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Archambaud C, Nunez N, da Silva RAG, Kline KA, Serror P. Enterococcus faecalis: an overlooked cell invader. Microbiol Mol Biol Rev 2024; 88:e0006924. [PMID: 39239986 PMCID: PMC11426025 DOI: 10.1128/mmbr.00069-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2024] Open
Abstract
SUMMARYEnterococcus faecalis and Enterococcus faecium are human pathobionts that exhibit a dual lifestyle as commensal and pathogenic bacteria. The pathogenic lifestyle is associated with specific conditions involving host susceptibility and intestinal overgrowth or the use of a medical device. Although the virulence of E. faecium appears to benefit from its antimicrobial resistance, E. faecalis is recognized for its higher pathogenic potential. E. faecalis has long been considered a predominantly extracellular pathogen; it adheres to and is taken up by a wide range of mammalian cells, albeit with less efficiency than classical intracellular enteropathogens. Carbohydrate structures, rather than proteinaceous moieties, are likely to be primarily involved in the adhesion of E. faecalis to epithelial cells. Consistently, few adhesins have been implicated in the adhesion of E. faecalis to epithelial cells. On the host side, very little is known about cognate receptors, except for the role of glycosaminoglycans during macrophage infection. Several lines of evidence indicate that E. faecalis internalization may involve a zipper-like mechanism as well as a macropinocytosis pathway. Conversely, E. faecalis can use several strategies to prevent engulfment in phagocytes. However, the bacterial and host mechanisms underlying cell infection by E. faecalis are still in their infancy. The most recent striking finding is the existence of an intracellular lifestyle where E. faecalis can replicate within a variety of host cells. In this review, we summarize and discuss the current knowledge of E. faecalis-host cell interactions and argue on the need for further mechanistic studies to prevent or reduce infections.
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Affiliation(s)
- Cristel Archambaud
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Natalia Nunez
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
| | - Ronni A G da Silva
- Singapore-MIT Alliance for Research and Technology, Antimicrobial Drug Resistance Interdisciplinary Research Group, Singapore, Singapore
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
| | - Kimberly A Kline
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore, Singapore
- Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland
| | - Pascale Serror
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, Jouy-en-Josas, France
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Brunson DN, Colomer-Winter C, Lam LN, Lemos JA. Identification of Multiple Iron Uptake Mechanisms in Enterococcus faecalis and Their Relationship to Virulence. Infect Immun 2023; 91:e0049622. [PMID: 36912636 PMCID: PMC10112239 DOI: 10.1128/iai.00496-22] [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: 11/03/2022] [Accepted: 02/17/2023] [Indexed: 03/14/2023] Open
Abstract
Among the unfavorable conditions bacteria encounter within the host is restricted access to essential trace metals such as iron. To overcome iron deficiency, bacteria deploy multiple strategies to scavenge iron from host tissues, with abundant examples of iron acquisition systems being implicated in bacterial pathogenesis. Yet the mechanisms utilized by the major nosocomial pathogen Enterococcus faecalis to maintain intracellular iron balance are poorly understood. In this study, we conducted a systematic investigation to identify and characterize the iron acquisition mechanisms of E. faecalis and to determine their contribution to virulence. Bioinformatic analysis and literature surveys revealed that E. faecalis possesses three conserved iron uptake systems. Through transcriptomics, we discovered two novel ABC-type transporters that mediate iron uptake. While inactivation of a single transporter had minimal impact on the ability of E. faecalis to maintain iron homeostasis, inactivation of all five systems (Δ5Fe strain) disrupted intracellular iron homeostasis and considerably impaired cell growth under iron deficiency. Virulence of the Δ5Fe strain was generally impaired in different animal models but showed niche-specific variations in mouse models, leading us to suspect that heme can serve as an iron source to E. faecalis during mammalian infections. Indeed, heme supplementation restored growth of Δ5Fe under iron depletion and virulence in an invertebrate infection model. This study revealed that the collective contribution of five iron transporters promotes E. faecalis virulence and that the ability to acquire and utilize heme as an iron source is critical to the systemic dissemination of E. faecalis.
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Affiliation(s)
- Debra N. Brunson
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, USA
| | - Cristina Colomer-Winter
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, USA
| | - Ling Ning Lam
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, USA
| | - José A. Lemos
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, USA
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Kang X, Wei Y, Fan X, Luo S, Luo X, Zhao S, Wang G. Analysis of virulence genes, drug resistance detection, and pathogenicity in Enterococcus from farm animals. Microb Pathog 2022; 171:105745. [PMID: 36057414 DOI: 10.1016/j.micpath.2022.105745] [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: 05/24/2022] [Revised: 08/20/2022] [Accepted: 08/25/2022] [Indexed: 11/28/2022]
Abstract
This study aimed to investigate the presence of eight virulence genes (ace, asa1, esp, efaA, gelE, cylA, agg, fsr) in Enterococcus from a variety of animals and to explore the drug resistance and pathogenicity. This could provide a theoretical basis for clinical treatment of Enterococcus infections. Anal swabs from pigs, chickens, cattle, and dogs in farms and pet hospitals were collected for Enterococcus isolation and identification. Eight virulence genes were detected (PCR method), and drug resistance was assessed (drug-sensitive paper method). The strains containing different virulence genes were then divided into EV1, EV2, and EV3 groups. The LD50 and pathogenicity was examined by intra-peritoneal injection to infect mice. Differences were found in the detection rates of virulence genes in Enterococcus from the different animals. The highest overall detection rate was for the esp gene (78.0%), and the lowest for the cylA gene (15.5%). Eight genes were detected most frequently in Enterococcus from dogs and least frequently from cattle. Among the Enterococcus strains from four variety of animals, drug resistance was highest against sulfamethoxazole (100%), cefotaxime (>97%), and cefotaxitin (>93%). Drug resistance was lowest against vancomycin (0%), levofloxacin (<12%) and ciprofloxacin (<13%). The LD50 for each of the three groups was EV1LD50=8.71×109CFU, EV2LD50=2.34×1010CFU,and EV3LD50=9.33×1010CFU. The Enterococcus12LD50 dose group caused significant clinical symptoms in mice, with pathological effects on the heart, liver, lungs, and kidneys, and particularly on the urinary system. The abundance of Enterococcus virulence genes, drug resistance, and pathogenicity vary among different animal origins, and the pathology caused by Enterococcus requires effective treatment protocols based on species and regional characteristics.
