1
|
Campos IC, Vilela FP, Saraiva MDMS, Junior AB, Falcão JP. Insights into the global genomic features of Salmonella enterica serovar Gallinarum biovars Gallinarum and Pullorum. J Appl Microbiol 2024; 135:lxae217. [PMID: 39165105 DOI: 10.1093/jambio/lxae217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Revised: 07/02/2024] [Accepted: 08/19/2024] [Indexed: 08/22/2024]
Abstract
AIMS Characterize global genomic features of 86 genomes of Salmonella Gallinarum (SG) and Pullorum (SP), which are important pathogens causing systemic infections in poultry. METHODS AND RESULTS All genomes harbored efflux pump encoding gene mdsA and gold tolerance genes golS and golT. Aminoglycoside (aac(6')-Ib, aadA5, aph(6)-Id, aph(3'')-Ib, ant(2'')-Ia), beta-lactam (blaTEM-1, blaTEM-135), efflux pump (mdsB), fosfomycin (fosA3), sulfonamide (sul1, sul2), tetracycline [tet(A)], trimethoprim (dfrA17), acid (asr), and disinfectant (qacEdelta1) resistance genes, gyrA, gyrB, and parC quinolone resistance point mutations, and mercury tolerance genes (mer) were found in different frequencies. Additionally, 310 virulence genes, pathogenicity islands (including SPI-1, 2, 3, 4, 5, 6, 9, 10, 12, 13, and 14), plasmids [IncFII(S), ColpVC, IncX1, IncN, IncX2, and IncC], and prophages (Fels-2, ST104, 500465-1, pro483, Gifsy-2, 103 203_sal5, Fels-1, RE-2010, vB_SenS-Ent2, and L-413C) were detected. MLST showed biovar-specific sequence types, and core genome MLST showed country-specific and global-related clusters. CONCLUSION SG and SP global strains carry many virulence factors and important antimicrobial resistance genes. The diverse plasmids and prophages suggest genetic variability. MLST and cgMLST differentiated biovars and showed profiles occurring locally or worldwide.
Collapse
Affiliation(s)
- Isabela C Campos
- Department of Pathology, Reproduction and One Health, School of Agriculture and Veterinarian Sciences, São Paulo State University, Via de Acesso Prof. Paulo Donato Castellane, s/n, CEP 14884-900 Jaboticabal, SP, Brazil
| | - Felipe Pinheiro Vilela
- Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. Prof. Dr. Zeferino Vaz, s/n, Campus da USP, CEP 14040-903 Ribeirão Preto, SP, Brazil
| | - Mauro de M S Saraiva
- Department of Pathology, Reproduction and One Health, School of Agriculture and Veterinarian Sciences, São Paulo State University, Via de Acesso Prof. Paulo Donato Castellane, s/n, CEP 14884-900 Jaboticabal, SP, Brazil
| | - Angelo Berchieri Junior
- Department of Pathology, Reproduction and One Health, School of Agriculture and Veterinarian Sciences, São Paulo State University, Via de Acesso Prof. Paulo Donato Castellane, s/n, CEP 14884-900 Jaboticabal, SP, Brazil
| | - Juliana Pfrimer Falcão
- Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Av. Prof. Dr. Zeferino Vaz, s/n, Campus da USP, CEP 14040-903 Ribeirão Preto, SP, Brazil
| |
Collapse
|
2
|
Oke MT, D’Costa VM. Functional Divergence of the Paralog Salmonella Effector Proteins SopD and SopD2 and Their Contributions to Infection. Int J Mol Sci 2024; 25:4191. [PMID: 38673776 PMCID: PMC11050076 DOI: 10.3390/ijms25084191] [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: 02/27/2024] [Revised: 04/05/2024] [Accepted: 04/05/2024] [Indexed: 04/28/2024] Open
Abstract
Salmonella enterica is a leading cause of bacterial food-borne illness in humans and is responsible for millions of cases annually. A critical strategy for the survival of this pathogen is the translocation of bacterial virulence factors termed effectors into host cells, which primarily function via protein-protein interactions with host proteins. The Salmonella genome encodes several paralogous effectors believed to have arisen from duplication events throughout the course of evolution. These paralogs can share structural similarities and enzymatic activities but have also demonstrated divergence in host cell targets or interaction partners and contributions to the intracellular lifecycle of Salmonella. The paralog effectors SopD and SopD2 share 63% amino acid sequence similarity and extensive structural homology yet have demonstrated divergence in secretion kinetics, intracellular localization, host targets, and roles in infection. SopD and SopD2 target host Rab GTPases, which represent critical regulators of intracellular trafficking that mediate diverse cellular functions. While SopD and SopD2 both manipulate Rab function, these paralogs display differences in Rab specificity, and the effectors have also evolved multiple mechanisms of action for GTPase manipulation. Here, we highlight this intriguing pair of paralog effectors in the context of host-pathogen interactions and discuss how this research has presented valuable insights into effector evolution.
Collapse
Affiliation(s)
- Mosopefoluwa T. Oke
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Centre for Infection, Immunity and Inflammation, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Vanessa M. D’Costa
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Centre for Infection, Immunity and Inflammation, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| |
Collapse
|
3
|
Oslan SNH, Yusof NY, Lim SJ, Ahmad NH. Rapid and sensitive detection of Salmonella in agro-Food and environmental samples: A review of advances in rapid tests and biosensors. J Microbiol Methods 2024; 219:106897. [PMID: 38342249 DOI: 10.1016/j.mimet.2024.106897] [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: 07/19/2023] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 02/13/2024]
Abstract
Salmonella is as an intracellular bacterium, causing many human fatalities when the host-specific serotypes reach the host gastrointestinal tract. Nontyphoidal Salmonella are responsible for numerous foodborne outbreaks and product recalls worldwide whereas typhoidal Salmonella are responsible for Typhoid fever cases in developing countries. Yet, Salmonella-related foodborne disease outbreaks through its food and water contaminations have urged the advancement of rapid and sensitive Salmonella-detecting methods for public health protection. While conventional detection methods are time-consuming and ineffective for monitoring foodstuffs with short shelf lives, advances in microbiology, molecular biology and biosensor methods have hastened the detection. Here, the review discusses Salmonella pathogenic mechanisms and its detection technology advancements (fundamental concepts, features, implementations, efficiency, benefits, limitations and prospects). The time-efficiency of each rapid test method is discussed in relation to their limit of detections (LODs) and time required from sample enrichment to final data analysis. Importantly, the matrix effects (LODs and sample enrichments) were compared within the methods to potentially speculate Salmonella detection from environmental, clinical or food matrices using certain techniques. Although biotechnological advancements have led to various time-efficient Salmonella-detecting techniques, one should consider the usage of sophisticated equipment to run the analysis by moderately to highly trained personnel. Ultimately, a fast, accurate Salmonella screening that is readily executed by untrained personnels from various matrices, is desired for public health procurement.
Collapse
Affiliation(s)
- Siti Nur Hazwani Oslan
- Faculty of Food Science and Nutrition, Universiti Malaysia Sabah, Jalan UMS, Kota Kinabalu 88400, Sabah, Malaysia; Food Security Research Laboratory, Faculty of Food Science and Nutrition, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia.
| | - Nik Yusnoraini Yusof
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Si Jie Lim
- Enzyme Technology and X-ray Crystallography Laboratory, VacBio 5, Institute of Bioscience, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; Enzyme and Microbial Technology (EMTech) Research Centre, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| | - Nurul Hawa Ahmad
- Department of Food Science, Faculty of Food Science and Technology, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| |
Collapse
|
4
|
Farhat M, Khayi S, Berrada J, Mouahid M, Ameur N, El-Adawy H, Fellahi S. Salmonella enterica Serovar Gallinarum Biovars Pullorum and Gallinarum in Poultry: Review of Pathogenesis, Antibiotic Resistance, Diagnosis and Control in the Genomic Era. Antibiotics (Basel) 2023; 13:23. [PMID: 38247582 PMCID: PMC10812584 DOI: 10.3390/antibiotics13010023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 11/18/2023] [Accepted: 12/12/2023] [Indexed: 01/23/2024] Open
Abstract
Salmonella enterica subsp. enterica serovar Gallinarum (SG) has two distinct biovars, Pullorum and Gallinarum. They are bacterial pathogens that exhibit host specificity for poultry and aquatic birds, causing severe systemic diseases known as fowl typhoid (FT) and Pullorum disease (PD), respectively. The virulence mechanisms of biovars Gallinarum and Pullorum are multifactorial, involving a variety of genes and pathways that contribute to their pathogenicity. In addition, these serovars have developed resistance to various antimicrobial agents, leading to the emergence of multidrug-resistant strains. Due to their economic and public health significance, rapid and accurate diagnosis is crucial for effective control and prevention of these diseases. Conventional methods, such as bacterial culture and serological tests, have been used for screening and diagnosis. However, molecular-based methods are becoming increasingly important due to their rapidity, high sensitivity, and specificity, opening new horizons for the development of innovative approaches to control FT and PD. The aim of this review is to highlight the current state of knowledge on biovars Gallinarum and Pullorum, emphasizing the importance of continued research into their pathogenesis, drug resistance and diagnosis to better understand and control these pathogens in poultry farms.
