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Liu B, Meng C, Han S, Li Q, Miao X, Wang Z, Xu C, Kang X, Jiao X, Pan Z. Development of a 1-step multiplex PCR assay for the detection of S. Enteritidis, S. Pullorum, S. Typhimurium, and S. Infantis associated with poultry production. Poult Sci 2024; 103:104043. [PMID: 39043031 DOI: 10.1016/j.psj.2024.104043] [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: 05/13/2024] [Revised: 06/23/2024] [Accepted: 06/24/2024] [Indexed: 07/25/2024] Open
Abstract
Salmonellosis in poultry is detrimental to the advancement of the breeding industry and poses hazards to human health. Approximately 2,600 Salmonella varieties exist, among which S. Enteritidis, S. Pullorum, S. Typhimurium, and S. Infantis are prevalent serotypes in the poultry industry in recent years. They can also infect humans by contaminating poultry eggs and meat. Therefore, identifying these serotypes is crucial for successful preventive and control interventions. The White-Kauffmann-Le Minor scheme is time-consuming and requires expensive reagents. Whole-genome sequencing (WGS) and other molecular biology techniques require skilled technical staff. In comparison, the polymerase chain reaction (PCR) is more accurate, rapid, and inexpensive, thus proving suitable for widespread application in the poultry industry. Here, we selected 4 specific primers: lygD, mdh, ipaJ, and SIN_02055, which correspond to detecting S. Enteritidis, S. Typhimurium, S. Pullorum, and S. Infantis, respectively. They were integrated into a 1-step multiplex PCR method. We optimized the PCR method by utilizing specificity test results to determine the optimal annealing temperature (57°C). The PCR method exhibited excellent sensitivity for genomic DNA and bacterial cultures. We used the developed method to determine 157 clinical Salmonella isolates from various stages of the poultry production chain. The results aligned with serotype data generated via WGS analysis, demonstrating the method's excellent accuracy. In conclusion, this study developed a 1-step multiplex PCR method that simultaneously identifies S. Enteritidis, S. Typhimurium, S. Pullorum, and S. Infantis, allowing routine mass detection in the grass-root poultry industry.
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Affiliation(s)
- Bowen Liu
- 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; Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou 225009, China
| | - Chuang Meng
- 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; Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou 225009, China
| | - Shunzi Han
- 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; Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Qing Li
- 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; Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China
| | - Xinyuan Miao
- 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; Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou 225009, China
| | - Zhenyu Wang
- 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; Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou 225009, China
| | - Chen Xu
- 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; Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou 225009, China
| | - Xilong Kang
- 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; Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou 225009, China
| | - Xinan Jiao
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou 225009, China
| | - Zhiming Pan
- Jiangsu Key Laboratory of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China; Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, Ministry of Agriculture of China, Yangzhou University, Yangzhou 225009, China; Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, Yangzhou 225009, China.
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2
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Guard J, Jones DR, Gast RK, Garcia JS, Rothrock MJ. Serotype Screening of Salmonella enterica Subspecies I by Intergenic Sequence Ribotyping (ISR): Critical Updates. Microorganisms 2022; 11:microorganisms11010097. [PMID: 36677389 PMCID: PMC9863722 DOI: 10.3390/microorganisms11010097] [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: 09/26/2022] [Revised: 12/20/2022] [Accepted: 12/21/2022] [Indexed: 01/03/2023] Open
Abstract
(1) Background: Foodborne illness from Salmonella enterica subspecies I is most associated with approximately 32 out of 1600 serotypes. While whole genome sequencing and other nucleic acid-based methods are preferred for serotyping, they require expertise in bioinformatics and often submission to an external agency. Intergenic Sequence Ribotyping (ISR) assigns serotype to Salmonella in coordination with information freely available at the National Center for Biotechnology Information. ISR requires updating because it was developed from 26 genomes while there are now currently 1804 genomes and 1685 plasmids. (2) Methods: Serotypes available for sequencing were analyzed by ISR to confirm primer efficacy and to identify any issues in application. Differences between the 2012 and 2022 ISR database were tabulated, nomenclature edited, and instances of multiple serotypes aligning to a single ISR were examined. (3) Results: The 2022 ISR database has 268 sequences and 40 of these were assigned new NCBI accession numbers that were not previously available. Extending boundaries of sequences resolved hdfR cross-alignment and reduced multiplicity of alignment for 37 ISRs. Comparison of gene cyaA sequences and some cell surface epitopes provided evidence that homologous recombination was potentially impacting results for this subset. There were 99 sequences that still had no match with an NCBI submission. (4) The 2022 ISR database is available for use as a serotype screening method for Salmonella enterica subspecies I. Finding that 36.9% of the sequences in the ISR database still have no match within the NCBI Salmonella enterica database suggests that there is more genomic heterogeneity yet to characterize.
