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Cohen E, Azriel S, Auster O, Gal A, Mikhlin S, Crauwels S, Rahav G, Gal-Mor O. A new Salmonella enterica serovar that was isolated from a wild sparrow presents a distinct genetic, metabolic and virulence profile. Microbes Infect 2024; 26:105249. [PMID: 37956735 DOI: 10.1016/j.micinf.2023.105249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 10/31/2023] [Accepted: 11/06/2023] [Indexed: 11/15/2023]
Abstract
Salmonella enterica is a ubiquitous and clinically-important bacterial pathogen, able to infect and cause different diseases in a wide range of hosts. Here, we report the isolation and characterization of a new S. enterica serovar (13,23:i:-; S. Tirat-Zvi), belonging to the Havana supper-lineage that was isolated from a wild house sparrow (Passer domesticus) in Israel. Whole genome sequencing and complete assembly of its genome indicated a plasmid-free, 4.7 Mb genome that carries the Salmonella pathogenicity islands 1-6, 9, 19 and an integrative and conjugative element (ICE), encoding arsenic resistance genes. Phenotypically, S. Tirat-Zvi isolate TZ282 was motile, readily formed biofilm, more versatile in carbon source utilization than S. Typhimurium and highly tolerant to arsenic, but impaired in host cell invasion. In-vivo infection studies indicated that while S. Tirat-Zvi was able to infect and cause an acute inflammatory enterocolitis in young chicks, it was compromised in mice colonization and did not cause an inflammatory colitis in mice compared to S. Typhimurium. We suggest that these phenotypes reflect the distinctive ecological niche of this new serovar and its evolutionary adaptation to passerine birds, as a permissive host. Moreover, these results further illuminate the genetic, phenotypic and ecological diversity of S. enterica pathovars.
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Affiliation(s)
- Emiliano Cohen
- The Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel
| | - Shalevet Azriel
- The Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel
| | - Oren Auster
- The Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel; Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Department of Clinical Microbiology and Immunology, Tel Aviv University, Tel Aviv, Israel
| | - Adiv Gal
- Faculty of Sciences, Kibbutzim College, Tel-Aviv, Israel
| | | | - Sam Crauwels
- Laboratory for Process Microbial Ecology and Bioinspirational Management (PME&BIM), Centre of Microbial and Plant Genetics (CMPG), Department of Microbial and Molecular Systems (M2S), KU Leuven, Leuven, Belgium
| | - Galia Rahav
- The Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel; Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ohad Gal-Mor
- The Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel; Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; Department of Clinical Microbiology and Immunology, Tel Aviv University, Tel Aviv, Israel.
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Wales A, Lawes J. JMM Profile: Salmonella enterica serovar Gallinarum, biovars Pullorum and Gallinarum. J Med Microbiol 2023; 72. [PMID: 36753431 DOI: 10.1099/jmm.0.001653] [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: 02/09/2023] Open
Abstract
Salmonella
serovar Gallinarum has two distinct biovars, Pullorum and Gallinarum. They are host-adapted avian pathogens that infect a number of wild and domesticated species but they pose a particular threat to farmed and backyard chickens and turkeys. Both biovars cause invasive and septicaemic disease, often resulting in high mortality. Pullorum is transmitted in eggs and typically affects birds soon after hatch. Gallinarum may cause disease in any age of bird, which often progresses through mature flocks. The establishment of clean breeding stock has resulted in freedom from the pathogens in many countries although even in these territories sporadic incursions still occur.
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Affiliation(s)
- Andrew Wales
- Department of Pathology and Infectious Diseases, School of Veterinary Medicine, University of Surrey, Guildford, Surrey, GU2 7AL, UK
| | - Joanna Lawes
- Department of Epidemiological Sciences, Animal and Plant Health Agency, Woodham Lane, Addlestone, Surrey, KT15 3NB, UK
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Basit A, Tahir H, Haider Z, Tariq H, Ullah A, Rehman SU. CRISPR/Cas9-Based Deletion of SpvB Gene From Salmonella gallinarum Leads to Loss of Virulence in Chicken. Front Bioeng Biotechnol 2022; 10:885227. [PMID: 35769104 PMCID: PMC9234527 DOI: 10.3389/fbioe.2022.885227] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 04/25/2022] [Indexed: 12/03/2022] Open
Abstract
Salmonella Gallinarum causes fowl typhoid in poultry leading to a huge economic loss to the poultry industry. The large virulence plasmid of S. gallinarum has been associated with various systemic infections in poultry. A five-gene spanning region (spvRABCD) of 7.8 kb on the large plasmid mainly confers virulence to the bacteria. However, the exact role of these genes in virulence has not been elucidated yet. SpvB exhibits delayed cell death by preventing actin polymerization followed by apoptosis during intracellular infection. The specific role of SpvB in causing the disease is not known yet. In the current study, the SpvB gene was deleted through CRISPR/Cas9 method from a large virulent plasmid of locally isolated S. gallinarum strain (SG18). The homology-directed repair method was used for complete deletion of SpvB gene using the modified pCas9 plasmid. The SpvB-deleted S. gallinarum strain (ΔSpvB_SG18), when tested for its virulence in broiler chicken showed no diseases signs and mortality. In addition, the avirulent strain does not affect the bird’s weight and was rapidly cleared from the liver after infection. However, it cleared from the intestine only after 4–5 days, which suggests that the ΔSpvB_SG18 strain is unable to invade from the intestine to the liver. This is the first study to report a complete gene deletion from the S. gallinarum virulent plasmid and its effect. This method will be useful for the deletion of virulent genes from S. gallinarum, to study their role in pathogenesis, and to prepare an effective vaccine strain for controlling fowl typhoid in poultry.
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Affiliation(s)
- Abdul Basit
- *Correspondence: Abdul Basit, ; Shafiq Ur Rehman ,
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Atypical Salmonella enterica Serovars in Murine and Human Macrophage Infection Models. Infect Immun 2020; 88:IAI.00353-19. [PMID: 32014897 DOI: 10.1128/iai.00353-19] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 01/28/2020] [Indexed: 11/20/2022] Open
Abstract
Nontyphoidal Salmonella species are globally disseminated pathogens and are the predominant cause of gastroenteritis. The pathogenesis of salmonellosis has been extensively studied using in vivo murine models and cell lines, typically challenged with Salmonella enterica serovar Typhimurium. Although S. enterica serovars Enteritidis and Typhimurium are responsible for most of the human infections reported to the Centers for Disease Control and Prevention (CDC), several other serovars also contribute to clinical cases of salmonellosis. Despite their epidemiological importance, little is known about their infection phenotypes. Here, we report the virulence characteristics and genomes of 10 atypical S. enterica serovars linked to multistate foodborne outbreaks in the United States. We show that the murine RAW 264.7 macrophage model of infection is unsuitable for inferring human-relevant differences in nontyphoidal Salmonella infections, whereas differentiated human THP-1 macrophages allowed these isolates to be further characterized in a more human-relevant context.
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Kim NH, Ha EJ, Ko DS, Lee CY, Kim JH, Kwon HJ. Molecular evolution of Salmonella enterica subsp. enterica serovar Gallinarum biovar Gallinarum in the field. Vet Microbiol 2019; 235:63-70. [PMID: 31282380 DOI: 10.1016/j.vetmic.2019.05.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 05/07/2019] [Accepted: 05/23/2019] [Indexed: 01/31/2023]
Abstract
Salmonella enterica subsp. enterica serovar Gallinarum biovar Gallinarum (SG) causes fowl typhoid (FT) and substantial economic loss in Korea due to egg drop syndrome and mortality. Despite the extensive use of vaccines, FT still occurs in the field. Therefore, the emergence of more pathogenic SG or the recovered pathogenicity of a vaccine strain has been suspected. SpvB, an ADP-ribosyl transferase, is a major pathogenesis determinant, and the length of the polyproline linker (PPL) of SpvB affects pathogenic potency. SG strains accumulate pseudogenes in their genomes during host adaptation, and pseudogene profiling may provide evolutionary information. In this study, we found that the PPL length of Korean SG isolates varied from 11 to 21 prolines and was longer than that of a live vaccine strain, SG 9R (9 prolines). According to growth competition in chickens, the growth of an SG isolate with a PPL length of 17 prolines exceeded that of an SG isolate with a PPL length of 15 prolines. We investigated the pseudogenes of the field isolates, SG 9R and reference strains in GenBank by resequencing and comparative genomics. The pseudogene profiles of the field isolates were notably different from those of the foreign SG strains, and they were subdivided into 7 pseudogene subgroups. Collectively, the field isolates had gradually evolved by changing PPL length and acquiring additional pseudogenes. Thus, the characterization of PPL length and pseudogene profiling may be useful to understand the molecular evolution of SG and the epidemiology of FT.
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Affiliation(s)
- Nam-Hyung Kim
- Laboratory of Avian Diseases, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Eun-Jin Ha
- Laboratory of Avian Diseases, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Dae-Sung Ko
- Laboratory of Avian Diseases, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Chung-Young Lee
- Laboratory of Avian Diseases, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea; Research Institute for Veterinary Science, College of Veterinary Medicine, BK21 for Veterinary Science, Seoul 08826, Republic of Korea
| | - Jae-Hong Kim
- Laboratory of Avian Diseases, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea; Research Institute for Veterinary Science, College of Veterinary Medicine, BK21 for Veterinary Science, Seoul 08826, Republic of Korea
| | - Hyuk-Joon Kwon
- Department of Farm Animal Medicine, College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea; Research Institute for Veterinary Science, College of Veterinary Medicine, BK21 for Veterinary Science, Seoul 08826, Republic of Korea; Farm Animal Clinical Training and Research Center (FACTRC), GBST, Seoul National University, Kangwon-do 25354, Republic of Korea.