Collapse
Affiliation(s)
- Mouad Farhat
- Department of Veterinary Pathology and Public Health, Agronomy and Veterinary Institute Hassan II, BP 6202, Rabat 10000, Morocco; (M.F.); (J.B.)
| | - Slimane Khayi
- Biotechnology Research Unit, Regional Center of Agricultural Research of Rabat, National Institute of Agricultural Research, Avenue Ennasr, Rabat Principale, BP 415, Rabat 10090, Morocco;
| | - Jaouad Berrada
- Department of Veterinary Pathology and Public Health, Agronomy and Veterinary Institute Hassan II, BP 6202, Rabat 10000, Morocco; (M.F.); (J.B.)
| | | | - Najia Ameur
- Department of Food Microbiology and Hygiene, National Institute of Hygiene. Av. Ibn Batouta, 27, BP 769, Rabat 10000, Morocco;
| | - Hosny El-Adawy
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, 07743 Jena, Germany;
- Faculty of Veterinary Medicine, Kafrelsheikh University, Kafr El-Sheikh 35516, Egypt
| | - Siham Fellahi
- Department of Veterinary Pathology and Public Health, Agronomy and Veterinary Institute Hassan II, BP 6202, Rabat 10000, Morocco; (M.F.); (J.B.)
| |
Collapse
|
5
|
Siddi G, Piras F, Meloni MP, Gymoese P, Torpdahl M, Fredriksson-Ahomaa M, Migoni M, Cabras D, Cuccu M, De Santis EPL, Scarano C. Hunted Wild Boars in Sardinia: Prevalence, Antimicrobial Resistance and Genomic Analysis of Salmonella and Yersinia enterocolitica. Foods 2023; 13:65. [PMID: 38201093 PMCID: PMC10778173 DOI: 10.3390/foods13010065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 12/15/2023] [Accepted: 12/22/2023] [Indexed: 01/12/2024] Open
Abstract
The objective of this investigation was to evaluate Salmonella and Yersinia enterocolitica prevalence in wild boars hunted in Sardinia and further characterize the isolates and analyse antimicrobial resistance (AMR) patterns. In order to assess slaughtering hygiene, an evaluation of carcasses microbial contamination was also carried out. Between 2020 and 2022, samples were collected from 66 wild boars hunted during two hunting seasons from the area of two provinces in northern and central Sardinia (Italy). Samples collected included colon content samples, mesenteric lymph nodes samples and carcass surface samples. Salmonella and Y. enterocolitica detection was conducted on each sample; also, on carcass surface samples, total aerobic mesophilic count and Enterobacteriaceae count were evaluated. On Salmonella and Y. enterocolitica isolates, antimicrobial susceptibility was tested and whole genome sequencing was applied. Salmonella was identified in the colon content samples of 3/66 (4.5%) wild boars; isolates were S. enterica subs. salamae, S. ser. elomrane and S. enterica subs. enterica. Y. enterocolitica was detected from 20/66 (30.3%) wild boars: in 18/66 (27.3%) colon contents, in 3/66 (4.5%) mesenteric lymph nodes and in 3/49 (6.1%) carcass surface samples. In all, 24 Y. enterocolitica isolates were analysed and 20 different sequence types were detected, with the most common being ST860. Regarding AMR, no resistance was detected in Salmonella isolates, while expected resistance towards β-lactams (blaA gene) and streptogramin (vatF gene) was observed in Y. enterocolitica isolates (91.7% and 4.2%, respectively). The low presence of AMR is probably due to the low anthropic impact in the wild areas. Regarding the surface contamination of carcasses, values (mean ± standard deviation log10 CFU/cm2) were 2.46 ± 0.97 for ACC and 1.07 ± 1.18 for Enterobacteriaceae. The results of our study confirm that wild boars can serve as reservoirs and spreaders of Salmonella and Y. enterocolitica; the finding of Y. enterocolitica presence on carcass surface highlights how meat may become superficially contaminated, especially considering that contamination is linked to the conditions related to the hunting, handling and processing of game animals.
Collapse
Affiliation(s)
- Giuliana Siddi
- Department of Veterinary Medicine, University of Sassari, Via Vienna 2, 07100 Sassari, Italy; (G.S.); (M.P.M.); (M.M.); (D.C.); (M.C.); (E.P.L.D.S.); (C.S.)
| | - Francesca Piras
- Department of Veterinary Medicine, University of Sassari, Via Vienna 2, 07100 Sassari, Italy; (G.S.); (M.P.M.); (M.M.); (D.C.); (M.C.); (E.P.L.D.S.); (C.S.)
| | - Maria Pina Meloni
- Department of Veterinary Medicine, University of Sassari, Via Vienna 2, 07100 Sassari, Italy; (G.S.); (M.P.M.); (M.M.); (D.C.); (M.C.); (E.P.L.D.S.); (C.S.)
| | - Pernille Gymoese
- Department of Bacteria, Parasites & Fungi, Statens Serum Institut, Artillerivej 5, 2300 Copenhagen, Denmark; (P.G.); (M.T.)
| | - Mia Torpdahl
- Department of Bacteria, Parasites & Fungi, Statens Serum Institut, Artillerivej 5, 2300 Copenhagen, Denmark; (P.G.); (M.T.)
| | - Maria Fredriksson-Ahomaa
- Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, FI-00014 Helsinki, Finland;
| | - Mattia Migoni
- Department of Veterinary Medicine, University of Sassari, Via Vienna 2, 07100 Sassari, Italy; (G.S.); (M.P.M.); (M.M.); (D.C.); (M.C.); (E.P.L.D.S.); (C.S.)
| | - Daniela Cabras
- Department of Veterinary Medicine, University of Sassari, Via Vienna 2, 07100 Sassari, Italy; (G.S.); (M.P.M.); (M.M.); (D.C.); (M.C.); (E.P.L.D.S.); (C.S.)
| | - Mario Cuccu
- Department of Veterinary Medicine, University of Sassari, Via Vienna 2, 07100 Sassari, Italy; (G.S.); (M.P.M.); (M.M.); (D.C.); (M.C.); (E.P.L.D.S.); (C.S.)
| | - Enrico Pietro Luigi De Santis
- Department of Veterinary Medicine, University of Sassari, Via Vienna 2, 07100 Sassari, Italy; (G.S.); (M.P.M.); (M.M.); (D.C.); (M.C.); (E.P.L.D.S.); (C.S.)
| | - Christian Scarano
- Department of Veterinary Medicine, University of Sassari, Via Vienna 2, 07100 Sassari, Italy; (G.S.); (M.P.M.); (M.M.); (D.C.); (M.C.); (E.P.L.D.S.); (C.S.)
| |
Collapse
|
6
|
Petrin S, Wijnands L, Benincà E, Mughini-Gras L, Delfgou-van Asch EHM, Villa L, Orsini M, Losasso C, Olsen JE, Barco L. Assessing phenotypic virulence of Salmonella enterica across serovars and sources. Front Microbiol 2023; 14:1184387. [PMID: 37346753 PMCID: PMC10279978 DOI: 10.3389/fmicb.2023.1184387] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2023] [Accepted: 05/15/2023] [Indexed: 06/23/2023] Open
Abstract
Introduction Whole genome sequencing (WGS) is increasingly used for characterizing foodborne pathogens and it has become a standard typing technique for surveillance and research purposes. WGS data can help assessing microbial risks and defining risk mitigating strategies for foodborne pathogens, including Salmonella enterica. Methods To test the hypothesis that (combinations of) different genes can predict the probability of infection [P(inf)] given exposure to a certain pathogen strain, we determined P(inf) based on invasion potential of 87 S. enterica strains belonging to 15 serovars isolated from animals, foodstuffs and human patients, in an in vitro gastrointestinal tract (GIT) model system. These genomes were sequenced with WGS and screened for genes potentially involved in virulence. A random forest (RF) model was applied to assess whether P(inf) of a strain could be predicted based on the presence/absence of those genes. Moreover, the association between P(inf) and biofilm formation in different experimental conditions was assessed. Results and Discussion P(inf) values ranged from 6.7E-05 to 5.2E-01, showing variability both among and within serovars. P(inf) values also varied between isolation sources, but no unambiguous pattern was observed in the tested serovars. Interestingly, serovars causing the highest number of human infections did not show better ability to invade cells in the GIT model system, with strains belonging to other serovars displaying even higher infectivity. The RF model did not identify any virulence factor as significant P(inf) predictors. Significant associations of P(inf) with biofilm formation were found in all the different conditions for a limited number of serovars, indicating that the two phenotypes are governed by different mechanisms and that the ability to form biofilm does not correlate with the ability to invade epithelial cells. Other omics techniques therefore seem more promising as alternatives to identify genes associated with P(inf), and different hypotheses, such as gene expression rather than presence/absence, could be tested to explain phenotypic virulence [P(inf)].
Collapse
Affiliation(s)
- Sara Petrin
- Microbial Ecology and Microrganisms Genomics Laboratory, Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, Padova, Italy
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Lucas Wijnands
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands
| | - Elisa Benincà
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands
| | - Lapo Mughini-Gras
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands
- Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, Netherlands
| | - Ellen H. M. Delfgou-van Asch
- Centre for Infectious Disease Control (CIb), National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands
| | - Laura Villa
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Massimiliano Orsini
- Microbial Ecology and Microrganisms Genomics Laboratory, Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, Padova, Italy
| | - Carmen Losasso
- Microbial Ecology and Microrganisms Genomics Laboratory, Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, Padova, Italy
| | - John E. Olsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark
| | - Lisa Barco
- WHOA and National Reference Laboratory for Salmonellosis, Istituto Zooprofilattico Sperimentale delle Venezie, Legnaro, Padova, Italy
| |
Collapse
|
7
|
Papudeshi B, Rusch DB, VanInsberghe D, Lively CM, Edwards RA, Bashey F. Host Association and Spatial Proximity Shape but Do Not Constrain Population Structure in the Mutualistic Symbiont Xenorhabdus bovienii. mBio 2023:e0043423. [PMID: 37154562 DOI: 10.1128/mbio.00434-23] [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: 05/10/2023] Open
Abstract
To what extent are generalist species cohesive evolutionary units rather than a compilation of recently diverged lineages? We examine this question in the context of host specificity and geographic structure in the insect pathogen and nematode mutualist Xenorhabdus bovienii. This bacterial species partners with multiple nematode species across two clades in the genus Steinernema. We sequenced the genomes of 42 X. bovienii strains isolated from four different nematode species and three field sites within a 240-km2 region and compared them to globally available reference genomes. We hypothesized that X. bovienii would comprise several host-specific lineages, such that bacterial and nematode phylogenies would be largely congruent. Alternatively, we hypothesized that spatial proximity might be a dominant signal, as increasing geographic distance might lower shared selective pressures and opportunities for gene flow. We found partial support for both hypotheses. Isolates clustered largely by nematode host species but did not strictly match the nematode phylogeny, indicating that shifts in symbiont associations across nematode species and clades have occurred. Furthermore, both genetic similarity and gene flow decreased with geographic distance across nematode species, suggesting differentiation and constraints on gene flow across both factors, although no absolute barriers to gene flow were observed across the regional isolates. Several genes associated with biotic interactions were found to be undergoing selective sweeps within this regional population. The interactions included several insect toxins and genes implicated in microbial competition. Thus, gene flow maintains cohesiveness across host associations in this symbiont and may facilitate adaptive responses to a multipartite selective environment. IMPORTANCE Microbial populations and species are notoriously hard to delineate. We used a population genomics approach to examine the population structure and the spatial scale of gene flow in Xenorhabdus bovienii, an intriguing species that is both a specialized mutualistic symbiont of nematodes and a broadly virulent insect pathogen. We found a strong signature of nematode host association, as well as evidence for gene flow connecting isolates associated with different nematode host species and collected from distinct study sites. Furthermore, we saw signatures of selective sweeps for genes involved with nematode host associations, insect pathogenicity, and microbial competition. Thus, X. bovienii exemplifies the growing consensus that recombination not only maintains cohesion but can also allow the spread of niche-beneficial alleles.
