular and Translational Sciences, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), 1425 Porter Street, Fort Detrick, Frederick, MD, 21702, USA.
| | - Sina Bavari
- Molecular and Translational Sciences, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), 1425 Porter Street, Fort Detrick, Frederick, MD, 21702, USA.
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Malmquist JA, Rogan MR, McGillivray SM. Galleria mellonella as an Infection Model for Bacillus anthracis Sterne. Front Cell Infect Microbiol 2019; 9:360. [PMID: 31681636 PMCID: PMC6813211 DOI: 10.3389/fcimb.2019.00360] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2019] [Accepted: 10/04/2019] [Indexed: 01/09/2023] Open
Abstract
Understanding bacterial virulence provides insight into the molecular basis behind infection and could identify new drug targets. However, assessing potential virulence determinants relies on testing in an animal model. The mouse is a well-validated model but it is constrained by the ethical and logistical challenges of using vertebrate animals. Recently the larva of the greater wax moth Galleria mellonella has been explored as a possible infection model for a number of pathogens. In this study, we developed G. mellonella as an infection model for Bacillus anthracis Sterne. We first validated two different infection assays, a survival assay and a competition assay, using mutants containing disruptions in known B. anthracis virulence genes. We next tested the utility of G. mellonella to assess the virulence of transposon mutants with unknown mutations that had increased susceptibility to hydrogen peroxide in in vitro assays. One of these transposon mutants also displayed significantly decreased virulence in G. mellonella. Further investigation revealed that this mutant had a disruption in the petrobactin biosynthesis operon (asbABCDEF), which has been previously implicated in both virulence and defense against oxidative stress. We conclude that G. mellonella can detect attenuated virulence of B. anthracis Sterne in a manner consistent with that of mammalian infection models. Therefore, G. mellonella could serve as a useful alternative to vertebrate testing, especially for early assessments of potential virulence genes when use of a mammalian model may not be ethical or practical.
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Affiliation(s)
- Jacob A Malmquist
- Department of Biology, Texas Christian University, Fort Worth, TX, United States
| | - Madison R Rogan
- Department of Biology, Texas Christian University, Fort Worth, TX, United States
| | - Shauna M McGillivray
- Department of Biology, Texas Christian University, Fort Worth, TX, United States
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Xu S, Hou X, Sun L, Zhang J, Ji X, Wang X, Li H, Li Z. An immunoproteomic approach to identify antigenic proteins in Nocardia farcinica IFM 10152. Microb Pathog 2019; 137:103705. [PMID: 31487535 DOI: 10.1016/j.micpath.2019.103705] [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: 06/02/2019] [Revised: 08/22/2019] [Accepted: 09/01/2019] [Indexed: 02/07/2023]
Abstract
Nocardia farcinica is the etiological agent of nocardiosis, leading to serious pulmonary or systemic infections. To uncover virulence factors and early diagnostic markers, secreted proteins of N. farcinica IFM 10152 were analyzed using an immunoproteome-based approach. A total of 5 proteins were identified by matrix-assisted laser desorption (MALDI-TOF-MS). Bioinformatic analyses showed that the identified proteins were involved in defense against the host innate immune system and required for pathogenesis. All proteins were expressed in E. coli and antigenicity was analyzed with Western blot. To our knowledge, these proteins with antigenicity were identified for the first time in N. farcinica and they may help elucidate the pathogenesis underlying Nocardia and provide potential future diagnostic markers.
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Affiliation(s)
- Shuai Xu
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xuexin Hou
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Lina Sun
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Jingshan Zhang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xingzhao Ji
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Xuebing Wang
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China
| | - Heqiao Li
- CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Zhenjun Li
- State Key Laboratory of Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China.