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Affiliation(s)
- Xinyun Kang
- Veterinary Pharmacology Lab, School of Agriculture, Ningxia University, 750021, Yinchuan, China
| | - Yanqin Wei
- Veterinary Pharmacology Lab, School of Agriculture, Ningxia University, 750021, Yinchuan, China
| | - Xiaofei Fan
- Veterinary Pharmacology Lab, School of Agriculture, Ningxia University, 750021, Yinchuan, China
| | - Shuangyan Luo
- Veterinary Pharmacology Lab, School of Agriculture, Ningxia University, 750021, Yinchuan, China
| | - Xiaofeng Luo
- Veterinary Pharmacology Lab, School of Agriculture, Ningxia University, 750021, Yinchuan, China
| | - Sijun Zhao
- Chinese Center for Animal Health and Epidemiology, Qingdao, Shandong, China.
| | - Guiqin Wang
- Veterinary Pharmacology Lab, School of Agriculture, Ningxia University, 750021, Yinchuan, China.
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Venkateswaran P, Lakshmanan PM, Muthukrishnan S, Bhagavathi H, Vasudevan S, Neelakantan P, Solomon AP. Hidden agenda of Enterococcus faecalis lifestyle transition: planktonic to sessile state. Future Microbiol 2022; 17:1051-1069. [PMID: 35899477 DOI: 10.2217/fmb-2021-0212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Enterococcus faecalis, a human gastrointestinal tract commensal, is known to cause nosocomial infections. Interestingly, the pathogen's host colonization and persistent infections are possibly linked to its lifestyle changes from planktonic to sessile state. Also, the multidrug resistance and survival fitness acquired in the sessile stage of E. faecalis has challenged treatment regimes. This situation exists because of the critical role played by several root genes and their molecular branches, which are part of quorum sensing, aggregation substance, surface adhesions, stress-related response and sex pheromones in the sessile state. It is therefore imperative to decode the hidden agenda of E. faecalis and understand the significant factors influencing biofilm formation. This would, in turn, augment the development of novel strategies to tackle E. faecalis infections.
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Affiliation(s)
- Parvathy Venkateswaran
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | - Priya M Lakshmanan
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | - Sudhiksha Muthukrishnan
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | - Hema Bhagavathi
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | - Sahana Vasudevan
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | | | - Adline P Solomon
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
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Ferchichi M, Sebei K, Boukerb AM, Karray-Bouraoui N, Chevalier S, Feuilloley MGJ, Connil N, Zommiti M. Enterococcus spp.: Is It a Bad Choice for a Good Use-A Conundrum to Solve? Microorganisms 2021; 9:2222. [PMID: 34835352 PMCID: PMC8622268 DOI: 10.3390/microorganisms9112222] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/18/2021] [Accepted: 10/19/2021] [Indexed: 12/12/2022] Open
Abstract
Since antiquity, the ubiquitous lactic acid bacteria (LAB) Enterococci, which are just as predominant in both human and animal intestinal commensal flora, have been used (and still are) as probiotics in food and feed production. Their qualities encounter several hurdles, particularly in terms of the array of virulence determinants, reflecting a notorious reputation that nearly prevents their use as probiotics. Additionally, representatives of the Enterococcus spp. genus showed intrinsic resistance to several antimicrobial agents, and flexibility to acquire resistance determinants encoded on a broad array of conjugative plasmids, transposons, and bacteriophages. The presence of such pathogenic aspects among some species represents a critical barrier compromising their use as probiotics in food. Thus, the genus neither has Generally Recognized as Safe (GRAS) status nor has it been included in the Qualified Presumption of Safety (QPS) list implying drastic legislation towards these microorganisms. To date, the knowledge of the virulence factors and the genetic structure of foodborne enterococcal strains is rather limited. Although enterococcal infections originating from food have never been reported, the consumption of food carrying virulence enterococci seems to be a risky path of transfer, and hence, it renders them poor choices as probiotics. Auspiciously, enterococcal virulence factors seem to be strain specific suggesting that clinical isolates carry much more determinants that food isolates. The latter remain widely susceptible to clinically relevant antibiotics and subsequently, have a lower potential for pathogenicity. In terms of the ideal enterococcal candidate, selected strains deemed for use in foods should not possess any virulence genes and should be susceptible to clinically relevant antibiotics. Overall, implementation of an appropriate risk/benefit analysis, in addition to the case-by-case assessment, the establishment of a strain's innocuity, and consideration for relevant guidelines, legislation, and regulatory aspects surrounding functional food development seem to be the crucial elements for industries, health-staff and consumers to accept enterococci, like other LAB, as important candidates for useful and beneficial applications in food industry and food biotechnology. The present review aims at shedding light on the world of hurdles and limitations that hampers the Enterococcus spp. genus and its representatives from being used or proposed for use as probiotics. The future of enterococci use as probiotics and legislation in this field are also discussed.