Collapse
Affiliation(s)
- Bhavya Papudeshi
- Flinders Accelerator for Microbiome Exploration, Flinders University, Adelaide, Australia
- National Centre for Genome Analysis Support, Pervasive Institute of Technology, Indiana University, Bloomington, Indiana, USA
| | - Douglas B Rusch
- Center for Genomics and Bioinformatics, Indiana University, Bloomington, Indiana, USA
| | | | - Curtis M Lively
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| | - Robert A Edwards
- Flinders Accelerator for Microbiome Exploration, Flinders University, Adelaide, Australia
| | - Farrah Bashey
- Department of Biology, Indiana University, Bloomington, Indiana, USA
| |
Collapse
|
8
|
Chacón RD, Ramírez M, Rodríguez-Cueva CL, Sánchez C, Quispe-Rojas WU, Astolfi-Ferreira CS, Piantino Ferreira AJ. Genomic Characterization and Genetic Profiles of Salmonella Gallinarum Strains Isolated from Layers with Fowl Typhoid in Colombia. Genes (Basel) 2023; 14:genes14040823. [PMID: 37107581 PMCID: PMC10138188 DOI: 10.3390/genes14040823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 03/28/2023] [Accepted: 03/28/2023] [Indexed: 04/29/2023] Open
Abstract
Salmonella Gallinarum (SG) is the causative agent of fowl typhoid (FT), a disease that is harmful to the poultry industry. Despite sanitation and prophylactic measures, this pathogen is associated with frequent disease outbreaks in developing countries, causing high morbidity and mortality. We characterized the complete genome sequence of Colombian SG strains and then performed a comparative genome analysis with other SG strains found in different regions worldwide. Eight field strains of SG plus a 9R-derived vaccine were subjected to whole-genome sequencing (WGS) and bioinformatics analysis, and the results were used for subsequent molecular typing; virulome, resistome, and mobilome characterization; and a comparative genome study. We identified 26 chromosome-located resistance genes that mostly encode efflux pumps, and point mutations were found in gyrase genes (gyrA and gyrB), with the gyrB mutation S464T frequently found in the Colombian strains. Moreover, we detected 135 virulence genes, mainly in 15 different Salmonella pathogenicity islands (SPIs). We generated an SPI profile for SG, including C63PI, CS54, ssaD, SPI-1, SPI-2, SPI-3, SPI-4, SPI-5, SPI-6, SPI-9, SPI-10, SPI-11, SPI-12, SPI-13, and SPI-14. Regarding mobile genetic elements, we found the plasmids Col(pHAD28) and IncFII(S) in most of the strains and 13 different prophage sequences, indicating a frequently obtained profile that included the complete phage Gifsy_2 and incomplete phage sequences resembling Escher_500465_2, Shigel_SfIV, Entero_mEp237, and Salmon_SJ46. This study presents, for the first time, the genomic content of Colombian SG strains and a profile of the genetic elements frequently found in SG, which can be further studied to clarify the pathogenicity and evolutionary characteristics of this serotype.
Collapse
Affiliation(s)
- Ruy D Chacón
- Department of Pathology, School of Veterinary Medicine, University of São Paulo, São Paulo 05508-270, Brazil
- Inter-Units Program in Biotechnology, University of São Paulo, São Paulo 05508-900, Brazil
| | - Manuel Ramírez
- Unidad de Bioinformática, Centro de Investigaciones Tecnológicas, Biomédicas y Medioambientales, Bellavista 07006, Peru
| | - Carmen L Rodríguez-Cueva
- Laboratory of Biology and Molecular Genetics, Faculty of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima 15021, Peru
| | - Christian Sánchez
- Department of Genetics, Physiology and Microbiology, Faculty of Biological Sciences, Complutense University of Madrid (UCM), 28040 Madrid, Spain
| | - Wilma Ursula Quispe-Rojas
- Laboratory of Molecular Microbiology and Biotechnology, Faculty of Biological Sciences, Universidad Nacional Mayor de San Marcos, Lima 15081, Peru
| | - Claudete S Astolfi-Ferreira
- Department of Pathology, School of Veterinary Medicine, University of São Paulo, São Paulo 05508-270, Brazil
| | - Antonio J Piantino Ferreira
- Department of Pathology, School of Veterinary Medicine, University of São Paulo, São Paulo 05508-270, Brazil
| |
Collapse
|
9
|
Wang F, Wang L, Ge H, Wang X, Guo Y, Xu Z, Geng S, Jiao X, Chen X. Safety of the Salmonella enterica serotype Dublin strain Sdu189-derived live attenuated vaccine—A pilot study. Front Vet Sci 2022; 9:986332. [PMID: 36246339 PMCID: PMC9554587 DOI: 10.3389/fvets.2022.986332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Accepted: 08/30/2022] [Indexed: 11/15/2022] Open
Abstract
Salmonella enterica serovar Dublin (S. Dublin) is an important zoonotic pathogen with high invasiveness. In the prevention and control of the Salmonella epidemic, the live attenuated vaccine plays a very important role. To prevent and control the epidemic of S. Dublin in cattle farms, the development of more effective vaccines is necessary. In this study, we constructed two gene deletion mutants, Sdu189ΔspiC and Sdu189ΔspiCΔaroA, with the parental strain S. Dublin Sdu189. The immunogenicity and protective efficacy were evaluated in the mice model. First, both mutant strains were much less virulent than the parental strain, as determined by the 50% lethal dose (LD50) for specific pathogen-free (SPF) 6-week-old female BALB/c mice. Second, the specific IgG antibody level and the expression level of cytokine TNF-α, IFN-γ, IL-4, and IL-18 were increased significantly in the vaccinated mice compared to the control group. In addition, the deletion strains were cleared rapidly from organs of immunized mice within 14 d after immunization, while the parental strain could still be detected in the spleen and liver after 21 d of infection. Compared with the parental strain infected group, no obvious lesions were detected in the liver, spleen, and cecum of the deletion strain vaccinated groups of mice. Immunization with Sdu189ΔspiC and Sdu189ΔspiCΔaroA both provided 100% protection against subsequent challenges with the wild-type Sdu189 strain. These results demonstrated that these two deletion strains showed the potential as live attenuated vaccines against S. Dublin infection. The present study established a foundation for screening a suitable live attenuated Salmonella vaccine.
Collapse
Affiliation(s)
- Fuzhong Wang
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality of Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou, China
| | - Lei Wang
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality of Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou, China
| | - Haojie Ge
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
| | - Xiaobo Wang
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
| | - Yaxin Guo
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality of Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou, China
| | - Zhengzhong Xu
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality of Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou, 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, China
| | - Xin'an Jiao
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality of Ministry of Agriculture and Rural Affairs, Yangzhou University, Yangzhou, China
- Xin'an Jiao
| | - Xiang Chen
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou, China
- *Correspondence: Xiang Chen
| |
Collapse
|
10
|
Feng Y, Wang Z, Chien KY, Chen HL, Liang YH, Hua X, Chiu CH. "Pseudo-pseudogenes" in bacterial genomes: Proteogenomics reveals a wide but low protein expression of pseudogenes in Salmonella enterica. Nucleic Acids Res 2022; 50:5158-5170. [PMID: 35489061 PMCID: PMC9122581 DOI: 10.1093/nar/gkac302] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 04/11/2022] [Accepted: 04/14/2022] [Indexed: 12/03/2022] Open
Abstract
Pseudogenes (genes disrupted by frameshift or in-frame stop codons) are ubiquitously present in the bacterial genome and considered as nonfunctional fossil. Here, we used RNA-seq and mass-spectrometry technologies to measure the transcriptomes and proteomes of Salmonella enterica serovars Paratyphi A and Typhi. All pseudogenes’ mRNA sequences remained disrupted, and were present at comparable levels to their intact homologs. At the protein level, however, 101 out of 161 pseudogenes suggested successful translation, with their low expression regardless of growth conditions, genetic background and pseudogenization causes. The majority of frameshifting detected was compensatory for -1 frameshift mutations. Readthrough of in-frame stop codons primarily involved UAG; and cytosine was the most frequent base adjacent to the codon. Using a fluorescence reporter system, fifteen pseudogenes were confirmed to express successfully in vivo in Escherichia coli. Expression of the intact copy of the fifteen pseudogenes in S. Typhi affected bacterial pathogenesis as revealed in human macrophage and epithelial cell infection models. The above findings suggest the need to revisit the nonstandard translation mechanism as well as the biological role of pseudogenes in the bacterial genome.
