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Abril AG, Quintela-Baluja M, Villa TG, Calo-Mata P, Barros-Velázquez J, Carrera M. Proteomic Characterization of Virulence Factors and Related Proteins in Enterococcus Strains from Dairy and Fermented Food Products. Int J Mol Sci 2022; 23:ijms231810971. [PMID: 36142880 PMCID: PMC9503237 DOI: 10.3390/ijms231810971] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/08/2022] [Accepted: 09/16/2022] [Indexed: 01/23/2023] Open
Abstract
Enterococcus species are Gram-positive bacteria that are normal gastrointestinal tract inhabitants that play a beneficial role in the dairy and meat industry. However, Enterococcus species are also the causative agents of health care-associated infections that can be found in dairy and fermented food products. Enterococcal infections are led by strains of Enterococcus faecalis and Enterococcus faecium, which are often resistant to antibiotics and biofilm formation. Enterococci virulence factors attach to host cells and are also involved in immune evasion. LC-MS/MS-based methods offer several advantages compared with other approaches because one can directly identify microbial peptides without the necessity of inferring conclusions based on other approaches such as genomics tools. The present study describes the use of liquid chromatography−electrospray ionization tandem mass spectrometry (LC−ESI−MS/MS) to perform a global shotgun proteomics characterization for opportunistic pathogenic Enterococcus from different dairy and fermented food products. This method allowed the identification of a total of 1403 nonredundant peptides, representing 1327 proteins. Furthermore, 310 of those peptides corresponded to proteins playing a direct role as virulence factors for Enterococcus pathogenicity. Virulence factors, antibiotic sensitivity, and proper identification of the enterococcal strain are required to propose an effective therapy. Data are available via ProteomeXchange with identifier PXD036435. Label-free quantification (LFQ) demonstrated that the majority of the high-abundance proteins corresponded to E. faecalis species. Therefore, the global proteomic repository obtained here can be the basis for further research into pathogenic Enterococcus species, thus facilitating the development of novel therapeutics.
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Affiliation(s)
- Ana G. Abril
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Santiago de Compostela, 15898 Santiago de Compostela, Spain
- Department of Food Technology, Spanish National Research Council (CSIC), Marine Research Institute (IIM), 36208 Vigo, Spain
| | - Marcos Quintela-Baluja
- Department of Analytical Chemistry, Nutrition and Food Science, Food Technology Division, School of Veterinary Sciences, University of Santiago de Compostela, Campus Lugo, 27002 Lugo, Spain
| | - Tomás G. Villa
- Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Santiago de Compostela, 15898 Santiago de Compostela, Spain
| | - Pilar Calo-Mata
- Department of Analytical Chemistry, Nutrition and Food Science, Food Technology Division, School of Veterinary Sciences, University of Santiago de Compostela, Campus Lugo, 27002 Lugo, Spain
| | - Jorge Barros-Velázquez
- Department of Analytical Chemistry, Nutrition and Food Science, Food Technology Division, School of Veterinary Sciences, University of Santiago de Compostela, Campus Lugo, 27002 Lugo, Spain
| | - Mónica Carrera
- Department of Food Technology, Spanish National Research Council (CSIC), Marine Research Institute (IIM), 36208 Vigo, Spain
- Correspondence:
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Exposing the secrets of two well-known Lactobacillus casei phages, J-1 and PL-1, by genomic and structural analysis. Appl Environ Microbiol 2014; 80:7107-21. [PMID: 25217012 DOI: 10.1128/aem.02771-14] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Bacteriophage J-1 was isolated in 1965 from an abnormal fermentation of Yakult using Lactobacillus casei strain Shirota, and a related phage, PL-1, was subsequently recovered from a strain resistant to J-1. Complete genome sequencing shows that J-1 and PL-1 are almost identical, but PL-1 has a deletion of 1.9 kbp relative to J-1, resulting in the loss of four predicted gene products involved in immunity regulation. The structural proteins were identified by mass spectrometry analysis. Similarly to phage A2, two capsid proteins are generated by a translational frameshift and undergo proteolytic processing. The structure of gene product 16 (gp16), a putative tail protein, was modeled based on the crystal structure of baseplate distal tail proteins (Dit) that form the baseplate hub in other Siphoviridae. However, two regions of the C terminus of gp16 could not be modeled using this template. The first region accounts for the differences between J-1 and PL-1 gp16 and showed sequence similarity to carbohydrate-binding modules (CBMs). J-1 and PL-1 GFP-gp16 fusions bind specifically to Lactobacillus casei/paracasei cells, and the addition of l-rhamnose inhibits binding. J-1 gp16 exhibited a higher affinity than PL-1 gp16 for cell walls of L. casei ATCC 27139 in phage adsorption inhibition assays, in agreement with differential adsorption kinetics observed for both phages in this strain. The data presented here provide insights into how Lactobacillus phages interact with their hosts at the first steps of infection.