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Affiliation(s)
- Mounir Ferchichi
- Unité de Protéomique Fonctionnelle et Potentiel Nutraceutique de la Biodiversité de Tunisie, Institut Supérieur des Sciences Biologiques Appliquées de Tunis, Université de Tunis El Manar, Tunis 1006, Tunisia; (M.F.); (K.S.)
| | - Khaled Sebei
- Unité de Protéomique Fonctionnelle et Potentiel Nutraceutique de la Biodiversité de Tunisie, Institut Supérieur des Sciences Biologiques Appliquées de Tunis, Université de Tunis El Manar, Tunis 1006, Tunisia; (M.F.); (K.S.)
| | - Amine Mohamed Boukerb
- Laboratoire de Microbiologie, Signaux et Microenvironnement (LMSM) EA 4312, Université de Rouen Normandie, 27000 Evreux, France; (A.M.B.); (S.C.); (M.G.J.F.); (N.C.)
| | - Najoua Karray-Bouraoui
- Laboratoire de Productivité Végétale et Contraintes Abiotiques, LR18ES04, Faculté des Sciences de Tunis, Université Tunis El Manar, Tunis 2092, Tunisia;
| | - Sylvie Chevalier
- Laboratoire de Microbiologie, Signaux et Microenvironnement (LMSM) EA 4312, Université de Rouen Normandie, 27000 Evreux, France; (A.M.B.); (S.C.); (M.G.J.F.); (N.C.)
| | - Marc G. J. Feuilloley
- Laboratoire de Microbiologie, Signaux et Microenvironnement (LMSM) EA 4312, Université de Rouen Normandie, 27000 Evreux, France; (A.M.B.); (S.C.); (M.G.J.F.); (N.C.)
| | - Nathalie Connil
- Laboratoire de Microbiologie, Signaux et Microenvironnement (LMSM) EA 4312, Université de Rouen Normandie, 27000 Evreux, France; (A.M.B.); (S.C.); (M.G.J.F.); (N.C.)
| | - Mohamed Zommiti
- Laboratoire de Microbiologie, Signaux et Microenvironnement (LMSM) EA 4312, Université de Rouen Normandie, 27000 Evreux, France; (A.M.B.); (S.C.); (M.G.J.F.); (N.C.)
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6
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Zheng C, Wei M, Qiu J, Jia M, Zhou X, Jiao X. TroR Negatively Regulates the TroABCD System and Is Required for Resistance to Metal Toxicity and Virulence in Streptococcus suis. Appl Environ Microbiol 2021; 87:e0137521. [PMID: 34378993 PMCID: PMC8478451 DOI: 10.1128/aem.01375-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 08/05/2021] [Indexed: 11/20/2022] Open
Abstract
Streptococcus suis is an emerging zoonotic pathogen that causes severe swine and human infections. Metals are essential nutrients for life; however, excess metals are toxic to bacteria. Therefore, maintenance of intracellular metal homeostasis is important for bacterial survival. Here, we characterize a DtxR family metalloregulator, TroR, in S. suis. TroR is located upstream of the troABCD operon, whose expression was found to be significantly downregulated in response to excess manganese (Mn). Deletion of troR resulted in reduced growth when S. suis was cultured in metal-replete medium supplemented with elevated concentrations of zinc (Zn), copper (Cu), or cobalt (Co). Mn supplementation could alleviate the growth defects of the ΔtroR mutant under Zn and Co excess conditions; however, it impaired the growth of the wild-type (WT) and complemented (CΔtroR) strains under Cu excess conditions. The growth of ΔtroR was also inhibited in metal-depleted medium supplemented with elevated concentrations of Mn. Moreover, the ΔtroR mutant accumulated increased levels of intracellular Mn and Co, rather than Zn and Cu. Deletion of troR in S. suis led to significant upregulation of the troABCD operon. Furthermore, troA expression in the WT strain was induced by ferrous iron [Fe(II)] and Co and repressed by Mn and Cu; the repression of troA was mediated by TroR. Finally, TroR is required for S. suis virulence in an intranasal mouse model. Together, these data suggest that TroR is a negative regulator of the TroABCD system and contributes to resistance to metal toxicity and virulence in S. suis. IMPORTANCE Metals are essential nutrients for life; however, the accumulation of excess metals in cells can be toxic to bacteria. In the present study, we identified a metalloregulator, TroR, in Streptococcus suis, which is an emerging zoonotic pathogen. In contrast to the observations in other species that TroR homologs usually contribute to the maintenance of homeostasis of one or two metals, we demonstrated that TroR is required for resistance to the toxicity conferred by multiple metals in S. suis. We also found that deletion of troR resulted in significant upregulation of the troABCD operon, which has been demonstrated to be involved in manganese acquisition in S. suis. Moreover, we demonstrated that TroR is required for the virulence of S. suis in an intranasal mouse model. Collectively, these results suggest that TroR is a negative regulator of the TroABCD system and contributes to resistance to metal toxicity and virulence in S. suis.
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Affiliation(s)
- Chengkun Zheng
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
| | - Man Wei
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
| | - Jun Qiu
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
| | - Mengdie Jia
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
| | - Xiaohui Zhou
- Department of Pathobiology and Veterinary Science, University of Connecticut, Storrs, Connecticut, USA
| | - Xinan Jiao
- Joint International Research Laboratory of Agriculture and Agri-Product Safety, the Ministry of Education of China, Yangzhou University, Yangzhou, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, the Ministry of Agriculture of China, Yangzhou University, Yangzhou, China
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Ramos Y, Sansone S, Morales DK. Sugarcoating it: Enterococcal polysaccharides as key modulators of host-pathogen interactions. PLoS Pathog 2021; 17:e1009822. [PMID: 34499702 PMCID: PMC8428557 DOI: 10.1371/journal.ppat.1009822] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Affiliation(s)
- Yusibeska Ramos
- Department of Obstetrics and Gynecology, Weill Cornell Medicine, New York, New York, United States of America
| | - Stephanie Sansone
- Department of Obstetrics and Gynecology, Weill Cornell Medicine, New York, New York, United States of America
- Department of Urology, Weill Cornell Medicine, New York, New York, United States of America
| | - Diana K. Morales
- Department of Obstetrics and Gynecology, Weill Cornell Medicine, New York, New York, United States of America
- * E-mail:
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Bosma EF, Rau MH, van Gijtenbeek LA, Siedler S. Regulation and distinct physiological roles of manganese in bacteria. FEMS Microbiol Rev 2021; 45:6284802. [PMID: 34037759 PMCID: PMC8632737 DOI: 10.1093/femsre/fuab028] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 05/21/2021] [Indexed: 02/06/2023] Open
Abstract
Manganese (Mn2+) is an essential trace element within organisms spanning the entire tree of life. In this review, we provide an overview of Mn2+ transport and the regulation of its homeostasis in bacteria, with a focus on its functions beyond being a cofactor for enzymes. Crucial differences in Mn2+ homeostasis exist between bacterial species that can be characterized to have an iron- or manganese-centric metabolism. Highly iron-centric species require minimal Mn2+ and mostly use it as a mechanism to cope with oxidative stress. As a consequence, tight regulation of Mn2+ uptake is required, while organisms that use both Fe2+ and Mn2+ need other layers of regulation for maintaining homeostasis. We will focus in detail on manganese-centric bacterial species, in particular lactobacilli, that require little to no Fe2+ and use Mn2+ for a wider variety of functions. These organisms can accumulate extraordinarily high amounts of Mn2+ intracellularly, enabling the nonenzymatic use of Mn2+ for decomposition of reactive oxygen species while simultaneously functioning as a mechanism of competitive exclusion. We further discuss how Mn2+ accumulation can provide both beneficial and pathogenic bacteria with advantages in thriving in their niches.