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Affiliation(s)
- Jean Guard
- Correspondence: ; Tel.: +1-706-546-3131 or +1-706-546-3445
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3
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Retamal P, Gaspar J, Benavides MB, Saenz L, Galarce N, Aravena T, Cornejo J, Lapierre L. Virulence and antimicrobial resistance factors in Salmonella enterica serotypes isolated from pigs and chickens in central Chile. Front Vet Sci 2022; 9:971246. [PMID: 36204291 PMCID: PMC9530323 DOI: 10.3389/fvets.2022.971246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 08/31/2022] [Indexed: 11/13/2022] Open
Abstract
Salmonella enterica is a food-borne pathogen with a wide host-range that during decades has been of public health concern in developed and developing countries. In Chile, the poultry and pig industries represent the biggest contribution of meat consumption in the population, and sanitary regulations have been imposed for Salmonella control. The aim of this work was to determine and characterize Salmonella strains isolated from pigs and chicken raised on commercials farms in Chile. For this, isolates belonging to pigs (n = 46) and poultry (n = 57) were genotyped by two multiplex PCR reactions and virulotyped by the PCR detection of virulence-associated genes. In addition, isolates were serotyped and analyzed by the Kirby Bauer assay to determine their antimicrobial resistance phenotypes. From these analyses 52 genotypes, six serotypes and several multidrug resistance phenotypes and different combinations of virulence-associated genes were detected. These results suggest that S. enterica in pigs and poultry in central Chile should be monitored due to potential consequences in public and animal health.
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Affiliation(s)
- Patricio Retamal
- Departamento de Medicina Preventiva Animal, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
| | - Joaquim Gaspar
- Departamento de Medicina Preventiva Animal, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
- Magister en Ciencias Animales y Veterinarias, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
| | - María Belén Benavides
- Departamento de Medicina Preventiva Animal, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
- Magister en Ciencias Animales y Veterinarias, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
| | - Leonardo Saenz
- Departamento de Ciencias Biológicas, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
| | - Nicolás Galarce
- Escuela de Medicina Veterinaria, Facultad de Ciencias de la Vida, Universidad Andrés Bello, Santiago, Chile
| | - Trinidad Aravena
- Departamento de Medicina Preventiva Animal, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
| | - Javiera Cornejo
- Departamento de Medicina Preventiva Animal, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
- Javiera Cornejo
| | - Lisette Lapierre
- Departamento de Medicina Preventiva Animal, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile
- *Correspondence: Lisette Lapierre
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4
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Zhao M, Xie R, Wang S, Huang X, Yang H, Wu W, Lin L, Chen H, Fan J, Hua L, Liang W, Zhang J, Wang X, Chen H, Peng Z, Wu B. Identification of a broad-spectrum lytic Myoviridae bacteriophage using multidrug resistant Salmonella isolates from pig slaughterhouses as the indicator and its application in combating Salmonella infections. BMC Vet Res 2022; 18:270. [PMID: 35821025 PMCID: PMC9277904 DOI: 10.1186/s12917-022-03372-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 07/04/2022] [Indexed: 11/30/2022] Open
Abstract
Background Salmonella is a leading foodborne and zoonotic pathogen, and is widely distributed in different nodes of the pork supply chain. In recent years, the increasing prevalence of antimicrobial resistant Salmonella poses a threat to global public health. The purpose of this study is to the prevalence of antimicrobial resistant Salmonella in pig slaughterhouses in Hubei Province in China, and explore the effect of using lytic bacteriophages fighting against antimicrobial resistant Salmonella. Results We collected a total of 1289 samples including anal swabs of pigs (862/1289), environmental swabs (204/1289), carcass surface swabs (36/1289) and environmental agar plates (187/1289) from eleven slaughterhouses in seven cities in Hubei Province and recovered 106 Salmonella isolates. Antimicrobial susceptibility testing revealed that these isolates showed a high rate of antimicrobial resistance; over 99.06% (105/106) of them were multidrug resistant. To combat these drug resistant Salmonella, we isolated 37 lytic phages using 106 isolates as indicator bacteria. One of them, designated ph 2–2, which belonged to the Myoviridae family, displayed good capacity to kill Salmonella under different adverse conditions (exposure to different temperatures, pHs, UV, and/or 75% ethanol) and had a wide lytic spectrum. Evaluation in mouse models showed that ph 2–2 was safe and saved 80% (administrated by gavage) and 100% (administrated through intraperitoneal injection) mice from infections caused by Salmonella Typhimurium. Conclusions The data presented herein demonstrated that Salmonella contamination remains a problem in some pig slaughter houses in China and Salmonella isolates recovered in slaughter houses displayed a high rate of antimicrobial resistance. In addition, broad-spectrum lytic bacteriophages may represent a good candidate for the development of anti-antimicrobial resistant Salmonella agents. Supplementary Information The online version contains supplementary material available at 10.1186/s12917-022-03372-8.