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Chang D, Zhu Y, An L, Liu J, Su L, Guo Y, Chen Z, Wang Y, Wang L, Wang J, Li T, Fang X, Fang C, Yang R, Liu C. A multi-omic analysis of an Enterococcus faecium mutant reveals specific genetic mutations and dramatic changes in mRNA and protein expression. BMC Microbiol 2013; 13:304. [PMID: 24373636 PMCID: PMC3879163 DOI: 10.1186/1471-2180-13-304] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 12/24/2013] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND For a long time, Enterococcus faecium was considered a harmless commensal of the mammalian gastrointestinal (GI) tract and was used as a probiotic in fermented foods. In recent decades, E. faecium has been recognised as an opportunistic pathogen that causes diseases such as neonatal meningitis, urinary tract infections, bacteremia, bacterial endocarditis and diverticulitis. E. faecium could be taken into space with astronauts and exposed to the space environment. Thus, it is necessary to observe the phenotypic and molecular changes of E. faecium after spaceflight. RESULTS An E. faecium mutant with biochemical features that are different from those of the wild-type strain was obtained from subculture after flight on the SHENZHOU-8 spacecraft. To understand the underlying mechanism causing these changes, the whole genomes of both the mutant and the WT strains were sequenced using Illumina technology. The genomic comparison revealed that dprA, a recombination-mediator gene, and arpU, a gene associated with cell wall growth, were mutated. Comparative transcriptomic and proteomic analyses showed that differentially expressed genes or proteins were involved with replication, recombination, repair, cell wall biogenesis, glycometabolism, lipid metabolism, amino acid metabolism, predicted general function and energy production/conversion. CONCLUSION This study analysed the comprehensive genomic, transcriptomic and proteomic changes of an E. faecium mutant from subcultures that were loaded on the SHENZHOU-8 spacecraft. The implications of these gene mutations and expression changes and their underlying mechanisms should be investigated in the future. We hope that the current exploration of multiple "-omics" analyses of this E. faecium mutant will provide clues for future studies on this opportunistic pathogen.
