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Yang Y, Wang P, Qaidi SE, Hardwidge PR, Huang J, Zhu G. Loss to gain: pseudogenes in microorganisms, focusing on eubacteria, and their biological significance. Appl Microbiol Biotechnol 2024; 108:328. [PMID: 38717672 PMCID: PMC11078800 DOI: 10.1007/s00253-023-12971-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 11/26/2023] [Accepted: 12/01/2023] [Indexed: 05/12/2024]
Abstract
Pseudogenes are defined as "non-functional" copies of corresponding parent genes. The cognition of pseudogenes continues to be refreshed through accumulating and updating research findings. Previous studies have predominantly focused on mammals, but pseudogenes have received relatively less attention in the field of microbiology. Given the increasing recognition on the importance of pseudogenes, in this review, we focus on several aspects of microorganism pseudogenes, including their classification and characteristics, their generation and fate, their identification, their abundance and distribution, their impact on virulence, their ability to recombine with functional genes, the extent to which some pseudogenes are transcribed and translated, and the relationship between pseudogenes and viruses. By summarizing and organizing the latest research progress, this review will provide a comprehensive perspective and improved understanding on pseudogenes in microorganisms. KEY POINTS: • Concept, classification and characteristics, identification and databases, content, and distribution of microbial pseudogenes are presented. • How pseudogenization contribute to pathogen virulence is highlighted. • Pseudogenes with potential functions in microorganisms are discussed.
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Affiliation(s)
- Yi Yang
- College of Veterinary Medicine, Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, Jiangsu, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China
- Joint Laboratory of International Cooperation On Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou, 225009, China
| | - Pengzhi Wang
- College of Veterinary Medicine, Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, Jiangsu, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China
- Joint Laboratory of International Cooperation On Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou, 225009, China
| | - Samir El Qaidi
- College of Veterinary Medicine, Kansas State University, Manhattan, KS, 66506, USA
| | - Philip R Hardwidge
- College of Veterinary Medicine, Kansas State University, Manhattan, KS, 66506, USA
| | - Jinlin Huang
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.
- Jiangsu Key Lab of Zoonosis, Yangzhou University, Yangzhou, 225009, Jiangsu, China.
- College of Bioscience and Biotechnology, Yangzhou University, 12 East Wenhui Road Yangzhou, Jiangsu, 225009, China.
| | - Guoqiang Zhu
- College of Veterinary Medicine, Yangzhou University, 12 East Wenhui Road, Yangzhou, 225009, Jiangsu, China.
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.
- Joint Laboratory of International Cooperation On Prevention and Control Technology of Important Animal Diseases and Zoonoses of Jiangsu Higher Education Institutions, Yangzhou, 225009, China.
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Martins IM, Seribelli AA, Machado Ribeiro TR, da Silva P, Lustri BC, Hernandes RT, Falcão JP, Moreira CG. Invasive non-typhoidal Salmonella (iNTS) aminoglycoside-resistant ST313 isolates feature unique pathogenic mechanisms to reach the bloodstream. INFECTION, GENETICS AND EVOLUTION : JOURNAL OF MOLECULAR EPIDEMIOLOGY AND EVOLUTIONARY GENETICS IN INFECTIOUS DISEASES 2023; 116:105519. [PMID: 37890808 DOI: 10.1016/j.meegid.2023.105519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 10/19/2023] [Accepted: 10/24/2023] [Indexed: 10/29/2023]
Abstract
Invasive non-typhoidal Salmonella (iNTS) from the clonal type ST313 (S. Typhimurium ST313) is the primary cause of invasive salmonellosis in Africa. Recently, in Brazil, iNTS ST313 strains have been isolated from different sources, but there is a lack of understanding of the mechanisms behind how these gut bacteria can break the gut barrier and reach the patient's bloodstream. Here, we compare 13 strains of S. Typhimurium ST313, previously unreported isolates, from human blood cultures, investigating aspects of virulence and mechanisms of resistance. Initially, RNAseq analyses between ST13-blood isolate and SL1344 (ST19) prototype revealed 15 upregulated genes directly related to cellular invasion and replication, such as sopD2, sifB, and pipB. Limited information is available about S. Typhimurium ST313 pathogenesis and epidemiology, especially related to the global distribution of strains. Herein, the correlation of strains isolated from different sources in Brazil was employed to compare clinical and non-clinical isolates, a total of 22 genomes were studied by single nucleotide polymorphism (SNPs). The epidemiological analysis of 22 genomes of S. Typhimurium ST313 strains grouped them into three distinct clusters (A, B, and C) by SNP analysis, where cluster A comprised five, group B six, and group C 11. The 13 clinical blood isolates were all resistant to streptomycin, 92.3% of strains were resistant to ampicillin and 15.39% were resistant to kanamycin. The resistance genes acrA, acrB, mdtK, emrB, emrR, mdsA, and mdsB related to the production of efflux pumps were detected in all (100%) strains studied, similar to pathogenic traits investigated. In conclusion, we evidenced that S. Typhimurium ST313 strains isolated in Brazil have unique epidemiology. The elevated frequencies of virulence genes such as sseJ, sopD2, and pipB are a major concern in these Brazilian isolates, showing a higher pathogenic potential.