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Affiliation(s)
- Mengfei Zhao
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Centre for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, China
| | - Rui Xie
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Centre for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, China
| | - Shuang Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Centre for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xi Huang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Centre for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hao Yang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Centre for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wenqing Wu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Centre for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, China
| | - Lin Lin
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Centre for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, China
| | - Hongjian Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Centre for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jie Fan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Centre for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, China
| | - Lin Hua
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Centre for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wan Liang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Centre for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, China.,Present address: Hubei Jin Xu Agricultural Development Limited by Share Ltd., Wuhan, China
| | - Jianmin Zhang
- National and Regional Joint Engineering Laboratory for Medicament of Zoonoses Prevention and Control, College of Veterinary Medicine, South China Agricultural University, Guangzhou, China
| | - Xiangru Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Centre for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, China
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China.,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Centre for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhong Peng
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China. .,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Centre for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, China. .,Hubei Hongshan Laboratory, Wuhan, China.
| | - Bin Wu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, 430070, China. .,Key Laboratory of Preventive Veterinary Medicine in Hubei Province, The Cooperative Innovation Centre for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, 430070, China.
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5
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A genoserotyping system for a fast and objective identification of Salmonella serotypes commonly isolated from poultry and pork food sectors in Belgium. Food Microbiol 2020; 91:103534. [PMID: 32539977 DOI: 10.1016/j.fm.2020.103534] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 04/22/2020] [Indexed: 11/23/2022]
Abstract
Humans are mostly contaminated by Salmonella through the consumption of pork- and poultry-derived food products. Therefore, a strict monitoring of Salmonella serotypes in food-producing animals is needed to limit the transmission of the pathogen to humans. Additionally, Salmonella can lead to economic loss in the food sector. Previously, a genoserotyping method using the MOL-PCR and Luminex technology was developed for the identification of the 6 Salmonella serotypes, and their variants, subjected to an official control in the Belgian food sector. In this study, 3 additional assays using the same technology were developed for the rapid and cost-effective detection of 13 dangerous highly invasive serotypes or other serotypes frequently isolated from the Belgian poultry and pork sector, i.e. Agona, Anatum, Brandenburg, Choleraesuis, Derby, Enteritidis vaccine strains, Gallinarum var. Gallinarum/Pullorum, Livingstone, Mbandaka, Minnesota, Ohio, Rissen and Senftenberg. Moreover, the previously developed first MOL-PCR assay was improved for S. Paratyphi B and serogroup O:3 detection. Finally, a Decision Support System hosted by a web application was created for an automatic and objective interpretation of the Luminex raw data. The 3 new assays and the modifications of the first assay were validated with a 100% accuracy, using 553 Salmonella and non-Salmonella strains in total.
