1
|
Grinevich D, Harden L, Thakur S, Callahan B. Serovar-level identification of bacterial foodborne pathogens from full-length 16S rRNA gene sequencing. mSystems 2024; 9:e0075723. [PMID: 38319092 PMCID: PMC10949465 DOI: 10.1128/msystems.00757-23] [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: 07/31/2023] [Accepted: 01/03/2024] [Indexed: 02/07/2024] Open
Abstract
The resolution of variation within species is critical for interpreting and acting on many microbial measurements. In the key foodborne pathogens Salmonella and Escherichia coli, the primary subspecies classification scheme used is serotyping: differentiating variants within these species by surface antigen profiles. Serotype prediction from whole-genome sequencing (WGS) of isolates is now seen as comparable or preferable to traditional laboratory methods where WGS is available. However, laboratory and WGS methods depend on an isolation step that is time-consuming and incompletely represents the sample when multiple strains are present. Community sequencing approaches that skip the isolation step are, therefore, of interest for pathogen surveillance. Here, we evaluated the viability of amplicon sequencing of the full-length 16S rRNA gene for serotyping Salmonella enterica and E. coli. We developed a novel algorithm for serotype prediction, implemented as an R package (Seroplacer), which takes as input full-length 16S rRNA gene sequences and outputs serovar predictions after phylogenetic placement into a reference phylogeny. We achieved over 89% accuracy in predicting Salmonella serotypes on in silico test data and identified key pathogenic serovars of Salmonella and E. coli in isolate and environmental test samples. Although serotype prediction from 16S rRNA gene sequences is not as accurate as serotype prediction from WGS of isolates, the potential to identify dangerous serovars directly from amplicon sequencing of environmental samples is intriguing for pathogen surveillance. The capabilities developed here are also broadly relevant to other applications where intraspecies variation and direct sequencing from environmental samples could be valuable.IMPORTANCEIn order to prevent and stop outbreaks of foodborne pathogens, it is important that we can detect when pathogenic bacteria are present in a food or food-associated site and identify connections between specific pathogenic bacteria present in different samples. In this work, we develop a new computational technology that allows the important foodborne pathogens Escherichia coli and Salmonella enterica to be serotyped (a subspecies level classification) from sequencing of a single-marker gene, and the 16S rRNA gene often used to surveil bacterial communities. Our results suggest current limitations to serotyping from 16S rRNA gene sequencing alone but set the stage for further progress that we consider likely given the rapid advance in the long-read sequencing technologies and genomic databases our work leverages. If this research direction succeeds, it could enable better detection of foodborne pathogens before they reach the public and speed the resolution of foodborne pathogen outbreaks.
Collapse
Affiliation(s)
- Dmitry Grinevich
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | - Lyndy Harden
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | - Siddhartha Thakur
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | - Benjamin Callahan
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
- Bioinformatics Research Center, North Carolina State University, Raleigh, North Carolina, USA
| |
Collapse
|
2
|
Grinevich D, Harden L, Thakur S, Callahan BJ. Serovar-level Identification of Bacterial Foodborne Pathogens From Full-length 16S rRNA Gene Sequencing. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.28.546915. [PMID: 37425822 PMCID: PMC10327058 DOI: 10.1101/2023.06.28.546915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
The resolution of variation within species is critical for interpreting and acting on many microbial measurements. In the key foodborne pathogens Escherichia coli and Salmonella, the primary sub-species classification scheme used is serotyping: differentiating variants within these species by surface antigen profiles. Serotype prediction from whole-genome sequencing (WGS) of isolates is now seen as comparable or preferable to traditional laboratory methods where WGS is available. However, laboratory and WGS methods depend on an isolation step that is time-consuming and incompletely represents the sample when multiple strains are present. Community sequencing approaches that skip the isolation step are therefore of interest for pathogen surveillance. Here we evaluated the viability of amplicon sequencing of the full-length 16S rRNA gene for serotyping S. enterica and E. coli. We developed a novel algorithm for serotype prediction, implemented as an R package (Seroplacer), which takes as input full-length 16S rRNA gene sequences and outputs serovar predictions after phylogenetic placement into a reference phylogeny. We achieved over 89% accuracy in predicting Salmonella serotypes on in silico test data, and identified key pathogenic serovars of Salmonella and E. coli in isolate and environmental test samples. Although serotype prediction from 16S sequences is not as accurate as serotype prediction from WGS of isolates, the potential to identify dangerous serovars directly from amplicon sequencing of environmental samples is intriguing for pathogen surveillance. The capabilities developed here are also broadly relevant to other applications where intra-species variation and direct sequencing from environmental samples could be valuable.