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Genomic, Phenotypic, and Virulence Analysis of Streptococcus sanguinis Oral and Infective-Endocarditis Isolates. Infect Immun 2018; 87:IAI.00703-18. [PMID: 30396893 DOI: 10.1128/iai.00703-18] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Accepted: 10/26/2018] [Indexed: 12/22/2022] Open
Abstract
Streptococcus sanguinis, an abundant and benign inhabitant of the oral cavity, is an important etiologic agent of infective endocarditis (IE), particularly in people with predisposing cardiac valvular damage. Although commonly isolated from patients with IE, little is known about the factors that make any particular S. sanguinis isolate more virulent than another or, indeed, whether significant differences in virulence exist among isolates. In this study, we compared the genomes of a collection of S. sanguinis strains comprised of both oral isolates and bloodstream isolates from patients diagnosed with IE. Oral and IE isolates could not be distinguished by phylogenetic analyses, and we did not succeed in identifying virulence genes unique to the IE strains. We then investigated the virulence of these strains in a rabbit model of IE using a variation of the Bar-seq (barcode sequencing) method wherein we pooled the strains and used Illumina sequencing to count unique barcodes that had been inserted into each isolate at a conserved intergenic region. After we determined that several of the genome sequences were misidentified in GenBank, our virulence results were used to inform our bioinformatic analyses, identifying genes that may explain the heterogeneity in virulence. We further characterized these strains by assaying for phenotypes potentially contributing to virulence. Neither strain competition via bacteriocin production nor biofilm formation showed any apparent relationship with virulence. Increased cell-associated manganese was, however, correlated with blood isolates. These results, combined with additional phenotypic assays, suggest that S. sanguinis virulence is highly variable and results from multiple genetic factors.
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Identification of Pathogenicity-Associated Loci in Klebsiella pneumoniae from Hospitalized Patients. mSystems 2018; 3:mSystems00015-18. [PMID: 29963640 PMCID: PMC6020474 DOI: 10.1128/msystems.00015-18] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Accepted: 05/29/2018] [Indexed: 12/14/2022] Open
Abstract
Despite insights gained through experimental models, the set of bacterial genes important for human infection is unclear for many of our most threatening pathogens. Klebsiella pneumoniae is a leading cause of health care-associated infections (HAIs) and commonly colonizes hospitalized patients, but the factors that determine whether a particular isolate causes disease or remains a colonizer are poorly understood. To identify bacterial genes associated with K. pneumoniae infection, a case-control study was performed comparing infected and asymptomatic colonized patients. Comparative bacterial genomics was combined with a conditional logit model that identified patient factors differentiating cases from controls. This method identified five gene loci associated with infection after adjustment for patient factors, including a psicose sugar utilization locus that was validated as a fitness factor during mouse lung infection. These results indicate that bacterial genome-wide association studies of patients can identify loci associated with HAIs and important in infection models. IMPORTANCE Klebsiella pneumoniae is a common cause of infections in the health care setting. This work supports a paradigm for K. pneumoniae pathogenesis where the accessory genome, composed of genes present in some but not all isolates, influences whether a strain causes infection or asymptomatic colonization, after accounting for patient-level factors. Identification of patients at high risk of infection could allow interventions to prevent or rapidly treat K. pneumoniae infections.
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12
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Belbahri L, Chenari Bouket A, Rekik I, Alenezi FN, Vallat A, Luptakova L, Petrovova E, Oszako T, Cherrad S, Vacher S, Rateb ME. Comparative Genomics of Bacillus amyloliquefaciens Strains Reveals a Core Genome with Traits for Habitat Adaptation and a Secondary Metabolites Rich Accessory Genome. Front Microbiol 2017; 8:1438. [PMID: 28824571 PMCID: PMC5541019 DOI: 10.3389/fmicb.2017.01438] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2017] [Accepted: 07/17/2017] [Indexed: 12/04/2022] Open
Abstract
The Gram positive, non-pathogenic endospore-forming soil inhabiting prokaryote Bacillus amyloliquefaciens is a plant growth-promoting rhizobacterium. Bacillus amyloliquefaciens processes wide biocontrol abilities and numerous strains have been reported to suppress diverse bacterial, fungal and fungal-like pathogens. Knowledge about strain level biocontrol abilities is warranted to translate this knowledge into developing more efficient biocontrol agents and bio-fertilizers. Ever-expanding genome studies of B. amyloliquefaciens are showing tremendous increase in strain-specific new secondary metabolite clusters which play key roles in the suppression of pathogens and plant growth promotion. In this report, we have used genome mining of all sequenced B. amyloliquefaciens genomes to highlight species boundaries, the diverse strategies used by different strains to promote plant growth and the diversity of their secondary metabolites. Genome composition of the targeted strains suggest regions of genomic plasticity that shape the structure and function of these genomes and govern strain adaptation to different niches. Our results indicated that B. amyloliquefaciens: (i) suffer taxonomic imprecision that blurs the debate over inter-strain genome diversity and dynamics, (ii) have diverse strategies to promote plant growth and development, (iii) have an unlocked, yet to be delimited impressive arsenal of secondary metabolites and products, (iv) have large number of so-called orphan gene clusters, i.e., biosynthetic clusters for which the corresponding metabolites are yet unknown, and (v) have a dynamic pan genome with a secondary metabolite rich accessory genome.