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Affiliation(s)
- Elleke F Bosma
- Chr. Hansen A/S, Discovery, R&D, 2970 Hoersholm, Denmark
| | - Martin H Rau
- Chr. Hansen A/S, Discovery, R&D, 2970 Hoersholm, Denmark
| | | | - Solvej Siedler
- Corresponding author: Boege Allé 10-12, 2970 Hoersholm, Denmark. Tel: +45 52 18 08 25; E-mail:
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The Important Role of Metal Ions for Survival of Francisella in Water within Amoeba Environment. BIOMED RESEARCH INTERNATIONAL 2021. [DOI: 10.1155/2021/6673642] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Francisella tularensis is a gram-negative facultative intracellular bacterium that resists harsh environments. Several outbreaks of tularemia are linked to the consumption and contact with spring water. The number of F. tularensis in some waters is high, while in others, this bacterium does not survive. Except organic compounds, metals could be important for the survival of F. tularensis in water. Some Francisella strains showed the association with amoeba, which may act as the environmental reservoir. This study was aimed at following the role of metal ions and/or amoeba in the existence and replication of F. novicida in spring waters by growth kinetics, acquisition of metals, and ultrastructural analyses of bacteria. The bacteria showed a longer survival in water with higher initial concentrations of Mn and Zn. Although Mn and Zn were necessary for the survival of F. novicida, the results also showed that the bacterium does not grow in water with high levels of Zn. In contrast, high levels of Mn did not have such a negative effect on the survival of this bacterium in water. In addition, while F. novicida benefits presence of amoeba in spring water, the number of amoebae is decreasing in a coculture model with F. novicida.
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Adaptation to Adversity: the Intermingling of Stress Tolerance and Pathogenesis in Enterococci. Microbiol Mol Biol Rev 2019; 83:83/3/e00008-19. [PMID: 31315902 DOI: 10.1128/mmbr.00008-19] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Enterococcus is a diverse and rugged genus colonizing the gastrointestinal tract of humans and numerous hosts across the animal kingdom. Enterococci are also a leading cause of multidrug-resistant hospital-acquired infections. In each of these settings, enterococci must contend with changing biophysical landscapes and innate immune responses in order to successfully colonize and transit between hosts. Therefore, it appears that the intrinsic durability that evolved to make enterococci optimally competitive in the host gastrointestinal tract also ideally positioned them to persist in hospitals, despite disinfection protocols, and acquire new antibiotic resistances from other microbes. Here, we discuss the molecular mechanisms and regulation employed by enterococci to tolerate diverse stressors and highlight the role of stress tolerance in the biology of this medically relevant genus.
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Fitness Restoration of a Genetically Tractable Enterococcus faecalis V583 Derivative To Study Decoration-Related Phenotypes of the Enterococcal Polysaccharide Antigen. mSphere 2019; 4:4/4/e00310-19. [PMID: 31292230 PMCID: PMC6620374 DOI: 10.1128/msphere.00310-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
E. faecalis strain VE14089 was derived from V583 cured of its plasmids. Although VE14089 had no major DNA rearrangements, it presented significant growth and host adaptation differences from the reference strain V583 of our collection. To construct a strain with better fitness, we sequenced the genome of VE14089, identified single nucleotide polymorphisms (SNPs), and repaired the genes that could account for these changes. Using this reference-derivative strain, we provide a novel genetic system to understand the role of the variable region of epa in the enterococcal lifestyle. Commensal and generally harmless in healthy individuals, Enterococcus faecalis causes opportunistic infections in immunocompromised patients. Plasmid-cured E. faecalis strain VE14089, derived from sequenced reference strain V583, is widely used for functional studies due to its improved genetic amenability. Although strain VE14089 has no major DNA rearrangements, with the exception of an ∼20-kb integrated region of pTEF1 plasmid, the strain presented significant growth differences from the V583 reference strain of our collection (renamed VE14002). In the present study, genome sequencing of strain VE14089 identified additional point mutations. Excision of the integrated pTEF1 plasmid region and sequential restoration of wild-type alleles showing nonsilent mutations were performed to obtain the VE18379 reference-derivative strain. Recovery of the growth ability of the restored VE18379 strain at a level similar to that seen with the reference strain points to GreA and Spx as bacterial fitness determinants. Virulence potential in Galleria mellonella and intestinal colonization in mouse demonstrated host adaptation of the VE18379 strain equivalent to VE14002 host adaptation. We further demonstrated that deletion of the 16.8-kb variable region of the epa locus recapitulates the key role of Epa decoration in host adaptation, providing a genetic system to study the role of specific epa-variable regions in host adaptation independently of other genetic variations. IMPORTANCEE. faecalis strain VE14089 was derived from V583 cured of its plasmids. Although VE14089 had no major DNA rearrangements, it presented significant growth and host adaptation differences from the reference strain V583 of our collection. To construct a strain with better fitness, we sequenced the genome of VE14089, identified single nucleotide polymorphisms (SNPs), and repaired the genes that could account for these changes. Using this reference-derivative strain, we provide a novel genetic system to understand the role of the variable region of epa in the enterococcal lifestyle.