Collapse
Affiliation(s)
- Dmitry Grinevich
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Lyndy Harden
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Siddhartha Thakur
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Benjamin J Callahan
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
- Bioinformatics Research Center, North Carolina State University, Raleigh, NC, USA
| |
Collapse
|
3
|
Hernández-Ledesma A, Cabrera-Díaz E, Arvizu-Medrano SM, Gómez-Baltazar A, Hernández-Iturriaga M, Godínez-Oviedo A. Virulence and antimicrobial resistance profiles of Salmonella enterica isolated from foods, humans, and the environment in Mexico. Int J Food Microbiol 2023; 391-393:110135. [PMID: 36827747 DOI: 10.1016/j.ijfoodmicro.2023.110135] [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: 11/03/2022] [Revised: 01/11/2023] [Accepted: 02/09/2023] [Indexed: 02/21/2023]
Abstract
Salmonella enterica genotypic and phenotypic characteristics play an important role in its pathogenesis, which could be influenced by its origin. This study evaluated the association among the antimicrobial resistance, virulence, and origin of circulating S. enterica strains in Mexico, isolated from foods, humans, and the environment. The antimicrobial susceptibility to fourteen antibiotics by the Kirby-Bauer method (n = 117), and the presence of thirteen virulence genes by multiplex PCR (n = 153) and by sequence alignments (n = 2963) were evaluated. In addition, a set of S. enterica isolates from Mexico (n = 344) previously characterized according to their genotypic and phenotypic print was included to increase the coverage of the association analysis. Strains with the presence of sopE and strains with the absence of sspH1 were significantly associated with multidrug-resistant (MDR) phenotypes (p < 0.05). The origin of the strains had significant associations with the antimicrobial profiles and some virulence genes (hilA, orgA, sifA, ssaQ, sseL, sspH1, pefA, and spvC) (p < 0.05). Animal-origin food isolates showed the highest frequency of MDR (57.2 %), followed by human isolates (30.0 %). Also, sspH1, pefA, and spvC were found in major frequency in human (32.4 %, 31.0 %, 31.7 %) and animal-origin foods (41.6 %, 10.6 %, 10.6 %) isolates. The findings highlighted that antimicrobial profiles and specific virulence genes of S. enterica strains are related to their origin. Similar genotypic and phenotypic characteristics between human and animal-origin foods isolates were found, suggesting that animal-origin foods isolates are the most responsible for human cases. The revealed associations can be used to improve risk estimation assessments in national food safety surveillance programs.
Collapse
Affiliation(s)
- A Hernández-Ledesma
- Departamento de Investigación y Posgrado de Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas s/n, Col. Las Campanas, 76010 Querétaro, Qro., Mexico
| | - E Cabrera-Díaz
- Departamento de Salud Pública, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, Camino Ramón Padilla Sánchez 2100, Zapopan, Jalisco 45200, Mexico
| | - S M Arvizu-Medrano
- Departamento de Investigación y Posgrado de Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas s/n, Col. Las Campanas, 76010 Querétaro, Qro., Mexico
| | - A Gómez-Baltazar
- Departamento de Investigación y Posgrado de Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas s/n, Col. Las Campanas, 76010 Querétaro, Qro., Mexico
| | - M Hernández-Iturriaga
- Departamento de Investigación y Posgrado de Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas s/n, Col. Las Campanas, 76010 Querétaro, Qro., Mexico
| | - A Godínez-Oviedo
- Departamento de Investigación y Posgrado de Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Cerro de las Campanas s/n, Col. Las Campanas, 76010 Querétaro, Qro., Mexico.
| |
Collapse
|
4
|
Sallami I, Turki Y, Werheni Ammeri R, Khelifi N, Hassen A. Effects of heavy metals on growth and biofilm-producing abilities of Salmonella enterica isolated from Tunisia. Arch Microbiol 2022; 204:225. [DOI: 10.1007/s00203-022-02836-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 02/19/2022] [Accepted: 03/10/2022] [Indexed: 11/30/2022]
|
5
|
Godínez-Oviedo A, Cabrera-Díaz E, Palacios-Marmolejo A, Pérez-Covarrubias OB, Vargas-Daniel RC, Tamplin ML, Bowman JP, Hernández-Iturriaga M. Detection, quantification, and characterization of Salmonella enterica in mango, tomato, and raw chicken purchased in the central region of Mexico. J Food Sci 2021; 87:370-382. [PMID: 34954835 DOI: 10.1111/1750-3841.16003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 11/18/2021] [Accepted: 11/19/2021] [Indexed: 11/29/2022]
Abstract
To estimate human exposure to Salmonella enterica, it is essential to understand the pathogen distribution and characteristics. Prevalence and concentration of S. enterica were determined in mango, tomato, and raw chicken samples purchased in three states (Aguascalientes, Querétaro, and Guadalajara) located in the central region of Mexico during two seasons. In addition, S. enterica isolates were characterized by absence/presence of 13 virulence genes (chromosomal, prophage, and plasmid) and resistance to 14 antibiotics. A total of 300 samples of mango, 272 of tomato, and 354 of raw chicken were analyzed. The mean of the prevalence (24.9%) and concentration (-0.61 Log MPN/g) of S. enterica in chicken was higher than in mango (1.3%, -1.7 Log MPN/g) and tomato (1.1%, -1.7 Log MPN). Among S. enterica isolates (284), there were 7 different virulotypes, belonging 68.7% of isolates to V2; there was high variability in the presence of mobile genetic elements. The occurrence of specific mobile elements ranged from 81.4% to 11.3% among isolates. Among the isolates, 91.5% were resistant to at least one antibiotic with ampicillin being the most frequent; 54.9% of isolates were multidrug resistant. Data from this study can be used for quantitative microbial risk assessment of S. enterica related to mango, tomato, and raw chicken consumption in the central region of Mexico. PRACTICAL APPLICATION: Data on the prevalence and concentration of Salmonella enterica obtained in this study can be used to estimate the exposure assessment for the consumption of mango, tomato, and chicken in the central region of Mexico. In addition, the characteristics of the S. enterica isolates could be used to select representative strains for future studies to evaluate the intraspecies variability.