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Affiliation(s)
- Lassaad Belbahri
- Laboratory of Soil Biology, University of NeuchatelNeuchatel, Switzerland.,NextBiotechAgareb, Tunisia
| | - Ali Chenari Bouket
- NextBiotechAgareb, Tunisia.,Graduate School of Life and Environmental Sciences, Osaka Prefecture UniversitySakai, Japan.,Young Researchers and Elite Club, Tabriz Branch, Islamic Azad UniversityTabriz, Iran
| | | | | | - Armelle Vallat
- Neuchâtel Platform of Analytical Chemistry, Institute of Chemistry, University of NeuchâtelNeuchâtel, Switzerland
| | - Lenka Luptakova
- NextBiotechAgareb, Tunisia.,Department of Biology and Genetics, Institute of Biology, Zoology and Radiobiology, University of Veterinary Medicine and PharmacyKosice, Slovakia
| | - Eva Petrovova
- Institute of Anatomy, University of Veterinary Medicine and PharmacyKosice, Slovakia
| | | | | | | | - Mostafa E Rateb
- School of Science and Sport, University of the West of ScotlandPaisley, United Kingdom
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13
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Ferreira TG, Moura H, Barr JR, Pilotto Domingues RMC, Ferreira EDO. Ribotypes associated with Clostridium difficile outbreaks in Brazil display distinct surface protein profiles. Anaerobe 2017; 45:120-128. [PMID: 28435010 DOI: 10.1016/j.anaerobe.2017.04.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 03/28/2017] [Accepted: 04/01/2017] [Indexed: 11/18/2022]
Abstract
Clostridium difficile is a spore-forming anaerobic intestinal pathogen that causes Clostridium difficile infection (CDI). C. difficile is the leading cause of toxin-mediated nosocomial antibiotic-associated diarrhea. The pathogenesis of CDI is attributed to two major virulence factors, TcdA and TcdB toxins, that cause the symptomatic infection. C. difficile also expresses a number of key proteins, including cell wall proteins (CWPs). S-layer proteins (SLPs) are CWPs that form a paracrystalline surface array that coats the surface of the bacterium. SLPs have a role in C. difficile binding to the gastrointestinal tract, but their importance in virulence need to be better elucidated. Here, we describe bottom-up proteomics analysis of surface-enriched proteins fractions obtained through glycine extraction of five C. difficile clinical isolates from Brazil using gel-based and gel-free approaches. We were able to identify approximately 250 proteins for each strain, among them SlpA, Cwp2, Cwp6, CwpV and Cwp84. Identified CWPs presented different amino acid coverage, which might suggest differences in post-translational modifications. Proteomic analysis of SLPs from ribotype 133, agent of C. difficile outbreaks in Brazil, revealed unique proteins and provided additional information towards in depth characterization of the strains causing CDI in Brazil.