Collapse
Affiliation(s)
- Ye Feng
- Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China.,Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Zeyu Wang
- Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China.,Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Kun-Yi Chien
- Graduate Institute of Biomedical Sciences, Chang Gung University College of Medicine, Taoyuan, Republic of China
| | - Hsiu-Ling Chen
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Taoyuan, Republic of China
| | - Yi-Hua Liang
- Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Taoyuan, Republic of China
| | - Xiaoting Hua
- Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, People's Republic of China
| | - Cheng-Hsun Chiu
- Graduate Institute of Biomedical Sciences, Chang Gung University College of Medicine, Taoyuan, Republic of China.,Molecular Infectious Disease Research Center, Chang Gung Memorial Hospital, Taoyuan, Republic of China.,Division of Pediatric Infectious Diseases, Department of Pediatrics, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Republic of China
| |
Collapse
|
11
|
Foster N, Tang Y, Berchieri A, Geng S, Jiao X, Barrow P. Revisiting Persistent Salmonella Infection and the Carrier State: What Do We Know? Pathogens 2021; 10:1299. [PMID: 34684248 PMCID: PMC8537056 DOI: 10.3390/pathogens10101299] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/28/2021] [Accepted: 09/29/2021] [Indexed: 11/17/2022] Open
Abstract
One characteristic of the few Salmonella enterica serovars that produce typhoid-like infections is that disease-free persistent infection can occur for months or years in a small number of individuals post-convalescence. The bacteria continue to be shed intermittently which is a key component of the epidemiology of these infections. Persistent chronic infection occurs despite high levels of circulating specific IgG. We have reviewed the information on the basis for persistence in S. Typhi, S. Dublin, S. Gallinarum, S. Pullorum, S. Abortusovis and also S. Typhimurium in mice as a model of persistence. Persistence appears to occur in macrophages in the spleen and liver with shedding either from the gall bladder and gut or the reproductive tract. The involvement of host genetic background in defining persistence is clear from studies with the mouse but less so with human and poultry infections. There is increasing evidence that the organisms (i) modulate the host response away from the typical Th1-type response normally associated with immune clearance of an acute infection to Th2-type or an anti-inflammatory response, and that (ii) the bacteria modulate transformation of macrophage from M1 to M2 type. The bacterial factors involved in this are not yet fully understood. There are early indications that it might be possible to remodulate the response back towards a Th1 response by using cytokine therapy.
Collapse
Affiliation(s)
- Neil Foster
- SRUC Aberdeen Campus, Craibstone Estate, Ferguson Building, Aberdeen AB21 9YA, UK
| | - Ying Tang
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen 518055, China;
| | - Angelo Berchieri
- Departamento de Patologia Veterinária, Faculdade de Ciências Agrárias e Veterinárias, Univ Estadual Paulista, Via de Acesso Paulo Donato Castellane, s/n, 14884-900 Jaboticabal, SP, Brazil;
| | - 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 225009, China; (S.G.); (X.J.)
| | - 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 225009, China; (S.G.); (X.J.)
| | - Paul Barrow
- School of Veterinary Medicine, University of Surrey, Daphne Jackson Road, Guildford GU2 7AL, UK;
| |
Collapse
|
12
|
AT Homopolymer Strings in Salmonella enterica Subspecies I Contribute to Speciation and Serovar Diversity. Microorganisms 2021; 9:microorganisms9102075. [PMID: 34683396 PMCID: PMC8538453 DOI: 10.3390/microorganisms9102075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 09/08/2021] [Accepted: 09/27/2021] [Indexed: 11/17/2022] Open
Abstract
Adenine and thymine homopolymer strings of at least 8 nucleotides (AT 8+mers) were characterized in Salmonella enterica subspecies I. The motif differed between other taxonomic classes but not between Salmonella enterica serovars. The motif in plasmids was possibly associated with serovar. Approximately 12.3% of the S. enterica motif loci had mutations. Mutability of AT 8+mers suggests that genomes undergo frequent repair to maintain optimal gene content, and that the motif facilitates self-recognition; in addition, serovar diversity is associated with plasmid content. A theory that genome regeneration accounts for both persistence of predominant Salmonella serovars and serovar diversity provides a new framework for investigating root causes of foodborne illness.
Collapse
|
13
|
Vaid RK, Thakur Z, Anand T, Kumar S, Tripathi BN. Comparative genome analysis of Salmonella enterica serovar Gallinarum biovars Pullorum and Gallinarum decodes strain specific genes. PLoS One 2021; 16:e0255612. [PMID: 34411120 PMCID: PMC8375982 DOI: 10.1371/journal.pone.0255612] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 07/19/2021] [Indexed: 12/27/2022] Open
Abstract
Salmonella enterica serovar Gallinarum biovar Pullorum (bvP) and biovar Gallinarum (bvG) are the etiological agents of pullorum disease (PD) and fowl typhoid (FT) respectively, which cause huge economic losses to poultry industry especially in developing countries including India. Vaccination and biosecurity measures are currently being employed to control and reduce the S. Gallinarum infections. High endemicity, poor implementation of hygiene and lack of effective vaccines pose challenges in prevention and control of disease in intensively maintained poultry flocks. Comparative genome analysis unravels similarities and dissimilarities thus facilitating identification of genomic features that aids in pathogenesis, niche adaptation and in tracing of evolutionary history. The present investigation was carried out to assess the genotypic differences amongst S.enterica serovar Gallinarum strains including Indian strain S. Gallinarum Sal40 VTCCBAA614. The comparative genome analysis revealed an open pan-genome consisting of 5091 coding sequence (CDS) with 3270 CDS belonging to core-genome, 1254 CDS to dispensable genome and strain specific genes i.e. singletons ranging from 3 to 102 amongst the analyzed strains. Moreover, the investigated strains exhibited diversity in genomic features such as virulence factors, genomic islands, prophage regions, toxin-antitoxin cassettes, and acquired antimicrobial resistance genes. Core genome identified in the study can give important leads in the direction of design of rapid and reliable diagnostics, and vaccine design for effective infection control as well as eradication. Additionally, the identified genetic differences among the S. enterica serovar Gallinarum strains could be used for bacterial typing, structure based inhibitor development by future experimental investigations on the data generated.
Collapse
Affiliation(s)
- Rajesh Kumar Vaid
- Bacteriology Laboratory, National Centre for Veterinary Type Cultures, ICAR-National Research Centre on Equines, Hisar, Haryana, India
| | - Zoozeal Thakur
- Bacteriology Laboratory, National Centre for Veterinary Type Cultures, ICAR-National Research Centre on Equines, Hisar, Haryana, India
| | - Taruna Anand
- Bacteriology Laboratory, National Centre for Veterinary Type Cultures, ICAR-National Research Centre on Equines, Hisar, Haryana, India
| | - Sanjay Kumar
- Bacteriology Laboratory, ICAR-National Research Centre on Equines, Hisar, Haryana, India
| | | |
Collapse
|
14
|
Salmonella enterica Serovars Dublin and Enteritidis Comparative Proteomics Reveals Differential Expression of Proteins Involved in Stress Resistance, Virulence, and Anaerobic Metabolism. Infect Immun 2021; 89:IAI.00606-20. [PMID: 33361201 DOI: 10.1128/iai.00606-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 12/10/2020] [Indexed: 11/20/2022] Open
Abstract
The Enteritidis and Dublin serovars of Salmonella enterica are phylogenetically closely related yet differ significantly in host range and virulence. S Enteritidis is a broad-host-range serovar that commonly causes self-limited gastroenteritis in humans, whereas S Dublin is a cattle-adapted serovar that can infect humans, often resulting in invasive extraintestinal disease. The mechanism underlying the higher invasiveness of S Dublin remains undetermined. In this work, we quantitatively compared the proteomes of clinical isolates of each serovar grown under gut-mimicking conditions. Compared to S Enteritidis, the S Dublin proteome was enriched in proteins linked to response to several stress conditions, such as those encountered during host infection, as well as to virulence. The S Enteritidis proteome contained several proteins related to central anaerobic metabolism pathways that were undetected in S Dublin. In contrast to what has been observed in other extraintestinal serovars, most of the coding genes for these pathways are not degraded in S Dublin. Thus, we provide evidence that S Dublin metabolic functions may be much more affected than previously reported based on genomic studies. Single and double null mutants in stress response proteins Dps, YciF, and YgaU demonstrate their relevance to S Dublin invasiveness in a murine model of invasive salmonellosis. All in all, this work provides a basis for understanding interserovar differences in invasiveness and niche adaptation, underscoring the relevance of using proteomic approaches to complement genomic studies.
Collapse
|
15
|
Optimized Detoxification of a Live Attenuated Vaccine Strain (SG9R) to Improve Vaccine Strategy against Fowl Typhoid. Vaccines (Basel) 2021; 9:vaccines9020122. [PMID: 33546449 PMCID: PMC7913755 DOI: 10.3390/vaccines9020122] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 12/03/2022] Open
Abstract
The live attenuated vaccine strain, SG9R, has been used against fowl typhoid worldwide, but it can revert to the pathogenic smooth strain owing to single nucleotide changes such as nonsense mutations in the rfaJ gene. As SG9R possesses an intact Salmonella plasmid with virulence genes, it exhibits dormant pathogenicity and can cause fowl typhoid in young chicks and stressed or immunocompromised brown egg-laying hens. To tackle these issues, we knocked out the rfaJ gene of SG9R (named Safe-9R) to eliminate the reversion risk and generated detoxified strains of Safe-9R by knocking out lpxL, lpxM, pagP, and phoP/phoQ genes to attenuate the virulence. Among the knockout strains, live ΔlpxL- (Dtx-9RL) and ΔlpxM-9R (Dtx-9RM) strains induced remarkably less expression of inflammatory cytokines in chicken macrophage cells, and oil emulsion (OE) Dtx-9RL did not cause body weight loss in chicks. Live Dtx-9RM exhibited efficacy against field strain challenge in one week without any bacterial re-isolation, while the un-detoxified strains showed the development of severe liver lesions and re-isolation of challenged strains. Thus, SG9R was optimally detoxified by knockout of lpxL and lpxM, and Dtx-9RL and Dtx-9RM might be applicable as OE and live vaccines, respectively, to prevent fowl typhoid irrespective of the age of chickens.