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6
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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: 38] [Impact Index Per Article: 7.6] [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.
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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
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7
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Moore MM, Nucci MJ, Madson SM, Wagley GS, Keys CE, Brown EW, McQUISTON JR, Fields PI. Evaluation of a Bead-Based Salmonella Molecular Serotyping Method for Salmonella Isolated from Food and Environmental Samples. J Food Prot 2019; 82:1973-1987. [PMID: 31644335 DOI: 10.4315/0362-028x.jfp-18-600] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Salmonella is a leading cause of foodborne illness worldwide, and foods containing Salmonella (except raw meat and poultry products) are considered adulterated. Serotyping of Salmonella is an essential part of surveillance and investigation of outbreaks. This study evaluated a bead-based Salmonella molecular serotyping (SMS) method, which included the O-group 1, H-antigen, alternate target, and O-group 2 assays, compared with traditional serotyping. Salmonella was isolated from food, pet food, and environmental samples or were reference strains. A total of 572 isolates were analyzed by using two formats of the SMS method in comparison with traditional methods: 485 were analyzed by using Radix SMS (a custom user-mixed format), 218 were analyzed by using Luminex SMS (a commercial kit format), and 131 of the total isolates were analyzed by both formats for comparison. The SMS method was evaluated on the basis of the successful identification of antigens by the probes included in the method. The method identified 550 (96.2%) isolates as expected, 6 (1.0%) isolates were not identified as initially expected but were shown to be correctly identified by SMS after reanalysis by traditional serotyping, and 16 (2.8%) isolates not identified as expected possessed an antigen that should have been detected by the method but was not. Among the isolates considered correctly identified, 255 (44.6%) were identified to a single serovar, 44 (7.7%) required additional biochemical testing to differentiate variants or subspecies, and 251 (43.9%) were partially serotyped because probes for some antigens were not in the assay or had allelic variation for known serovars. Whole genome sequencing, SeqSero, and the Salmonella In Silico Typing Resource gave added confirmation for three isolates. Addition of the O-group 2 assay enabled the identification of 55 (9.6%) of 572 isolates. The SMS method could fully or partially serotype most isolates within a day. The SMS method should be a valuable tool when faster screening methods are needed, such as outbreaks and screening large numbers of environmental isolates.
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Affiliation(s)
- M M Moore
- U.S. Food and Drug Administration, Office of Regulatory Affairs, Pacific Northwest Laboratory, Applied Technology Center, Bothell, Washington 98021
| | - M J Nucci
- U.S. Food and Drug Administration, Office of Regulatory Affairs, Denver Laboratory, Lakewood, Colorado 80225
| | - S M Madson
- U.S. Food and Drug Administration, Office of Regulatory Affairs, Arkansas Laboratory, Jefferson, Arkansas 72079
| | - G S Wagley
- U.S. Food and Drug Administration, Office of Regulatory Affairs, Southeast Food and Feed Laboratory, Atlanta, Georgia 30309
| | - C E Keys
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Regulatory Science, College Park, Maryland 20740
| | - E W Brown
- U.S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Regulatory Science, College Park, Maryland 20740
| | - J R McQUISTON
- Centers for Disease Control and Prevention, Division of Foodborne, Waterborne and Environmental Diseases, Enteric Diseases Laboratory Branch, Atlanta, Georgia 30333, USA
| | - P I Fields
- Centers for Disease Control and Prevention, Division of Foodborne, Waterborne and Environmental Diseases, Enteric Diseases Laboratory Branch, Atlanta, Georgia 30333, USA
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8