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Affiliation(s)
- Isabela Mancini Martins
- Faculdade de Ciências Farmacêuticas de Araraquara, Universidade Estadual Paulista- UNESP- Departamento de Ciências Biológicas, Araraquara, SP, Brazil
| | - Amanda Aparecida Seribelli
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo- USP, Ribeirão Preto, SP, Brazil
| | - Tamara R Machado Ribeiro
- Faculdade de Ciências Farmacêuticas de Araraquara, Universidade Estadual Paulista- UNESP- Departamento de Ciências Biológicas, Araraquara, SP, Brazil
| | - Patrick da Silva
- Faculdade de Ciências Farmacêuticas de Araraquara, Universidade Estadual Paulista- UNESP- Departamento de Ciências Biológicas, Araraquara, SP, Brazil
| | - Bruna Cardinali Lustri
- Faculdade de Ciências Farmacêuticas de Araraquara, Universidade Estadual Paulista- UNESP- Departamento de Ciências Biológicas, Araraquara, SP, Brazil
| | - Rodrigo T Hernandes
- Instituto de Biociências, Universidade Estadual Paulista- UNESP, Botucatu, SP, Brazil
| | - Juliana Pfrimer Falcão
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo- USP, Ribeirão Preto, SP, Brazil.
| | - Cristiano Gallina Moreira
- Faculdade de Ciências Farmacêuticas de Araraquara, Universidade Estadual Paulista- UNESP- Departamento de Ciências Biológicas, Araraquara, SP, Brazil; Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA.
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Akinyemi KO, Fakorede CO, Linde J, Methner U, Wareth G, Tomaso H, Neubauer H. Whole genome sequencing of Salmonella enterica serovars isolated from humans, animals, and the environment in Lagos, Nigeria. BMC Microbiol 2023; 23:164. [PMID: 37312043 DOI: 10.1186/s12866-023-02901-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 05/17/2023] [Indexed: 06/15/2023] Open
Abstract
BACKGROUND Salmonella infections remain an important public health issue worldwide. Some serovars of non-typhoidal Salmonella (NTS) have been associated with bloodstream infections and gastroenteritis, especially in children in Sub-Saharan Africa with circulating S. enterica serovars with drug resistance and virulence genes. This study identified and verified the clonal relationship of Nigerian NTS strains isolated from humans, animals, and the environment. METHODS In total, 2,522 samples were collected from patients, animals (cattle and poultry), and environmental sources between December 2017 and May 2019. The samples were subjected to a standard microbiological investigation. All the isolates were identified using Microbact 24E, and MALDI-TOF MS. The isolates were serotyped using the Kauffmann-White scheme. Antibiotic susceptibility testing was conducted using the disc diffusion method and the Vitek 2 compact system. Virulence and antimicrobial resistance genes, sequence type, and cluster analysis were investigated using WGS data. RESULTS Forty-eight (48) NTS isolates (1.9%) were obtained. The prevalence of NTS from clinical sources was 0.9%, while 4% was recorded for animal sources. The serovars identified were S. Cotham (n = 17), S. Give (n = 16), S. Mokola (n = 6), S. Abony (n = 4), S. Typhimurium (n = 4), and S. Senftenberg (n = 1). All 48 Salmonella isolates carried intrinsic and acquired resistant genes such as aac.6…Iaa, mdf(A), qnrB, qnrB19 genes and golT, golS, pcoA, and silP, mediated by plasmid Col440I_1, incFIB.B and incFII. Between 100 and 118 virulence gene markers distributed across several Salmonella pathogenicity islands (SPIs), clusters, prophages, and plasmid operons were found in each isolate. WGS revealed that strains of each Salmonella serovar could be assigned to a single 7-gene MLST cluster, and strains within the clusters were identical strains and closely related as defined by the 0 and 10 cgSNPs and likely shared a common ancestor. The dominant sequence types were S. Give ST516 and S. Cotham ST617. CONCLUSION We found identical Salmonella sequence types in human, animal, and environmental samples in the same locality, which demonstrates the great potential of the applied tools to trace back outbreak strains. Strategies to control and prevent the spread of NTS in the context of one's health are essential to prevent possible outbreaks.
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Affiliation(s)
| | | | - Jörg Linde
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institute, Jena, Germany
| | - Ulrich Methner
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institute, Jena, Germany
| | - Gamal Wareth
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institute, Jena, Germany
- Department of Bacteriology, Immunology, and Mycology, Faculty of Veterinary Medicine, Benha University, PO Box 13736, Toukh, Moshtohor, Egypt
- Institute of Infectious Diseases and Infection Control, Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany
| | - Herbert Tomaso
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institute, Jena, Germany
| | - Heinrich Neubauer
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institute, Jena, Germany
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Wang BX, Butler DS, Hamblin M, Monack DM. One species, different diseases: the unique molecular mechanisms that underlie the pathogenesis of typhoidal Salmonella infections. Curr Opin Microbiol 2023; 72:102262. [PMID: 36640585 PMCID: PMC10023398 DOI: 10.1016/j.mib.2022.102262] [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: 10/12/2022] [Revised: 12/07/2022] [Accepted: 12/16/2022] [Indexed: 01/15/2023]
Abstract
Salmonella enterica is one of the most widespread bacterial pathogens found worldwide, resulting in approximately 100 million infections and over 200 000 deaths per year. Salmonella isolates, termed 'serovars', can largely be classified as either nontyphoidal or typhoidal Salmonella, which differ in regard to disease manifestation and host tropism. Nontyphoidal Salmonella causes gastroenteritis in many hosts, while typhoidal Salmonella is human-restricted and causes typhoid fever, a systemic disease with a mortality rate of up to 30% without treatment. There has been considerable interest in understanding how different Salmonella serovars cause different diseases, but the molecular details that underlie these infections have not yet been fully characterized, especially in the case of typhoidal Salmonella. In this review, we highlight the current state of research into understanding the pathogenesis of both nontyphoidal and typhoidal Salmonella, with a specific interest in serovar-specific traits that allow human-adapted strains of Salmonella to cause enteric fever. Overall, a more detailed molecular understanding of how different Salmonella isolates infect humans will provide critical insights into how we can eradicate these dangerous enteric pathogens.