Collapse
|
16
|
Abstract
A balanced gut microbiota contributes to health, but the mechanisms maintaining homeostasis remain elusive. Microbiota assembly during infancy is governed by competition between species and by environmental factors, termed habitat filters, that determine the range of successful traits within the microbial community. These habitat filters include the diet, host-derived resources, and microbiota-derived metabolites, such as short-chain fatty acids. Once the microbiota has matured, competition and habitat filtering prevent engraftment of new microbes, thereby providing protection against opportunistic infections. Competition with endogenous Enterobacterales, habitat filtering by short-chain fatty acids, and a host-derived habitat filter, epithelial hypoxia, also contribute to colonization resistance against Salmonella serovars. However, at a high challenge dose, these frank pathogens can overcome colonization resistance by using their virulence factors to trigger intestinal inflammation. In turn, inflammation increases the luminal availability of host-derived resources, such as oxygen, nitrate, tetrathionate, and lactate, thereby creating a state of abnormal habitat filtering that enables the pathogen to overcome growth inhibition by short-chain fatty acids. Thus, studying the process of ecosystem invasion by Salmonella serovars clarifies that colonization resistance can become weakened by disrupting host-mediated habitat filtering. This insight is relevant for understanding how inflammation triggers dysbiosis linked to noncommunicable diseases, conditions in which endogenous Enterobacterales expand in the fecal microbiota using some of the same growth-limiting resources required by Salmonella serovars for ecosystem invasion. In essence, ecosystem invasion by Salmonella serovars suggests that homeostasis and dysbiosis simply represent states where competition and habitat filtering are normal or abnormal, respectively.
Collapse
|
17
|
Campioni F, Gomes CN, Bergamini AMM, Rodrigues DP, Tiba-Casas MR, Falcão JP. Comparison of cell invasion, macrophage survival and inflammatory cytokines profiles between Salmonella enterica serovars Enteritidis and Dublin from Brazil. J Appl Microbiol 2020; 130:2123-2131. [PMID: 33150646 DOI: 10.1111/jam.14924] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 09/28/2020] [Accepted: 10/31/2020] [Indexed: 01/03/2023]
Abstract
AIMS This study compared the capacity of strains of Salmonella enterica serovars Enteritidis and Dublin isolated in Brazil to invade epithelial cells, to be internalized by and survive within macrophages, and to stimulate cytokine release in vitro. METHODS AND RESULTS Both serovars infected 75 and 73% Caco-2 (human) and MDBK (bovine) epithelial cells respectively. Salmonella Dublin and S. Enteritidis (i) were internalized at the respective rates of 79·6 and 65·0% (P ≤ 0·05) by U937 (human) macrophages, and 70·4 and 66·9% by HD11 (chicken) macrophages; and (ii) multiplied at the respective rates of 3·2- and 2·7-fold within U937 cells, and 1·9- and 1·1-fold (P ≤ 0·05) within HD11 cells respectively. Seventy per cent of 10 S. Dublin strains stimulated IL-8 production, while 70% of S. Enteritidis strains enhanced production of IL-1β, IL-6, IL-8, IL-10, IL-12p70 and TNF in Caco-2 cells. CONCLUSIONS Compared with S. Enteritidis, S. Dublin had stronger ability to survive within macrophages and induced weak cytokine production, which may explain the higher incidence of invasive diseases caused by S. Dublin in humans. SIGNIFICANCE AND IMPACT OF THE STUDY This study compared S. enterica serovars Enteritidis and Dublin to provide comparative data about the profile of the two serovars in cells from humans, the common host and their respective natural animal hosts and vice versa in order to check the differences between these two phylogenetically closely related serovars that share antigenic properties but present different phenotypic behaviours.
Collapse
Affiliation(s)
- F Campioni
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto - USP, Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Ribeirão Preto, SP, Brazil
| | - C N Gomes
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto - USP, Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Ribeirão Preto, SP, Brazil
| | - A M M Bergamini
- Instituto Adolfo Lutz - Centro de Laboratórios Regionais - Ribeirão Preto VI, Laboratório de Microbiologia de Alimentos, Ribeirão Preto, SP, Brazil
| | - D P Rodrigues
- Fundação Oswaldo Cruz - FIOCRUZ - Laboratório de Enterobactérias, Rio de Janeiro, RJ, Brazil
| | - M R Tiba-Casas
- Instituto Adolfo Lutz - Centro de Bacteriologia, São Paulo, SP, Brazil
| | - J P Falcão
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto - USP, Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Ribeirão Preto, SP, Brazil
| |
Collapse
|
18
|
Anast JM, Bobik TA, Schmitz-Esser S. The Cobalamin-Dependent Gene Cluster of Listeria monocytogenes: Implications for Virulence, Stress Response, and Food Safety. Front Microbiol 2020; 11:601816. [PMID: 33240255 PMCID: PMC7677406 DOI: 10.3389/fmicb.2020.601816] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 10/19/2020] [Indexed: 12/21/2022] Open
Abstract
Several genes of the eut, pdu, and cob/cbi operons are responsible for the metabolism of ethanolamine (EA) and 1,2-propanediol (PD) and are essential during the pathogenic lifecycles of various enteric pathogens. Studies concerning EA and PD metabolism have primarily focused on bacterial genera from the family Enterobacteriaceae, especially the genus Salmonella. Listeria monocytogenes is a member of the Firmicutes phylum and is the causative agent of the rare but highly fatal foodborne disease listeriosis. The eut, pdu, and cob/cbi operons are organized as a single large locus collectively referred to as the cobalamin-dependent gene cluster (CDGC). The CDGC is well conserved in L. monocytogenes; however, functional characterization of the genes in this cluster and how they may contribute to Listeria virulence and stress tolerance in food production environments is highly limited. Previous work suggests that the degradation pathway of PD is essential for L. monocytogenes establishment in the gastrointestinal tract. In contrast, EA metabolism may be more important during intracellular replication. Other studies indicate that the CDGC is utilized when L. monocytogenes is exposed to food and food production relevant stress conditions. Perhaps most noteworthy, L. monocytogenes exhibits attenuated growth at cold temperatures when a key EA utilization pathway gene was deleted. This review aims to summarize the current knowledge of these pathways in L. monocytogenes and their significance in virulence and stress tolerance, especially considering recent developments.
Collapse
Affiliation(s)
- Justin M Anast
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, United States.,Department of Animal Science, Iowa State University, Ames, IA, United States
| | - Thomas A Bobik
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, United States.,Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, United States
| | - Stephan Schmitz-Esser
- Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, United States.,Department of Animal Science, Iowa State University, Ames, IA, United States
| |
Collapse
|
19
|
Wang H, Zeng X, Lin J. Enterobactin-specific antibodies inhibit in vitro growth of different gram-negative bacterial pathogens. Vaccine 2020; 38:7764-7773. [PMID: 33164800 DOI: 10.1016/j.vaccine.2020.10.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 09/26/2020] [Accepted: 10/12/2020] [Indexed: 01/17/2023]
Abstract
Enterobactin (Ent)-mediated high affinity iron acquisition is critically important for Gram-negative bacterial pathogens to survive and infect the host. Recently, we reported an efficient method to prepare novel Ent conjugate vaccines for inducing high level of Ent-specific antibodies, which displayed similar bacteriostatic feature as lipocalins, the host innate immune effectors with potent Ent-binding ability. The Ent-specific antibodies also showed a significant advantage over lipocalins by cross-reacting to various Ent derivatives including salmochelins, the glycosylated Ent that can help enteric pathogens evade the siderophore sequestration by host lipocalins. To demonstrate significant potential of the Ent conjugate vaccine for broader applications to prevent and control various Gram-negative infections in human and animal, in this study, we examined inhibitory effect of Ent-specific antibodies on the in vitro growth of three significant Gram-negative pathogens: Escherichia coli (n = 27), Salmonella enterica (n = 8), and Campylobacter spp. (n = 6). The tested strains were diverse with respect to hosts, geographical origins, serotypes, infection sites and siderophore productions. The Ent-specific antibodies significantly suppressed the growth of each tested strain under iron-restricted conditions. For example, the Ent-specific antibodies consistently exerted 2-5 log10 units of growth reduction on most tested avian pathogenic E. coli (9 of 10 strains) isolated in five countries. Despite various dynamic growth responses observed, notably, the Ent-specific antibodies displayed significantly higher magnitude of growth reduction than lipocalin-2 (up to 5 log10 units of difference) on majority of tested E. coli and S. enterica, which is likely due to sequestration of other siderophores (e.g., salmochelins) by the Ent-specific antibodies. Production of a variety of major siderophores by the tested E. coli and S. enterica strains was examined and confirmed by ultra high performance liquid chromatography-high resolution mass spectrometry analysis. Collectively, this study provides critical and compelling in vitro evidence supporting the feasibility of Ent-based immune interventions against several Gram-negative pathogens.