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Jean-Gilles Beaubrun J, Tall BD, Flamer ML, Patel I, Gopinath G, Auguste W, Jean C, George M, Tartera C, Ewing L, Hanes DE. Increased secretion of exopolysaccharide and virulence potential of a mucoid variant of Salmonella enterica serovar Montevideo under environmental stress. Microb Pathog 2016; 103:107-113. [PMID: 28012986 DOI: 10.1016/j.micpath.2016.12.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 12/07/2016] [Accepted: 12/08/2016] [Indexed: 11/16/2022]
Abstract
During an investigation to increase the recovery of Salmonella enterica from Oregano, an increased expression of exopolysaccharide was induced in Salmonella serovar Montevideo. The atypical mucoid (SAL242S) and the non-mucoid (SAL242) strains of Montevideo were compared and characterized using various methods. Serotyping analysis demonstrated that both strains are the same serovar Montevideo. Electron microscopy (EM) of cultured SAL242S cells revealed the production of a prominent EPS-like structure enveloping aggregates of cells that are composed of cellulose. Mucoid cells possessed a higher binding affinity for Calcofluor than that of the non-mucoid strain. Genotypic analysis revealed no major genomic differences between these morphotypes, while expression analyses using a DNA microarray shows that the mucoid variant exhibited heightened expression of genes encoding proteins produced by the SPI-1 type III secretion system. This increased expression of SPI1 genes may play a role in protecting Salmonella from environmental stressors. Based on these observations, Salmonella serovar Montevideo mucoid variant under stressful or low-nutrient environments presented atypical growth patterns and phenotypic changes, as well as an upregulated expression of virulence factors. These findings are significant in the understanding of survival abilities of Salmonella in a various food matrices.
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Affiliation(s)
| | - Ben D Tall
- U.S. Food and Drug Administration, Laurel, MD 20708, United States
| | - M-L Flamer
- U.S. Food and Drug Administration, Laurel, MD 20708, United States; UMCP JIFSAN Program, 5201 Paint Branch Pkwy Patapsco Building Suite 2134, University of Maryland, College Park 20742, United States
| | - I Patel
- U.S. Food and Drug Administration, Laurel, MD 20708, United States
| | - G Gopinath
- U.S. Food and Drug Administration, Laurel, MD 20708, United States
| | - Winny Auguste
- U.S. Food and Drug Administration, Laurel, MD 20708, United States; Frostburg State University, 101 Braddock Rd, Frostburg MD 21532, United States
| | - Catherine Jean
- U.S. Food and Drug Administration, Laurel, MD 20708, United States; Branch High School 14121 Old Columbia Pike, Burtonsville MD 20866, United States
| | - Melvin George
- U.S. Food and Drug Administration, Laurel, MD 20708, United States; Branch High School 14121 Old Columbia Pike, Burtonsville MD 20866, United States
| | - Carmen Tartera
- U.S. Food and Drug Administration, Laurel, MD 20708, United States
| | - L Ewing
- U.S. Food and Drug Administration, Laurel, MD 20708, United States
| | - D E Hanes
- U.S. Food and Drug Administration, Laurel, MD 20708, United States
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9
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Wilson MR, Brown E, Keys C, Strain E, Luo Y, Muruvanda T, Grim C, Jean-Gilles Beaubrun J, Jarvis K, Ewing L, Gopinath G, Hanes D, Allard MW, Musser S. Whole Genome DNA Sequence Analysis of Salmonella subspecies enterica serotype Tennessee obtained from related peanut butter foodborne outbreaks. PLoS One 2016; 11:e0146929. [PMID: 27258142 PMCID: PMC4892500 DOI: 10.1371/journal.pone.0146929] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 12/23/2015] [Indexed: 11/19/2022] Open
Abstract