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Affiliation(s)
- Thais Gonçalves Ferreira
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Laboratório de Biologia de Anaeróbios, Rio de Janeiro, Brazil
| | - Hercules Moura
- Centers for Disease Control and Prevention - CDC, Division of Laboratory Sciences, Atlanta, GA, USA
| | - John R Barr
- Centers for Disease Control and Prevention - CDC, Division of Laboratory Sciences, Atlanta, GA, USA
| | - Regina M C Pilotto Domingues
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Laboratório de Biologia de Anaeróbios, Rio de Janeiro, Brazil.
| | - Eliane de Oliveira Ferreira
- Universidade Federal do Rio de Janeiro, Instituto de Microbiologia Paulo de Góes, Laboratório de Biologia de Anaeróbios, Rio de Janeiro, Brazil; Universidade Federal do Rio de Janeiro - Polo Xerém, Rio de Janeiro, Brazil
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14
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Affiliation(s)
- Ryan J Blower
- a School of Systems Biology, George Mason University , Manassas , VA , USA
| | - Serguei G Popov
- a School of Systems Biology, George Mason University , Manassas , VA , USA
| | - Monique L van Hoek
- a School of Systems Biology, George Mason University , Manassas , VA , USA
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15
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BOCIAN A, HUS K, JAROMIN M, TYRKA M, ŁYSKOWSKI A. Identification of proteins differentially accumulated in Enterococcus faecalis under acrylamide exposure. Turk J Biol 2017. [DOI: 10.3906/biy-1606-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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16
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Kim SK, Jung KH, Chai YG. Changes in Bacillus anthracis CodY regulation under host-specific environmental factor deprived conditions. BMC Genomics 2016; 17:645. [PMID: 27530340 PMCID: PMC4987991 DOI: 10.1186/s12864-016-3004-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 08/09/2016] [Indexed: 02/07/2023] Open
Abstract
Background Host-specific environmental factors induce changes in Bacillus anthracis gene transcription during infection. A global transcription regulator, CodY, plays a pivotal role in regulating central metabolism, biosynthesis, and virulence in B. anthracis. In this study, we utilized RNA-sequencing to assess changes in the transcriptional patterns of CodY-regulated B. anthracis genes in response to three conditions of environmental starvation: iron, CO2, or glucose deprivation. In addition, we performed chromatin immunoprecipitation on newly identified CodY-mediated genes. Results Environmental deprivation induced transcriptional changes in CodY-regulated genes in both wild-type and codY null strains, and both CodY-specific and environment-specific patterns were observed. In the iron-depleted condition, overexpression of iron homeostasis genes was observed independent of codY deletion; however, transcription of siderophore and amino acid biosynthesis genes was CodY dependent. Although CodY has a significant regulatory role in central metabolism and the carbon overflow pathway, metabolism-associated genes exhibited CodY-independent expression patterns under glucose starvation. Genes that were differentially expressed in response to CO2 availability showed CodY-dependent regulation, though their maximal expression did require a supply of CO2/bicarbonate. Conclusions We speculate that CodY regulates the expression of environmental-responsive genes in a hierarchical manner and is likely associated with other transcription regulators that are specific for a particular environmental change. Electronic supplementary material The online version of this article (doi:10.1186/s12864-016-3004-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Se Kye Kim
- Department of Molecular and Life Science, Hanyang University ERICA, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Gyeonggi-do, 15588, Republic of Korea
| | - Kyoung Hwa Jung
- Department of Molecular and Life Science, Hanyang University ERICA, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Gyeonggi-do, 15588, Republic of Korea
| | - Young Gyu Chai
- Department of Molecular and Life Science, Hanyang University ERICA, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Gyeonggi-do, 15588, Republic of Korea. .,Department of Bionanotechnology, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 04763, Republic of Korea.