Collapse
Affiliation(s)
- Huiwen Wang
- Department of Animal Science, The University of Tennessee, Knoxville, TN, USA
| | - Ximin Zeng
- Department of Animal Science, The University of Tennessee, Knoxville, TN, USA
| | - Jun Lin
- Department of Animal Science, The University of Tennessee, Knoxville, TN, USA.
| |
Collapse
|
20
|
Pilar AVC, Petronella N, Dussault FM, Verster AJ, Bekal S, Levesque RC, Goodridge L, Tamber S. Similar yet different: phylogenomic analysis to delineate Salmonella and Citrobacter species boundaries. BMC Genomics 2020; 21:377. [PMID: 32471418 PMCID: PMC7257147 DOI: 10.1186/s12864-020-06780-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 05/13/2020] [Indexed: 12/14/2022] Open
Abstract
Background Salmonella enterica is a leading cause of foodborne illness worldwide resulting in considerable public health and economic costs. Testing for the presence of this pathogen in food is often hampered by the presence of background microflora that may present as Salmonella (false positives). False positive isolates belonging to the genus Citrobacter can be difficult to distinguish from Salmonella due to similarities in their genetics, cell surface antigens, and other phenotypes. In order to understand the genetic basis of these similarities, a comparative genomic approach was used to define the pan-, core, accessory, and unique coding sequences of a representative population of Salmonella and Citrobacter strains. Results Analysis of the genomic content of 58 S. enterica strains and 37 Citrobacter strains revealed the presence of 31,130 and 1540 coding sequences within the pan- and core genome of this population. Amino acid sequences unique to either Salmonella (n = 1112) or Citrobacter (n = 195) were identified and revealed potential niche-specific adaptations. Phylogenetic network analysis of the protein families encoded by the pan-genome indicated that genetic exchange between Salmonella and Citrobacter may have led to the acquisition of similar traits and also diversification within the genera. Conclusions Core genome analysis suggests that the Salmonella enterica and Citrobacter populations investigated here share a common evolutionary history. Comparative analysis of the core and pan-genomes was able to define the genetic features that distinguish Salmonella from Citrobacter and highlight niche specific adaptations.
Collapse
Affiliation(s)
| | - Nicholas Petronella
- Bureau of Food Surveillance and Science Integration, Health Canada, Ottawa, Ontario, Canada
| | - Forest M Dussault
- Bureau of Food Surveillance and Science Integration, Health Canada, Ottawa, Ontario, Canada
| | - Adrian J Verster
- Bureau of Food Surveillance and Science Integration, Health Canada, Ottawa, Ontario, Canada
| | - Sadjia Bekal
- Laboratoire de santé publique du Québec, Ste-Anne-de-Bellevue, Quebec, Canada
| | - Roger C Levesque
- Institute for Integrative and Systems Biology (IBIS), Université Laval, Quebec, Quebec, Canada
| | - Lawrence Goodridge
- Department of Food Science and Agricultural Chemistry, Faculty of Agricultural and Environmental Sciences, McGill University, Ste-Anne-de-Bellevue, Quebec, Canada.,Food Science Department, University of Guelph, Guelph, Ontario, Canada
| | - Sandeep Tamber
- Bureau of Microbial Hazards, Health Canada, Ottawa, Ontario, Canada.
| |
Collapse
|
21
|
Characterization of Salmonella Dublin isolated from bovine and human hosts. BMC Microbiol 2019; 19:226. [PMID: 31619165 PMCID: PMC6796477 DOI: 10.1186/s12866-019-1598-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 09/13/2019] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Salmonella enterica subsp. enterica serovar Dublin (S. Dublin), a cattle adapted serovar causes enteritis, and systemic disease in bovines. The invasive index of this serovar far exceeds that of the other serovars and human infections often present as fatal or highly resistant infections. In this, observational study, phenotypic properties of human and bovine-derived isolates of S. Dublin along with antibiogram of common antimicrobials were evaluated. The multiplex PCR confirmed isolates were genotyped using 7-gene legacy MLST. MIC assay was done by broth microdilution method. Previously published protocols were used to assess the motility, biofilm formation and morphotype. Vi antigen was agglutinated using commercial antiserum. Caenorhabditis elegans infection model was used to evaluate the virulence potiential. Phenotyping experiments were done in duplicates while virulence assay was done in triplicates. Whole-genome sequencing was used to predict the genes responsible for acquired resistance and a genotype-phenotype comparison was made. RESULTS We evaluated 96 bovine and 10 human isolates in this study. All the isolates belonged to ST10 in eBG53 and were negative for Vi-antigen. The swarming motility, biofilm formation and morphotype were variable in the isolates of both groups. Resistance to sulfamethoxazole, ampicillin, chloramphenicol, tetracycline was > 90% in animal isolates whereas resistance to sulfamethoxazole was > 70% in human isolates. MDR was also higher in animal isolates. Human isolates were significantly (P < 0.0001) more virulent than animal isolates on C. elegans infection model. The genomic comparison based on the core SNPs showed a high degree of homogeneity between the isolates. The carriage of IncA/C2 plasmid was seen as a typical feature of isolates from the bovine hosts. CONCLUSION Human isolates showed more diversity in the phenotypic assays. Animal isolates showed a higher degree of antimicrobial resistance with greater MDR but human isolates formed more biofilm and had greater swarming motility as well as increased virulence to the nematode C. elegans. The carriage of IncA/C2 plasmid could contribute to the distinguishing feature of the bovine isolates. The tandem use of genotypic-phenotypic assays improves the understanding of diversity and differential behaviour of the same serovar from unrelated host sources.
Collapse
|
22
|
Uelze L, Borowiak M, Deneke C, Jacobs C, Szabó I, Tausch SH, Malorny B. First complete genome sequence and comparative analysis of Salmonella enterica subsp. diarizonae serovar 61:k:1,5,(7) indicates host adaptation traits to sheep. Gut Pathog 2019; 11:48. [PMID: 31636715 PMCID: PMC6791114 DOI: 10.1186/s13099-019-0330-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Accepted: 09/27/2019] [Indexed: 11/10/2022] Open
Abstract
Background The Salmonella enterica subsp. diarizonae serovar 61:k:1,5,(7) (SASd) has been found to be host-adapted to sheep, with a high prevalence in sheep herds worldwide. Infections are usually sub-clinical, however the serovar has the potential to cause diarrhea, abortions and chronic proliferative rhinitis. Although occurrence and significance of SASd infections in sheep have been extensively studied, the genetic mechanism underlying this unusual host-adaptation have remained unknown, due to a lack of (a) available high-quality genome sequence(s). Results We utilized Nanopore and Illumina sequencing technologies to generate a de novo assembly of the 4.88-Mbp complete genome sequence of the SASd strain 16-SA00356, isolated from the organs of a deceased sheep in 2016. We annotated and analyzed the genome sequence with the aim to gain a deeper understanding of the genome characteristics associated with its pathogenicity and host adaptation to sheep. Overall, we found a number of interesting genomic features such as several prophage regions, a VirB4/D4 plasmid and novel genomic islands. By comparing the genome of 16-SA00356 to other S. enterica serovars we found that SASd features an increased number of pseudogenes as well as a high level of genomic rearrangements, both known indicators of host-adaptation. Conclusions With this sequence, we provide the first complete and closed genome sequence of a SASd strain. With this study, we provide an important basis for an understanding of the genetic mechanism that underlie pathogenicity and host adaptation of SASd to sheep.
Collapse
Affiliation(s)
- Laura Uelze
- 1Bundesinstitut für Risikobewertung (BfR), Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
| | - Maria Borowiak
- 1Bundesinstitut für Risikobewertung (BfR), Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
| | - Carlus Deneke
- 1Bundesinstitut für Risikobewertung (BfR), Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
| | - Cécile Jacobs
- Landeslabor Schleswig-Holstein, Max-Eyth-Straße 5, 24537 Neumünster, Germany
| | - István Szabó
- 1Bundesinstitut für Risikobewertung (BfR), Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
| | - Simon H Tausch
- 1Bundesinstitut für Risikobewertung (BfR), Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
| | - Burkhard Malorny
- 1Bundesinstitut für Risikobewertung (BfR), Max-Dohrn-Str. 8-10, 10589 Berlin, Germany
| |
Collapse
|
23
|
Fenske GJ, Thachil A, McDonough PL, Glaser A, Scaria J. Geography Shapes the Population Genomics of Salmonella enterica Dublin. Genome Biol Evol 2019; 11:2220-2231. [PMID: 31329231 PMCID: PMC6703130 DOI: 10.1093/gbe/evz158] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/16/2019] [Indexed: 01/11/2023] Open
Abstract
Salmonella enterica serotype Dublin (S. Dublin) is a bovine-adapted serotype that can cause serious systemic infections in humans. Despite the increasing prevalence of human infections and the negative impact on agricultural processes, little is known about the population structure of the serotype. To this end, we compiled a manually curated data set comprising of 880 S. Dublin genomes. Core genome phylogeny and ancestral state reconstruction revealed that region-specific clades dominate the global population structure of S. Dublin. Strains of S. Dublin in the UK are genomically distinct from US, Brazilian, and African strains. The geographical partitioning impacts the composition of the core genome as well as the ancillary genome. Antibiotic resistance genes are almost exclusively found in US genomes and are mediated by an IncA/C2 plasmid. Phage content and the S. Dublin virulence plasmid were strongly conserved in the serotype. Comparison of S. Dublin to a closely related serotype, S. enterica serotype Enteritidis, revealed that S. Dublin contains 82 serotype specific genes that are not found in S. Enteritidis. Said genes encode metabolic functions involved in the uptake and catabolism of carbohydrates and virulence genes associated with type VI secretion systems and fimbria assembly respectively.