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Affiliation(s)
- Benjamin X Wang
- Department of Microbiology & Immunology, Stanford University, Stanford, CA, USA
| | - Daniel Sc Butler
- Department of Microbiology & Immunology, Stanford University, Stanford, CA, USA
| | - Meagan Hamblin
- Department of Microbiology & Immunology, Stanford University, Stanford, CA, USA
| | - Denise M Monack
- Department of Microbiology & Immunology, Stanford University, Stanford, CA, USA.
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Feng Y, Wang Z, Chien KY, Chen HL, Liang YH, Hua X, Chiu CH. "Pseudo-pseudogenes" in bacterial genomes: Proteogenomics reveals a wide but low protein expression of pseudogenes in Salmonella enterica. Nucleic Acids Res 2022; 50:5158-5170. [PMID: 35489061 PMCID: PMC9122581 DOI: 10.1093/nar/gkac302] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 04/11/2022] [Accepted: 04/14/2022] [Indexed: 12/03/2022] Open
Abstract
Pseudogenes (genes disrupted by frameshift or in-frame stop codons) are ubiquitously present in the bacterial genome and considered as nonfunctional fossil. Here, we used RNA-seq and mass-spectrometry technologies to measure the transcriptomes and proteomes of Salmonella enterica serovars Paratyphi A and Typhi. All pseudogenes’ mRNA sequences remained disrupted, and were present at comparable levels to their intact homologs. At the protein level, however, 101 out of 161 pseudogenes suggested successful translation, with their low expression regardless of growth conditions, genetic background and pseudogenization causes. The majority of frameshifting detected was compensatory for -1 frameshift mutations. Readthrough of in-frame stop codons primarily involved UAG; and cytosine was the most frequent base adjacent to the codon. Using a fluorescence reporter system, fifteen pseudogenes were confirmed to express successfully in vivo in Escherichia coli. Expression of the intact copy of the fifteen pseudogenes in S. Typhi affected bacterial pathogenesis as revealed in human macrophage and epithelial cell infection models. The above findings suggest the need to revisit the nonstandard translation mechanism as well as the biological role of pseudogenes in the bacterial genome.
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Affiliation(s)
- Ye Feng
- Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China.,Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Zeyu Wang
- Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China.,Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Kun-Yi Chien
- Graduate Institute of Biomedical Sciences, Chang Gung University College of Medicine, Taoyuan, Republic of China
| | - Hsiu-Ling Chen
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Taoyuan, Republic of China
| | - Yi-Hua Liang
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Taoyuan, Republic of China
| | - Xiaoting Hua
- Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Cheng-Hsun Chiu
- Graduate Institute of Biomedical Sciences, Chang Gung University College of Medicine, Taoyuan, Republic of China.,Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Taoyuan, Republic of China.,Division of Pediatric Infectious Diseases, Department of Pediatrics, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Republic of China
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Genomic and phenotypic comparison of two Salmonella Typhimurium strains responsible for consecutive salmonellosis outbreaks in New Zealand. Int J Med Microbiol 2021; 311:151534. [PMID: 34564018 DOI: 10.1016/j.ijmm.2021.151534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 03/20/2021] [Accepted: 08/16/2021] [Indexed: 11/20/2022] Open
Abstract
Salmonella enterica serovar Typhimurium DT160 was the predominant cause of notified human salmonellosis cases in New Zealand from 2000 to 2010, before it was superseded by another S. Typhimurium strain, DT56 variant (DT56v). Whole genome sequencing and phenotypic testing were used to compare 109 DT160 isolates with eight DT56v isolates from New Zealand animal and human sources. Phylogenetic analysis provided evidence that DT160 and DT56v strains were distantly related with an estimated date of common ancestor between 1769 and 1821. The strains replicated at different rates but had similar antimicrobial susceptibility profiles. Both strains were resistant to the phage expressed from the chromosome of the other strain, which may have contributed to the emergence of DT56v. DT160 contained the pSLT virulence plasmid, and the sseJ and sseK2 genes that may have contributed to the higher reported prevalence compared to DT56v. A linear pBSSB1-family plasmid was also found in one of the DT56v isolates, but there was no evidence that this plasmid affected bacterial replication or antimicrobial susceptibility. One of the DT56v isolates was also sequenced using long-read technology and found to contain an uncommon chromosome arrangement for a Typhimurium isolate. This study demonstrates how comparative genomics and phenotypic testing can help identify strain-specific elements and factors that may have influenced the emergence and supersession of bacterial strains of public health importance.