Collapse
Affiliation(s)
- Angélica Godínez-Oviedo
- Departamento de Investigación y Posgrado de Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario Cerro de las Campanas S/N, Querétaro, México
| | - Elisa Cabrera-Díaz
- Departamento de Salud Pública, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, Zapopan, México
| | | | - Olga Berenice Pérez-Covarrubias
- Departamento de Salud Pública, Centro Universitario de Ciencias Biológicas y Agropecuarias, Universidad de Guadalajara, Zapopan, México
| | | | - Mark L Tamplin
- Food Safety and Innovation Centre, Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Australia
| | - John P Bowman
- Food Safety and Innovation Centre, Tasmanian Institute of Agriculture, University of Tasmania, Hobart, Australia
| | - Montserrat Hernández-Iturriaga
- Departamento de Investigación y Posgrado de Alimentos, Facultad de Química, Universidad Autónoma de Querétaro, Centro Universitario Cerro de las Campanas S/N, Querétaro, México
| |
Collapse
|
6
|
Luo Y, Huang C, Ye J, Octavia S, Wang H, Dunbar SA, Jin D, Tang YW, Lan R. Comparison of xMAP Salmonella Serotyping Assay With Traditional Serotyping and Discordance Resolution by Whole Genome Sequencing. Front Cell Infect Microbiol 2020; 10:452. [PMID: 33014887 PMCID: PMC7504902 DOI: 10.3389/fcimb.2020.00452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 07/23/2020] [Indexed: 11/14/2022] Open
Abstract
Salmonella spp. are a major cause of foodborne illness throughout the world. Traditional serotyping by antisera agglutination has been used as a standard identification method for many years but newer nucleic acid-based tests have become available that may provide advantages in workflow and test turnaround time. In this study, we evaluated the Luminex® xMAP® Salmonella Serotyping Assay (SSA), a multiplex nucleic acid test capable of identifying 85% of the most common Salmonella serotypes, in comparison to the traditional serum agglutination test (SAT) on 4 standard strains and 255 isolates from human (224), environmental, and food (31) samples. Of the total of 259 isolates, 256 could be typed by the SSA. Of these, 197 (77.0%) were fully typed and 59 (23.0%) were partially typed. By SAT, 246 of the 259 isolates (95%) were successfully typed. Sixty isolates had discrepant results between SAT and SSA and were resolved using whole genome sequencing (WGS). By SAT, 80.0% (48/60) of the isolates were consistent with WGS while by SSA 91.7% (55/60) were partially consistent with WGS. By serovar, all 30 serovars except one tested were fully or partially typable. The workflow comparison showed that SSA provided advantages over SAT with a hands-on time (HOT) of 3.5 min and total turnaround time (TAT) of 6 h, as compared to 1 h HOT and 2–6 days TAT for SAT. Overall, this study showed that molecular serotyping is promising as a rapid method for Salmonella serotyping with good accuracy for typing most common Salmonella serovars circulating in China.
Collapse
Affiliation(s)
- Yun Luo
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia.,Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Chen Huang
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Julian Ye
- Zhejiang Provincial Center for Disease Control and Prevention, Hangzhou, China
| | - Sophie Octavia
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Huanying Wang
- Key Laboratory of Microbial Technology and Bioinformatics of Zhejiang Province, Zhejiang Institute of Microbiology, Hangzhou, China
| | | | - Dazhi Jin
- Centre of Laboratory Medicine, Zhejiang Provincial People Hospital, People's Hospital of Hangzhou Medical College, Hangzhou, China.,School of Laboratory Medicine, Hangzhou Medical College, Hangzhou, China
| | - Yi-Wei Tang
- Department of Laboratory Medicine, Memorial Sloan Kettering Cancer Center, New York, NY, United States.,Department of Pathology and Laboratory Medicine, Weill Medical College of Cornell University, New York, NY, United States.,Cepheid, Danaher Diagnostic Platform, Shanghai, China
| | - Ruiting Lan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, Australia
| |
Collapse
|
7
|
Shen Y, Nie J, Kuang L, Zhang J, Li H. DNA sequencing, genomes and genetic markers of microbes on fruits and vegetables. Microb Biotechnol 2020; 14:323-362. [PMID: 32207561 PMCID: PMC7936329 DOI: 10.1111/1751-7915.13560] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 03/01/2020] [Accepted: 03/02/2020] [Indexed: 12/20/2022] Open
Abstract
The development of DNA sequencing technology has provided an effective method for studying foodborne and phytopathogenic microorganisms on fruits and vegetables (F & V). DNA sequencing has successfully proceeded through three generations, including the tens of operating platforms. These advances have significantly promoted microbial whole‐genome sequencing (WGS) and DNA polymorphism research. Based on genomic and regional polymorphisms, genetic markers have been widely obtained. These molecular markers are used as targets for PCR or chip analyses to detect microbes at the genetic level. Furthermore, metagenomic analyses conducted by sequencing the hypervariable regions of ribosomal DNA (rDNA) have revealed comprehensive microbial communities in various studies on F & V. This review highlights the basic principles of three generations of DNA sequencing, and summarizes the WGS studies of and available DNA markers for major bacterial foodborne pathogens and phytopathogenic fungi found on F & V. In addition, rDNA sequencing‐based bacterial and fungal metagenomics are summarized under three topics. These findings deepen the understanding of DNA sequencing and its application in studies of foodborne and phytopathogenic microbes and shed light on strategies for the monitoring of F & V microbes and quality control.