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Abstract
Pullorum disease, an acute poultry septicemia caused by Salmonella Gallinarum biovar Pullorum, is fatal for young chickens and is a heavy burden on poultry industry. The pathogen is rare in most developed countries but still extremely difficult to eliminate in China. Efficient epidemiological surveillance necessitates clarifying the origin of the isolates from different regions and their phylogenic relationships. Genomic epidemiological analysis of 97 S. Pullorum strains was carried out to reconstruct the phylogeny and transmission history of S. Pullorum. Further analysis demonstrated that functional gene loss and acquisition occurred simultaneously throughout the evolution of S. Pullorum, both of which reflected adaptation to the changing environment. The result of our study will be helpful in surveillance and prevention of pullorum disease. Salmonella enterica subspecies enterica serovar Gallinarum biovar Pullorum (S. Pullorum) is the etiological agent of pullorum disease, causing white diarrhea with high mortality in chickens. There are many unsolved issues surrounding the epidemiology of S. Pullorum, including its origin and transmission history as well as the discordance between its phenotypic heterogeneity and genetic monomorphism. In this paper, we report the results of whole-genome sequencing of a panel of 97 S. Pullorum strains isolated between 1962 and 2014 from four countries across three continents. We utilized 6,795 core genome single nucleotide polymorphisms (SNPs) to reconstruct a phylogenetic tree within a spatiotemporal Bayesian framework, estimating that the most recent common ancestor of S. Pullorum emerged in ∼914 CE (95% confidence interval [95%CI], 565 to 1273 CE). The extant S. Pullorum strains can be divided into four distinct lineages, each of which is significantly associated with geographical distribution. The intercontinental transmissions of lineages III and IV can be traced to the mid-19th century and are probably related to the “Hen Fever” prevalent at that time. Further genomic analysis indicated that the loss or pseudogenization of functional genes involved in metabolism and virulence in S. Pullorum has been ongoing since before and after divergence from the ancestor. In contrast, multiple prophages and plasmids have been acquired by S. Pullorum, and these have endowed it with new characteristics, especially the multidrug resistance conferred by two large plasmids in lineage I. The results of this study provide insight into the evolution of S. Pullorum and prove the efficiency of whole-genome sequencing in epidemiological surveillance of pullorum disease. IMPORTANCE Pullorum disease, an acute poultry septicemia caused by Salmonella Gallinarum biovar Pullorum, is fatal for young chickens and is a heavy burden on poultry industry. The pathogen is rare in most developed countries but still extremely difficult to eliminate in China. Efficient epidemiological surveillance necessitates clarifying the origin of the isolates from different regions and their phylogenic relationships. Genomic epidemiological analysis of 97 S. Pullorum strains was carried out to reconstruct the phylogeny and transmission history of S. Pullorum. Further analysis demonstrated that functional gene loss and acquisition occurred simultaneously throughout the evolution of S. Pullorum, both of which reflected adaptation to the changing environment. The result of our study will be helpful in surveillance and prevention of pullorum disease.
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Alves Batista DF, de Freitas Neto OC, Maria de Almeida A, Maboni G, de Carvalho TF, de Carvalho TP, Barrow PA, Berchieri A. Evaluation of pathogenicity of Salmonella Gallinarum strains harbouring deletions in genes whose orthologues are conserved pseudogenes in S. Pullorum. PLoS One 2018; 13:e0200585. [PMID: 30028856 PMCID: PMC6054384 DOI: 10.1371/journal.pone.0200585] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Accepted: 06/29/2018] [Indexed: 12/12/2022] Open
Abstract
The diseases caused by Salmonella Gallinarum and S. Pullorum in chickens known as fowl typhoid and pullorum disease, respectively, pose a great threat to the poultry industry mainly in developing countries, since they have already been controlled in the developed ones. These bacteria are very similar at the genomic level but develop distinct host-pathogen relationships with chickens. Therefore, a deep understanding of the molecular mechanisms whereby S. Gallinarum and S. Pullorum interact with the host could lead to the development of new approaches to control and, perhaps, eradicate both diseases from the chicken flocks worldwide. Based on our previous study, it was hypothesised that metabolism-related pseudogenes, fixed in S. Pullorum genomes, could play a role in the distinct host-pathogen interaction with susceptible chickens. To test this idea, three genes (idnT, idnO and ccmH) of S. Gallinarum str. 287/91, which are pseudogenes on the S. Pullorum chromosomes, were inactivated by mutations. These genetically engineered strains grew well on the solid media without any colony morphology difference. In addition, similar growth curves were obtained by cultivation in M9 minimal medium containing D-gluconate as the sole carbon source. Infection of chickens with idnTO mutants led to increased numbers of bacteria in the livers and spleens at 5 days post-infection, but with slightly decreased heterophil infiltration in the spleens when compared to the wild-type strain. On the other hand, no significant phenotypic change was caused by mutation to ccmH genes. Apart from the above-mentioned alterations, all S. Gallinarum strains provoked similar infections, since mortality, clinical signs, macroscopic alterations and immune response were similar to the infected chickens. Therefore, according to the model applied to this study, mutation to the idnTO and ccmH genes showed minor impact on the fowl typhoid pathogenesis and so they may be relics from the ancestor genome. Our data hints at a more complex mechanism driving the distinct host-pathogen interaction of S. Gallinarum/Pullorum with chickens than differential inactivation of a few genes.
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Affiliation(s)
- Diego Felipe Alves Batista
- Post Graduate Program in Agricultural and Livestock Microbiology, Department of Veterinary Pathology, School of Agriculture and Veterinarian Sciences, São Paulo State University (Unesp), campus at Jaboticabal, São Paulo, Brazil
| | - Oliveiro Caetano de Freitas Neto
- Post Graduate Program in Agricultural and Livestock Microbiology, Department of Veterinary Pathology, School of Agriculture and Veterinarian Sciences, São Paulo State University (Unesp), campus at Jaboticabal, São Paulo, Brazil
- Department of Veterinary Sciences, Federal University of Paraíba, Areia, Paraíba, Brazil
- * E-mail:
| | - Adriana Maria de Almeida
- Post Graduate Program in Agricultural and Livestock Microbiology, Department of Veterinary Pathology, School of Agriculture and Veterinarian Sciences, São Paulo State University (Unesp), campus at Jaboticabal, São Paulo, Brazil
| | - Grazieli Maboni
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, United Kingdom
| | - Tatiane Furtado de Carvalho
- Department of Veterinary Clinic and Surgery, School of Veterinary, Federal University of Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil
| | - Thaynara Parente de Carvalho
- Department of Veterinary Clinic and Surgery, School of Veterinary, Federal University of Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil
| | - Paul Andrew Barrow
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, United Kingdom
| | - Angelo Berchieri
- Post Graduate Program in Agricultural and Livestock Microbiology, Department of Veterinary Pathology, School of Agriculture and Veterinarian Sciences, São Paulo State University (Unesp), campus at Jaboticabal, São Paulo, Brazil
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Eriksson H, Söderlund R, Ernholm L, Melin L, Jansson DS. Diagnostics, epidemiological observations and genomic subtyping in an outbreak of pullorum disease in non-commercial chickens. Vet Microbiol 2018; 217:47-52. [DOI: 10.1016/j.vetmic.2018.02.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Revised: 02/02/2018] [Accepted: 02/23/2018] [Indexed: 10/18/2022]
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Batista DFA, de Freitas Neto OC, de Almeida AM, Barrow PA, de Oliveira Barbosa F, Berchieri Junior A. Molecular identification of Salmonella enterica subsp. enterica serovar Gallinarum biovars Gallinarum and Pullorum by a duplex PCR assay. J Vet Diagn Invest 2016; 28:419-22. [DOI: 10.1177/1040638716651466] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Salmonella enterica subsp. enterica serovar Gallinarum biovar Gallinarum ( S. Gallinarum) and biovar Pullorum ( S. Pullorum) are 2 poultry pathogens that cause major economic losses to the poultry industry worldwide. Control of both diseases mainly relies on the adoption of biosecurity programs, and success is dependent on accurate and fast detection. Based on this concept, we developed a duplex PCR assay, targeting 2 chromosomal sequences, which allowed us to precisely identify and differentiate S. Gallinarum and S. Pullorum field strains. This assay was validated by testing genomic DNA from 40 S. Gallinarum and 29 S. Pullorum field strains, 87 other Salmonella serovars, and 7 non- Salmonella strains. The serovar identifier region (SIR) primers produced a fragment only in S. Gallinarum and S. Pullorum strains, whereas the fragment from the ratA coding sequence, which was previously demonstrated to differentiate the 2 biovars, was also amplified from other Salmonella serovars. Our results showed that the combination of both SIR and ratA amplifications could be used to identify as well as to differentiate colonies of S. Gallinarum and S. Pullorum reliably. Thus, we believe this methodology can be a useful ancillary tool for routine veterinary diagnostic laboratories by providing rapid, accurate results.
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Affiliation(s)
- Diego Felipe Alves Batista
- Faculty of Agriculture and Veterinary Sciences, São Paulo State University, Jaboticabal, São Paulo, Brazil (Batista, Almeida, Barbosa, Berchieri Jr)
- Agronomical Science Centre, Federal University of Paraíba, Campus II, Areia, Paraíba, Brazil (Freitas Neto)
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, United Kingdom (Barrow)
| | - Oliveiro Caetano de Freitas Neto
- Faculty of Agriculture and Veterinary Sciences, São Paulo State University, Jaboticabal, São Paulo, Brazil (Batista, Almeida, Barbosa, Berchieri Jr)
- Agronomical Science Centre, Federal University of Paraíba, Campus II, Areia, Paraíba, Brazil (Freitas Neto)
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, United Kingdom (Barrow)
| | - Adriana Maria de Almeida
- Faculty of Agriculture and Veterinary Sciences, São Paulo State University, Jaboticabal, São Paulo, Brazil (Batista, Almeida, Barbosa, Berchieri Jr)
- Agronomical Science Centre, Federal University of Paraíba, Campus II, Areia, Paraíba, Brazil (Freitas Neto)
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, United Kingdom (Barrow)
| | - Paul Andrew Barrow
- Faculty of Agriculture and Veterinary Sciences, São Paulo State University, Jaboticabal, São Paulo, Brazil (Batista, Almeida, Barbosa, Berchieri Jr)
- Agronomical Science Centre, Federal University of Paraíba, Campus II, Areia, Paraíba, Brazil (Freitas Neto)
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, United Kingdom (Barrow)
| | - Fernanda de Oliveira Barbosa
- Faculty of Agriculture and Veterinary Sciences, São Paulo State University, Jaboticabal, São Paulo, Brazil (Batista, Almeida, Barbosa, Berchieri Jr)
- Agronomical Science Centre, Federal University of Paraíba, Campus II, Areia, Paraíba, Brazil (Freitas Neto)
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, United Kingdom (Barrow)
| | - Angelo Berchieri Junior
- Faculty of Agriculture and Veterinary Sciences, São Paulo State University, Jaboticabal, São Paulo, Brazil (Batista, Almeida, Barbosa, Berchieri Jr)
- Agronomical Science Centre, Federal University of Paraíba, Campus II, Areia, Paraíba, Brazil (Freitas Neto)
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, United Kingdom (Barrow)
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Yin J, Cheng Z, Xu L, Li Q, Geng S, Pan Z, Jiao X. Immunogenicity and protective efficacy of Salmonella enterica serovar Pullorum pathogenicity island 2 mutant as a live attenuated vaccine candidate. BMC Vet Res 2015. [PMID: 26205518 PMCID: PMC4513372 DOI: 10.1186/s12917-015-0497-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Background Salmonella enterica serovar Pullorum (S. Pullorum) causes Pullorum disease (PD), a severe systemic disease of poultry and results in considerable economic losses in developing countries. In order to develop a safe and immunogenic vaccine, the immunogenicity and protective efficacy of S06004ΔSPI2, a Salmonella pathogenicity island 2 (SPI2) deleted mutant of S. Pullorum was evaluated in 2-day old chickens. Results Single intramuscular vaccination with S06004ΔSPI2 (2 × 107 CFU) of chickens revealed no differences in body weight or clinical symptoms compared to control group. S06004ΔSPI2 bacteria can colonize and persistent in liver and spleen of vaccinated chickens approximately 14 days, and specific humoral and cellular immune responses were significantly induced. Vaccination of chickens offered efficient protection against S. Pullorum strain S06004 and S. Gallinarum strain SG9 challenge, respectively, at 10 days post vaccination (dpv) based on mortality and clinical symptoms compared to control group. Conclusions These findings suggest that S06004ΔSPI2 appears to be a highly immunogenic and efficient live attenuated vaccine candidate.