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Fiore E, Van Tyne D, Gilmore MS. Pathogenicity of Enterococci. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0053-2018. [PMID: 31298205 PMCID: PMC6629438 DOI: 10.1128/microbiolspec.gpp3-0053-2018] [Citation(s) in RCA: 208] [Impact Index Per Article: 41.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Indexed: 12/19/2022] Open
Abstract
Enterococci are unusually well adapted for survival and persistence in a variety of adverse environments, including on inanimate surfaces in the hospital environment and at sites of infection. This intrinsic ruggedness undoubtedly played a role in providing opportunities for enterococci to interact with other overtly drug-resistant microbes and acquire additional resistances on mobile elements. The rapid rise of antimicrobial resistance among hospital-adapted enterococci has rendered hospital-acquired infections a leading therapeutic challenge. With about a quarter of a genome of additional DNA conveyed by mobile elements, there are undoubtedly many more properties that have been acquired that help enterococci persist and spread in the hospital setting and cause diseases that have yet to be defined. Much remains to be learned about these ancient and rugged microbes, particularly in the area of pathogenic mechanisms involved with human diseases.
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Affiliation(s)
- Elizabeth Fiore
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA 02114
- Department of Microbiology, Harvard Medical School, Boston, MA 02115
| | - Daria Van Tyne
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA 02114
- Department of Microbiology, Harvard Medical School, Boston, MA 02115
| | - Michael S Gilmore
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA 02114
- Department of Microbiology, Harvard Medical School, Boston, MA 02115
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13
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Abstract
The study of the genetics of enterococci has focused heavily on mobile genetic elements present in these organisms, the complex regulatory circuits used to control their mobility, and the antibiotic resistance genes they frequently carry. Recently, more focus has been placed on the regulation of genes involved in the virulence of the opportunistic pathogenic species Enterococcus faecalis and Enterococcus faecium. Little information is available concerning fundamental aspects of DNA replication, partition, and division; this article begins with a brief overview of what little is known about these issues, primarily by comparison with better-studied model organisms. A variety of transcriptional and posttranscriptional mechanisms of regulation of gene expression are then discussed, including a section on the genetics and regulation of vancomycin resistance in enterococci. The article then provides extensive coverage of the pheromone-responsive conjugation plasmids, including sections on regulation of the pheromone response, the conjugative apparatus, and replication and stable inheritance. The article then focuses on conjugative transposons, now referred to as integrated, conjugative elements, or ICEs, and concludes with several smaller sections covering emerging areas of interest concerning the enterococcal mobilome, including nonpheromone plasmids of particular interest, toxin-antitoxin systems, pathogenicity islands, bacteriophages, and genome defense.
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14
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Colomer-Winter C, Flores-Mireles AL, Baker SP, Frank KL, Lynch AJL, Hultgren SJ, Kitten T, Lemos JA. Manganese acquisition is essential for virulence of Enterococcus faecalis. PLoS Pathog 2018; 14:e1007102. [PMID: 30235334 PMCID: PMC6147510 DOI: 10.1371/journal.ppat.1007102] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 08/08/2018] [Indexed: 01/20/2023] Open
Abstract
Manganese (Mn) is an essential micronutrient that is not readily available to pathogens during infection due to an active host defense mechanism known as nutritional immunity. To overcome this nutrient restriction, bacteria utilize high-affinity transporters that allow them to compete with host metal-binding proteins. Despite the established role of Mn in bacterial pathogenesis, little is known about the relevance of Mn in the pathophysiology of E. faecalis. Here, we identified and characterized the major Mn acquisition systems of E. faecalis. We discovered that the ABC-type permease EfaCBA and two Nramp-type transporters, named MntH1 and MntH2, work collectively to promote cell growth under Mn-restricted conditions. The simultaneous inactivation of EfaCBA, MntH1 and MntH2 (ΔefaΔmntH1ΔmntH2 strain) led to drastic reductions (>95%) in cellular Mn content, severe growth defects in body fluids (serum and urine) ex vivo, significant loss of virulence in Galleria mellonella, and virtually complete loss of virulence in rabbit endocarditis and murine catheter-associated urinary tract infection (CAUTI) models. Despite the functional redundancy of EfaCBA, MntH1 and MntH2 under in vitro or ex vivo conditions and in the invertebrate model, dual inactivation of efaCBA and mntH2 (ΔefaΔmntH2 strain) was sufficient to prompt maximal sensitivity to calprotectin, a Mn- and Zn-chelating host antimicrobial protein, and for the loss of virulence in mammalian models. Interestingly, EfaCBA appears to play a prominent role during systemic infection, whereas MntH2 was more important during CAUTI. The different roles of EfaCBA and MntH2 in these sites could be attributed, at least in part, to the differential expression of efaA and mntH2 in cells isolated from hearts or from bladders. Collectively, this study demonstrates that Mn acquisition is essential for the pathogenesis of E. faecalis and validates Mn uptake systems as promising targets for the development of new antimicrobials.
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Affiliation(s)
- Cristina Colomer-Winter
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, United States of America
| | - Ana L. Flores-Mireles
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Center for Women’s Infectious Disease Research, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Shannon P. Baker
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Kristi L. Frank
- Department of Microbiology and Immunology, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
| | - Aaron J. L. Lynch
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Scott J. Hultgren
- Center for Women’s Infectious Disease Research, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Todd Kitten
- Philips Institute for Oral Health Research, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - José A. Lemos
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, Florida, United States of America
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15
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Clauss-Lendzian E, Vaishampayan A, de Jong A, Landau U, Meyer C, Kok J, Grohmann E. Stress response of a clinical Enterococcus faecalis isolate subjected to a novel antimicrobial surface coating. Microbiol Res 2017; 207:53-64. [PMID: 29458868 DOI: 10.1016/j.micres.2017.11.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 04/21/2017] [Accepted: 11/07/2017] [Indexed: 12/17/2022]
Abstract
Emerging antibiotic resistance among pathogenic bacteria, paired with their ability to form biofilms on medical and technical devices, represents a serious problem for effective and long-term decontamination in health-care environments and gives rise to an urgent need for new antimicrobial materials. Here we present the impact of AGXX®, a novel broad-spectrum antimicrobial surface coating consisting of micro-galvanic elements formed by silver and ruthenium, on the transcriptome of Enterococcus faecalis. A clinical E. faecalis isolate was subjected to metal stress by growing it for different periods in presence of the antimicrobial coating or silver-coated steel meshes. Subsequently, total RNA was isolated and next-generation RNA sequencing was performed to analyze variations in gene expression in presence of the antimicrobial materials with focus on known stress genes. Exposure to the antimicrobial coating had a large impact on the transcriptome of E. faecalis. After 24min almost 1/5 of the E. faecalis genome displayed differential expression. At each time-point the cop operon was strongly up-regulated, providing indirect evidence for the presence of free Ag+-ions. Moreover, exposure to the antimicrobial coating induced a broad general stress response in E. faecalis. Genes coding for the chaperones GroEL and GroES and the Clp proteases, ClpE and ClpB, were among the top up-regulated heat shock genes. Differential expression of thioredoxin, superoxide dismutase and glutathione synthetase genes indicates a high level of oxidative stress. We postulate a mechanism of action where the combination of Ag+-ions and reactive oxygen species generated by AGXX® results in a synergistic antimicrobial effect, superior to that of conventional silver coatings.