Collapse
Affiliation(s)
- Youming Shen
- Institute of Pomology, Chinese Academy of Agricultural Sciences/Laboratory of Quality & Safety Risk Assessment for Fruit (Xingcheng), Ministry of Agriculture and Rural Affairs/Quality Inspection and Test Center for Fruit and Nursery Stocks (Xingcheng), Ministry of Agriculture and Rural Affairs, Xingcheng, 125100, China
| | - Jiyun Nie
- Institute of Pomology, Chinese Academy of Agricultural Sciences/Laboratory of Quality & Safety Risk Assessment for Fruit (Xingcheng), Ministry of Agriculture and Rural Affairs/Quality Inspection and Test Center for Fruit and Nursery Stocks (Xingcheng), Ministry of Agriculture and Rural Affairs, Xingcheng, 125100, China.,College of Horticulture, Qingdao Agricultural University, Qingdao, 266109, China
| | - Lixue Kuang
- Institute of Pomology, Chinese Academy of Agricultural Sciences/Laboratory of Quality & Safety Risk Assessment for Fruit (Xingcheng), Ministry of Agriculture and Rural Affairs/Quality Inspection and Test Center for Fruit and Nursery Stocks (Xingcheng), Ministry of Agriculture and Rural Affairs, Xingcheng, 125100, China
| | - Jianyi Zhang
- Institute of Pomology, Chinese Academy of Agricultural Sciences/Laboratory of Quality & Safety Risk Assessment for Fruit (Xingcheng), Ministry of Agriculture and Rural Affairs/Quality Inspection and Test Center for Fruit and Nursery Stocks (Xingcheng), Ministry of Agriculture and Rural Affairs, Xingcheng, 125100, China
| | - Haifei Li
- Institute of Pomology, Chinese Academy of Agricultural Sciences/Laboratory of Quality & Safety Risk Assessment for Fruit (Xingcheng), Ministry of Agriculture and Rural Affairs/Quality Inspection and Test Center for Fruit and Nursery Stocks (Xingcheng), Ministry of Agriculture and Rural Affairs, Xingcheng, 125100, China
| |
Collapse
|
8
|
Carvalho D, Kunert-Filho HC, Simoni C, de Moraes LB, Furian TQ, Borges KA, Breunig JG, Medeiros LP, Kobayashi RKT, de Brito KCT, de Brito BG. Antimicrobial susceptibility and detection of virulence-associated genes of Escherichia coli and Salmonella spp. isolated from domestic pigeons (Columba livia) in Brazil. Folia Microbiol (Praha) 2020; 65:735-745. [PMID: 32180120 DOI: 10.1007/s12223-020-00781-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 02/18/2020] [Indexed: 12/16/2022]
Abstract
Overpopulation of domestic pigeons is considered to be one of the major problems of urban centers, as these birds are responsible for the dissemination of relevant pathogens to animal and human health. The aim of this study was to detect potentially pathogenic Escherichia coli and Salmonella spp. in domestic pigeons captured in areas near silos used for grain and feed storage, analyzing the antimicrobial sensitivity and the presence of virulence-associated genes. We evaluated 41 pigeons. From each bird, cecal contents and a pool of viscera (heart, spleen, and liver) were collected. Fifty strains of E. coli and three strains of S. Typhimurium were isolated. The antimicrobial susceptibility assay showed that 2% of the isolates of E. coli were resistant to chloramphenicol and the combination of sulfamethoxazole + trimethoprim and 4% to tetracycline, doxycycline, and sulfonamide. The three S. Typhimurium strains were sensitive to all antimicrobials tested. The pathogenicity profile demonstrated that no E. coli isolates showed a STEC compatible profile. Regarding the APEC pathotype, all genes were observed in 8% of E. coli, 6% had only the iss gene and 4% presented ompT, hlyF, and iutA genes. invA, hilA, avrA, and lpfA genes were detected in 100% of Salmonella isolates. The sitC and pefA genes were only present in one strain and the remaining genes were detected in two. In conclusion, it was found that pigeons living in the vicinity of silos are carriers of important pathogens, and control measures should be taken to minimize animal and human health risks.
Collapse
Affiliation(s)
- Daiane Carvalho
- Centro de Diagnóstico e Pesquisa em Patologia Aviária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 8824, Porto Alegre, RS, CEP 91540-000, Brazil
| | - Hiran Castagnino Kunert-Filho
- Centro de Diagnóstico e Pesquisa em Patologia Aviária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 8824, Porto Alegre, RS, CEP 91540-000, Brazil
| | - Cintia Simoni
- Laboratório de Saúde das Aves & Inovação Tecnológica, Instituto de Pesquisas Veterinárias Desidério Finamor, Departamento de Diagnóstico e Pesquisa Agropecuária, Secretaria da Agricultura, Pecuária e Desenvolvimento Rural do Rio Grande do Sul, Estrada do Conde 6000, Eldorado do Sul, RS, CEP 92990-000, Brazil
| | - Lucas Brunelli de Moraes
- Laboratório de Histopatologia, Instituto de Pesquisas Veterinárias Desidério Finamor, Departamento de Diagnóstico e Pesquisa Agropecuária, Secretaria da Agricultura, Pecuária e Desenvolvimento Rural do Rio Grande do Sul, Estrada do Conde 6000, Eldorado do Sul, RS, CEP 92990-000, Brazil
| | - Thales Quedi Furian
- Centro de Diagnóstico e Pesquisa em Patologia Aviária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 8824, Porto Alegre, RS, CEP 91540-000, Brazil
| | - Karen Apellanis Borges
- Centro de Diagnóstico e Pesquisa em Patologia Aviária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Av. Bento Gonçalves 8824, Porto Alegre, RS, CEP 91540-000, Brazil.