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Affiliation(s)
- De Chang
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | - Yuanfang Zhu
- BGI-Shenzhen, Shenzhen, People’s Republic of China
| | - Li An
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | - Jinwen Liu
- BGI-Shenzhen, Shenzhen, People’s Republic of China
| | - Longxiang Su
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | - Yinghua Guo
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | - Zhenhong Chen
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | - Yajuan Wang
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | - Li Wang
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | - Junfeng Wang
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | - Tianzhi Li
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | - Xiangqun Fang
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
| | | | - Ruifu Yang
- BGI-Shenzhen, Shenzhen, People’s Republic of China
- State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China
| | - Changting Liu
- Nanlou Respiratory Diseases Department, Chinese PLA General Hospital, Beijing 100853, China
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Quiles-Puchalt N, Tormo-Más MÁ, Campoy S, Toledo-Arana A, Monedero V, Lasa I, Novick RP, Christie GE, Penadés JR. A super-family of transcriptional activators regulates bacteriophage packaging and lysis in Gram-positive bacteria. Nucleic Acids Res 2013; 41:7260-75. [PMID: 23771138 PMCID: PMC3753634 DOI: 10.1093/nar/gkt508] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The propagation of bacteriophages and other mobile genetic elements requires exploitation of the phage mechanisms involved in virion assembly and DNA packaging. Here, we identified and characterized four different families of phage-encoded proteins that function as activators required for transcription of the late operons (morphogenetic and lysis genes) in a large group of phages infecting Gram-positive bacteria. These regulators constitute a super-family of proteins, here named late transcriptional regulators (Ltr), which share common structural, biochemical and functional characteristics and are unique to this group of phages. They are all small basic proteins, encoded by genes present at the end of the early gene cluster in their respective phage genomes and expressed under cI repressor control. To control expression of the late operon, the Ltr proteins bind to a DNA repeat region situated upstream of the terS gene, activating its transcription. This involves the C-terminal part of the Ltr proteins, which control specificity for the DNA repeat region. Finally, we show that the Ltr proteins are the only phage-encoded proteins required for the activation of the packaging and lysis modules. In summary, we provide evidence that phage packaging and lysis is a conserved mechanism in Siphoviridae infecting a wide variety of Gram-positive bacteria.
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Affiliation(s)
- Nuria Quiles-Puchalt
- Instituto de Biomedicina de Valencia (IBV-CSIC), 46010 Valencia, Spain, Centro de Investigación y Tecnología Animal, Instituto Valenciano de Investigaciones Agrarias (CITA-IVIA), Apdo. 187, 12.400 Segorbe, Castellón, Spain, Departamento de Ciencias Biomédicas, Universidad CEU Cardenal Herrera, 46113 Moncada, Valencia, Spain, Departament de Genètica i Microbiologia, Universitat Autònoma de Barcelona, 08193 Barcelona, Spain, Instituto de Agrobiotecnología, CSIC-Universidad Pública de Navarra, 31006 Pamplona, Navarra, Spain, Laboratorio de Bacterias Lacticas y Probioticos, Instituto de Agroquimica y Tecnologia de Alimentos-CSIC, 46980 Paterna, Valencia, Spain, Skirball Institute Program in Molecular Pathogenesis and Departments of Microbiology and Medicine, New York University Medical Center, 540 First Avenue, New York, NY 10016, USA, Department of Microbiology and Immunology, Virginia Commonwealth University School of Medicine, Richmond, VA 23298-0678, USA and Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, G12 8TA Glasgow, UK
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5
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Genome sequence of Enterococcus hirae (Streptococcus faecalis) ATCC 9790, a model organism for the study of ion transport, bioenergetics, and copper homeostasis. J Bacteriol 2012; 194:5126-7. [PMID: 22933757 DOI: 10.1128/jb.01075-12] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enterococcus hirae ATCC 9790 is a Gram-positive lactic acid bacterium that has been used in basic research for over 4 decades. Here we report the sequence and annotation of the 2.8-Mb genome of E. hirae and its endemic 29-kb plasmid pTG9790.
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6
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Chan TS, Wu MS, Suk FM, Chen CN, Chen YF, Hou YH, Lien GS. Enterococcus hirae-related acute pyelonephritis and cholangitis with bacteremia: an unusual infection in humans. Kaohsiung J Med Sci 2011; 28:111-4. [PMID: 22313539 DOI: 10.1016/j.kjms.2011.06.027] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2010] [Accepted: 01/31/2011] [Indexed: 10/17/2022] Open
Abstract
Very few reports are available from the literature related to Enterococcus hirae infection in humans, which is more frequently seen in animals and birds. We report two patients with E hirae bacteremia caused by acute pyelonephritis and acute cholangitis. The clinical courses have been smooth on use of sensitive antibiotic therapy. In both cases, the primary sources and portals of entry are clearly identified.