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Affiliation(s)
- Emanuel Clauss-Lendzian
- Division of Infectious Diseases, University Medical Center Freiburg, Hugstetter Straße 55, 79106 Freiburg im Breisgau, Baden-Württemberg, Germany
| | - Ankita Vaishampayan
- School of Life Sciences and Technology, Beuth University of Applied Sciences, Seestrasse 64, 13347 Berlin, Germany
| | - Anne de Jong
- Department of Molecular Genetics, University of Groningen, Nijenborgh 7, 9747 Groningen, The Netherlands
| | - Uwe Landau
- Largentec GmbH, Am Waldhaus 32, 14129 Berlin, Germany
| | - Carsten Meyer
- Largentec GmbH, Am Waldhaus 32, 14129 Berlin, Germany
| | - Jan Kok
- Department of Molecular Genetics, University of Groningen, Nijenborgh 7, 9747 Groningen, The Netherlands
| | - Elisabeth Grohmann
- Division of Infectious Diseases, University Medical Center Freiburg, Hugstetter Straße 55, 79106 Freiburg im Breisgau, Baden-Württemberg, Germany; School of Life Sciences and Technology, Beuth University of Applied Sciences, Seestrasse 64, 13347 Berlin, Germany.
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16
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Association of Metal Homeostasis and (p)ppGpp Regulation in the Pathophysiology of Enterococcus faecalis. Infect Immun 2017; 85:IAI.00260-17. [PMID: 28483855 DOI: 10.1128/iai.00260-17] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 05/02/2017] [Indexed: 01/30/2023] Open
Abstract
In Enterococcus faecalis, the regulatory nucleotides pppGpp and ppGpp, collectively, (p)ppGpp, are required for growth in blood, survival within macrophages, and virulence. However, a clear understanding of how (p)ppGpp promotes virulence in E. faecalis and other bacterial pathogens is still lacking. In the host, the essential transition metals iron (Fe) and manganese (Mn) are not readily available to invading pathogens because of a host-driven process called nutritional immunity. Considering its central role in adaptation to nutritional stresses, we hypothesized that (p)ppGpp mediates E. faecalis virulence through regulation of metal homeostasis. Indeed, supplementation of serum with either Fe or Mn restored growth and survival of the Δrel ΔrelQ [(p)ppGpp0] strain to wild-type levels. Using a chemically defined medium, we found that (p)ppGpp accumulates in response to either Fe depletion or Mn depletion and that the (p)ppGpp0 strain has a strong growth requirement for Mn that is alleviated by Fe supplementation. Although inactivation of the nutrient-sensing regulator codY restored some phenotypes of the (p)ppGpp0 strain, transcriptional analysis showed that the (p)ppGpp/CodY network does not promote transcription of known metal transporters. Interestingly, physiologic and enzymatic investigations suggest that the (p)ppGpp0 strain requires higher levels of Mn in order to cope with high levels of endogenously produced reactive oxygen species (ROS). Because (p)ppGpp mediates antibiotic persistence and virulence in several bacteria, our findings have broad implications and provide new leads for the development of novel therapeutic and preventive strategies against E. faecalis and beyond.
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17
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Chajęcka-Wierzchowska W, Zadernowska A, Łaniewska-Trokenheim Ł. Virulence factors of Enterococcus spp. presented in food. Lebensm Wiss Technol 2017. [DOI: 10.1016/j.lwt.2016.10.026] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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18
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Chlorhexidine Induces VanA-Type Vancomycin Resistance Genes in Enterococci. Antimicrob Agents Chemother 2016; 60:2209-21. [PMID: 26810654 DOI: 10.1128/aac.02595-15] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 01/20/2016] [Indexed: 11/20/2022] Open
Abstract
Chlorhexidine is a bisbiguanide antiseptic used for infection control. Vancomycin-resistantE. faecium(VREfm) is among the leading causes of hospital-acquired infections. VREfm may be exposed to chlorhexidine at supra- and subinhibitory concentrations as a result of chlorhexidine bathing and chlorhexidine-impregnated central venous catheter use. We used RNA sequencing to investigate how VREfm responds to chlorhexidine gluconate exposure. Among the 35 genes upregulated ≥10-fold after 15 min of exposure to the MIC of chlorhexidine gluconate were those encoding VanA-type vancomycin resistance (vanHAX) and those associated with reduced daptomycin susceptibility (liaXYZ). We confirmed thatvanAupregulation was not strain or species specific by querying other VanA-type VRE. VanB-type genes were not induced. ThevanHpromoter was found to be responsive to subinhibitory chlorhexidine gluconate in VREfm, as was production of the VanX protein. UsingvanHreporter experiments withBacillus subtilisand deletion analysis in VREfm, we found that this phenomenon is VanR dependent. Deletion ofvanRdid not result in increased chlorhexidine susceptibility, demonstrating thatvanHAXinduction is not protective against chlorhexidine. As expected, VanA-type VRE is more susceptible to ceftriaxone in the presence of sub-MIC chlorhexidine. Unexpectedly, VREfm is also more susceptible to vancomycin in the presence of subinhibitory chlorhexidine, suggesting that chlorhexidine-induced gene expression changes lead to additional alterations in cell wall synthesis. We conclude that chlorhexidine induces expression of VanA-type vancomycin resistance genes and genes associated with daptomycin nonsusceptibility. Overall, our results indicate that the impacts of subinhibitory chlorhexidine exposure on hospital-associated pathogens should be further investigated in laboratory studies.