| | - Jônatas Grellmann Breunig
- Laboratório de Saúde das Aves & Inovação Tecnológica, Instituto de Pesquisas Veterinárias Desidério Finamor, Departamento de Diagnóstico e Pesquisa Agropecuária, Secretaria da Agricultura, Pecuária e Desenvolvimento Rural do Rio Grande do Sul, Estrada do Conde 6000, Eldorado do Sul, RS, CEP 92990-000, Brazil
| | - Leonardo Pinto Medeiros
- Laboratório de Bacteriologia Básica e Aplicada, Universidade Estadual de Londrina, Rodovia Celso Garcia Cid, PR 445 - Km 380, Londrina, PR, CEP 86057-970, Brazil
| | - Renata Katsuko Takayama Kobayashi
- Laboratório de Bacteriologia Básica e Aplicada, Universidade Estadual de Londrina, Rodovia Celso Garcia Cid, PR 445 - Km 380, Londrina, PR, CEP 86057-970, Brazil
| | - Kelly Cristina Tagliari de Brito
- Laboratório de Saúde das Aves & Inovação Tecnológica, Instituto de Pesquisas Veterinárias Desidério Finamor, Departamento de Diagnóstico e Pesquisa Agropecuária, Secretaria da Agricultura, Pecuária e Desenvolvimento Rural do Rio Grande do Sul, Estrada do Conde 6000, Eldorado do Sul, RS, CEP 92990-000, Brazil
| | - Benito Guimarães de Brito
- Laboratório de Saúde das Aves & Inovação Tecnológica, Instituto de Pesquisas Veterinárias Desidério Finamor, Departamento de Diagnóstico e Pesquisa Agropecuária, Secretaria da Agricultura, Pecuária e Desenvolvimento Rural do Rio Grande do Sul, Estrada do Conde 6000, Eldorado do Sul, RS, CEP 92990-000, Brazil
| |
Collapse
|
9
|
Diep B, Barretto C, Portmann AC, Fournier C, Karczmarek A, Voets G, Li S, Deng X, Klijn A. Salmonella Serotyping; Comparison of the Traditional Method to a Microarray-Based Method and an in silico Platform Using Whole Genome Sequencing Data. Front Microbiol 2019; 10:2554. [PMID: 31781065 PMCID: PMC6859910 DOI: 10.3389/fmicb.2019.02554] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 10/22/2019] [Indexed: 11/13/2022] Open
Abstract
Salmonella is one of the most common causes of food-borne diseases worldwide. While Salmonella molecular subtyping by Whole Genome Sequencing (WGS) is increasingly used for outbreak and source tracking investigations, serotyping remains as a first-line characterization of Salmonella isolates. The traditional phenotypic method for serotyping is logistically challenging, as it requires the use of more than 150 specific antisera and well trained personnel to interpret the results. Consequently, it is not a routine method for the majority of laboratories. Several rapid molecular methods targeting O and H loci or surrogate genomic markers have been developed as alternative solutions. With the expansion of WGS, in silico Salmonella serotype prediction using WGS data is available. Here, we compared a microarray method using molecular markers, the Check and Trace Salmonella assay (CTS) and a WGS-based serotype prediction tool that targets molecular determinants of serotype (SeqSero) to the traditional phenotypic method using 100 strains representing 45 common and uncommon serotypes. Compared to the traditional method, the CTS assay correctly serotyped 97% of the strains, four strains gave a double serotype prediction. Among the inconclusive data, one strain was not predicted and two strains were incorrectly identified. SeqSero was evaluated with two versions (SeqSero 1 and the alpha test version of SeqSero 2). The correct antigenic formula was predicted by SeqSero 1 for 96 and 95% of strains using raw reads and assembly, respectively. However, 34 and 33% of these predictions included multiple serotypes by raw reads and assembly. With raw reads, one strain was not identified and three strains were discordant with phenotypic serotyping result. With assembly, three strains were not predicted and two strains were incorrectly predicted. While still under development, SeqSero 2 maintained the accuracy of antigenic formula prediction at 98% and reduced multiple serotype prediction rate to 13%. One strain had no prediction and one strain was incorrectly predicted. Our study indicates that the CTS assay is a good alternative for routine laboratories as it is an easy to use method with a short turn-around-time. SeqSero is a reliable replacement for phenotypic serotyping if WGS is routinely implemented.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Shaoting Li
- Center for Food Safety, University of Georgia, Athens, GA, United States
| | - Xiangyu Deng
- Center for Food Safety, University of Georgia, Athens, GA, United States
| | | |
Collapse
|
10
|
Borges KA, Furian TQ, de Souza SN, Menezes R, Salle CTP, de Souza Moraes HL, Tondo EC, do Nascimento VP. Phenotypic and Molecular Characterization of Salmonella Enteritidis SE86 Isolated from Poultry and Salmonellosis Outbreaks. Foodborne Pathog Dis 2017; 14:742-754. [PMID: 29106298 DOI: 10.1089/fpd.2017.2327] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Salmonella Enteritidis remains a standout among the leading causes of foodborne diseases worldwide. Previous studies have demonstrated that a unique clonal group of Salmonella Enteritidis, named SE86, is involved in foodborne outbreaks in southern Brazil and is frequently identified among strains isolated from poultry. The aim of this study was to determine the influence of the isolation source (food products involved in salmonellosis outbreaks and poultry sources) on the phenotypic and molecular characteristics of Salmonella Enteritidis SE86. A biofilm formation assay, antimicrobial susceptibility test, polymerase chain reaction identification of virulence-associated genes, and phage type 4 (PT4) assessment were performed to characterize Salmonella Enteritidis SE86. The human strains presented less antimicrobial resistance than the poultry strains. Resistance to some substances was related to the isolation source of the strain. Strains of the same clonal group presented different biofilm production abilities. Biofilm formation was independent of the isolation source at all temperatures. Temperature influenced biofilm formation only by the poultry strains. Most of the investigated genes presented a high frequency and a regular distribution, regardless of the isolation source. The spvB, spiA, pagC, sipB, prgH, spaN, sitC, and lpfC genes were associated with the avian strains, whereas iroN was associated with the strains isolated from food products involved in salmonellosis outbreaks. Most strains belonged to PT4. No relationship was found between biofilm production and antimicrobial resistance or between the virulence profile and biofilm production or antimicrobial resistance.