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Affiliation(s)
- Junlei Yin
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, 225009, P R China
| | - Zhao Cheng
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, 225009, P R China
| | - Lijuan Xu
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, 225009, P R China
| | - Qiuchun Li
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, 225009, P R China
| | - Shizhong Geng
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, 225009, P R China
| | - Zhiming Pan
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, 225009, P R China
| | - Xinan Jiao
- Jiangsu Key Laboratory of Zoonosis, Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, Jiangsu, 225009, P R China.
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Rivera-Chávez F, Bäumler AJ. The Pyromaniac Inside You: Salmonella Metabolism in the Host Gut. Annu Rev Microbiol 2015; 69:31-48. [PMID: 26002180 DOI: 10.1146/annurev-micro-091014-104108] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A metabolically diverse microbial community occupies all available nutrient-niches in the lumen of the mammalian intestine, making it difficult for pathogens to establish themselves in this highly competitive environment. Salmonella serovars sidestep the competition by using their virulence factors to coerce the host into creating a novel nutrient-niche. Inflammation-derived nutrients available in this new niche support a bloom of Salmonella serovars, thereby ensuring transmission of the pathogen to the next susceptible host by the fecal-oral route. Here we review the anaerobic food chain that characterizes resident gut-associated microbial communities along with the winning metabolic strategy Salmonella serovars use to edge out competing microbes in the inflamed intestine.
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Affiliation(s)
- Fabian Rivera-Chávez
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, California 95616;
| | - Andreas J Bäumler
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, California 95616;
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Evaluation of the Salmonella enterica Serovar Pullorum Pathogenicity Island 2 Mutant as a Candidate Live Attenuated Oral Vaccine. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2015; 22:706-10. [PMID: 25924763 DOI: 10.1128/cvi.00130-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Accepted: 04/21/2015] [Indexed: 11/20/2022]
Abstract
Salmonella enterica serovar Pullorum (S. Pullorum) is a highly adapted pathogen that causes pullorum disease (PD), an important systemic disease of poultry that causes severe economic losses in developing countries. In the interests of developing a safe and immunogenic oral vaccine, the efficacy of a Salmonella pathogenicity island 2 (SPI2)-deleted mutant of S. Pullorum (S06004ΔSPI2) was evaluated in chickens. S06004ΔSPI2 was severely less virulent than the parental wild-type strain S06004 as determined by the 50% lethal dose (LD50) for 3-day-old chickens when injected intramuscularly. Two-day-old chickens immunized with a single oral dose of S06004ΔSPI2 showed no differences in body weight or clinical symptoms compared with those in the negative-control group. S06004ΔSPI2 bacteria were not isolated from livers or spleens of immunized chickens after a short period of time, and specific humoral and cellular immune responses were significantly induced. Immunized chickens were challenged with S. Pullorum strain S06004 and Salmonella enterica serovar Gallinarum (S. Gallinarum) strain SG9 at 10 days postimmunization (dpi), and efficient protection against the challenges was observed. None of the immunized chickens died, the clinical symptoms were slight and temporary following challenge in immunized chickens compared with those in the control group, and these chickens recovered by 3 to 5 dpi. Overall, these results demonstrate that S06004ΔSPI2 can be used as a live attenuated oral vaccine.
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Identification and characterization of regions of difference between the Salmonella Gallinarum biovar Gallinarum and the Salmonella Gallinarum biovar Pullorum genomes. INFECTION GENETICS AND EVOLUTION 2015; 30:74-81. [DOI: 10.1016/j.meegid.2014.12.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 12/01/2014] [Accepted: 12/04/2014] [Indexed: 11/18/2022]
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Cheraghchi N, Khaki P, Moradi Bidhendi S, Sabokbar A. Identification of Isolated Salmonella enterica Serotype gallinarum Biotype Pullorum and Gallinarum by PCR-RFLP. Jundishapur J Microbiol 2014; 7:e19135. [PMID: 25485068 PMCID: PMC4255383 DOI: 10.5812/jjm.19135] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2014] [Revised: 05/31/2014] [Accepted: 06/09/2014] [Indexed: 11/16/2022] Open
Abstract
Background: Salmonella spp. is the major bacterial pathogen in poultry and is responsible for significant economic losses of the poultry industry in many parts of the world. Among Salmonella spp., Salmonellagallinarum and Salmonella.pullorum are the most common causative agents of chicken salmonellosis resulting in high mortality and morbidity. Objectives: The aim of this study was to identify S. gallinarum and S. pullorum by using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Materials and Methods: In this study, 13 samples of Salmonella, isolated from local poultry, were obtained from Razi Type Culture Collection (RTCC). For the PCR-RFLP method based on the fliC gene, extracted DNA was used as a template for amplifying of the fliC gene (197bp) using specific primers. PCR products were subjected to digestion using Hinp1I restriction endonuclease. Results: For the PCR, 197 bp fliC fragment was amplified from all 13 isolates. Ten out of 13 were S.gallinarum and the other three were S. pullorum. As part of the PCR-RFLP, two fragments were obtained (82 bp and 115 bp) for all S.gallinarum, whereas no digestion was observed in S. pullorum, and 197 bp fragment was seen. Conclusions: PCR-RFLP with fliC gene and Hinp1I endonuclease were successfully applied to differentiate the two biotypes. The results suggested that this technique could be effective in detecting S. gallinarum and S. pullorum.
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Affiliation(s)
- Narges Cheraghchi
- Department of Microbiology, College of Basic Sciences, Karaj Branch, Islamic Azad University, Karaj, IR Iran
| | - Pejvak Khaki
- Department of Microbiology, Razi Vaccine and Serum Research Institute, Karaj, IR Iran
| | - Soheila Moradi Bidhendi
- Department of Microbiology, Razi Vaccine and Serum Research Institute, Karaj, IR Iran
- Corresponding author: Soheila Moradi Bidhendi, Department of Microbiology, Razi Vaccine and Serum Research Institute, P.C. 3197619751, Karaj, IR Iran. Tel: +98-2634570038/+98-9123182404, Fax: +98-2634552194, E-mail:
| | - Azar Sabokbar
- Department of Microbiology, College of Basic Sciences, Karaj Branch, Islamic Azad University, Karaj, IR Iran
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Pulido-Landínez M, Sánchez-Ingunza R, Guard J, do Nascimento VP. Presence ofSalmonellaEnteritidis andSalmonellaGallinarum in Commercial Laying Hens Diagnosed with Fowl Typhoid Disease in Colombia. Avian Dis 2014; 58:165-70. [DOI: 10.1637/10598-062613-case.1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Draft Genome Sequence of Salmonella enterica subsp. enterica Serovar Gallinarum Biovar Pullorum Strain FCAV198, a Brazilian Chicken Pathogen. GENOME ANNOUNCEMENTS 2014; 2:2/1/e00028-14. [PMID: 24558231 PMCID: PMC3931352 DOI: 10.1128/genomea.00028-14] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Salmonella enterica subsp. enterica serovar Gallinarum biovar Pullorum is a bird-restricted pathogen which causes pullorum disease. The strain FCAV198 was isolated from a pool of chicken ovaries in Brazil, and its genome may be helpful for studies involving molecular mechanisms related to pathogenesis and other related applications.
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Foley SL, Johnson TJ, Ricke SC, Nayak R, Danzeisen J. Salmonella pathogenicity and host adaptation in chicken-associated serovars. Microbiol Mol Biol Rev 2013; 77:582-607. [PMID: 24296573 PMCID: PMC3973385 DOI: 10.1128/mmbr.00015-13] [Citation(s) in RCA: 185] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Enteric pathogens such as Salmonella enterica cause significant morbidity and mortality. S. enterica serovars are a diverse group of pathogens that have evolved to survive in a wide range of environments and across multiple hosts. S. enterica serovars such as S. Typhi, S. Dublin, and S. Gallinarum have a restricted host range, in which they are typically associated with one or a few host species, while S. Enteritidis and S. Typhimurium have broad host ranges. This review examines how S. enterica has evolved through adaptation to different host environments, especially as related to the chicken host, and continues to be an important human pathogen. Several factors impact host range, and these include the acquisition of genes via horizontal gene transfer with plasmids, transposons, and phages, which can potentially expand host range, and the loss of genes or their function, which would reduce the range of hosts that the organism can infect. S. Gallinarum, with a limited host range, has a large number of pseudogenes in its genome compared to broader-host-range serovars. S. enterica serovars such as S. Kentucky and S. Heidelberg also often have plasmids that may help them colonize poultry more efficiently. The ability to colonize different hosts also involves interactions with the host's immune system and commensal organisms that are present. Thus, the factors that impact the ability of Salmonella to colonize a particular host species, such as chickens, are complex and multifactorial, involving the host, the pathogen, and extrinsic pressures. It is the interplay of these factors which leads to the differences in host ranges that we observe today.
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Batista DFA, de Freitas Neto OC, Lopes PD, de Almeida AM, Barrow PA, Berchieri A. Polymerase chain reaction assay based on ratA gene allows differentiation between Salmonella enterica subsp. enterica serovar Gallinarum biovars Gallinarum and Pullorum. J Vet Diagn Invest 2013; 25:259-62. [DOI: 10.1177/1040638713479361] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Salmonella Pullorum and Salmonella Gallinarum are classified as biovars of Salmonella enterica subsp. enterica serovar Gallinarum. These salmonellae are the causative agents of Pullorum disease and fowl typhoid, respectively, and are widely distributed throughout the world. Although many developed countries have eradicated these diseases from commercial poultry, they are still the cause of significant economic loss in developing countries. When serovar Gallinarum is isolated, it is difficult to immediately differentiate between biovars because they are antigenically identical by serotyping. However, they cause distinct diseases with different epidemiology, and therefore it is important to differentiate them. This may be done biochemically but takes 2 to 3 days. In the present study, S. Pullorum and S. Gallinarum whole genomes were compared, and 1 genomic region of difference, which is part of the ratA gene, was chosen as a molecular marker for a polymerase chain reaction assay to differentiate rapidly between these organisms. In all, 26 strains of S. Gallinarum and 17 S. Pullorum strains were tested and successfully differentiated by the assay.