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19
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Ma C, Hao Z, Huysmans G, Lesiuk A, Bullough P, Wang Y, Bartlam M, Phillips SE, Young JD, Goldman A, Baldwin SA, Postis VLG. A Versatile Strategy for Production of Membrane Proteins with Diverse Topologies: Application to Investigation of Bacterial Homologues of Human Divalent Metal Ion and Nucleoside Transporters. PLoS One 2015; 10:e0143010. [PMID: 26606682 PMCID: PMC4659628 DOI: 10.1371/journal.pone.0143010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 10/29/2015] [Indexed: 01/01/2023] Open
Abstract
Membrane proteins play key roles in many biological processes, from acquisition of nutrients to neurotransmission, and are targets for more than 50% of current therapeutic drugs. However, their investigation is hampered by difficulties in their production and purification on a scale suitable for structural studies. In particular, the nature and location of affinity tags introduced for the purification of recombinant membrane proteins can greatly influence their expression levels by affecting their membrane insertion. The extent of such effects typically depends on the transmembrane topologies of the proteins, which for proteins of unknown structure are usually uncertain. For example, attachment of oligohistidine tags to the periplasmic termini of membrane proteins often interferes with folding and drastically impairs expression in Escherichia coli. To circumvent this problem we have employed a novel strategy to enable the rapid production of constructs bearing a range of different affinity tags compatible with either cytoplasmic or periplasmic attachment. Tags include conventional oligohistidine tags compatible with cytoplasmic attachment and, for attachment to proteins with a periplasmic terminus, either tandem Strep-tag II sequences or oligohistidine tags fused to maltose binding protein and a signal sequence. Inclusion of cleavage sites for TEV or HRV-3C protease enables tag removal prior to crystallisation trials or a second step of purification. Together with the use of bioinformatic approaches to identify members of membrane protein families with topologies favourable to cytoplasmic tagging, this has enabled us to express and purify multiple bacterial membrane transporters. To illustrate this strategy, we describe here its use to purify bacterial homologues of human membrane proteins from the Nramp and ZIP families of divalent metal cation transporters and from the concentrative nucleoside transporter family. The proteins are expressed in E. coli in a correctly folded, functional state and can be purified in amounts suitable for structural investigations.
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Affiliation(s)
- Cheng Ma
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Zhenyu Hao
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), College of Environmental Science and Engineering, Nankai University, Tianjin, China
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Gerard Huysmans
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Amelia Lesiuk
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Per Bullough
- Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, University of Sheffield, Firth Court, Western Bank, Sheffield, United Kingdom
| | - Yingying Wang
- Key Laboratory of Pollution Processes and Environmental Criteria (Ministry of Education), College of Environmental Science and Engineering, Nankai University, Tianjin, China
| | - Mark Bartlam
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
- College of Life Sciences, Nankai University, Tianjin, China
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin, China
| | - Simon E. Phillips
- Research Complex at Harwell, Harwell Science and Innovation Campus, Didcot, Oxfordshire, United Kingdom
| | - James D. Young
- Department of Physiology, University of Alberta, Edmonton, Canada
| | - Adrian Goldman
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
- College of Life Sciences, Nankai University, Tianjin, China
- Division of Biochemistry, Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - Stephen A. Baldwin
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - Vincent L. G. Postis
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
- Biomedicine Research Group, Faculty of Health and Social Sciences, Leeds Beckett University, Leeds, LS1 3HE, United Kingdom
- * E-mail:
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20
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Sabatino R, Di Cesare A, Pasquaroli S, Vignaroli C, Citterio B, Amiri M, Rossi L, Magnani M, Mauro A, Biavasco F. Adherence and intracellular survival within human macrophages of Enterococcus faecalis isolates from coastal marine sediment. Microbes Infect 2015; 17:660-4. [DOI: 10.1016/j.micinf.2015.06.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 06/04/2015] [Accepted: 06/05/2015] [Indexed: 11/25/2022]
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21
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Arntzen MØ, Karlskås IL, Skaugen M, Eijsink VGH, Mathiesen G. Proteomic Investigation of the Response of Enterococcus faecalis V583 when Cultivated in Urine. PLoS One 2015; 10:e0126694. [PMID: 25915650 PMCID: PMC4411035 DOI: 10.1371/journal.pone.0126694] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 04/07/2015] [Indexed: 11/19/2022] Open
Abstract
Enterococcus faecalis is a robust bacterium, which is able to survive in and adapt to hostile environments such as the urinary tract and bladder. In this label-free quantitative proteomic study based on MaxQuant LFQ algorithms, we identified 127 proteins present in the secretome of the clinical vancomycin-resistant isolate E. faecalis V583 and we compared proteins secreted in the initial phase of cultivation in urine with the secretome during cultivation in standard laboratory medium, 2xYT. Of the 54 identified proteins predicted to be secreted, six were exclusively found after cultivation in urine including the virulence factor EfaA ("endocarditis specific antigen") and its homologue EF0577 ("adhesion lipoprotein"). These two proteins are both involved in manganese transport, known to be an important determinant of colonization and infection, and may additionally function as adhesins. Other detected urine-specific proteins are involved in peptide transport (EF0063 and EF3106) and protease inhibition (EF3054). In addition, we found an uncharacterized protein (EF0764), which had not previously been linked to the adaptation of V583 to a urine environment, and which is unique to E. faecalis. Proteins found in both environments included a histone-like protein, EF1550, that was up-regulated during cultivation in urine and that has a homologue in streptococci (HlpA) known to be involved in bacterial adhesion to host cells. Up-regulated secreted proteins included autolysins. These results from secretome analyses are largely compatible with previously published data from transcriptomics studies. All in all, the present data indicate that transport, in particular metal transport, adhesion, cell wall remodelling and the unknown function carried out by the unique EF0764 are important for enterococcal adaptation to the urine environment. These results provide a basis for a more targeted exploration of novel proteins involved in the adaptability and pathogenicity of E. faecalis.