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17
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Kim SK, Jung KH, Yoon SN, Kim YK, Chai YG. Late-Exponential Gene Expression in codY-Deficient Bacillus anthracis in a Host-Like Environment. Curr Microbiol 2016; 73:714-720. [PMID: 27515669 DOI: 10.1007/s00284-016-1120-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2016] [Accepted: 08/05/2016] [Indexed: 11/26/2022]
Abstract
CodY is a pleiotropic regulator commonly found in Gram-positive bacteria and regulates various biological processes during the stringent response in a nutrient-limiting environment. CodY also participates in virulence factor expression in many low G+C Gram-positive pathogens, as observed in Bacillus anthracis. However, the mechanism by which B. anthracis CodY regulates metabolism and virulence factors in response to environmental changes is unclear. Here, we attempted to identify the link between CodY and B. anthracis regulation with codY-deficient and codY-overexpressing mutants using high-throughput transcriptional analysis. Growth pattern analyses of codY mutants in both rich and minimal media showed defects in early cell proliferation, with opposite patterns in the early stationary phase: CodY overexpression prolonged bacterial growth, whereas deletion inhibited growth. RNA sequencing of codY-deficient B. anthracis showed both positive and negative changes in the gene expression of proteases and virulence factors as well as genes related to stringent response-related metabolism and biosynthetic processing. We also found that changes in codY expression could alter virulence gene expression of B. anthracis, suggesting modes of regulation in its virulence in a CodY concentration-dependent manner. Collectively, we conclude from these results that CodY can both positively and negatively regulate its regulon via direct and/or indirect approaches, and that its mode of regulation may be concentration dependent.
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Affiliation(s)
- Se Kye Kim
- Department of Molecular and Life Science, Hanyang University, 1271, Ansan, Gyeonggi-do, 15588, Republic of Korea
| | - Kyoung Hwa Jung
- Department of Molecular and Life Science, Hanyang University, 1271, Ansan, Gyeonggi-do, 15588, Republic of Korea
| | | | - Yun Ki Kim
- Samyang Chemical Co., Ltd, Seoul, Republic of Korea
| | - Young Gyu Chai
- Department of Molecular and Life Science, Hanyang University, 1271, Ansan, Gyeonggi-do, 15588, Republic of Korea.
- Department of Bionanotechnology, Hanyang University, Seoul, Republic of Korea.
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18
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Findlay F, Proudfoot L, Stevens C, Barlow PG. Cationic host defense peptides; novel antimicrobial therapeutics against Category A pathogens and emerging infections. Pathog Glob Health 2016; 110:137-47. [PMID: 27315342 DOI: 10.1080/20477724.2016.1195036] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Cationic Host Defense Peptides (HDP, also known as antimicrobial peptides) are crucial components of the innate immune system and possess broad-spectrum antibacterial, antiviral, and immunomodulatory activities. They can contribute to the rapid clearance of biological agents through direct killing of the organisms, inhibition of pro-inflammatory mediators such as lipopolysaccharide, and by modulating the inflammatory response to infection. Category A biological agents and materials, as classified by the United States National Institutes for Health, the US Centers for Disease Control and Prevention, and the US Department of Homeland Security, carry the most severe threat in terms of human health, transmissibility, and preparedness. As such, there is a pressing need for novel frontline approaches for prevention and treatment of diseases caused by these organisms, and exploiting the broad antimicrobial activity exhibited by cationic host defense peptides represents an exciting priority area for clinical research. This review will summarize what is known about the antimicrobial and antiviral effects of the two main families of cationic host defense peptides, cathelicidins, and defensins in the context of Category A biological agents which include, but are not limited to; anthrax (Bacillus anthracis), plague (Yersinia pestis), smallpox (Variola major), tularemia (Francisella tularensis). In addition, we highlight priority areas, particularly emerging viral infections, where more extensive research is urgently required.