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Affiliation(s)
- Tze-Sian Chan
- Division of Gastroenterology, Department of Internal Medicine, Taipei Medical University, Wanfang Hospital, Taipei, Taiwan
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7
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Ferrer MD, Quiles-Puchalt N, Harwich MD, Tormo-Más MÁ, Campoy S, Barbé J, Lasa I, Novick RP, Christie GE, Penadés JR. RinA controls phage-mediated packaging and transfer of virulence genes in Gram-positive bacteria. Nucleic Acids Res 2011; 39:5866-78. [PMID: 21450808 PMCID: PMC3152322 DOI: 10.1093/nar/gkr158] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Phage-mediated transfer of microbial genetic elements plays a crucial role in bacterial life style and evolution. In this study, we identify the RinA family of phage-encoded proteins as activators required for transcription of the late operon in a large group of temperate staphylococcal phages. RinA binds to a tightly regulated promoter region, situated upstream of the terS gene, that controls expression of the morphogenetic and lysis modules of the phage, activating their transcription. As expected, rinA deletion eliminated formation of functional phage particles and significantly decreased the transfer of phage and pathogenicity island encoded virulence factors. A genetic analysis of the late promoter region showed that a fragment of 272 bp contains both the promoter and the region necessary for activation by RinA. In addition, we demonstrated that RinA is the only phage-encoded protein required for the activation of this promoter region. This region was shown to be divergent among different phages. Consequently, phages with divergent promoter regions carried allelic variants of the RinA protein, which specifically recognize its own promoter sequence. Finally, most Gram-postive bacteria carry bacteriophages encoding RinA homologue proteins. Characterization of several of these proteins demonstrated that control by RinA of the phage-mediated packaging and transfer of virulence factor is a conserved mechanism regulating horizontal gene transfer.
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Affiliation(s)
- María Desamparados Ferrer
- Departamento de Química, Bioquímica y Biología Molecular, Universidad CEU Cardenal Herrera, 46113 Moncada, Valencia, Spain.
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8
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van der Mee-Marquet N, Domelier AS, Mereghetti L, Lanotte P, Rosenau A, van Leeuwen W, Quentin R. Prophagic DNA fragments in Streptococcus agalactiae strains and association with neonatal meningitis. J Clin Microbiol 2006; 44:1049-58. [PMID: 16517893 PMCID: PMC1393083 DOI: 10.1128/jcm.44.3.1049-1058.2006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We identified-by randomly amplified polymorphic DNA (RAPD) analysis at the population level followed by DNA differential display, cloning, and sequencing-three prophage DNA fragments (F5, F7, and F10) in Streptococcus agalactiae that displayed significant sequence similarity to the DNA of S. agalactiae and Streptococcus pyogenes. The F5 sequence aligned with a prophagic gene encoding the large subunit of a terminase, F7 aligned with a phage-associated cell wall hydrolase and a phage-associated lysin, and F10 aligned with a transcriptional regulator (ArpU family) and a phage-associated endonuclease. We first determined the prevalence of F5, F7, and F10 by PCR in a collection of 109 strains isolated in the 1980s and divided into two populations: one with a high risk of causing meningitis (HR group) and the other with a lower risk of causing meningitis (LR group). These fragments were significantly more prevalent in the HR group than in the LR group (P < 0.001). Our findings suggest that lysogeny has increased the ability of some S. agalactiae strains to invade the neonatal brain endothelium. We then determined the prevalence of F5, F7, and F10 by PCR in a collection of 40 strains recently isolated from neonatal meningitis cases for comparison with the cerebrospinal fluid (CSF) strains isolated in the 1980s. The prevalence of the three prophage DNA fragments was similar in these two populations isolated 15 years apart. We suggest that the prophage DNA fragments identified have remained stable in many CSF S. agalactiae strains, possibly due to their importance in virulence or fitness.