Establishing an association between possible food sources and clinical isolates requires discriminating the suspected pathogen from an environmental background, and distinguishing it from other closely-related foodborne pathogens. We used whole genome sequencing (WGS) to Salmonella subspecies enterica serotype Tennessee (S. Tennessee) to describe genomic diversity across the serovar as well as among and within outbreak clades of strains associated with contaminated peanut butter. We analyzed 71 isolates of S. Tennessee from disparate food, environmental, and clinical sources and 2 other closely-related Salmonella serovars as outgroups (S. Kentucky and S. Cubana), which were also shot-gun sequenced. A whole genome single nucleotide polymorphism (SNP) analysis was performed using a maximum likelihood approach to infer phylogenetic relationships. Several monophyletic lineages of S. Tennessee with limited SNP variability were identified that recapitulated several food contamination events. S. Tennessee clades were separated from outgroup salmonellae by more than sixteen thousand SNPs. Intra-serovar diversity of S. Tennessee was small compared to the chosen outgroups (1,153 SNPs), suggesting recent divergence of some S. Tennessee clades. Analysis of all 1,153 SNPs structuring an S. Tennessee peanut butter outbreak cluster revealed that isolates from several food, plant, and clinical isolates were very closely related, as they had only a few SNP differences between them. SNP-based cluster analyses linked specific food sources to several clinical S. Tennessee strains isolated in separate contamination events. Environmental and clinical isolates had very similar whole genome sequences; no markers were found that could be used to discriminate between these sources. Finally, we identified SNPs within variable S. Tennessee genes that may be useful markers for the development of rapid surveillance and typing methods, potentially aiding in traceback efforts during future outbreaks. Using WGS can delimit contamination sources for foodborne illnesses across multiple outbreaks and reveal otherwise undetected DNA sequence differences essential to the tracing of bacterial pathogens as they emerge.
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Affiliation(s)
- Mark R. Wilson
- Center for Food Science and Applied Nutrition (CFSAN), Food and Drug Administration (FDA), College Park, Maryland, United States of America
| | - Eric Brown
- Battelle Memorial Institute, Crystal City, Virginia, United States of America
| | - Chris Keys
- Battelle Memorial Institute, Crystal City, Virginia, United States of America
| | - Errol Strain
- Battelle Memorial Institute, Crystal City, Virginia, United States of America
| | - Yan Luo
- Battelle Memorial Institute, Crystal City, Virginia, United States of America
| | - Tim Muruvanda
- Battelle Memorial Institute, Crystal City, Virginia, United States of America
| | - Christopher Grim
- Battelle Memorial Institute, Crystal City, Virginia, United States of America
- Division of Virulence Assessment (DVA), Virulence Mechanisms Branch (VMB), CFSAN/FDA, Office of Applied Research and Safety Assessment (OARSA), Laurel, Maryland, United States of America
| | - Junia Jean-Gilles Beaubrun
- Division of Virulence Assessment (DVA), Virulence Mechanisms Branch (VMB), CFSAN/FDA, Office of Applied Research and Safety Assessment (OARSA), Laurel, Maryland, United States of America
| | - Karen Jarvis
- Division of Virulence Assessment (DVA), Virulence Mechanisms Branch (VMB), CFSAN/FDA, Office of Applied Research and Safety Assessment (OARSA), Laurel, Maryland, United States of America
| | - Laura Ewing
- Division of Virulence Assessment (DVA), Virulence Mechanisms Branch (VMB), CFSAN/FDA, Office of Applied Research and Safety Assessment (OARSA), Laurel, Maryland, United States of America
| | - Gopal Gopinath
- Division of Virulence Assessment (DVA), Virulence Mechanisms Branch (VMB), CFSAN/FDA, Office of Applied Research and Safety Assessment (OARSA), Laurel, Maryland, United States of America
| | - Darcy Hanes
- Division of Virulence Assessment (DVA), Virulence Mechanisms Branch (VMB), CFSAN/FDA, Office of Applied Research and Safety Assessment (OARSA), Laurel, Maryland, United States of America
| | - Marc W. Allard
- Battelle Memorial Institute, Crystal City, Virginia, United States of America
| | - Steven Musser
- Battelle Memorial Institute, Crystal City, Virginia, United States of America
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10
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Evaluation of Molecular Methods for Identification of Salmonella Serovars. J Clin Microbiol 2016; 54:1992-8. [PMID: 27194688 DOI: 10.1128/jcm.00262-16] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 05/10/2016] [Indexed: 11/20/2022] Open