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Affiliation(s)
- Magnus Øverlie Arntzen
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
- * E-mail:
| | - Ingrid Lea Karlskås
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
| | - Morten Skaugen
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
| | - Vincent G. H. Eijsink
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
| | - Geir Mathiesen
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, N-1432 Ås, Norway
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22
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Abrantes MC, Kok J, Silva Lopes MDF. Enterococcus faecalis zinc-responsive proteins mediate bacterial defence against zinc overload, lysozyme and oxidative stress. MICROBIOLOGY-SGM 2014; 160:2755-2762. [PMID: 25312746 DOI: 10.1099/mic.0.080341-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Two Enterococcus faecalis genes encoding the P-type ATPase EF1400 and the putative SapB protein EF0759 were previously shown to be strongly upregulated in the presence of high concentrations of zinc. In the present work, we showed that a Zn(2+)-responsive DNA-binding motif (zim) is present in the promoter regions of these genes. Both proteins were further studied with respect to their involvement in zinc homeostasis and invasion of the host. EF0759 contributed to intramacrophage survival by an as-yet unknown mechanism(s). EF1400, here renamed ZntAEf, is an ATPase with specificity for zinc and plays a role in dealing with several host defences, i.e. zinc overload, oxidative stress and lysozyme; it provides E. faecalis cells with the ability to survive inside macrophages. As these three host defence mechanisms are important at several sites in the host, i.e. inside macrophages and in saliva, this work suggested that ZntAEf constitutes a crucial E. faecalis defence mechanism that is likely to contribute to the ability of this bacterium to endure life inside its host.
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Affiliation(s)
- Marta C Abrantes
- Department of Molecular Genetics, University of Groningen, The Netherlands.,Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida da República, 2780-157 Oeiras, Portugal
| | - Jan Kok
- Department of Molecular Genetics, University of Groningen, The Netherlands
| | - Maria de Fátima Silva Lopes
- IBET, Apartado 12, 2781-901 Oeiras, Portugal.,Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenida da República, 2780-157 Oeiras, Portugal
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23
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Lisher JP, Giedroc DP. Manganese acquisition and homeostasis at the host-pathogen interface. Front Cell Infect Microbiol 2013; 3:91. [PMID: 24367765 PMCID: PMC3851752 DOI: 10.3389/fcimb.2013.00091] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Accepted: 11/18/2013] [Indexed: 11/21/2022] Open
Abstract
Pathogenic bacteria acquire transition metals for cell viability and persistence of infection in competition with host nutritional defenses. The human host employs a variety of mechanisms to stress the invading pathogen with both cytotoxic metal ions and oxidative and nitrosative insults while withholding essential transition metals from the bacterium. For example, the S100 family protein calprotectin (CP) found in neutrophils is a calcium-activated chelator of extracellular Mn and Zn and is found in tissue abscesses at sites of infection by Staphylococcus aureus. In an adaptive response, bacteria have evolved systems to acquire the metals in the face of this competition while effluxing excess or toxic metals to maintain a bioavailability of transition metals that is consistent with a particular inorganic "fingerprint" under the prevailing conditions. This review highlights recent biological, chemical and structural studies focused on manganese (Mn) acquisition and homeostasis and connects this process to oxidative stress resistance and iron (Fe) availability that operates at the human host-pathogen interface.
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Affiliation(s)
- John P. Lisher
- Graduate Program in Biochemistry, Indiana UniversityBloomington, IN, USA
| | - David P. Giedroc
- Graduate Program in Biochemistry, Indiana UniversityBloomington, IN, USA
- Department of Chemistry, Indiana UniversityBloomington, IN, USA
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24
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Brophy MB, Nakashige TG, Gaillard A, Nolan EM. Contributions of the S100A9 C-terminal tail to high-affinity Mn(II) chelation by the host-defense protein human calprotectin. J Am Chem Soc 2013; 135:17804-17. [PMID: 24245608 PMCID: PMC3892207 DOI: 10.1021/ja407147d] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Human calprotectin (CP) is an antimicrobial protein that coordinates Mn(II) with high affinity in a Ca(II)-dependent manner at an unusual histidine-rich site (site 2) formed at the S100A8/S100A9 dimer interface. We present a 16-member CP mutant family where mutations in the S100A9 C-terminal tail (residues 96-114) are employed to evaluate the contributions of this region, which houses three histidines and four acidic residues, to Mn(II) coordination at site 2. The results from analytical size-exclusion chromatography, Mn(II) competition titrations, and electron paramagnetic resonance spectroscopy establish that the C-terminal tail is essential for high-affinity Mn(II) coordination by CP in solution. The studies indicate that His103 and His105 (HXH motif) of the tail complete the Mn(II) coordination sphere in solution, affording an unprecedented biological His6 site. These solution studies are in agreement with a Mn(II)-CP crystal structure reported recently (Damo, S. M.; et al. Proc. Natl. Acad. Sci. U.S.A. 2013, 110, 3841). Remarkably high-affinity Mn(II) binding is retained when either H103 or H105 are mutated to Ala, when the HXH motif is shifted from positions 103-105 to 104-106, and when the human tail is substituted by the C-terminal tail of murine S100A9. Nevertheless, antibacterial activity assays employing human CP mutants reveal that the native disposition of His residues is important for conferring growth inhibition against Escherichia coli and Staphylococcus aureus. Within the S100 family, the S100A8/S100A9 heterooligomer is essential for providing high-affinity Mn(II) binding; the S100A7, S100A9(C3S), S100A12, and S100B homodimers do not exhibit such Mn(II)-binding capacity.
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Affiliation(s)
- Megan Brunjes Brophy
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Toshiki G. Nakashige
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Aleth Gaillard
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139
| | - Elizabeth M. Nolan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139
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