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9
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Tuohimaa A, Riipinen KA, Brandt K, Alatossava T. The genome of the virulent phage Lc-Nu of probiotic Lactobacillus rhamnosus, and comparative genomics with Lactobacillus casei phages. Arch Virol 2005; 151:947-65. [PMID: 16328134 DOI: 10.1007/s00705-005-0672-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2005] [Accepted: 09/28/2005] [Indexed: 12/01/2022]
Abstract
The complete 36,466-bp genome sequence of the virulent phage Lc-Nu of probiotic Lactobacillus rhamnosus was determined. The linear dsDNA with a GC-content of 44.2% contained 3' single-stranded cohesive ends of 12 nucleotides. A total of 51 putative open reading frames (orfs) were predicted. Lc-Nu showed to be evolutionary closely related to the temperate Lactobacillus casei phages phi AT3 and A2. High DNA homology with phi AT3 was shared over the late transcribed genes, and the highest homology with A2 was within the genetic switch region. The truncated cI-like repressor was the only lysogeny related gene left, which strongly suggested Lc-Nu to be recently evolved from a temperate origin. Three putative methylases and endonucleases were detected from the region of early-transcribed genes. The putative origin of replication within the putative gene orf34 homologous to replisome organizers resembled to that of lambdoid phages. The present study suggested Lc-Nu to be a new candidate for the proposed Sfi21-like species.
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Affiliation(s)
- A Tuohimaa
- Department of Biology, University of Oulu, Oulu, Finland
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10
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Yokoi KJ, Kawasaki KI, Taketo A, Kodaira KI. Characterization of lytic enzyme activities of Lactobacillus gasseri with special reference to autolysis. Int J Food Microbiol 2004; 96:273-9. [PMID: 15454317 DOI: 10.1016/j.ijfoodmicro.2004.03.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2003] [Revised: 03/01/2004] [Accepted: 03/08/2004] [Indexed: 11/23/2022]
Abstract
Lactobacillus gasseri JCM 1130 and JCM 1131(T) exhibited autolytic activity in agar containing autoclaved cells of each strain as substrate. By zymogram analysis of JCM 1131(T), two lytic bands with apparent molecular masses of 54.5 and 35 kDa, were detected. Similarly, JCM 1130 yielded two lytic bands with apparent molecular masses of 35 and 33.5 kDa. In simple buffers as well, JCM 1131(T) suffered a drastic decrease in cell turbidity, but JCM 1130 did not undergo the decrease. The optimal pH for autolysis of JCM 1131(T) was in the range of 6.0-7.0, and the lysis was completely inhibited at pH 4-5. The lysis of JCM 1131(T) was suppressed by NaCl, in a concentration-dependent way. When subjected to UV irradiation or mitomycin C (MMC) treatment, cultures of both strains elicited conspicuous turbidity decrease after 2-4 h of growth, suggesting the occurrence of prophage induction. The 35-kDa lytic band of JCM 1131(T) and the 33.5-kDa protein of JCM 1130 were considerably increased by UV irradiation.
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Affiliation(s)
- Ken-ji Yokoi
- Molecular Biology Group, Faculty of Engineering, Toyama University, 3190 Gofuku, Toyama 930-8555, Japan.
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Carroll SA, Hain T, Technow U, Darji A, Pashalidis P, Joseph SW, Chakraborty T. Identification and characterization of a peptidoglycan hydrolase, MurA, of Listeria monocytogenes, a muramidase needed for cell separation. J Bacteriol 2004; 185:6801-8. [PMID: 14617644 PMCID: PMC262698 DOI: 10.1128/jb.185.23.6801-6808.2003] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A novel cell wall hydrolase encoded by the murA gene of Listeria monocytogenes is reported here. Mature MurA is a 66-kDa cell surface protein that is recognized by the well-characterized L. monocytogenes-specific monoclonal antibody EM-7G1. MurA displays two characteristic features: (i) an N-terminal domain with homology to muramidases from several gram-positive bacterial species and (ii) four copies of a cell wall-anchoring LysM repeat motif present within its C-terminal domain. Purified recombinant MurA produced in Escherichia coli was confirmed to be an authentic cell wall hydrolase with lytic properties toward cell wall preparations of Micrococcus lysodeikticus. An isogenic mutant with a deletion of murA that lacked the 66-kDa cell wall hydrolase grew as long chains during exponential growth. Complementation of the mutant strain by chromosomal reintegration of the wild-type gene restored expression of this murein hydrolase activity and cell separation levels to those of the wild-type strain. Studies reported herein suggest that the MurA protein is involved in generalized autolysis of L. monocytogenes.