Abstract
Classification by serotyping is the essential first step in the characterization of Salmonella isolates and is important for surveillance, source tracking, and outbreak detection. To improve detection and reduce the burden of salmonellosis, several rapid and high-throughput molecular Salmonella serotyping methods have been developed.The aim of this study was to compare three commercial kits, Salm SeroGen (Salm Sero-Genotyping AS-1 kit), Check&Trace (Check-Points), and xMAP (xMAP Salmonella serotyping assay), to the Salmonella genoserotyping array (SGSA) developed by our laboratory. They were assessed using a panel of 321 isolates that represent commonly reported serovars from human and nonhuman sources globally. The four methods correctly identified 73.8% to 94.7% of the isolates tested. The methods correctly identified 85% and 98% of the clinically important Salmonella serovars Enteritidis and Typhimurium, respectively. The methods correctly identified 75% to 100% of the nontyphoidal, broad host range Salmonella serovars, including Heidelberg, Hadar, Infantis, Kentucky, Montevideo, Newport, and Virchow. The sensitivity and specificity of Salmonella serovars Typhimurium and Enteritidis ranged from 85% to 100% and 99% to 100%, respectively.It is anticipated that whole-genome sequencing will replace serotyping in public health laboratories in the future. However, at present, it is approximately three times more expensive than molecular methods. Until consistent standards and methodologies are deployed for whole-genome sequencing, data analysis and interlaboratory comparability remain a challenge. The use of molecular serotyping will provide a valuable high-throughput alternative to traditional serotyping. This comprehensive analysis provides a detailed comparison of commercial kits available for the molecular serotyping of Salmonella.
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11
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Liang D, Lu J, Wu Q, Ke B, Jiang C, Long J, Fang Y, Lin L, Zeng N, Fu L, Jiang L. Comparing the ability of luminex xMAP®
salmonella serotyping assay and traditional serotyping method for serotyping salmonella isolated from southern Chinese population. J Appl Microbiol 2016; 120:1668-76. [PMID: 26914944 DOI: 10.1111/jam.13106] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 01/27/2016] [Accepted: 02/17/2016] [Indexed: 11/26/2022]
Affiliation(s)
- D.W. Liang
- Center of Clinical Laboratory; Zhujiang Hospital; Southern Medical University; Guangzhou China
| | - J.H. Lu
- Department of Laboratory Medicine; The First People's Hospital of Shunde District; Foshan China
| | - Q. Wu
- Haizhu district Center for Disease Control and Prevention; Guangzhou China
| | - B.X. Ke
- Institute of Microbiology; Guangdong Provincial Center for Disease Control and Prevention; Guangzhou China
| | - C.H. Jiang
- Center of Clinical Laboratory; Zhujiang Hospital; Southern Medical University; Guangzhou China
| | - J. Long
- Center of Clinical Laboratory; Zhujiang Hospital; Southern Medical University; Guangzhou China
| | - Y.P. Fang
- Center of Clinical Laboratory; Zhujiang Hospital; Southern Medical University; Guangzhou China
| | - L.J. Lin
- Center of Clinical Laboratory; Zhujiang Hospital; Southern Medical University; Guangzhou China
| | - N.Y. Zeng
- Center of Clinical Laboratory; Zhujiang Hospital; Southern Medical University; Guangzhou China
| | - L. Fu
- Center of Clinical Laboratory; Zhujiang Hospital; Southern Medical University; Guangzhou China
| | - L.X. Jiang
- Center of Clinical Laboratory; Zhujiang Hospital; Southern Medical University; Guangzhou China
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12