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Affiliation(s)
- Fern Findlay
- a School of Life, Sport and Social Sciences , Edinburgh Napier University , Sighthill Campus, Edinburgh EH11 4BN , UK
| | - Lorna Proudfoot
- a School of Life, Sport and Social Sciences , Edinburgh Napier University , Sighthill Campus, Edinburgh EH11 4BN , UK
| | - Craig Stevens
- a School of Life, Sport and Social Sciences , Edinburgh Napier University , Sighthill Campus, Edinburgh EH11 4BN , UK
| | - Peter G Barlow
- a School of Life, Sport and Social Sciences , Edinburgh Napier University , Sighthill Campus, Edinburgh EH11 4BN , UK
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19
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Role of Tellurite Resistance Operon in Filamentous Growth of Yersinia pestis in Macrophages. PLoS One 2015; 10:e0141984. [PMID: 26536670 PMCID: PMC4633105 DOI: 10.1371/journal.pone.0141984] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Accepted: 10/15/2015] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Yersinia pestis initiates infection by parasitism of host macrophages. In response to macrophage infections, intracellular Y. pestis can assume a filamentous cellular morphology which may mediate resistance to host cell innate immune responses. We previously observed the expression of Y. pestis tellurite resistance proteins TerD and TerE from the terZABCDE operon during macrophage infections. Others have observed a filamentous response associated with expression of tellurite resistance operon in Escherichia coli exposed to tellurite. Therefore, in this study we examine the potential role of Y. pestis tellurite resistance operon in filamentous cellular morphology during macrophage infections. PRINCIPAL FINDINGS In vitro treatment of Y. pestis culture with sodium tellurite (Na2TeO3) caused the bacterial cells to assume a filamentous phenotype similar to the filamentous phenotype observed during macrophage infections. A deletion mutant for genes terZAB abolished the filamentous morphologic response to tellurite exposure or intracellular parasitism, but without affecting tellurite resistance. However, a terZABCDE deletion mutant abolished both filamentous morphologic response and tellurite resistance. Complementation of the terZABCDE deletion mutant with terCDE, but not terZAB, partially restored tellurite resistance. When the terZABCDE deletion mutant was complemented with terZAB or terCDE, Y. pestis exhibited filamentous morphology during macrophage infections as well as while these complemented genes were being expressed under an in vitro condition. Further in E. coli, expression of Y. pestis terZAB, but not terCDE, conferred a filamentous phenotype. CONCLUSIONS These findings support the role of Y. pestis terZAB mediation of the filamentous response phenotype; whereas, terCDE confers tellurite resistance. Although the beneficial role of filamentous morphological responses by Y. pestis during macrophage infections is yet to be fully defined, it may be a bacterial adaptive strategy to macrophage associated stresses.
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20
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Du XJ, Han R, Li P, Wang S. Comparative proteomic analysis of Cronobacter sakazakii isolates with different virulences. J Proteomics 2015; 128:344-51. [PMID: 26327241 DOI: 10.1016/j.jprot.2015.08.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Revised: 07/24/2015] [Accepted: 08/21/2015] [Indexed: 10/23/2022]
Abstract
UNLABELLED Cronobacter is a genus of widespread, opportunistic, foodborne pathogens that can result in serious illnesses in at-risk infants because of their immature immunity and high dependence on powdered formula, which is one of the foods most often contaminated by this pathogen. However, limited information is available regarding the pathogenesis and the specific virulence factors of this species. In this study, the virulences of 42 Cronobacter sakazakii isolates were analyzed by infecting neonatal SD rats. A comparison of the typing patterns of the isolates enabled groups with close relationships but that exhibited distinct pathogenesis to be identified. Among these groups, 2 strains belonging to the same group but showing distinct virulences were selected, and 2-DE was applied to identify differentially expressed proteins, focusing on virulence-related proteins. A total of 111 protein spots were identified using matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF/TOF-MS), and 89 were successfully identified. Further analysis suggested that at least 11 of these proteins may be involved in the pathogenesis of this pathogen. Real-time PCR was carried out to further confirm the differential expression pattern of the genes, and the results indicated that the mRNA expression levels were consistent with the protein expression levels. BIOLOGICAL SIGNIFICANCE The virulence factors and pathogenesis of Cronobacter are largely unknown. In combination with animal toxicological experiments and subtyping results of C. sakazakii, comparative proteomics analysis was performed to comprehensively evaluate the differentially expressed proteins of two isolates that exhibited distinct virulence but were closely related. These procedures made it possible to identify the virulence-related of factors of Cronobacter. Among the 89 total identified proteins, at least 11 show virulence-related potential. This work provides comprehensive candidates for the further investigation of the pathogenesis of Cronobacter.