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Affiliation(s)
- Shannon A Carroll
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742, USA
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12
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Fournier B, Aras R, Hooper DC. Expression of the multidrug resistance transporter NorA from Staphylococcus aureus is modified by a two-component regulatory system. J Bacteriol 2000; 182:664-71. [PMID: 10633099 PMCID: PMC94328 DOI: 10.1128/jb.182.3.664-671.2000] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
To dissect genetically the regulation of NorA, a multidrug transporter of Staphylococcus aureus, we analyzed the differential expression of the norA promoter using a transcriptional fusion with a beta-lactamase reporter gene. Expression studies with an arlS mutant revealed that the norA promoter is ArlS dependent. The arlR-arlS locus was shown to code for a two-component regulatory system. The protein ArlR has strong similarity to response regulators, and ArlS has strong similarity to protein histidine kinases. We have also analyzed the 350-bp region upstream of the Shine-Dalgarno sequence of norA by gel mobility shift experiments. It was shown that only the 115-bp region upstream of the promoter was necessary for multiple binding of an 18-kDa protein. From transcriptional fusions, we have localized four different putative boxes of 6 bp, which appear to play a role in the binding of the 18-kDa protein and in the up-regulation of norA expression in the presence of the arlS mutation. Furthermore, the gel mobility shift of the 18-kDa protein was modified in the presence of the arlS mutation, and the arlS mutation altered the growth-phase regulation of NorA. These results indicate that expression of norA is modified by a two-component regulatory system.
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Affiliation(s)
- B Fournier
- Infectious Disease Division and Medical Services, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114-2696, USA
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13
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Lucchini S, Desiere F, Brüssow H. The genetic relationship between virulent and temperate Streptococcus thermophilus bacteriophages: whole genome comparison of cos-site phages Sfi19 and Sfi21. Virology 1999; 260:232-43. [PMID: 10417258 DOI: 10.1006/viro.1999.9814] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The virulent cos-site Streptococcus thermophilus bacteriophage Sfi19 has a 37,392-bp-long genome consisting of 44 open reading frames all encoded on the same DNA strand. The genome of the temperate cos-site S. thermophilus phage Sfi21 is 3.3 kb longer (40,740 bp, 53 orfs). Both genomes are very similarly organized and differed mainly by gene deletion and DNA rearrangement events in the lysogeny module; gene replacement, duplication, and deletion events in the DNA replication module, and numerous point mutations. The level of point mutations varied from <1% (lysis and DNA replication modules) to >15% (DNA packaging and head morphogenesis modules). A dotplot analysis showed nearly a straight line over the left 25 kb of their genomes. Over the right genome half, a more variable dotplot pattern was observed. The entire lysogeny module from Sfi21 comprising 12 genes was replaced by 7 orfs in Sfi19, six showed similarity with genes from temperate pac-site S. thermophilus phages. None of the genes implicated in the establishment of the lysogenic state (integrase, superinfection immunity, repressor) or remnants of it were conserved in Sfi19, while a Cro-like repressor was detected. Downstream of the highly conserved DNA replication module 11 and 13 orfs were found in Sfi19 and phiSfi21, respectively: Two orfs from Sfi21 were replaced by a different gene and a duplication of the phage origin of replication in Sfi19; a further orf was only found in Sfi21. All other orfs from this region, which included a second putative phage repressor, were closely related between both phages. Two noncoding regions of Sfi19 showed sequence similarity to pST1, a small cryptic plasmid of S. thermophilus.