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Affiliation(s)
- Diego Felipe Alves Batista
- Faculty of Agriculture and Veterinary Sciences, Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil (Batista, Freitas Neto, Lopes, Almeida, Berchieri Jr)
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, UK (Barrow)
| | - Oliveiro Caetano de Freitas Neto
- Faculty of Agriculture and Veterinary Sciences, Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil (Batista, Freitas Neto, Lopes, Almeida, Berchieri Jr)
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, UK (Barrow)
| | - Priscila Diniz Lopes
- Faculty of Agriculture and Veterinary Sciences, Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil (Batista, Freitas Neto, Lopes, Almeida, Berchieri Jr)
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, UK (Barrow)
| | - Adriana Maria de Almeida
- Faculty of Agriculture and Veterinary Sciences, Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil (Batista, Freitas Neto, Lopes, Almeida, Berchieri Jr)
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, UK (Barrow)
| | - Paul Andrew Barrow
- Faculty of Agriculture and Veterinary Sciences, Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil (Batista, Freitas Neto, Lopes, Almeida, Berchieri Jr)
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, UK (Barrow)
| | - Angelo Berchieri
- Faculty of Agriculture and Veterinary Sciences, Universidade Estadual Paulista, Jaboticabal, São Paulo, Brazil (Batista, Freitas Neto, Lopes, Almeida, Berchieri Jr)
- School of Veterinary Medicine and Science, University of Nottingham, Sutton Bonington, Leicestershire, UK (Barrow)
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Achtman M, Wain J, Weill FX, Nair S, Zhou Z, Sangal V, Krauland MG, Hale JL, Harbottle H, Uesbeck A, Dougan G, Harrison LH, Brisse S. Multilocus sequence typing as a replacement for serotyping in Salmonella enterica. PLoS Pathog 2012; 8:e1002776. [PMID: 22737074 PMCID: PMC3380943 DOI: 10.1371/journal.ppat.1002776] [Citation(s) in RCA: 448] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Accepted: 05/10/2012] [Indexed: 12/15/2022] Open
Abstract
Salmonella enterica subspecies enterica is traditionally subdivided into serovars by serological and nutritional characteristics. We used Multilocus Sequence Typing (MLST) to assign 4,257 isolates from 554 serovars to 1092 sequence types (STs). The majority of the isolates and many STs were grouped into 138 genetically closely related clusters called eBurstGroups (eBGs). Many eBGs correspond to a serovar, for example most Typhimurium are in eBG1 and most Enteritidis are in eBG4, but many eBGs contained more than one serovar. Furthermore, most serovars were polyphyletic and are distributed across multiple unrelated eBGs. Thus, serovar designations confounded genetically unrelated isolates and failed to recognize natural evolutionary groupings. An inability of serotyping to correctly group isolates was most apparent for Paratyphi B and its variant Java. Most Paratyphi B were included within a sub-cluster of STs belonging to eBG5, which also encompasses a separate sub-cluster of Java STs. However, diphasic Java variants were also found in two other eBGs and monophasic Java variants were in four other eBGs or STs, one of which is in subspecies salamae and a second of which includes isolates assigned to Enteritidis, Dublin and monophasic Paratyphi B. Similarly, Choleraesuis was found in eBG6 and is closely related to Paratyphi C, which is in eBG20. However, Choleraesuis var. Decatur consists of isolates from seven other, unrelated eBGs or STs. The serological assignment of these Decatur isolates to Choleraesuis likely reflects lateral gene transfer of flagellar genes between unrelated bacteria plus purifying selection. By confounding multiple evolutionary groups, serotyping can be misleading about the disease potential of S. enterica. Unlike serotyping, MLST recognizes evolutionary groupings and we recommend that Salmonella classification by serotyping should be replaced by MLST or its equivalents. Microbiologists have used serological and nutritional characteristics to subdivide pathogenic bacteria for nearly 100 years. These subdivisions in Salmonella enterica are called serovars, some of which are thought to be associated with particular diseases and epidemiology. We used MultiLocus Sequence-based Typing (MLST) to identify clusters of S. enterica isolates that are related by evolutionary descent. Some clusters correspond to serovars on a one to one basis. But many clusters include multiple serovars, which is of public health significance, and most serovars span multiple, unrelated clusters. Despite its broad usage, serological typing of S. enterica has resulted in confusing systematics, with a few exceptions. We recommend that serotyping for strain discrimination of S. enterica be replaced by a DNA-based method, such as MLST. Serotyping and other non-sequence based typing methods are routinely used for detecting outbreaks and to support public health responses. Moving away from these methods will require a major shift in thinking by public health microbiology laboratories as well as national and international agencies. However, a transition to the routine use of MLST, supplemented where appropriate by even more discriminatory sequence-based typing methods based on entire genomes, will provide a clearer picture of long-term transmission routes of Salmonella, facilitate data transfer and support global control measures.
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Affiliation(s)
- Mark Achtman
- Environmental Research Institute and Department of Microbiology, University College Cork, Cork, Ireland.
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21
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Paiva JB, Penha Filho RAC, Junior AB, Lemos MVF. Requirement for cobalamin by Salmonella enterica serovars Typhimurium, Pullorum, Gallinarum and Enteritidis during infection in chickens. Braz J Microbiol 2011; 42:1409-18. [PMID: 24031771 PMCID: PMC3768742 DOI: 10.1590/s1517-838220110004000024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Revised: 01/26/2011] [Accepted: 05/16/2011] [Indexed: 11/22/2022] Open
Abstract
Salmonella enterica serovar Typhimurium synthesizes cobalamin (vitamin B12) only during anaerobiosis. Two percent of the S. Typhimurium genome is devoted to the synthesis and uptake of vitamin B12 and to B12-dependent reactions. To understand the requirement for cobalamin synthesis better, we constructed mutants of Salmonella serovars Enteritidis and Pullorum that are double-defective in cobalamin biosynthesis (ΔcobSΔcbiA). We compared the virulence of these mutants to that of their respective wild type strains and found no impairment in their ability to cause disease in chickens. We then assessed B12 production in these mutants and their respective wild type strains, as well as in S. Typhimurium ΔcobSΔcbiA, Salmonella Gallinarum ΔcobSΔcbiA, and their respective wild type strains. None of the mutants was able to produce detectable B12. B12 was detectable in S. Enteritidis, S. Pullorum and S. Typhimurium wild type strains but not in S. Gallinarum. In conclusion, the production of vitamin B12in vitro differed across the tested Salmonella serotypes and the deletion of the cbiA and cobS genes resulted in different levels of alteration in the host parasite interaction according to Salmonella serotype tested.
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Affiliation(s)
- Jacqueline Boldrin Paiva
- Departamento de Patologia Veterinária, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista , Jaboticabal, SP , Brasil
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22
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Strugnell BW, Bennett G, Davies RH, Horton RA. Bovine abortion associated with Salmonella 9, 12:-:-NM in a U.K. dairy herd. Vet Rec 2011; 169:208. [PMID: 21778145 DOI: 10.1136/vr.d4301] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- B W Strugnell
- Animal Health and Veterinary Laboratories Agency-Thirsk, West House, Station Road, Thirsk, North Yorkshire YO7 1PZ, UK.
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23
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Petty NK, Feltwell T, Pickard D, Clare S, Toribio AL, Fookes M, Roberts K, Monson R, Nair S, Kingsley RA, Bulgin R, Wiles S, Goulding D, Keane T, Corton C, Lennard N, Harris D, Willey D, Rance R, Yu L, Choudhary JS, Churcher C, Quail MA, Parkhill J, Frankel G, Dougan G, Salmond GPC, Thomson NR. Citrobacter rodentium is an unstable pathogen showing evidence of significant genomic flux. PLoS Pathog 2011; 7:e1002018. [PMID: 21490962 PMCID: PMC3072379 DOI: 10.1371/journal.ppat.1002018] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 02/18/2011] [Indexed: 11/18/2022] Open
Abstract
Citrobacter rodentium is a natural mouse pathogen that causes attaching and effacing (A/E) lesions. It shares a common virulence strategy with the clinically significant human A/E pathogens enteropathogenic E. coli (EPEC) and enterohaemorrhagic E. coli (EHEC) and is widely used to model this route of pathogenesis. We previously reported the complete genome sequence of C. rodentium ICC168, where we found that the genome displayed many characteristics of a newly evolved pathogen. In this study, through PFGE, sequencing of isolates showing variation, whole genome transcriptome analysis and examination of the mobile genetic elements, we found that, consistent with our previous hypothesis, the genome of C. rodentium is unstable as a result of repeat-mediated, large-scale genome recombination and because of active transposition of mobile genetic elements such as the prophages. We sequenced an additional C. rodentium strain, EX-33, to reveal that the reference strain ICC168 is representative of the species and that most of the inactivating mutations were common to both isolates and likely to have occurred early on in the evolution of this pathogen. We draw parallels with the evolution of other bacterial pathogens and conclude that C. rodentium is a recently evolved pathogen that may have emerged alongside the development of inbred mice as a model for human disease.