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Feng Y, Chen CL, Chang YJ, Li YH, Chiou CS, Su LH, Li HC, Yang HP, Chiu CH. Microbiological and genomic investigations of invasive Salmonella enterica serovar Panama from a large outbreak in Taiwan. J Formos Med Assoc 2021; 121:660-669. [PMID: 34294499 DOI: 10.1016/j.jfma.2021.07.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/26/2021] [Accepted: 07/03/2021] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND/PURPOSE Salmonella Panama was considered an invasive non-typhoidal Salmonella (iNTS) serovar. Comprehensive clinical, microbiological, and genomic studies on S. Panama are scarce. We aimed to characterize the clinical and microbiological characteristics of S. Panama infection. Virulence mechanism of S. Panama and other iNTS serovars were also examined. METHODS Based on data from the longitudinal surveillance system for Salmonella deployed in Taiwan since 2004, a case-control study was undertaken to evaluate clinical characteristics of S. Panama infection during an outbreak in 2015-2016. Cellular experiments were conducted to compare pathogenicity of S. Panama and other iNTS with S. Typhimurium. RESULTS Most patients (41/44, 93.2%) infected by S. Panama were <5 years old (median, 1.3 years). The case-control study showed that 28 out of the 41 (68.3%) manifested as bacteremia, compared to S. Typhimurium (11.1%). Patients infected by S. Panama had longer durations of fever (P = 0.005) and hospitalization (P < 0.001). Genomic analyses split the isolates into three clades: two clones caused the outbreak, whereas another one accounted for the sporadic infections before 2015. Cellular experiments revealed that S. Panama and other iNTS serovars showed higher monolayer penetration and intracellular survival within macrophages, compared to S. Typhimurium. CONCLUSION This study confirmed that S. Panama is a clinically invasive serovar. Different iNTS serovars express common virulence phenotypes, but they may acquire invasiveness through distinct expression or combinations of virulence genes.
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Affiliation(s)
- Ye Feng
- Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China; Institute for Translational Medicine, Zhejiang University School of Medicine, Hangzhou, China
| | - Chyi-Liang Chen
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Yi-Jung Chang
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan; Division of Pediatric Infectious Diseases, Department of Pediatrics, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Yi-Hua Li
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Chien-Shun Chiou
- Center for Research, Diagnostics and Vaccine Development, Taiwan Centers for Disease Control, Taichung, Taiwan
| | - Lin-Hui Su
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Hsin-Chieh Li
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Hsin-Ping Yang
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Cheng-Hsun Chiu
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan; Division of Pediatric Infectious Diseases, Department of Pediatrics, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan.
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Ma S, Liu X, Ma S, Jiang L. SopA inactivation or reduced expression is selected in intracellular Salmonella and contributes to systemic Salmonella infection. Res Microbiol 2020; 172:103795. [PMID: 33347947 DOI: 10.1016/j.resmic.2020.103795] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 12/13/2020] [Accepted: 12/14/2020] [Indexed: 11/17/2022]
Abstract
Pseudogenes are accumulated in host-restricted Salmonella enterica serovars, while pseudogenization is primarily regarded as a process that purges unnecessary genes from the genome. Here we showed that the inactivation of sopA, which encodes an effector of Salmonella Pathogenicity Island 1, in human-restricted S. enterica serovar Typhi (S. Ty) and Paratyphi A (S. PA) is under positive selection and aimed to reduce bacterial cytotoxicity toward host macrophages. Moreover, we found that the expression of sopA in Salmonella Typhimurium (S. Tm), a broad-host-range serovar which causes systemic disease in mice, was negatively regulated during mice infection and survival in murine macrophages. The sopA repression in S. Tm is mediated by IsrM, a small RNA absent from the genome of S. Ty and S. PA. Due to the lack of IsrM, sopA expression was unregulated in S. Ty and S. PA, which might have facilitated the convergent inactivation of sopA in these two serovars. In conclusion, our findings demonstrate that sopA inactivation or intracellular repression is the target of positive selection during the systemic infection caused by S. enterica serovars.
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Affiliation(s)
- Shuangshuang Ma
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China; TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin 300457, China.
| | - Xiaoqian Liu
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China; TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin 300457, China.
| | - Shuai Ma
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China; TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin 300457, China.
| | - Lingyan Jiang
- The Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300457, China; TEDA Institute of Biological Sciences and Biotechnology, Nankai University, TEDA, Tianjin 300457, China.