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Affiliation(s)
- S Lucchini
- Nestlé Research Centre, Nestec Ltd., Vers-chez-les-Blanc, Lausanne 26, CH-1000, Switzerland
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14
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Stanley E, Fitzgerald GF, Marrec CL, Fayard B, van Sinderen D. Sequence analysis and characterization of phi O1205, a temperate bacteriophage infecting Streptococcus thermophilus CNRZ1205. MICROBIOLOGY (READING, ENGLAND) 1997; 143 ( Pt 11):3417-3429. [PMID: 9387220 DOI: 10.1099/00221287-143-11-3417] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The complete nucleotide sequence of phi O1205, a temperate bacteriophage infecting Streptococcus thermophilus strain CNRZ1205, was determined. The phage genome has a unit length of 43,075 bp and appears to be packaged by the so-called headful mechanism. The genomic organization and structure of phi O1205 resemble those of several temperate lactococcal phages that display a life-cycle-specific organization, where ORFs believed to be involved in the lysogenic life-cycle are clustered and arranged in an orientation opposite to the ORFs supposedly involved in the lytic life-cycle. Database searches revealed putative functions for several identified ORFs and further indicated that phi O1205 is genetically related to a particular group of lactococcal phages. Three genes encoding the major structural proteins were identified on the phi O1205 genome. The phage attachment site attP, the bacterial attachment site attB, and the two phage/chromosome junctions attL and attR were identified and found to contain a 40 bp common core sequence.
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Affiliation(s)
- Elizabeth Stanley
- National Food Biotechnology Centre, University College,Cork,Ireland
- Department of Microbiology, University College,Cork,Ireland
| | - Gerald F Fitzgerald
- National Food Biotechnology Centre, University College,Cork,Ireland
- Department of Microbiology, University College,Cork,Ireland
| | | | - Blandine Fayard
- National Food Biotechnology Centre, University College,Cork,Ireland
| | - Douwe van Sinderen
- National Food Biotechnology Centre, University College,Cork,Ireland
- Department of Microbiology, University College,Cork,Ireland
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Buist G, Karsens H, Nauta A, van Sinderen D, Venema G, Kok J. Autolysis of Lactococcus lactis caused by induced overproduction of its major autolysin, AcmA. Appl Environ Microbiol 1997; 63:2722-8. [PMID: 9212419 PMCID: PMC168568 DOI: 10.1128/aem.63.7.2722-2728.1997] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The optical density of a culture of lactococcus lactis MG1363 was reduced more than 60% during prolonged stationary phase. Reduction in optical density (autolysis) was almost absent in a culture of an isogenic mutant containing a deletion in the major autolysin gene, acmA. An acmA mutant carrying multiple coples of a plasmid encoding AcmA lysed to a greater extent than the wild-type strain did. Intercellular action of AcmA was shown by mixing end-exponential-phase cultures of an acmA deletion mutant and a tripeptidase (pepT) deletion mutant. PepT, produced by the acmA mutant, was detected in the supernatant of the mixed culture, but no PepT was present in the culture supernatant of the acmA mutant. A plasmid was constructed in which acmA, lacking its own promoter, was placed downstream of the inducible promoter/operator region of the temperate lactococcal bacteriophage r1t. After mitomycin induction of an exponential-phase culture of L. lactis LL302 carrying this plasmid, the cells became subject to autolysis, resulting in the release of intracellular proteins.
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Affiliation(s)
- G Buist
- Department of Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Haren, The Netherlands
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Abstract
In this report, the characterization of a Staphylococcus aureus operon containing two LytSR-regulated genes, lrgA and lrgB, is described. Sequence and mutagenesis studies of these genes suggest that lrgA encodes a murein hydrolase exporter similar to bacteriophage holin proteins while lrgB may encode a protein having murein hydrolase activity.
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Affiliation(s)
- E W Brunskill
- Program in Molecular and Cell Biology, University of Maryland, Baltimore County 21228, USA
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