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Affiliation(s)
- Nicola K. Petty
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
- Department of Biochemistry, University of
Cambridge, Cambridge, United Kingdom
| | - Theresa Feltwell
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Derek Pickard
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Simon Clare
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Ana L. Toribio
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Maria Fookes
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Kevin Roberts
- Department of Biochemistry, University of
Cambridge, Cambridge, United Kingdom
| | - Rita Monson
- Department of Biochemistry, University of
Cambridge, Cambridge, United Kingdom
| | - Satheesh Nair
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Robert A. Kingsley
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Richard Bulgin
- Centre for Molecular Microbiology and
Infection, Division of Cell and Molecular Biology, Imperial College London,
London, United Kingdom
| | - Siouxsie Wiles
- Centre for Molecular Microbiology and
Infection, Division of Cell and Molecular Biology, Imperial College London,
London, United Kingdom
| | - David Goulding
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Thomas Keane
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Craig Corton
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Nicola Lennard
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - David Harris
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - David Willey
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Richard Rance
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Lu Yu
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Jyoti S. Choudhary
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Carol Churcher
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Michael A. Quail
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Julian Parkhill
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Gad Frankel
- Centre for Molecular Microbiology and
Infection, Division of Cell and Molecular Biology, Imperial College London,
London, United Kingdom
| | - Gordon Dougan
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | | | - Nicholas R. Thomson
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
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Barrow PA, Neto OCF. Pullorum disease and fowl typhoid—new thoughts on old diseases: a review. Avian Pathol 2011; 40:1-13. [DOI: 10.1080/03079457.2010.542575] [Citation(s) in RCA: 167] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Trombert AN, Berrocal L, Fuentes JA, Mora GC. S. Typhimurium sseJ gene decreases the S. Typhi cytotoxicity toward cultured epithelial cells. BMC Microbiol 2010; 10:312. [PMID: 21138562 PMCID: PMC3004891 DOI: 10.1186/1471-2180-10-312] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2010] [Accepted: 12/07/2010] [Indexed: 11/25/2022] Open
Abstract
Background Salmonella enterica serovar Typhi and Typhimurium are closely related serovars as indicated by >96% DNA sequence identity between shared genes. Nevertheless, S. Typhi is a strictly human-specific pathogen causing a systemic disease, typhoid fever. In contrast, S. Typhimurium is a broad host range pathogen causing only a self-limited gastroenteritis in immunocompetent humans. We hypothesize that these differences have arisen because some genes are unique to each serovar either gained by horizontal gene transfer or by the loss of gene activity due to mutation, such as pseudogenes. S. Typhi has 5% of genes as pseudogenes, much more than S. Typhimurium which contains 1%. As a consequence, S. Typhi lacks several protein effectors implicated in invasion, proliferation and/or translocation by the type III secretion system that are fully functional proteins in S. Typhimurium. SseJ, one of these effectors, corresponds to an acyltransferase/lipase that participates in SCV biogenesis in human epithelial cell lines and is needed for full virulence of S. Typhimurium. In S. Typhi, sseJ is a pseudogene. Therefore, we suggest that sseJ inactivation in S. Typhi has an important role in the development of the systemic infection. Results We investigated whether the S. Typhi trans-complemented with the functional sseJ gene from S. Typhimurium (STM) affects the cytotoxicity toward cultured cell lines. It was found that S. Typhi harbouring sseJSTM presents a similar cytotoxicity level and intracellular retention/proliferation of cultured epithelial cells (HT-29 or HEp-2) as wild type S. Typhimurium. These phenotypes are significantly different from wild type S. Typhi Conclusions Based on our results we conclude that the mutation that inactivate the sseJ gene in S. Typhi resulted in evident changes in the behaviour of bacteria in contact with eukaryotic cells, plausibly contributing to the S. Typhi adaptation to the systemic infection in humans.
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Affiliation(s)
- A Nicole Trombert
- Laboratorio de Microbiologia, Facultad de Ciencias Biologicas y Facultad de Medicina, Universidad Andres Bello, Santiago, Chile
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26
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Matthews TD, Edwards R, Maloy S. Chromosomal rearrangements formed by rrn recombination do not improve replichore balance in host-specific Salmonella enterica serovars. PLoS One 2010; 5:e13503. [PMID: 20976060 PMCID: PMC2957434 DOI: 10.1371/journal.pone.0013503] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Accepted: 09/23/2010] [Indexed: 01/16/2023] Open
Abstract
Background Most of the ∼2,600 serovars of Salmonella enterica have a broad host range as well as a conserved gene order. In contrast, some Salmonella serovars are host-specific and frequently exhibit large chromosomal rearrangements from recombination between rrn operons. One hypothesis explaining these rearrangements suggests that replichore imbalance introduced from horizontal transfer of pathogenicity islands and prophages drives chromosomal rearrangements in an attempt to improve balance. Methodology/Principal Findings This hypothesis was directly tested by comparing the naturally-occurring chromosomal arrangement types to the theoretically possible arrangement types, and estimating their replichore balance using a calculator. In addition to previously characterized strains belonging to host-specific serovars, the arrangement types of 22 serovar Gallinarum strains was also determined. Only 48 out of 1,440 possible arrangement types were identified in 212 host-specific strains. While the replichores of most naturally-occurring arrangement types were well-balanced, most theoretical arrangement types had imbalanced replichores. Furthermore, the most common types of rearrangements did not change replichore balance. Conclusions/Significance The results did not support the hypothesis that replichore imbalance causes these rearrangements, and suggest that the rearrangements could be explained by aspects of a host-specific lifestyle.
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Affiliation(s)
- T. David Matthews
- Center for Microbial Sciences, Department of Biology, San Diego State University, San Diego, California, United States of America
| | - Robert Edwards
- Center for Microbial Sciences, Department of Biology, San Diego State University, San Diego, California, United States of America
- Department of Computer Science, San Diego State University, San Diego, California, United States of America
- Mathematics and Computer Science Division, Argonne National Laboratory, Argonne, Illinois, United States of America
| | - Stanley Maloy
- Center for Microbial Sciences, Department of Biology, San Diego State University, San Diego, California, United States of America
- * E-mail:
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27
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Winter SE, Winter MG, Godinez I, Yang HJ, Rüssmann H, Andrews-Polymenis HL, Bäumler AJ. A rapid change in virulence gene expression during the transition from the intestinal lumen into tissue promotes systemic dissemination of Salmonella. PLoS Pathog 2010; 6:e1001060. [PMID: 20808848 PMCID: PMC2924370 DOI: 10.1371/journal.ppat.1001060] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Accepted: 07/22/2010] [Indexed: 12/12/2022] Open
Abstract
Bacterial pathogens causing systemic disease commonly evolve from organisms associated with localized infections but differ from their close relatives in their ability to overcome mucosal barriers by mechanisms that remain incompletely understood. Here we investigated whether acquisition of a regulatory gene, tviA, contributed to the ability of Salmonella enterica serotype Typhi to disseminate from the intestine to systemic sites of infection during typhoid fever. To study the consequences of acquiring a new regulator by horizontal gene transfer, tviA was introduced into the chromosome of S. enterica serotype Typhimurium, a closely related pathogen causing a localized gastrointestinal infection in immunocompetent individuals. TviA repressed expression of flagellin, a pathogen associated molecular pattern (PAMP), when bacteria were grown at osmotic conditions encountered in tissue, but not at higher osmolarity present in the intestinal lumen. TviA-mediated flagellin repression enabled bacteria to evade sentinel functions of human model epithelia and resulted in increased bacterial dissemination to the spleen in a chicken model. Collectively, our data point to PAMP repression as a novel pathogenic mechanism to overcome the mucosal barrier through innate immune evasion.
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Affiliation(s)
- Sebastian E. Winter
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, California, United States of America
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität München, München, Germany
| | - Maria G. Winter
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, California, United States of America
| | - Ivan Godinez
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, California, United States of America
| | - Hee-Jeong Yang
- Department of Microbial and Molecular Pathogenesis, College of Medicine, Texas A&M University System Health Science Center, College Station, Texas, United States of America
| | - Holger Rüssmann
- Max von Pettenkofer-Institut für Hygiene und Medizinische Mikrobiologie, Ludwig-Maximilians-Universität München, München, Germany
- HELIOS Klinikum Emil von Behring, Institut für Mikrobiologie, Immunologie und Laboratoriumsmedizin, Berlin, Germany
| | - Helene L. Andrews-Polymenis
- Department of Microbial and Molecular Pathogenesis, College of Medicine, Texas A&M University System Health Science Center, College Station, Texas, United States of America
| | - Andreas J. Bäumler
- Department of Medical Microbiology and Immunology, School of Medicine, University of California at Davis, Davis, California, United States of America
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Berchieri A, Murphy CK, Marston K, Barrow PA. Observations on the persistence and vertical transmission ofSalmonella entericaserovars Pullorum and Gallinarum in chickens: Effect of bacterial and host genetic background. Avian Pathol 2010; 30:221-31. [DOI: 10.1080/03079450120054631] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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Lim H, Choi K, Mandal P, Baatartsog O, Lee C, Lee J, Kim H. Transcriptional Profiling of Spleen Lymphocyte in Fowl Typhoid of Broilers. ACTA ACUST UNITED AC 2009. [DOI: 10.3923/ajava.2009.66.75] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Pullinger GD, Dziva F, Charleston B, Wallis TS, Stevens MP. Identification of Salmonella enterica serovar Dublin-specific sequences by subtractive hybridization and analysis of their role in intestinal colonization and systemic translocation in cattle. Infect Immun 2008; 76:5310-21. [PMID: 18794283 PMCID: PMC2573319 DOI: 10.1128/iai.00960-08] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Revised: 08/16/2008] [Accepted: 09/04/2008] [Indexed: 11/20/2022] Open
Abstract
Salmonella enterica serovar Dublin is a host-restricted serovar associated with typhoidal disease in cattle. In contrast, the fowl-associated serovar S. enterica serovar Gallinarum is avirulent in calves, yet it invades ileal mucosa and induces enteritis at levels comparable to those induced by S. enterica serovar Dublin. Suppression subtractive hybridization was employed to identify S. enterica serovar Dublin strain SD3246 genes absent from S. enterica serovar Gallinarum strain SG9. Forty-one S. enterica serovar Dublin fragments were cloned and sequenced. Among these, 24 mobile-element-associated genes were identified, and 12 clones exhibited similarity with sequences of known or predicted function in other serovars. Three S. enterica serovar Dublin-specific regions were homologous to regions from the genome of Enterobacter sp. strain 638. Sequencing of fragments adjacent to these three sequences revealed the presence of a 21-kb genomic island, designated S. enterica serovar Dublin island 1 (SDI-1). PCR analysis and Southern blotting showed that SDI-1 is highly conserved within S. enterica serovar Dublin isolates but rarely found in other serovars. To probe the role of genes identified by subtractive hybridization in vivo, 24 signature-tagged S. enterica serovar Dublin SD3246 mutants lacking loci not present in Salmonella serovar Gallinarum SG9 were created and screened by oral challenge of cattle. Though attenuation of tagged SG9 and SD3246 Salmonella pathogenicity island-1 (SPI-1) and SPI-2 mutant strains was detected, no obvious defects of these 24 mutants were detected. Subsequently, a DeltaSDI-1 mutant was found to exhibit weak but significant attenuation compared with the parent strain in coinfection of calves. SDI-1 mutation did not impair invasion, intramacrophage survival, or virulence in mice, implying that SDI-1 does not influence fitness per se and may act in a host-specific manner.