Collapse
Affiliation(s)
- Karen Apellanis Borges
- 1 Departamento de Medicina Animal, Faculdade de Veterinária, Centro de Diagnóstico e Pesquisa em Patologia Aviária (CDPA), Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre, Brazil
| | - Thales Quedi Furian
- 1 Departamento de Medicina Animal, Faculdade de Veterinária, Centro de Diagnóstico e Pesquisa em Patologia Aviária (CDPA), Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre, Brazil
| | - Sara Neves de Souza
- 1 Departamento de Medicina Animal, Faculdade de Veterinária, Centro de Diagnóstico e Pesquisa em Patologia Aviária (CDPA), Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre, Brazil
| | - Rafaela Menezes
- 1 Departamento de Medicina Animal, Faculdade de Veterinária, Centro de Diagnóstico e Pesquisa em Patologia Aviária (CDPA), Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre, Brazil
| | - Carlos Tadeu Pippi Salle
- 1 Departamento de Medicina Animal, Faculdade de Veterinária, Centro de Diagnóstico e Pesquisa em Patologia Aviária (CDPA), Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre, Brazil
| | - Hamilton Luiz de Souza Moraes
- 1 Departamento de Medicina Animal, Faculdade de Veterinária, Centro de Diagnóstico e Pesquisa em Patologia Aviária (CDPA), Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre, Brazil
| | - Eduardo César Tondo
- 2 Instituto de Ciência e Tecnologia dos Alimentos (ICTA) , Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Vladimir Pinheiro do Nascimento
- 1 Departamento de Medicina Animal, Faculdade de Veterinária, Centro de Diagnóstico e Pesquisa em Patologia Aviária (CDPA), Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre, Brazil
| |
Collapse
|
11
|
Zappelini L, Martone-Rocha S, Dropa M, Matté MH, Tiba MR, Breternitz BS, Razzolini MTP. Effective characterization of Salmonella Enteritidis by most probable number (MPN) followed by multiplex polymerase chain reaction (PCR) methods. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2017; 24:4828-4834. [PMID: 27987122 DOI: 10.1007/s11356-016-8109-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 11/14/2016] [Indexed: 06/06/2023]
Abstract
Nontyphoidal Salmonella (NTS) is a relevant pathogen involved in gastroenteritis outbreaks worldwide. In this study, we determined the capacity to combine the most probable number (MPN) and multiplex polymerase chain reaction (PCR) methods to characterize the most important Salmonella serotypes in raw sewage. A total of 499 isolates were recovered from 27 raw sewage samples and screened using two previously described multiplex PCR methods. From those, 123 isolates were selected based on PCR banding pattern-identical or similar to Salmonella Enteritidis and Salmonella Typhimurium-and submitted to conventional serotyping. Results showed that both PCR assays correctly serotyped Salmonella Enteritidis, however, they presented ambiguous results for Salmonella Typhimurium identification. These data highlight that MPN and multiplex PCR can be useful methods to describe microbial quality in raw sewage and suggest two new PCR patterns for Salmonella Enteritidis identification.
Collapse
Affiliation(s)
- Lincohn Zappelini
- Department of Environmental Health, School of Public Health, University of São Paulo, São Paulo, SP, Brazil.
| | - Solange Martone-Rocha
- Department of Environmental Health, School of Public Health, University of São Paulo, São Paulo, SP, Brazil
| | - Milena Dropa
- Department of Environmental Health, School of Public Health, University of São Paulo, São Paulo, SP, Brazil
| | - Maria Helena Matté
- Department of Public Health Practice, School of Public Health, University of São Paulo, São Paulo, SP, Brazil
| | - Monique Ribeiro Tiba
- Center of Enteric Diseases and Special Pathogens Infections, Bacteriology Center, Adolfo Lutz Institute, São Paulo, SP, Brazil
| | - Bruna Suellen Breternitz
- Department of Environmental Health, School of Public Health, University of São Paulo, São Paulo, SP, Brazil
| | | |
Collapse
|
12
|
Salazar JK, Wang Y, Yu S, Wang H, Zhang W. Polymerase chain reaction-based serotyping of pathogenic bacteria in food. J Microbiol Methods 2015; 110:18-26. [DOI: 10.1016/j.mimet.2015.01.009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Revised: 01/09/2015] [Accepted: 01/14/2015] [Indexed: 10/24/2022]
|
13
|
Chui L, Li V. Technical and Software Advances in Bacterial Pathogen Typing. METHODS IN MICROBIOLOGY 2015. [DOI: 10.1016/bs.mim.2015.06.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
14
|
Krzyzanowski F, Zappelini L, Martone-Rocha S, Dropa M, Matté MH, Nacache F, Razzolini MTP. Quantification and characterization of Salmonella spp. isolates in sewage sludge with potential usage in agriculture. BMC Microbiol 2014; 14:263. [PMID: 25927729 PMCID: PMC4207900 DOI: 10.1186/s12866-014-0263-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Accepted: 10/02/2014] [Indexed: 11/10/2022] Open
Abstract
Background This study aims to scrutinize Salmonella spp. and its serotypes in sewage sludge samples from wastewater treatment plants, and assesses the presence of virulence genes and antibiotics resistant to the profile. Samples (n = 54) were collected and analyzed in accordance with the EPA Method 1682/2006. For positive serological reaction, 40 strains were selected for PCR analyses and detection of spvC, invA and sseL virulence genes, plasmid presence and resistance to antibiotics. Results Salmonella spp. was detected in 38.9% of the samples collected (<0.006473 to 12.19 MPN/gTS). The most prevalent serotype was Salmonella Infantis. All Salmonella spp. (n = 35) presented at least one of the three virulence genes mentioned above and 40% harboured plasmids. Salmonella Typhimurium strains were isolated harbouring at least one of the following virulence genes: spvC, invA or sseL. Four Salmonella spp. isolates were resistant to tetracycline; three were resistant to trimethoprim-sulfamethoxazole, and one isolate was resistant to ciprofloxacin. Two Salmonella spp. strains presented multi resistance to antimicrobial agents. Conclusions The results obtained demonstrated that Salmonella spp. have been found in sewage sludge, thus it is essential to set measures to mitigate human health risks when it is intended to be applied on agricultural soils.