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Johnson R, Mylona E, Frankel G. TyphoidalSalmonella: Distinctive virulence factors and pathogenesis. Cell Microbiol 2018; 20:e12939. [DOI: 10.1111/cmi.12939] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/06/2018] [Accepted: 07/13/2018] [Indexed: 01/13/2023]
Affiliation(s)
- Rebecca Johnson
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences; Imperial College London; London UK
| | - Elli Mylona
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences; Imperial College London; London UK
| | - Gad Frankel
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences; Imperial College London; London UK
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The Type III Secretion System Effector SeoC of Salmonella enterica subsp. salamae and S. enterica subsp. arizonae ADP-Ribosylates Src and Inhibits Opsonophagocytosis. Infect Immun 2016; 84:3618-3628. [PMID: 27736780 PMCID: PMC5116738 DOI: 10.1128/iai.00704-16] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 10/02/2016] [Indexed: 01/23/2023] Open
Abstract
Salmonella species utilize type III secretion systems (T3SSs) to translocate effectors into the cytosol of mammalian host cells, subverting cell signaling and facilitating the onset of gastroenteritis. In this study, we compared a draft genome assembly of Salmonella enterica subsp. salamae strain 3588/07 against the genomes of S. enterica subsp. enterica serovar Typhimurium strain LT2 and Salmonella bongori strain 12419. S. enterica subsp. salamae encodes the Salmonella pathogenicity island 1 (SPI-1), SPI-2, and the locus of enterocyte effacement (LEE) T3SSs. Though several key S Typhimurium effector genes are missing (e.g., avrA, sopB, and sseL), S. enterica subsp. salamae invades HeLa cells and contains homologues of S. bongori sboK and sboC, which we named seoC SboC and SeoC are homologues of EspJ from enteropathogenic and enterohemorrhagic Escherichia coli (EPEC and EHEC, respectively), which inhibit Src kinase-dependent phagocytosis by ADP-ribosylation. By screening 73 clinical and environmental Salmonella isolates, we identified EspJ homologues in S. bongori, S. enterica subsp. salamae, and Salmonella enterica subsp. arizonae The β-lactamase TEM-1 reporter system showed that SeoC is translocated by the SPI-1 T3SS. All the Salmonella SeoC/SboC homologues ADP-ribosylate Src E310 in vitro Ectopic expression of SeoC/SboC inhibited phagocytosis of IgG-opsonized beads into Cos-7 cells stably expressing green fluorescent protein (GFP)-FcγRIIa. Concurrently, S. enterica subsp. salamae infection of J774.A1 macrophages inhibited phagocytosis of beads, in a seoC-dependent manner. These results show that S. bongori, S. enterica subsp. salamae, and S. enterica subsp. arizonae share features of the infection strategy of extracellular pathogens EPEC and EHEC and shed light on the complexities of the T3SS effector repertoires of Enterobacteriaceae.
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Ortega A, Villagra N, Urrutia I, Valenzuela L, Talamilla-Espinoza A, Hidalgo A, Rodas P, Gil F, Calderón I, Paredes-Sabja D, Mora G, Fuentes J. Lose to win: marT pseudogenization in Salmonella enterica serovar Typhi contributed to the surV -dependent survival to H 2 O 2 , and inside human macrophage-like cells. INFECTION GENETICS AND EVOLUTION 2016; 45:111-121. [DOI: 10.1016/j.meegid.2016.08.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 08/17/2016] [Accepted: 08/22/2016] [Indexed: 02/06/2023]
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What's in a Name? Species-Wide Whole-Genome Sequencing Resolves Invasive and Noninvasive Lineages of Salmonella enterica Serotype Paratyphi B. mBio 2016; 7:mBio.00527-16. [PMID: 27555304 PMCID: PMC4999539 DOI: 10.1128/mbio.00527-16] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
For 100 years, it has been obvious that Salmonella enterica strains sharing the serotype with the formula 1,4,[5],12:b:1,2—now known as Paratyphi B—can cause diseases ranging from serious systemic infections to self-limiting gastroenteritis. Despite considerable predicted diversity between strains carrying the common Paratyphi B serotype, there remain few methods that subdivide the group into groups that are congruent with their disease phenotypes. Paratyphi B therefore represents one of the canonical examples in Salmonella where serotyping combined with classical microbiological tests fails to provide clinically informative information. Here, we use genomics to provide the first high-resolution view of this serotype, placing it into a wider genomic context of the Salmonella enterica species. These analyses reveal why it has been impossible to subdivide this serotype based upon phenotypic and limited molecular approaches. By examining the genomic data in detail, we are able to identify common features that correlate with strains of clinical importance. The results presented here provide new diagnostic targets, as well as posing important new questions about the basis for the invasive disease phenotype observed in a subset of strains. Salmonella enterica strains carrying the serotype Paratyphi B have long been known to possess Jekyll and Hyde characteristics; some cause gastroenteritis, while others cause serious invasive disease. Understanding what makes up the population of strains carrying this serotype, as well as the source of their invasive disease, is a 100-year-old puzzle that we address here using genomics. Our analysis provides the first high-resolution view of this serotype, placing strains carrying serotype Paratyphi B into the wider genomic context of the Salmonella enterica species. This work reveals a history of disease dating back to the middle ages, caused by a group of distinct lineages with various abilities to cause invasive disease. By quantifying the key genomic differences between the invasive and noninvasive populations, we are able to identify key virulence-related targets that can form the basis of simple, rapid, point-of-care tests.