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Affiliation(s)
- Xin-jun Du
- Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Ran Han
- Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Ping Li
- Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin 300457, China
| | - Shuo Wang
- Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin 300457, China.
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21
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Santos LSD, Antunes CA, Santos CSD, Pereira JAA, Sabbadini PS, Luna MDGD, Azevedo V, Hirata Júnior R, Burkovski A, Asad LMBDO, Mattos-Guaraldi AL. Corynebacterium diphtheriae putative tellurite-resistance protein (CDCE8392_0813) contributes to the intracellular survival in human epithelial cells and lethality of Caenorhabditis elegans. Mem Inst Oswaldo Cruz 2015; 110:662-8. [PMID: 26107188 PMCID: PMC4569831 DOI: 10.1590/0074-02760140479] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Accepted: 05/15/2015] [Indexed: 11/29/2022] Open
Abstract
Corynebacterium diphtheriae, the aetiologic agent of diphtheria,
also represents a global medical challenge because of the existence of invasive
strains as causative agents of systemic infections. Although tellurite
(TeO32-) is toxic to most microorganisms, TeO32--resistant
bacteria, including C. diphtheriae, exist in
nature. The presence of TeO32--resistance (TeR)
determinants in pathogenic bacteria might provide selective advantages in the natural
environment. In the present study, we investigated the role of the putative
TeR determinant (CDCE8392_813gene) in the virulence
attributes of diphtheria bacilli. The disruption of CDCE8392_0813 gene expression in
the LDCIC-L1 mutant increased susceptibility to TeO32- and reactive oxygen
species (hydrogen peroxide), but not to other antimicrobial agents. The LDCIC-L1
mutant also showed a decrease in both the lethality of Caenorhabditis elegans
and the survival inside of human epithelial cells compared to wild-type
strain. Conversely, the haemagglutinating activity and adherence to and formation of
biofilms on different abiotic surfaces were not regulated through the CDCE8392_0813
gene. In conclusion, the CDCE8392_813 gene contributes to the TeR and
pathogenic potential of C. diphtheriae.
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Affiliation(s)
- Louisy Sanches Dos Santos
- Departamento de Microbiologia, Imunologia e Parasitologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, BR
| | - Camila Azevedo Antunes
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, BR
| | - Cintia Silva Dos Santos
- Departamento de Microbiologia, Imunologia e Parasitologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, BR
| | - José Augusto Adler Pereira
- Departamento de Microbiologia, Imunologia e Parasitologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, BR
| | - Priscila Soares Sabbadini
- Laboratório de Doenças Bacterianas, Centro de Ciências da Saúde, Centro Universitário do Maranhão, São Luís, MA, BR
| | - Maria das Graças de Luna
- Departamento de Microbiologia, Imunologia e Parasitologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, BR
| | - Vasco Azevedo
- Departamento de Biologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, BR
| | - Raphael Hirata Júnior
- Departamento de Microbiologia, Imunologia e Parasitologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, BR
| | - Andreas Burkovski
- Lehrstuhl fuer Mikrobiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, DE
| | - Lídia Maria Buarque de Oliveira Asad
- Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcântara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, BR
| | - Ana Luíza Mattos-Guaraldi
- Departamento de Microbiologia, Imunologia e Parasitologia, Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, RJ, BR
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22
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Association of tellurite resistance with hypervirulent clonal groups of Klebsiella pneumoniae. J Clin Microbiol 2015; 53:1380-2. [PMID: 25631812 DOI: 10.1128/jcm.03053-14] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Tellurite-based selective growth media are used for several bacterial pathogens. We found that, in Klebsiella pneumoniae, tellurite resistance is strongly associated with hypervirulent clonal group 23 (CG23), CG65, and CG86, providing a novel approach for screening environmental or carriage samples. The terW gene was also associated with these groups.
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