Collapse
Affiliation(s)
- Flávio Krzyzanowski
- Instituto Federal de Educação, Ciência e Tecnologia de São Paulo - Brasil, Rua Pedro Vicente 625, 01109-010, São Paulo, Brazil. .,School of Public Health of University of São Paulo-Brazil, Av. Dr Arnaldo 715, 1°andar, 01246-904, São Paulo, Brasil.
| | - Lincohn Zappelini
- Instituto Federal de Educação, Ciência e Tecnologia de São Paulo - Brasil, Rua Pedro Vicente 625, 01109-010, São Paulo, Brazil. .,School of Public Health of University of São Paulo-Brazil, Av. Dr Arnaldo 715, 1°andar, 01246-904, São Paulo, Brasil.
| | - Solange Martone-Rocha
- School of Public Health of University of São Paulo-Brazil, Av. Dr Arnaldo 715, 1°andar, 01246-904, São Paulo, Brasil.
| | - Milena Dropa
- School of Public Health of University of São Paulo-Brazil, Av. Dr Arnaldo 715, 1°andar, 01246-904, São Paulo, Brasil.
| | - Maria Helena Matté
- School of Public Health of University of São Paulo-Brazil, Av. Dr Arnaldo 715, 1°andar, 01246-904, São Paulo, Brasil.
| | - Flávia Nacache
- School of Public Health of University of São Paulo-Brazil, Av. Dr Arnaldo 715, 1°andar, 01246-904, São Paulo, Brasil.
| | - Maria Tereza Pepe Razzolini
- School of Public Health of University of São Paulo-Brazil, Av. Dr Arnaldo 715, 1°andar, 01246-904, São Paulo, Brasil.
| |
Collapse
|
15
|
Yoshida C, Lingohr EJ, Trognitz F, MacLaren N, Rosano A, Murphy SA, Villegas A, Polt M, Franklin K, Kostic T, Kropinski AM, Card RM. Multi-laboratory evaluation of the rapid genoserotyping array (SGSA) for the identification of Salmonella serovars. Diagn Microbiol Infect Dis 2014; 80:185-90. [PMID: 25219780 DOI: 10.1016/j.diagmicrobio.2014.08.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Revised: 07/31/2014] [Accepted: 08/21/2014] [Indexed: 10/24/2022]
Abstract
Salmonella serotyping is an essential first step for identification of isolates associated with disease outbreaks. The Salmonella genoserotyping array (SGSA) is a microarray-based alternative to standard serotyping designed to rapidly identify 57 of the most commonly reported serovars through detection of the genes encoding surface O and H antigens and reporting the corresponding serovar in accordance with the existing White-Kaufmann-Le Minor serotyping scheme. In this study, we evaluated the SGSA at 4 laboratories in 3 countries by testing 1874 isolates from human and non-human sources. The SGSA correctly identified 96.7% of isolates from the target 57 serovars. For the prevalent and clinically important Salmonella serovars Enteritidis and Typhimurium, test specificity and sensitivity were greater than 98% and 99%, respectively. Due to its high-throughput nature, the SGSA is a rapid and cost-effective alternative to standard serotyping for identifying the most prevalent serovars of Salmonella.
Collapse
Affiliation(s)
- Catherine Yoshida
- Laboratory for Foodborne Zoonoses, Public Health Agency of Canada (PHAC), Guelph, Ontario, Canada N1G 3W4.