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Affiliation(s)
- Gillian D Pullinger
- Division of Microbiology, Institute for Animal Health, Compton, Berkshire RG20 7NN, United Kingdom
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31
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Hong Y, Liu T, Lee MD, Hofacre CL, Maier M, White DG, Ayers S, Wang L, Berghaus R, Maurer JJ. Rapid screening of Salmonella enterica serovars Enteritidis, Hadar, Heidelberg and Typhimurium using a serologically-correlative allelotyping PCR targeting the O and H antigen alleles. BMC Microbiol 2008; 8:178. [PMID: 18845003 PMCID: PMC2577679 DOI: 10.1186/1471-2180-8-178] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Accepted: 10/09/2008] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Classical Salmonella serotyping is an expensive and time consuming process that requires implementing a battery of O and H antisera to detect 2,541 different Salmonella enterica serovars. For these reasons, we developed a rapid multiplex polymerase chain reaction (PCR)-based typing scheme to screen for the prevalent S. enterica serovars Enteritidis, Hadar, Heidelberg, and Typhimurium. RESULTS By analyzing the nucleotide sequences of the genes for O-antigen biosynthesis including wba operon and the central variable regions of the H1 and H2 flagellin genes in Salmonella, designated PCR primers for four multiplex PCR reactions were used to detect and differentiate Salmonella serogroups A/D1, B, C1, C2, or E1; H1 antigen types i, g, m, r or z10; and H2 antigen complexes, I: 1,2; 1,5; 1,6; 1,7 or II: e,n,x; e,n,z15. Through the detection of these antigen gene allele combinations, we were able to distinguish among S. enterica serovars Enteritidis, Hadar, Heidelberg, and Typhimurium. The assays were useful in identifying Salmonella with O and H antigen gene alleles representing 43 distinct serovars. While the H2 multiplex could discriminate between unrelated H2 antigens, the PCR could not discern differences within the antigen complexes, 1,2; 1,5; 1,6; 1,7 or e,n,x; e,n,z15, requiring a final confirmatory PCR test in the final serovar reporting of S. enterica. CONCLUSION Multiplex PCR assays for detecting specific O and H antigen gene alleles can be a rapid and cost-effective alternative approach to classical serotyping for presumptive identification of S. enterica serovars Enteritidis, Hadar, Heidelberg, and Typhimurium.
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Affiliation(s)
- Yang Hong
- Department of Population Health, The University of Georgia, Athens, GA 30602, USA
- Department of Infectious Diseases, The University of Georgia, Athens, GA, USA
| | - Tongrui Liu
- Department of Population Health, The University of Georgia, Athens, GA 30602, USA
- USDA ARS, Russell Research Center, 950 College Station road, Athens, GA 30605. T. Liu- Emory University, 1701 Uppergate Drive, Atlanta, GA 30322, USA
| | - Margie D Lee
- Department of Population Health, The University of Georgia, Athens, GA 30602, USA
- Center for Food Safety and Quality Enhancement, The University of Georgia, Griffin, GA 30223, USA
| | - Charles L Hofacre
- Department of Population Health, The University of Georgia, Athens, GA 30602, USA
- Center for Food Safety and Quality Enhancement, The University of Georgia, Griffin, GA 30223, USA
| | - Marie Maier
- Department of Population Health, The University of Georgia, Athens, GA 30602, USA
- USDA ARS, Russell Research Center, 950 College Station road, Athens, GA 30605. T. Liu- Emory University, 1701 Uppergate Drive, Atlanta, GA 30322, USA
| | - David G White
- Center for Veterinary Medicine, U.S. Food and Drug Administration, Laurel, MD 20708, USA
| | - Sherry Ayers
- Center for Veterinary Medicine, U.S. Food and Drug Administration, Laurel, MD 20708, USA
| | - Lihua Wang
- Department of Statistics, The University of Georgia, Athens, GA 30602, USA
| | - Roy Berghaus
- Department of Population Health, The University of Georgia, Athens, GA 30602, USA
| | - John J Maurer
- Department of Population Health, The University of Georgia, Athens, GA 30602, USA
- Center for Food Safety and Quality Enhancement, The University of Georgia, Griffin, GA 30223, USA
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Thomson NR, Clayton DJ, Windhorst D, Vernikos G, Davidson S, Churcher C, Quail MA, Stevens M, Jones MA, Watson M, Barron A, Layton A, Pickard D, Kingsley RA, Bignell A, Clark L, Harris B, Ormond D, Abdellah Z, Brooks K, Cherevach I, Chillingworth T, Woodward J, Norberczak H, Lord A, Arrowsmith C, Jagels K, Moule S, Mungall K, Sanders M, Whitehead S, Chabalgoity JA, Maskell D, Humphrey T, Roberts M, Barrow PA, Dougan G, Parkhill J. Comparative genome analysis of Salmonella Enteritidis PT4 and Salmonella Gallinarum 287/91 provides insights into evolutionary and host adaptation pathways. Genome Res 2008; 18:1624-37. [PMID: 18583645 DOI: 10.1101/gr.077404.108] [Citation(s) in RCA: 323] [Impact Index Per Article: 20.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We have determined the complete genome sequences of a host-promiscuous Salmonella enterica serovar Enteritidis PT4 isolate P125109 and a chicken-restricted Salmonella enterica serovar Gallinarum isolate 287/91. Genome comparisons between these and other Salmonella isolates indicate that S. Gallinarum 287/91 is a recently evolved descendent of S. Enteritidis. Significantly, the genome of S. Gallinarum has undergone extensive degradation through deletion and pseudogene formation. Comparison of the pseudogenes in S. Gallinarum with those identified previously in other host-adapted bacteria reveals the loss of many common functional traits and provides insights into possible mechanisms of host and tissue adaptation. We propose that experimental analysis in chickens and mice of S. Enteritidis-harboring mutations in functional homologs of the pseudogenes present in S. Gallinarum could provide an experimentally tractable route toward unraveling the genetic basis of host adaptation in S. enterica.
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Affiliation(s)
- Nicholas R Thomson
- The Pathogen Sequencing Unit, The Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, United Kingdom.
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McQuiston JR, Fields PI, Tauxe RV, Logsdon JM. Do Salmonella carry spare tyres? Trends Microbiol 2008; 16:142-8. [PMID: 18375124 DOI: 10.1016/j.tim.2008.01.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2008] [Revised: 01/18/2008] [Accepted: 01/18/2008] [Indexed: 11/30/2022]
Abstract
Salmonellae are enterobacteria that have the unique ability to change their flagellar composition by switching expression among two loci that encode the major flagellin protein. This property is not available to all Salmonella, but is species, subspecies and serotype specific. Curiously, the subsequent loss of the second locus in some lineages of Salmonella has apparently been tolerated and, indeed, has led to considerable success for some lineages. We discuss here an evolutionary model for maintenance of this unique function and the possible evolutionary advantages of loss or preservation of this mechanism. We hypothesize that the second flagellin locus is a genetic 'spare tyre' used in particular environmental circumstances.
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Affiliation(s)
- John R McQuiston
- Graduate Program in Population Biology, Ecology and Evolution, Emory University, Atlanta, GA 30322, USA
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Kim HJ, Park SH, Kim HY. Comparison of Salmonella enterica serovar Typhimurium LT2 and non-LT2 salmonella genomic sequences, and genotyping of salmonellae by using PCR. Appl Environ Microbiol 2006; 72:6142-51. [PMID: 16957240 PMCID: PMC1563604 DOI: 10.1128/aem.00138-06] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Genes of Salmonella enterica serovar Typhimurium LT2 expected to be specifically present in Salmonella were selected using the Basic Local Alignment Search Tool (BLAST) program. The 152 selected genes were compared with 11 genomic sequences of Salmonella serovars, including Salmonella enterica subsp. I and IIIb and Salmonella bongori (V), and were clustered into 17 groups by their comparison patterns. A total of 38 primer pairs were constructed to represent each of the 17 groups, and PCR was performed with various Salmonella subspecies including Salmonella enterica subsp. I, II, IIIa, IIIb, IV, VI, and V to evaluate a comprehensive DNA-based scheme for identification of Salmonella subspecies and the major disease-causing Salmonella serovars. Analysis of PCR results showed that Salmonella enterica subsp. I was critically divided from other subspecies, and Salmonella strains belonging to S. enterica subsp. I were clustered based on their serovars. In addition, genotypic relationships within S. enterica subsp. I by PCR results were investigated. Also, Salmonella signature genes, Salmonella enterica serovar Typhimurium signature genes, and Salmonella enterica subsp. I signature genes were demonstrated based on their PCR results. The described PCR method suggests a rapid and convenient method for identification of Salmonella serovars that can be used by nonspecialized laboratories. Genome sequence comparison can be a useful tool in epidemiologic and taxonomic studies of Salmonella.
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Affiliation(s)
- Hyun-Joong Kim
- Institute of Life Sciences and Resources and Graduate School of Biotechnology, Kyung Hee University, Suwon 449-701, Korea.
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35
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Kim HJ, Park SH, Lee TH, Nahm BH, Chung YH, Seo KH, Kim HY. Identification of Salmonella enterica serovar Typhimurium using specific PCR primers obtained by comparative genomics in Salmonella serovars. J Food Prot 2006; 69:1653-61. [PMID: 16865900 DOI: 10.4315/0362-028x-69.7.1653] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Salmonella enterica serovar Typhimurium is a major foodborne pathogen throughout the world. Until now, the specific target genes for the detection and identification of serovar Typhimurium have not been developed. To determine the specific probes for serovar Typhimurium, the genes of serovar Typhimurium LT2 that were expected to be unique were selected with the BLAST (Basic Local Alignment Search Tool) program within GenBank. The selected genes were compared with 11 genomic sequences of various Salmonella serovars by BLAST. Of these selected genes, 10 were expected to be specific to serovar Typhimurium and were not related to virulence factor genes of Salmonella pathogenicity island or to genes of the O and H antigens of Salmonella. Primers for the 10 selected genes were constructed, and PCRs were evaluated with various genomic DNAs of Salmonella and non-Salmonella strains for the specific identification of Salmonella serovar Typhimurium. Among all the primer sets for the 10 genes, STM4497 showed the highest degree of specificity to serovar Typhimurium. In this study, a specific primer set for Salmonella serovar Typhimurium was developed on the basis of the comparison of genomic sequences between Salmonella serovars and was validated with PCR. This method of comparative genomics to select target genes or sequences can be applied to the specific detection of microorganisms.