Collapse
Affiliation(s)
- Gavin J Fenske
- Department of Veterinary and Biomedical Sciences, South Dakota State University
| | - Anil Thachil
- Department of Population Medicine and Diagnostic Sciences, Cornell University
| | - Patrick L McDonough
- Department of Population Medicine and Diagnostic Sciences, Cornell University
| | - Amy Glaser
- Department of Population Medicine and Diagnostic Sciences, Cornell University
| | - Joy Scaria
- Department of Veterinary and Biomedical Sciences, South Dakota State University
| |
Collapse
|
24
|
Rakov AV, Mastriani E, Liu SL, Schifferli DM. Association of Salmonella virulence factor alleles with intestinal and invasive serovars. BMC Genomics 2019; 20:429. [PMID: 31138114 PMCID: PMC6540521 DOI: 10.1186/s12864-019-5809-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 05/20/2019] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND The role of Salmonella virulence factor (VF) allelic variation in modulating pathogenesis or host specificity has only been demonstrated in a few cases, mostly through serendipitous findings. Virulence factor (VF) alleles from Salmonella enterica subsp. enterica genomes were compared to identify potential associations with the host-adapted invasive serovars Typhi, Dublin, Choleraesuis, and Gallinarum, and with the broad host-range intestinal serovars Typhimurium, Enteritidis, and Newport. RESULTS Through a bioinformatics analysis of 500 Salmonella genomes, we have identified allelic variants of 70 VFs, many of which are associated with either one of the four host-adapted invasive Salmonella serovars or one of the three broad host-range intestinal serovars. In addition, associations between specific VF alleles and intra-serovar clusters, sequence types (STs) and/or host-adapted FimH adhesins were identified. Moreover, new allelic VF associations with non-typhoidal S. Enteritidis and S. Typhimurium (NTS) or invasive NTS (iNTS) were detected. CONCLUSIONS By analogy to the previously shown association of specific FimH adhesin alleles with optimal binding by host adapted Salmonella serovars, lineages or strains, we predict that some of the identified association of other VF alleles with host-adapted serovars, lineages or strains will reflect specific contributions to host adaptation and/or pathogenesis. The identification of these allelic associations will support investigations of the biological impact of VF alleles and better characterize the role of allelic variation in Salmonella pathogenesis. Most relevant functional experiments will test the potential causal contribution of the detected FimH-associated VF variants in host adapted virulence.
Collapse
Affiliation(s)
- Alexey V. Rakov
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania USA
- Present Address: Somov Institute of Epidemiology and Microbiology, Vladivostok, Russia
| | - Emilio Mastriani
- Systemomics Center, College of Pharmacy, Genomics Research Center, State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Harbin Medical University, Harbin, China
- HMU-UCCSM Centre for Infection and Genomics, Harbin Medical University, Harbin, China
| | - Shu-Lin Liu
- Systemomics Center, College of Pharmacy, Genomics Research Center, State-Province Key Laboratories of Biomedicine-Pharmaceutics of China, Harbin Medical University, Harbin, China
- HMU-UCCSM Centre for Infection and Genomics, Harbin Medical University, Harbin, China
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, Canada
| | - Dieter M. Schifferli
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania USA
| |
Collapse
|
25
|
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.
Collapse
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.
| |
Collapse
|
26
|
Ricke SC, Kim SA, Shi Z, Park SH. Molecular-based identification and detection of Salmonella in food production systems: current perspectives. J Appl Microbiol 2018; 125:313-327. [PMID: 29675864 DOI: 10.1111/jam.13888] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 04/03/2018] [Accepted: 04/10/2018] [Indexed: 12/25/2022]
Abstract
Salmonella remains a prominent cause of foodborne illnesses and can originate from a wide range of food products. Given the continued presence of pathogenic Salmonella in food production systems, there is a consistent need to improve identification and detection methods that can identify this pathogen at all stages in food systems. Methods for subtyping have evolved over the years, and the introduction of whole genome sequencing and advancements in PCR technologies have greatly improved the resolution for differentiating strains within a particular serovar. This, in turn, has led to the continued improvement in Salmonella detection technologies for utilization in food production systems. In this review, the focus will be on recent advancements in these technologies, as well as potential issues associated with the application of these tools in food production. In addition, the recent and emerging research developments on Salmonella detection and identification methodologies and their potential application in food production systems will be discussed.
Collapse
Affiliation(s)
- S C Ricke
- Department of Food Science, Center for Food Safety, University of Arkansas, Fayetteville, AR, USA
| | - S A Kim
- Department of Food Science, Center for Food Safety, University of Arkansas, Fayetteville, AR, USA
| | - Z Shi
- Department of Food Science, Center for Food Safety, University of Arkansas, Fayetteville, AR, USA
| | - S H Park
- Department of Food Science, Center for Food Safety, University of Arkansas, Fayetteville, AR, USA
| |
Collapse
|
27
|
Hiyoshi H, Tiffany CR, Bronner DN, Bäumler AJ. Typhoidal Salmonella serovars: ecological opportunity and the evolution of a new pathovar. FEMS Microbiol Rev 2018; 42:527-541. [DOI: 10.1093/femsre/fuy024] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 05/19/2018] [Indexed: 12/20/2022] Open
Affiliation(s)
- Hirotaka Hiyoshi
- Department of Medial Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA 95616, USA
| | - Connor R Tiffany
- Department of Medial Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA 95616, USA
| | - Denise N Bronner
- Department of Medial Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA 95616, USA
| | - Andreas J Bäumler
- Department of Medial Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA 95616, USA
| |
Collapse
|
28
|
Comparative genomics identifies distinct lineages of S. Enteritidis from Queensland, Australia. PLoS One 2018; 13:e0191042. [PMID: 29338017 PMCID: PMC5770046 DOI: 10.1371/journal.pone.0191042] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 12/27/2017] [Indexed: 11/19/2022] Open
Abstract
Salmonella enterica is a major cause of gastroenteritis and foodborne illness in Australia where notification rates in the state of Queensland are the highest in the country. S. Enteritidis is among the five most common serotypes reported in Queensland and it is a priority for epidemiological surveillance due to concerns regarding its emergence in Australia. Using whole genome sequencing, we have analysed the genomic epidemiology of 217 S. Enteritidis isolates from Queensland, and observed that they fall into three distinct clades, which we have differentiated as Clades A, B and C. Phage types and MLST sequence types differed between the clades and comparative genomic analysis has shown that each has a unique profile of prophage and genomic islands. Several of the phage regions present in the S. Enteritidis reference strain P125109 were absent in Clades A and C, and these clades also had difference in the presence of pathogenicity islands, containing complete SPI-6 and SPI-19 regions, while P125109 does not. Antimicrobial resistance markers were found in 39 isolates, all but one of which belonged to Clade B. Phylogenetic analysis of the Queensland isolates in the context of 170 international strains showed that Queensland Clade B isolates group together with the previously identified global clade, while the other two clades are distinct and appear largely restricted to Australia. Locally sourced environmental isolates included in this analysis all belonged to Clades A and C, which is consistent with the theory that these clades are a source of locally acquired infection, while Clade B isolates are mostly travel related.
Collapse
|
29
|
|
30
|
Draft Genome Sequences of 23 Salmonella enterica Strains Isolated from Cattle in Ibadan, Nigeria, Representing 21 Salmonella Serovars. GENOME ANNOUNCEMENTS 2017; 5:5/46/e01128-17. [PMID: 29146845 PMCID: PMC5690322 DOI: 10.1128/genomea.01128-17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To provide a better understanding of the diversity of Salmonella enterica, we report the assembled genome sequences of 23 Salmonella enterica strains isolated from fecal samples of cattle in Nigeria comprising 21 different Salmonella serovars.
Collapse
|
31
|
Grange ZL, Biggs PJ, Rose SP, Gartrell BD, Nelson NJ, French NP. Genomic Epidemiology and Management of Salmonella in Island Ecosystems Used for Takahe Conservation. MICROBIAL ECOLOGY 2017; 74:735-744. [PMID: 28361266 DOI: 10.1007/s00248-017-0959-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 02/24/2017] [Indexed: 06/07/2023]
Abstract
Translocation and isolation of threatened wildlife in new environments may have unforeseen consequences on pathogen transmission and evolution in host populations. Disease threats associated with intensive conservation management of wildlife remain speculative without gaining an understanding of pathogen dynamics in meta-populations and how location attributes may determine pathogen prevalence. We determined the prevalence and population structure of an opportunistic pathogen, Salmonella, in geographically isolated translocated sub-populations of an endangered New Zealand flightless bird, the takahe (Porphyrio hochstetteri). Out of the nine sub-populations tested, Salmonella was only isolated from takahe living on one private island. The apparent prevalence of Salmonella in takahe on the private island was 32% (95% CI 13-57%), with two serotypes, Salmonella Mississippi and Salmonella houtenae 40:gt-, identified. Epidemiological investigation of reservoirs on the private island and another island occupied by takahe identified environmental and reptile sources of S. Mississippi and S. houtenae 40:gt- on the private island. Single nucleotide polymorphism analysis of core genomes revealed low-level diversity among isolates belonging to the same serotype and little differentiation according to host and environmental source. The pattern observed may be representative of transmission between sympatric hosts and environmental sources, the presence of a common unsampled source, and/or evidence of a recent introduction into the ecosystem. This study highlights how genomic epidemiology can be used to ascertain and understand disease dynamics to inform the management of disease threats in endangered wildlife populations.
Collapse
Affiliation(s)
- Zoë L Grange
- Allan Wilson Centre, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand.
- mEpiLab, Infectious Disease Research Centre, Hopkirk Research Institute, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand.
- Wildbase, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand.