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Berrocal L, Fuentes JA, Trombert AN, Jofré MR, Villagra NA, Valenzuela LM, Mora GC. stg fimbrial operon from S. Typhi STH2370 contributes to association and cell disruption of epithelial and macrophage-like cells. Biol Res 2015; 48:34. [PMID: 26149381 PMCID: PMC4494162 DOI: 10.1186/s40659-015-0024-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 06/23/2015] [Indexed: 11/10/2022] Open
Abstract
Background Salmonella enterica serovar Typhi (S. Typhi) stg operon, encoding a chaperone/usher fimbria (CU), contributes to an increased adherence to human epithelial cells. However, one report suggests that the presence of the Stg fimbria impairs the monocyte—bacteria association, as deduced by the lower level of invasion to macrophage-like cells observed when the stg fimbrial cluster was overexpressed. Nevertheless, since other CU fimbrial structures increase the entry of S. Typhi into macrophages, and considering that transcriptomic analyses revealed that stg operon is indeed expressed in macrophages, we reassessed the role of the stg operon in the interaction between S. Typhi strain STH2370 and human cells, including macrophage-like cells and mononuclear cells directly taken from human peripheral blood. Results We compared S. Typhi STH2370 WT, a Chilean clinical strain, and the S. Typhi STH2370 Δstg mutant with respect to association and invasion using epithelial and macrophage-like cells. We observed that deletion of stg operon reduced the association and invasion of S. Typhi, in both cellular types. The presence of the cloned stg operon restored the WT phenotype in all the cases. Moreover, we compared Salmonella enterica sv. Typhimurium 14028s (S. Typhimurium, a serovar lacking stg operon) and S. Typhimurium heterologously expressing S. Typhi stg. We found that the latter presents an increased cell disruption of polarized epithelial cells and an increased association in both epithelial and macrophage-like cells. Conclusions S. Typhi stg operon encodes a functional adhesin that participates in the interaction bacteria—eukaryotic cells, including epithelial cells and macrophages-like cells. The phenotypes associated to stg operon include increased association and consequent invasion in bacteria—eukaryotic cells, and cell disruption. Electronic supplementary material The online version of this article (doi:10.1186/s40659-015-0024-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Liliana Berrocal
- Laboratorio de Microbiología, Facultad de Ciencias Biológicas, Universidad Andres Bello, República 217, Santiago, Chile. .,Escuela de Medicina, Facultad de Medicina, Universidad Finis Terrae, Santiago, Av. Pedro de Valdivia 1509, Providencia, Santiago, Chile.
| | - Juan A Fuentes
- Laboratorio de Microbiología, Facultad de Ciencias Biológicas, Universidad Andres Bello, República 217, Santiago, Chile.
| | - A Nicole Trombert
- Laboratorio de Microbiología, Facultad de Ciencias Biológicas, Universidad Andres Bello, República 217, Santiago, Chile. .,Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Santiago, Camino La Pirámide 5750, Huechuraba, Santiago, Chile.
| | - Matías R Jofré
- Laboratorio de Microbiología, Facultad de Ciencias Biológicas, Universidad Andres Bello, República 217, Santiago, Chile. .,Escuela de Medicina, Facultad de Medicina, Universidad Finis Terrae, Santiago, Av. Pedro de Valdivia 1509, Providencia, Santiago, Chile.
| | - Nicolás A Villagra
- Laboratorio de Microbiología, Facultad de Medicina, Universidad Andres Bello, República 313, Santiago, Chile.
| | - Luis M Valenzuela
- Laboratorio de Microbiología, Facultad de Ciencias Biológicas, Universidad Andres Bello, República 217, Santiago, Chile.
| | - Guido C Mora
- Laboratorio de Microbiología, Facultad de Medicina, Universidad Andres Bello, República 313, Santiago, Chile.
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Pseudogenization of sopA and sopE2 is functionally linked and contributes to virulence of Salmonella enterica serovar Typhi. INFECTION GENETICS AND EVOLUTION 2015; 33:131-42. [DOI: 10.1016/j.meegid.2015.04.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 04/13/2015] [Accepted: 04/21/2015] [Indexed: 12/11/2022]
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Matthews TD, Schmieder R, Silva GGZ, Busch J, Cassman N, Dutilh BE, Green D, Matlock B, Heffernan B, Olsen GJ, Farris Hanna L, Schifferli DM, Maloy S, Dinsdale EA, Edwards RA. Genomic Comparison of the Closely-Related Salmonella enterica Serovars Enteritidis, Dublin and Gallinarum. PLoS One 2015; 10:e0126883. [PMID: 26039056 PMCID: PMC4454671 DOI: 10.1371/journal.pone.0126883] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 04/08/2015] [Indexed: 11/18/2022] Open
Abstract
The Salmonella enterica serovars Enteritidis, Dublin, and Gallinarum are closely related but differ in virulence and host range. To identify the genetic elements responsible for these differences and to better understand how these serovars are evolving, we sequenced the genomes of Enteritidis strain LK5 and Dublin strain SARB12 and compared these genomes to the publicly available Enteritidis P125109, Dublin CT 02021853 and Dublin SD3246 genome sequences. We also compared the publicly available Gallinarum genome sequences from biotype Gallinarum 287/91 and Pullorum RKS5078. Using bioinformatic approaches, we identified single nucleotide polymorphisms, insertions, deletions, and differences in prophage and pseudogene content between strains belonging to the same serovar. Through our analysis we also identified several prophage cargo genes and pseudogenes that affect virulence and may contribute to a host-specific, systemic lifestyle. These results strongly argue that the Enteritidis, Dublin and Gallinarum serovars of Salmonella enterica evolve by acquiring new genes through horizontal gene transfer, followed by the formation of pseudogenes. The loss of genes necessary for a gastrointestinal lifestyle ultimately leads to a systemic lifestyle and niche exclusion in the host-specific serovars.