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Affiliation(s)
- H J Kim
- Institute of Life Sciences and Resources and Graduate School of Biotechnology, Kyung Hee University, Suwon, 449-701, Korea
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36
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McMeechan A, Lovell MA, Cogan TA, Marston KL, Humphrey TJ, Barrow PA. Glycogen production by different Salmonella enterica serotypes: contribution of functional glgC to virulence, intestinal colonization and environmental survival. MICROBIOLOGY-SGM 2006; 151:3969-3977. [PMID: 16339941 DOI: 10.1099/mic.0.28292-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In enteric bacteria, the contribution of endogenous energy sources to survival both inside and outside the host is poorly understood. The contribution of glycogen production to the virulence, colonization and environmental survival of different Salmonella enterica serotypes was assessed. Of 19 serotypes (339 strains) tested for glycogen production, 17 (256 strains) were positive. The avian-specific serovars S. Gallinarum (62 strains) and S. Pullorum (21 strains) did not produce glycogen. The sequence of glgC in three S. Gallinarum strains tested revealed an identical deletion of 11 consecutive bases, which was not present in S. Pullorum, and a CCC insertion after position 597. Transduction of S. Gallinarum and S. Pullorum to a glycogen-positive phenotype did not change the ability to colonize the intestine or affect virulence in the chicken. Mortality rates in chickens following oral infection with a S. Typhimurium glycogen mutant (glgC : : km) were not significantly reduced, although colonization of the intestine was reduced over the first 4 weeks of the trial. Growth and yield of the glgC : : km mutant were comparable to the parent. The glgC mutant survived less well in faeces and in water at 4 degrees C when the strain was grown in LB broth containing 0.5 % glucose, and in saline it died off more rapidly after 7 days. The data suggest that glycogen has a complex but comparatively minor role in virulence and colonization, but a more significant role in survival.
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Affiliation(s)
- Alisdair McMeechan
- School of Clinical Veterinary Science, University of Bristol, Langford House, Langford, Bristol BS40 5DU, UK
| | - Margaret A Lovell
- Institute for Animal Health (IAH), Compton Laboratory, Compton, Newbury, Berkshire RG20 7NN, UK
| | - Tristan A Cogan
- School of Clinical Veterinary Science, University of Bristol, Langford House, Langford, Bristol BS40 5DU, UK
| | - Kerrie L Marston
- Institute for Animal Health (IAH), Compton Laboratory, Compton, Newbury, Berkshire RG20 7NN, UK
| | - Tom J Humphrey
- School of Clinical Veterinary Science, University of Bristol, Langford House, Langford, Bristol BS40 5DU, UK
| | - Paul A Barrow
- Institute for Animal Health (IAH), Compton Laboratory, Compton, Newbury, Berkshire RG20 7NN, UK
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van Asten AJAM, van Dijk JE. Distribution of "classic" virulence factors among Salmonella spp. ACTA ACUST UNITED AC 2006; 44:251-9. [PMID: 15907446 DOI: 10.1016/j.femsim.2005.02.002] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2004] [Revised: 01/27/2005] [Accepted: 02/02/2005] [Indexed: 11/16/2022]
Abstract
Whether an infection with Salmonella spp. leads to a disease largely depends on the virulence of the strain and the constitution of the host. The virulence of the strain is determined by so-called virulence factors. Whereas a number of virulence factors of Salmonella have been identified only recently, others have been studied for decades. These latter virulence factors i.e., virulence-plasmids, toxins, fimbriae and flagella are therefore referred to as "classic" virulence factors. Here we present an overview on the distribution of (genes coding for) these virulence factors among Salmonella spp. The pathogenicity islands of Salmonella are also reviewed, all be it briefly, since they contain a major part of the virulence genes.
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Affiliation(s)
- Alphons J A M van Asten
- Department of Pathobiology, Division Pathology, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, P.O. Box 80.158, 3508TD, Utrecht, The Netherlands.
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38
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Wallis TS, Barrow PA. Salmonella Epidemiology and Pathogenesis in Food-Producing Animals. EcoSal Plus 2005; 1. [PMID: 26443521 DOI: 10.1128/ecosalplus.8.6.2.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2005] [Indexed: 06/05/2023]
Abstract
This review reviews the pathogenesis of different phases of Salmonella infections. The nature of Salmonella infections in several domesticated animal species is described to highlight differences in the epidemiology and pathogenesis of salmonellosis in different hosts. The biology of Salmonella serovar host specificity is discussed in the context of our current understanding of the molecular basis of pathogenesis and the potential impact of different virulence determinants on Salmonella natural history. The ability to colonize the intestine, as evidenced by the shedding of relatively large numbers of bacteria in the feces over a long period, is shared unequally by Salmonella serovars. Studies probing the molecular basis of Salmonella intestinal colonization have been carried out by screening random transposon mutant banks of serovar Typhimurium in a range of avian and mammalian species. It is becoming increasingly clear that Salmonella pathogenicity island 2 (SPI2) is a major virulence factor during infection of food-producing animals, including cattle and poultry. The prevalence of Salmonella serovars in domestic fowl varies in different countries and with time. Although chickens are the natural hosts of serovars Gallinarum and Pullorum, natural outbreaks caused by these serovars in turkeys, guinea fowl, and other avian species have been described. There are two possible explanations to account for the apparent host specificity of certain Salmonella serovars. Environmental factors may increase exposure of particular animal species to certain serovars. Alternatively, there are genetic differences between these serovars, which allow them to survive and/or grow in specific niches only found within ruminants or pigs.
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Affiliation(s)
- Timothy S Wallis
- Division of Microbiology, Institute for Animal Health, Compton Laboratory, Berkshire RG20 7NN, United Kingdom
| | - Paul A Barrow
- Division of Microbiology, Institute for Animal Health, Compton Laboratory, Berkshire RG20 7NN, United Kingdom
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39
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Wu KY, Liu GR, Liu WQ, Wang AQ, Zhan S, Sanderson KE, Johnston RN, Liu SL. The genome of Salmonella enterica serovar gallinarum: distinct insertions/deletions and rare rearrangements. J Bacteriol 2005; 187:4720-7. [PMID: 15995186 PMCID: PMC1169526 DOI: 10.1128/jb.187.14.4720-4727.2005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Salmonella enterica serovar Gallinarum is a fowl-adapted pathogen, causing typhoid fever in chickens. It has the same antigenic formula (1,9,12:--:--) as S. enterica serovar Pullorum, which is also adapted to fowl but causes pullorum disease (diarrhea). The close relatedness but distinct pathogeneses make this pair of fowl pathogens good models for studies of bacterial genomic evolution and the way these organisms acquired pathogenicity. To locate and characterize the genomic differences between serovar Gallinarum and other salmonellae, we constructed a physical map of serovar Gallinarum strain SARB21 by using I-CeuI, XbaI, and AvrII with pulsed-field gel electrophoresis techniques. In the 4,740-kb genome, we located two insertions and six deletions relative to the genome of S. enterica serovar Typhimurium LT2, which we used as a reference Salmonella genome. Four of the genomic regions with reduced lengths corresponded to the four prophages in the genome of serovar Typhimurium LT2, and the others contained several smaller deletions relative to serovar Typhimurium LT2, including regions containing srfJ, std, and stj and gene clusters encoding a type I restriction system in serovar Typhimurium LT2. The map also revealed some rare rearrangements, including two inversions and several translocations. Further characterization of these insertions, deletions, and rearrangements will provide new insights into the molecular basis for the specific host-pathogen interactions and mechanisms of genomic evolution to create a new pathogen.
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Affiliation(s)
- Kai-Yu Wu
- Department of Microbiology and Infectious Diseases, University of Calgary, Alberta, Canada
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40
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Imre A, Olasz F, Nagy B. Development of a PCR system for the characterisation of Salmonella flagellin genes. Acta Vet Hung 2005; 53:163-72. [PMID: 15959975 DOI: 10.1556/avet.53.2005.2.2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Analysis of flagellin genes was carried out on strains of Salmonella Typhimurium, Salmonella Hadar, Salmonella Abortusequi, Salmonella Enteritidis and Salmonella Gallinarum serovars, using a PCR system designed in this study. The purpose of these studies was to explore the flagellin genes of biphasic and monophasic Salmonellae for future targeted genetic interventions. The PCR primers were designed for two different structural genes of flagellin (fliC, fljB), for the repressor of fliC (fljA), for the operator region of fliC, and for the invertase system responsible for phase variation in Salmonella (hin, hixL, hixR). PCR analysis revealed that all of the examined genes (fliC, fliC-operator, fljB, fljA, hin, hixL, hixR) were present in all S. Typhimurium (n = 10) and S. Hadar (n = 10) strains tested. The results obtained on S. Typhimurium and S. Hadar strains confirmed their biphasic character at DNA level. However, the S. Enteritidis (n = 46) and S. Gallinarum (n = 5) strains lacked the invertase system (hin, hixL, hixR) as well as the fljA and fljB genes, while fliC and its operator were detectable. Consequently, the S. Enteritidis strains could only express fliC gene resulting in phase H1 flagellin. The examined S. Gallinarum strains were also demonstrated to have a cryptic flagellin gene (fliC). On the other hand, PCR results on S. Abortusequi (n = 2) indicated that both flagellin genes (fliC, fljB) and the whole phase variation system were present in both strains tested but only the H2 phase gene (fljB) was expressed. The phenotype of these strains could be clarified by motility test and/or by classical flagellar serology. The findings are also substantiated by the results of serovar-specific PCR for S. Typhimurium and S. Enteritidis. In conclusion, the PCR system developed in this study proved to be suitable for characterisation of Salmonella flagellin genes and confirmed serological results regarding all S. Typhimurium, S. Hadar and S. Enteritidis strains. This system could also identify cryptic flagellar genes of S. Abortusequi and S. Gallinarum.
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Affiliation(s)
- A Imre
- Veterinary Medical Research Institute of the Hungarian Academy of Sciences, H-1581 Budapest, PO Box 18, Hungary
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41
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Shah DH, Park JH, Cho MR, Kim MC, Chae JS. Allele-specific PCR method based on rfbS sequence for distinguishing Salmonella gallinarum from Salmonella pullorum: serotype-specific rfbS sequence polymorphism. J Microbiol Methods 2005; 60:169-77. [PMID: 15590091 DOI: 10.1016/j.mimet.2004.09.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2004] [Revised: 03/30/2004] [Accepted: 09/10/2004] [Indexed: 11/30/2022]
Abstract
Cloning and sequence analysis of rfbS gene identified two polymorphic nucleotides, one at position 598 (Salmonella gallinarum-specific) and other at position 237 (Salmonella pullorum-specific). Based on S. gallinarum-specific nucleotide found at position 598, an allele-specific PCR method was developed for serotype-specific detection of S. gallinarum. This PCR method was able to discriminate pure cultures of S. gallinarum from S. pullorum and other Salmonella serotypes from serogroup D in less than 3 h. Serotype-specific detection of S. gallinarum was possible in less than 24 h when the PCR was applied on the presumptive Salmonella colonies obtained after overnight incubation of selective media plates streaked with the clinical material from diseased chickens. As little as 100 pg of genomic DNA could be detected with S. gallinarum-specific primers; no PCR product was detected in non-S. gallinarum serotypes of serogroup D and other closely related non-salmonella organisms. This rfbS allele-specific amplification assay is specific, reproducible and less time consuming than the standard bacteriological methods used to detect S. gallinarum and could be an effective molecular tool for rapid definitive diagnosis of fowl typhoid in the areas of endemicity where fowl typhoid infection exists.