- One Health Institute, University of California Davis, Davis, CA, USA.
| | - Patrick J Biggs
- Allan Wilson Centre, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand
- mEpiLab, Infectious Disease Research Centre, Hopkirk Research Institute, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand
| | - Shanna P Rose
- Allan Wilson Centre, School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Brett D Gartrell
- Allan Wilson Centre, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand
- Wildbase, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand
| | - Nicola J Nelson
- Allan Wilson Centre, School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Nigel P French
- Allan Wilson Centre, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand
- mEpiLab, Infectious Disease Research Centre, Hopkirk Research Institute, Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand
| |
Collapse
|
32
|
Wigley P. Salmonella enterica serovar Gallinarum: addressing fundamental questions in bacteriology sixty years on from the 9R vaccine. Avian Pathol 2017; 46:119-124. [DOI: 10.1080/03079457.2016.1240866] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Paul Wigley
- Department of Infection Biology, Institute for Infection & Global Health and School of Veterinary Science, University of Liverpool, Neston, UK
| |
Collapse
|
33
|
Faber F, Thiennimitr P, Spiga L, Byndloss MX, Litvak Y, Lawhon S, Andrews-Polymenis HL, Winter SE, Bäumler AJ. Respiration of Microbiota-Derived 1,2-propanediol Drives Salmonella Expansion during Colitis. PLoS Pathog 2017; 13:e1006129. [PMID: 28056091 PMCID: PMC5215881 DOI: 10.1371/journal.ppat.1006129] [Citation(s) in RCA: 124] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Accepted: 12/14/2016] [Indexed: 12/16/2022] Open
Abstract
Intestinal inflammation caused by Salmonella enterica serovar Typhimurium increases the availability of electron acceptors that fuel a respiratory growth of the pathogen in the intestinal lumen. Here we show that one of the carbon sources driving this respiratory expansion in the mouse model is 1,2-propanediol, a microbial fermentation product. 1,2-propanediol utilization required intestinal inflammation induced by virulence factors of the pathogen. S. Typhimurium used both aerobic and anaerobic respiration to consume 1,2-propanediol and expand in the murine large intestine. 1,2-propanediol-utilization did not confer a benefit in germ-free mice, but the pdu genes conferred a fitness advantage upon S. Typhimurium in mice mono-associated with Bacteroides fragilis or Bacteroides thetaiotaomicron. Collectively, our data suggest that intestinal inflammation enables S. Typhimurium to sidestep nutritional competition by respiring a microbiota-derived fermentation product. Salmonella enterica serovar Typhimurium induces intestinal inflammation to induce the generation of host-derived respiratory electron acceptors, thereby driving a respiratory pathogen expansion, which aids infectious transmission by the fecal oral route. However, the identity of nutrients serving as electron donors to enable S. Typhimurium to edge out competing microbes in the competitive environment of the gut are just beginning to be worked out. Here we demonstrate that aerobic and anaerobic respiratory pathways cooperate to promote growth of Salmonella on the microbial fermentation product 1,2-propanediol. We propose that pathogen-induced intestinal inflammation enables Salmonella to sidestep nutritional competition with the largely anaerobic microbiota by respiring a microbe-derived metabolite that cannot be consumed by fermentation.
Collapse
Affiliation(s)
- Franziska Faber
- Department of Medial Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA, United States of America
| | - Parameth Thiennimitr
- Department of Microbiology, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand
| | - Luisella Spiga
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, United States of America
| | - Mariana X. Byndloss
- Department of Medial Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA, United States of America
| | - Yael Litvak
- Department of Medial Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA, United States of America
| | - Sara Lawhon
- Department of Veterinary Pathobiology, College of Veterinary Medicine, Texas A&M University, College Station, TX, United States of America
| | - Helene L. Andrews-Polymenis
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, United States of America
| | - Sebastian E. Winter
- Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, TX, United States of America
| | - Andreas J. Bäumler
- Department of Medial Microbiology and Immunology, School of Medicine, University of California Davis, Davis, CA, United States of America
- * E-mail:
| |
Collapse
|
34
|
Abstract
Salmonella Enteritidis (SE) is the predominant cause of the food-borne salmonellosis in humans, in part because this serotype has the unique ability to contaminate chicken eggs without causing discernible illness in the infected birds. Attempts to develop effective vaccines and eradicate SE from chickens are undermined by significant limitations in our current understanding of the genetic basis of pathogenesis of SE in this reservoir host. In this chapter, we summarize the infection kinetics and provide an overview of the current understanding of genetic factors underlying SE infection in the chicken host. We also discuss the important knowledge gaps that, if addressed, will improve our understanding of the complex biology of SE in young chickens and in egg laying hens.
Collapse
|
35
|
Ortega A, Villagra N, Urrutia I, Valenzuela L, Talamilla-Espinoza A, Hidalgo A, Rodas P, Gil F, Calderón I, Paredes-Sabja D, Mora G, Fuentes J. Lose to win: marT pseudogenization in Salmonella enterica serovar Typhi contributed to the surV -dependent survival to H 2 O 2 , and inside human macrophage-like cells. INFECTION GENETICS AND EVOLUTION 2016; 45:111-121. [DOI: 10.1016/j.meegid.2016.08.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2016] [Revised: 08/17/2016] [Accepted: 08/22/2016] [Indexed: 02/06/2023]
|
36
|
Lokken KL, Walker GT, Tsolis RM. Disseminated infections with antibiotic-resistant non-typhoidal Salmonella strains: contributions of host and pathogen factors. Pathog Dis 2016; 74:ftw103. [PMID: 27765795 DOI: 10.1093/femspd/ftw103] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/07/2016] [Indexed: 11/14/2022] Open
Abstract
Non-typhoidal Salmonella enterica serovars (NTS) are generally associated with gastroenteritis; however, the very young and elderly, as well as individuals with compromised immunity, are at risk of developing disseminated infection that can manifest as bacteremia or focal infections at systemic sites. Disseminated NTS infections can be fatal and are responsible for over 600 000 deaths annually. Most of these deaths are in sub-Saharan Africa, where multidrug-resistant NTS clones are currently circulating in a population with a high proportion of individuals that are susceptible to disseminated disease. This review considers how genome degradation observed in African NTS isolates has resulted in phenotypic differences in traits related to environmental persistence and host-pathogen interactions. Further, it discusses host mechanisms promoting susceptibility to invasive infection with NTS in individuals with immunocompromising conditions. We conclude that mechanistic knowledge of how risk factors compromise immunity to disseminated NTS infection will be important for the design of interventions to protect against systemic disease.
Collapse
Affiliation(s)
- Kristen L Lokken
- Medical Microbiology and Immunology, University of California, One Shields Avenue, Davis, CA 95616, USA
| | - Gregory T Walker
- Medical Microbiology and Immunology, University of California, One Shields Avenue, Davis, CA 95616, USA
| | - Renée M Tsolis
- Medical Microbiology and Immunology, University of California, One Shields Avenue, Davis, CA 95616, USA
| |
Collapse
|
37
|
Di Cesare A, Losasso C, Barco L, Eckert EM, Conficoni D, Sarasini G, Corno G, Ricci A. Diverse distribution of Toxin-Antitoxin II systems in Salmonella enterica serovars. Sci Rep 2016; 6:28759. [PMID: 27357537 PMCID: PMC4928088 DOI: 10.1038/srep28759] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 06/06/2016] [Indexed: 11/09/2022] Open
Abstract
Type II Toxin-Antitoxin systems (TAs), known for their presence in virulent and antibiotic resistant bacterial strains, were recently identified in Salmonella enterica isolates. However, the relationships between the presence of TAs (ccdAB and vapBC) and the epidemiological and genetic features of different non-typhoidal Salmonella serovars are largely unknown, reducing our understanding of the ecological success of different serovars. Salmonella enterica isolates from different sources, belonging to different serovars and epidemiologically unrelated according to ERIC profiles, were investigated for the presence of type II TAs, plasmid content, and antibiotic resistance. The results showed the ubiquitous presence of the vapBC gene in all the investigated Salmonella isolates, but a diverse distribution of ccdAB, which was detected in the most widespread Salmonella serovars, only. Analysis of the plasmid toxin ccdB translated sequence of four selected Salmonella isolates showed the presence of the amino acid substitution R99W, known to impede in vitro the lethal effect of CcdB toxin in the absence of its cognate antitoxin CcdA. These findings suggest a direct role of the TAs in promoting adaptability and persistence of the most prevalent Salmonella serovars, thus implying a wider eco-physiological role for these type II TAs.
Collapse
Affiliation(s)
- Andrea Di Cesare
- Microbial Ecology Group, National Research Council – Institute of Ecosystem Study (CNR-ISE), Largo Tonolli 50,28822, Verbania, Italy
| | - Carmen Losasso
- Food Safety Department, Istituto Zooprofilattico Sperimentale delle Venezie, viale dell’Università 10, 35020, Legnaro, Italy
| | - Lisa Barco
- Food Safety Department, Istituto Zooprofilattico Sperimentale delle Venezie, viale dell’Università 10, 35020, Legnaro, Italy
| | - Ester M. Eckert
- Microbial Ecology Group, National Research Council – Institute of Ecosystem Study (CNR-ISE), Largo Tonolli 50,28822, Verbania, Italy
| | - Daniele Conficoni
- Department Animal Medicine, Production and Health, University of Padua, viale dell’Università, 35020, Legnaro, Italy
| | - Giulia Sarasini
- Microbial Ecology Group, National Research Council – Institute of Ecosystem Study (CNR-ISE), Largo Tonolli 50,28822, Verbania, Italy
| | - Gianluca Corno
- Microbial Ecology Group, National Research Council – Institute of Ecosystem Study (CNR-ISE), Largo Tonolli 50,28822, Verbania, Italy
| | - Antonia Ricci
- Food Safety Department, Istituto Zooprofilattico Sperimentale delle Venezie, viale dell’Università 10, 35020, Legnaro, Italy
| |
Collapse
|
38
|
Whole genome sequencing provides insights into the genetic determinants of invasiveness in Salmonella Dublin. Epidemiol Infect 2016; 144:2430-9. [PMID: 26996313 DOI: 10.1017/s0950268816000492] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Salmonella enterica subsp. enterica serovar Dublin (S. Dublin) is one of the non-typhoidal Salmonella (NTS); however, a relatively high proportion of human infections are associated with invasive disease. We applied whole genome sequencing to representative invasive and non-invasive clinical isolates of S. Dublin to determine the genomic variations among them and to investigate the underlying genetic determinants associated with invasiveness in S. Dublin. Although no particular genomic variation was found to differentiate in invasive and non-invasive isolates four virulence factors were detected within the genome of all isolates including two different type VI secretion systems (T6SS) encoded on two Salmonella pathogenicity islands (SPI), including SPI-6 (T6SSSPI-6) and SPI-19 (T6SSSPI-19), an intact lambdoid prophage (Gifsy-2-like prophage) that contributes significantly to the virulence and pathogenesis of Salmonella serotypes in addition to a virulence plasmid. These four virulence factors may all contribute to the potential of S. Dublin to cause invasive disease in humans.
Collapse
|