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Affiliation(s)
- T. David Matthews
- Department of Biology, San Diego State University, San Diego, California, 92182, United States of America
| | - Robert Schmieder
- Department of Computer Science, San Diego State University, San Diego, California, 92182, United States of America
| | - Genivaldo G. Z. Silva
- Computational Science Research Center, San Diego State University, San Diego, California, 92182, United States of America
| | - Julia Busch
- Department of Biology, San Diego State University, San Diego, California, 92182, United States of America
| | - Noriko Cassman
- Department of Biology, San Diego State University, San Diego, California, 92182, United States of America
| | - Bas E. Dutilh
- Theoretical Biology and Bioinformatics, Utrecht University, Utrecht, The Netherlands
- Centre for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Centre, Nijmegen, The Netherlands
| | - Dawn Green
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Brian Matlock
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Brian Heffernan
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Gary J. Olsen
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
| | - Leigh Farris Hanna
- Molecular Sciences Department, University of Tennessee Health Sciences Center, 858 Madison Ave, Memphis, Tennessee, United States of America
| | - Dieter M. Schifferli
- University of Pennsylvania School of Veterinary Medicine, 3800 Spruce St, Philadelphia, Pennsylvania, 19104, United States of America
| | - Stanley Maloy
- Department of Biology, San Diego State University, San Diego, California, 92182, United States of America
| | - Elizabeth A. Dinsdale
- Department of Biology, San Diego State University, San Diego, California, 92182, United States of America
| | - Robert A. Edwards
- Department of Biology, San Diego State University, San Diego, California, 92182, United States of America
- Department of Computer Science, San Diego State University, San Diego, California, 92182, United States of America
- Department of Marine Biology, Institute of Biology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Argonne National Laboratory, 9700 S. Cass Ave, Argonne, Illinois, 60349, United States of America
- * E-mail:
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Abstract
Salmonellae invasion and intracellular replication within host cells result in a range of diseases, including gastroenteritis, bacteraemia, enteric fever and focal infections. In recent years, considerable progress has been made in our understanding of the molecular mechanisms that salmonellae use to alter host cell physiology; through the delivery of effector proteins with specific activities and through the modulation of defence and stress response pathways. In this Review, we summarize our current knowledge of the complex interplay between bacterial and host factors that leads to inflammation, disease and, in most cases, control of the infection by its animal hosts, with a particular focus on Salmonella enterica subsp. enterica serovar Typhimurium. We also highlight gaps in our knowledge of the contributions of salmonellae and the host to disease pathogenesis, and we suggest future avenues for further study.
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Affiliation(s)
- Doris L. LaRock
- Department of Microbiology, University of Washington, Seattle, WA 98195
| | - Anu Chaudhary
- Department of Microbiology, University of Washington, Seattle, WA 98195
| | - Samuel I. Miller
- Department of Microbiology, University of Washington, Seattle, WA 98195
- Department of Genome Sciences, University of Washington, Seattle, WA 98195
- Department of Immunology, University of Washington, Seattle, WA 98195
- Department of Medicine, University of Washington, Seattle, WA 98195
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Dougan G, Baker S. Salmonella entericaSerovar Typhi and the Pathogenesis of Typhoid Fever. Annu Rev Microbiol 2014; 68:317-36. [DOI: 10.1146/annurev-micro-091313-103739] [Citation(s) in RCA: 191] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Gordon Dougan
- The Wellcome Trust Sanger Institute, The Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom;
| | - Stephen Baker
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Program, Oxford University, Clinical Research Unit, Ho Chi Minh City, Vietnam;
- Centre for Tropical Medicine, Oxford University, Oxford OX3 7FZ, United Kingdom
- The London School of Hygiene and Tropical Medicine, London WC1E 7HT, United Kingdom
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Abstract
Attenuated Salmonella vaccines can be administered orally to deliver recombinant antigens to mucosal surfaces inducing a protective immune response against a variety of targeted pathogens. A number of exciting new approaches and technologies for attenuated Salmonella vaccines have been developed recently. However, a disconnect remains between results obtained with mice in preclinical studies and results obtained in human clinical trials. This is due to an incomplete understanding of Salmonella Typhi interactions with human hosts and inadequate animal models available for study. In this review, the authors describe recent progress in identifying important differences underlying S. Typhi-host interactions, the development of novel approaches to vaccine design and six recent clinical trials evaluating Salmonella-vectored vaccines.
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Affiliation(s)
- Kenneth L Roland
- The Biodesign Institute, Arizona State University, 1001 S. McAllister Avenue, Tempe, AZ 85287-5401, USA
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Draft Genome Sequence of Salmonella enterica Serovar Typhi Strain STH2370. GENOME ANNOUNCEMENTS 2014; 2:2/1/e00104-14. [PMID: 24558245 PMCID: PMC3931366 DOI: 10.1128/genomea.00104-14] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report the draft genome sequence of Salmonella enterica serovar Typhi strain STH2370, isolated from a typhoid fever patient in Santiago, Chile. This clinical isolate has been used as the reference wild-type strain in numerous studies conducted in our laboratories during the last 15 years.