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Affiliation(s)
- Devendra H Shah
- Biosafety Research Institute, Department of Veterinary Internal Medicine, College of Veterinary Medicine, Chonbuk National University, Jeonbuk, Jeonju 561-756, South Korea
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42
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Touron A, Berthe T, Pawlak B, Petit F. Detection of Salmonella in environmental water and sediment by a nested-multiplex polymerase chain reaction assay. Res Microbiol 2005; 156:541-53. [PMID: 15862453 DOI: 10.1016/j.resmic.2005.01.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2004] [Revised: 12/17/2004] [Accepted: 01/05/2005] [Indexed: 11/27/2022]
Abstract
From 1995 to 2002, 53 serovars of Salmonella were isolated in the Seine estuary (France). The 3 serovars most frequently found were S. enterica serovar Typhimurium, S. enterica serovar Infantis and S. enterica serovar Virchow. A nested multiplex PCR (nm-PCR) assay was developed to detect the presence of Salmonella in estuarine water and sediment samples. The target gene used was the phase 1 flagellin fliC chromosomal gene, present in all Salmonella serovars. A set of 4 primers was first used to amplify an 890-bp sequence of the fliC gene, and then a second set of 3 primers was used for the nested PCR. The nmPCR method has been successfully tested for 28 serovars, 13 of which are of epidemiological significance. The detection limit of the assay, without any pre-enrichment step, was estimated at 1 CFU in deionized water, and at 4-5 CFU in the reaction mixture when tested on estuarine water seeded with a Salmonella strain. When the nmPCR was used together with the classical culture method in environmental samples, it gave additional positive results for 11.3% of the sediment samples and 20% of the water samples despite a high background of other bacteria. Overall, the results demonstrated that this molecular approach informed us about the contamination by Salmonella of estuarine water and sediment samples. Positive amplifications suggested the presence of Salmonella DNA and could thus provide information about a recent (culturable) or past (non-culturable, released DNA) contamination of environmental samples by this pathogenic bacteria.
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Affiliation(s)
- Aurélie Touron
- Laboratoire de Microbiologie du Froid, UPRES 2123, Groupe Biodiversité et Environnement, Faculté des Sciences, 76821 Mont Saint Aignan cedex, France.
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La Ragione RM, Cooley WA, Parmar DDG, Ainsworth HL. Attaching and effacing Escherichia coli O103:K+:H- in red-legged partridges. Vet Rec 2005; 155:397-8. [PMID: 15499813 DOI: 10.1136/vr.155.13.397] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- R M La Ragione
- Department of Food and Environmental Safety, Veterinary Laboratories Agency - Weybridge, Woodham Lane, Addlestone, Surrey KT15 3NB
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Abstract
Over the past 120 to 160 million years, the genus Salmonella has evolved into a complex group of more than 2,300 genetically and phenotypically diverse serovars. Members of this genus are able to infect a wide diversity of vertebrate and invertebrate hosts; disease manifestations in humans range from gastroenteritis to typhoid fever. The evolution of the genus Salmonella and the divergence and radiation of particular lineages within this group have resulted from selection acting on new genetic variation generated by events such as the gain, loss, and/or rearrangement of genetic material. These types of genetic events have contributed to the speciation of Salmonella from its ancestral association with cold-blood animals to a pathogen of warm-blooded hosts. Moreover, adaptive radiation due to changes in gene content within S. enterica subspecies I has impacted host specificity and aided in the selection of host-restricted, host-adapted, and non-host-adapted serovars. In addition to the genetic diversity important for the wide phenotypic heterogeneity within the genus, a subset of core Salmonella-specific genes present in all Salmonella species and serovars has been identified that may contribute to the conserved aspects of the lifestyle of this microorganism, including the ability to survive in nutrient-poor nonhost environments such as soil and water. Whole-genome comparisons of isolates differing in host range and virulence will continue to elucidate the genetic mechanisms that have contributed to the evolution and diverse ecology of the genus Salmonella.
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Torpdahl M, Ahrens P. Population structure of Salmonella investigated by amplified fragment length polymorphism. J Appl Microbiol 2004; 97:566-73. [PMID: 15281937 DOI: 10.1111/j.1365-2672.2004.02337.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIMS This study was undertaken to investigate the usefulness of amplified fragment length polymorphism (AFLP) in determining the population structure of Salmonella. METHODS AND RESULTS A total of 89 strains were subjected to AFLP analysis using the enzymes BglII and BspDI, a combination that is novel in Salmonella. Both species S. bongori and S. enterica and all subsp. of S. enterica were represented with emphasis on S. enterica subsp. enterica using a local strain collection and strains from the Salmonella Reference Collection B (SARB). The amplified fragments were used in a band-based cluster analysis. The tree resulting from the subgroup analysis clearly separated all subgroups with high bootstrap values with the species S. bongori being the most distantly related of the subgroups. The tree resulting from the analysis of the SARB collection showed that some serotypes are very clonal whereas others are highly divergent. CONCLUSIONS AFLP clearly clustered strains representing the subgroups of Salmonella together with high bootstrap values and the serotypes of subspecies enterica were divided into polyphyletic or monophyletic types corresponding well with multilocus enzyme electrophoresis (MLEE) and sequence-based studies of the population structure in Salmonella. SIGNIFICANCE AND IMPACT OF THE STUDY AFLP with the enzyme combination BglII and BspDI allows discrimination of individual strains and provides evidence for the usefulness of AFLP in studies of population structure in Salmonella.
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Affiliation(s)
- M Torpdahl
- Danish Institute for Food and Veterinary Research, Bülowsvej, Copenhagen V, Denmark.
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Abstract
After rising in the early 1980s, the number of recorded human cases of Salmonella enterica subsp. enterica in the UK has fallen in the last 5 years, with a particular decline in cases of infection with serovar Enteritidis. This decline has been concomitant with the introduction of vaccination of egg-laying hens against serovar Enteritidis. It is likely that other factors such as improved biosecurity in egg-laying flocks, a build-up of immunity in other animals and the rise in the number of livestock infections with host-adapted serovars of Salmonella have also played a part in this decline. Although human Salmonella cases are currently at their lowest level since 1987, it is important to remember that the reasons for the dominance of Enteritidis in human infection are poorly understood and it is possible that other serovars could share similar properties and the eradication of Enteritidis may leave a niche for them to fill.
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Affiliation(s)
- T A Cogan
- PHLS Food Microbiology Collaborating Laboratory, University of Bristol, Bristol BS40 5DU, UK
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Chan K, Baker S, Kim CC, Detweiler CS, Dougan G, Falkow S. Genomic comparison of Salmonella enterica serovars and Salmonella bongori by use of an S. enterica serovar typhimurium DNA microarray. J Bacteriol 2003; 185:553-63. [PMID: 12511502 PMCID: PMC145314 DOI: 10.1128/jb.185.2.553-563.2003] [Citation(s) in RCA: 185] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The genus Salmonella consists of over 2,200 serovars that differ in their host range and ability to cause disease despite their close genetic relatedness. The genetic factors that influence each serovar's level of host adaptation, how they evolved or were acquired, their influence on the evolution of each serovar, and the phylogenic relationships between the serovars are of great interest as they provide insight into the mechanisms behind these differences in host range and disease progression. We have used an Salmonella enterica serovar Typhimurium spotted DNA microarray to perform genomic hybridizations of various serovars and strains of both S. enterica (subspecies I and IIIa) and Salmonella bongori to gain insight into the genetic organization of the serovars. Our results are generally consistent with previously published DNA association and multilocus enzyme electrophoresis data. Our findings also reveal novel information. We observe a more distant relationship of serovar Arizona (subspecies IIIa) from the subspecies I serovars than previously measured. We also observe variability in the Arizona SPI-2 pathogenicity island, indicating that it has evolved in a manner distinct from the other serovars. In addition, we identify shared genetic features of S. enterica serovars Typhi, Paratyphi A, and Sendai that parallel their unique ability to cause enteric fever in humans. Therefore, whereas the taxonomic organization of Salmonella into serogroups provides a good first approximation of genetic relatedness, we show that it does not account for genomic changes that contribute to a serovar's degree of host adaptation.
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Affiliation(s)
- Kaman Chan
- Department of Microbiology and Immunology, Stanford University School of Medicine, California 94305-5124, USA.
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Parker CT, Harmon B, Guard-Petter J. Mitigation of avian reproductive tract function by Salmonella enteritidis producing high-molecular-mass lipopolysaccharide. Environ Microbiol 2002; 4:538-45. [PMID: 12220411 DOI: 10.1046/j.1462-2920.2002.00333.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Hens were infected with a wild-type Salmonella enteritidis and its wzz mutant, which lacked the ability to make high-molecular-mass lipopolysaccharide (LPS), in six experiments paired by dosage and route of exposure. Involution of the reproductive tract occurred in 86% of hens that were injected subcutaneously with 108 cfu of the wild-type strain, but none did so when injected with the wzz mutant. In spite of the lack of a specific effect on the reproductive tract, infection of hens with the mutant produced more contaminated eggs and heterophilic granulomas in developing ova (yolks) than wild type; thus, overall, the mutant appeared to be more virulent except after intravenous injection. The mutant also decreased shell quality more often than wild type, regardless of dosage or route of infection. These results suggest that egg-contaminating Salmonella enteritidis that produces high-molecular-mass LPS mitigates signs of illness in poultry by altering the response of the avian reproductive tract to infection, but without altering the incidence of egg contamination following bacteraemia. Further research is warranted to determine whether analyses of shell quality might aid in identification of flocks at risk of producing contaminated eggs.
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Affiliation(s)
- Craig T Parker
- United States Department of Agriculture, Western Regional Research Center, Albany, CA 947101, USA
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Kingsley RA, Bäumler AJ. Pathogenicity Islands and Host Adaptation of Salmonella Serovars. Curr Top Microbiol Immunol 2002. [DOI: 10.1007/978-3-642-56031-6_5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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50
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Kingsley RA, Bäumler AJ. Pathogenicity Islands and Host Adaptation of Salmonella Serovars. Curr Top Microbiol Immunol 2002. [DOI: 10.1007/978-3-662-09217-0_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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