| | - Erika J Lingohr
- Laboratory for Foodborne Zoonoses, Public Health Agency of Canada (PHAC), Guelph, Ontario, Canada N1G 3W4
| | | | - Nikki MacLaren
- Animal Health and Veterinary Laboratories Agency (AHVLA), New Haw, Addlestone, Surrey, United Kingdom KT15 3NB
| | - Andrea Rosano
- Laboratory for Foodborne Zoonoses, Public Health Agency of Canada (PHAC), Guelph, Ontario, Canada N1G 3W4
| | - Stephanie A Murphy
- Laboratory for Foodborne Zoonoses, Public Health Agency of Canada (PHAC), Guelph, Ontario, Canada N1G 3W4
| | - Andre Villegas
- Laboratory for Foodborne Zoonoses, Public Health Agency of Canada (PHAC), Guelph, Ontario, Canada N1G 3W4
| | - Marlies Polt
- Austrian Institute of Technology (AIT), 3430 Tulln an der Donau, Austria
| | - Kristyn Franklin
- Laboratory for Foodborne Zoonoses, Public Health Agency of Canada (PHAC), Guelph, Ontario, Canada N1G 3W4
| | - Tanja Kostic
- Austrian Institute of Technology (AIT), 3430 Tulln an der Donau, Austria
| | | | | | - Andrew M Kropinski
- Laboratory for Foodborne Zoonoses, Public Health Agency of Canada (PHAC), Guelph, Ontario, Canada N1G 3W4
| | - Roderick M Card
- Animal Health and Veterinary Laboratories Agency (AHVLA), New Haw, Addlestone, Surrey, United Kingdom KT15 3NB
| |
Collapse
|
16
|
Shi C, Singh P, Ranieri ML, Wiedmann M, Moreno Switt AI. Molecular methods for serovar determination of Salmonella. Crit Rev Microbiol 2013; 41:309-25. [PMID: 24228625 DOI: 10.3109/1040841x.2013.837862] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Salmonella is a diverse foodborne pathogen, which has more than 2600 recognized serovars. Classification of Salmonella isolates into serovars is essential for surveillance and epidemiological investigations; however, determination of Salmonella serovars, by traditional serotyping, has some important limitations (e.g. labor intensive, time consuming). To overcome these limitations, multiple methods have been investigated to develop molecular serotyping schemes. Currently, molecular methods to predict Salmonella serovars include (i) molecular subtyping methods (e.g. PFGE, MLST), (ii) classification using serovar-specific genomic markers and (iii) direct methods, which identify genes encoding antigens or biosynthesis of antigens used for serotyping. Here, we reviewed reported methodologies for Salmonella molecular serotyping and determined the "serovar-prediction accuracy", as the percentage of isolates for which the serovar was correctly classified by a given method. Serovar-prediction accuracy ranged from 0 to 100%, 51 to 100% and 33 to 100% for molecular subtyping, serovar-specific genomic markers and direct methods, respectively. Major limitations of available schemes are errors in predicting closely related serovars (e.g. Typhimurium and 4,5,12:i:-), and polyphyletic serovars (e.g. Newport, Saintpaul). The high diversity of Salmonella serovars represents a considerable challenge for molecular serotyping approaches. With the recent improvement in sequencing technologies, full genome sequencing could be developed into a promising molecular approach to serotype Salmonella.
Collapse
Affiliation(s)
- Chunlei Shi
- Department of Food Science, Cornell University , Ithaca, NY , USA and
| | | | | | | | | |
Collapse
|
17
|
Unc A, Zurek L, Peterson G, Narayanan S, Springthorpe SV, Sattar SA. Microarray assessment of virulence, antibiotic, and heavy metal resistance in an agricultural watershed creek. JOURNAL OF ENVIRONMENTAL QUALITY 2012; 41:534-543. [PMID: 22370416 DOI: 10.2134/jeq2011.0172] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Potential risks associated with impaired surface water quality have commonly been evaluated by indirect description of potential sources using various fecal microbial indicators and derived source-tracking methods. These approaches are valuable for assessing and monitoring the impacts of land-use changes and changes in management practices at the source of contamination. A more detailed evaluation of putative etiologically significant genetic determinants can add value to these assessments. We evaluated the utility of using a microarray that integrates virulence genes with antibiotic and heavy metal resistance genes to describe and discriminate among spatially and seasonally distinct water samples from an agricultural watershed creek in Eastern Ontario. Because microarray signals may be analyzed as binomial distributions, the significance of ambiguous signals can be easily evaluated by using available off-the-shelf software. The FAMD software was used to evaluate uncertainties in the signal data. Analysis of multilocus fingerprinting data sets containing missing data has shown that, for the tested system, any variability in microarray signals had a marginal effect on data interpretation. For the tested watershed, results suggest that in general the wet fall season increased the downstream detection of virulence and resistance genes. Thus, the tested microarray technique has the potential to rapidly describe the quality of surface waters and thus to provide a qualitative tool to augment quantitative microbial risk assessments.
Collapse
Affiliation(s)
- Adrian Unc
- Department of Plant and Environmental Sciences, New Mexico State University, Las Cruces, NM, USA.
| | | | | | | | | | | |
Collapse
|
18
|
Methodologies for Salmonella enterica subsp. enterica subtyping: gold standards and alternatives. Appl Environ Microbiol 2011; 77:7877-85. [PMID: 21856826 DOI: 10.1128/aem.05527-11] [Citation(s) in RCA: 169] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
For more than 80 years, subtyping of Salmonella enterica has been routinely performed by serotyping, a method in which surface antigens are identified based on agglutination reactions with specific antibodies. The serotyping scheme, which is continuously updated as new serovars are discovered, has generated over time a data set of the utmost significance, allowing long-term epidemiological surveillance of Salmonella in the food chain and in public health control. Conceptually, serotyping provides no information regarding the phyletic relationships inside the different Salmonella enterica subspecies. In epidemiological investigations, identification and tracking of salmonellosis outbreaks require the use of methods that can fingerprint the causative strains at a taxonomic level far more specific than the one achieved by serotyping. During the last 2 decades, alternative methods that could successfully identify the serovar of a given strain by probing its DNA have emerged, and molecular biology-based methods have been made available to address phylogeny and fingerprinting issues. At the same time, accredited diagnostics have become increasingly generalized, imposing stringent methodological requirements in terms of traceability and measurability. In these new contexts, the hand-crafted character of classical serotyping is being challenged, although it is widely accepted that classification into serovars should be maintained. This review summarizes and discusses modern typing methods, with a particular focus on those having potential as alternatives for classical serotyping or for subtyping Salmonella strains at a deeper level.
Collapse
|
19
|
Liu B, Zhang L, Zhu X, Shi C, Chen J, Liu W, He X, Shi X. PCR identification of Salmonella serogroups based on specific targets obtained by comparative genomics. Int J Food Microbiol 2011; 144:511-8. [DOI: 10.1016/j.ijfoodmicro.2010.11.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Revised: 11/01/2010] [Accepted: 11/07/2010] [Indexed: 11/28/2022]
|