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van der Heijden J, Finlay BB. Type III effector-mediated processes in Salmonella infection. Future Microbiol 2012; 7:685-703. [DOI: 10.2217/fmb.12.49] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Salmonella is one of the most successful bacterial pathogens that infect humans in both developed and developing countries. In order to cause infection, Salmonella uses type III secretion systems to inject bacterial effector proteins into host cells. In the age of antibiotic resistance, researchers have been looking for new strategies to reduce Salmonella infection. To understand infection and to analyze type III secretion as a potential therapeutic target, research has focused on identification of effectors, characterization of effector functions and how they contribute to disease. Many effector-mediated processes have been identified that contribute to infection but thus far no specific treatment has been found. In this perspective we discuss our current understanding of effector-mediated processes and discuss new techniques and approaches that may help us to find a solution to this worldwide problem.
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Affiliation(s)
- Joris van der Heijden
- Michael Smith Laboratories, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
- Department of Microbiology & Immunology, University of British Columbia, Vancouver, BC, Canada
| | - B Brett Finlay
- Department of Biochemistry & Molecular Biology, University of British Columbia, Vancouver, BC, Canada
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Trombert AN, Rodas PI, Mora GC. Reduced invasion to human epithelial cell lines of Salmonella enterica serovar Typhi carrying S. Typhimurium sopD2. FEMS Microbiol Lett 2011; 322:150-6. [PMID: 21707735 DOI: 10.1111/j.1574-6968.2011.02347.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Salmonella enterica serovar Typhi and Typhimurium are closely related serovars. However, S. Typhi, a human-specific pathogen, has 5% of genes as pseudogenes, far more than S. Typhimurium, which only has 1%. One of these pseudogenes corresponds to sopD2, which in S. Typhimurium encodes an effector protein involved in Salmonella-containing vacuole biogenesis in human epithelial cell lines, which is needed for full virulence of the pathogen. We investigated whether S. Typhi trans-complemented with the functional sopD2 gene from S. Typhimurium (sopD2(STM) ) would reduce the invasion of human epithelial cell lines. Our results showed that the presence of sopD2(STM) in S. Typhi significantly modified the bacterial ability to alter cellular permeability and decrease the CFUs recovered after cell invasion of human epithelial cell line. These results add to mounting evidence that pseudogenes contribute to S. Typhi adaptation to humans.
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Affiliation(s)
- Annette N Trombert
- Laboratorio de Microbiología, Facultad de Medicina, Universidad Andrés Bello, Santiago, Chile
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Rodas PI, Trombert AN, Mora GC. A holin remnant protein encoded by STY1365 is involved in envelope stability of Salmonella enterica serovar Typhi. FEMS Microbiol Lett 2011; 321:58-66. [PMID: 21592194 DOI: 10.1111/j.1574-6968.2011.02310.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
We characterized STY1365, a small ORF of Salmonella enterica serovar Typhi. This 174-bp ORF encodes a putative product of 57 amino acid residues with a premature stop codon. Nevertheless, bioinformatic analyses revealed that the predicted product of STY1365 has similarity to putative holin genes of Escherichia coli and bacteriophage ΦP27. STY1365 showed a high-level expression at the early log phase and a small corresponding protein product was detected mainly in the inner membrane fraction. Cloning of STY1365 in pSU19 mid-copy-vector produced retardation in S. Typhi growth, increased cell permeability to crystal violet and altered the inner membrane protein profile. Similar results were obtained when STY1365 was induced with isopropyl-β-d-thio-galactoside in pCC1(™) single-copy vector. Our results support the fact that S. Typhi STY1365 encodes a holin remnant protein that is involved in the stability of the bacterial envelope.
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Affiliation(s)
- Paula I Rodas
- Programa de Doctorado en Bioquímica, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago, Chile
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Malik-Kale P, Jolly CE, Lathrop S, Winfree S, Luterbach C, Steele-Mortimer O. Salmonella - at home in the host cell. Front Microbiol 2011; 2:125. [PMID: 21687432 PMCID: PMC3109617 DOI: 10.3389/fmicb.2011.00125] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2011] [Accepted: 05/19/2011] [Indexed: 11/16/2022] Open
Abstract
The Gram-negative bacterium Salmonella enterica has developed an array of sophisticated tools to manipulate the host cell and establish an intracellular niche, for successful propagation as a facultative intracellular pathogen. While Salmonella exerts diverse effects on its host cell, only the cell biology of the classic “trigger”-mediated invasion process and the subsequent development of the Salmonella-containing vacuole have been investigated extensively. These processes are dependent on cohorts of effector proteins translocated into host cells by two type III secretion systems (T3SS), although T3SS-independent mechanisms of entry may be important for invasion of certain host cell types. Recent studies into the intracellular lifestyle of Salmonella have provided new insights into the mechanisms used by this pathogen to modulate its intracellular environment. Here we discuss current knowledge of Salmonella-host interactions including invasion and establishment of an intracellular niche within the host.
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Affiliation(s)
- Preeti Malik-Kale
- Laboratory of Intracellular Parasites, Rocky Mountain Laboratories, National Institutes of Allergy and Infectious Disease, National Institute of Health Hamilton, MT, USA
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