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Guard J, Abdo Z, Byers SO, Kriebel P, Rothrock MJ. Subtyping of Salmonella enterica Subspecies I Using Single-Nucleotide Polymorphisms in Adenylate Cyclase. Foodborne Pathog Dis 2016; 13:350-62. [PMID: 27035032 PMCID: PMC4939371 DOI: 10.1089/fpd.2015.2088] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Methods to rapidly identify serotypes of Salmonella enterica subspecies I are of vital importance for protecting the safety of food. To supplement the serotyping method dkgB-linked intergenic sequence ribotyping (ISR), single-nucleotide polymorphisms were characterized within adenylate cyclase (cyaA). The National Center for Biotechnology Information (NCBI) database had 378 cyaA sequences from S. enterica subspecies I, which included 42 unique DNA sequences and 19 different amino acid sequences. Five representative isolates, namely serotypes Typhimurium, Kentucky, Enteritidis phage type PT4, and two variants of Enteritidis phage type PT13a, were differentiated within a microsphere-based fluidics system in cyaA by allele-specific primer extension. Validation against 25 poultry-related environmental Salmonella isolates representing 11 serotypes yielded a ∼89% success rate at identifying the serotype of the isolate, and a different region could be targeted to achieve 100%. When coupled with ISR, all serotypes were differentiated. Phage lineages of serotype Enteritidis 13a and 4 were identified, and a biofilm-forming strain of PT13a was differentiated from a smooth phenotype within phage type. Comparative ranking of mutation indices to genes such as the tRNA transferases, the diguanylate cyclases, and genes used for multilocus sequence typing indicated that cyaA is an appropriate gene for assessing epidemiological trends of Salmonella because of its relative stability in nucleotide composition.
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Affiliation(s)
- Jean Guard
- 1 U.S. National Poultry Research Center , U.S. Department of Agriculture, Athens, Georgia
| | - Zaid Abdo
- 1 U.S. National Poultry Research Center , U.S. Department of Agriculture, Athens, Georgia
| | | | - Patrick Kriebel
- 2 Department of Statistics, University of Georgia , Athens, Georgia
| | - Michael J Rothrock
- 1 U.S. National Poultry Research Center , U.S. Department of Agriculture, Athens, Georgia
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13
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Jean-Gilles Beaubrun J, Flamer ML, Addy N, Ewing L, Gopinath G, Jarvis K, Grim C, Hanes DE. Evaluation of corn oil as an additive in the pre-enrichment step to increase recovery of Salmonella enterica from oregano. Food Microbiol 2016; 57:195-203. [PMID: 27052719 DOI: 10.1016/j.fm.2016.03.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 01/26/2016] [Accepted: 03/09/2016] [Indexed: 10/22/2022]
Abstract
Phenolic compounds associated with essential oils of spices and herbs possess a variety of antioxidant and antimicrobial properties that interfere with Salmonella detection from fresh and dried products. Finding a compound to neutralize the effect of these antimicrobial compounds, while allowing Salmonella growth during pre-enrichment, is a crucial step in both traditional pathogen isolation and molecular detection from these foods. This study evaluated the effectiveness of corn oil as a component of the pre-enrichment broth to counteract antimicrobial compounds properties and increase the recovery of Salmonella from spices. Oregano samples artificially contaminated with Salmonella enterica were pre-enriched in modified Buffered Peptone Water (mBPW) supplemented with and without 2% (vol/vol) corn oil respectively. Samples were incubated overnight at 37 °C. The results showed that recovery of Salmonella from oregano samples was increased by ≥50% when pre-enriched with corn oil. Serovars were confirmed using a PCR serotyping method. In addition, shot-gun metagenomics analyses demonstrated bacterial diversity and the effect of corn oil on the relative prevalence of Salmonella in the oregano samples. Modifying pre-enrichment broths with corn oil improved the detection and isolation of Salmonella from oregano, and may provide an alternative method for pathogen detection in dried food matrices such as spices.
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Affiliation(s)
| | - Marie-Laure Flamer
- U.S. Food and Drug Administration, Laurel, MD, 20708, USA; UMCP JIFSAN Program, 5201 Paint Branch Pkwy Patapsco Building Suite 2134, University of Maryland, College Park, 20742, USA
| | - Nicole Addy
- U.S. Food and Drug Administration, Laurel, MD, 20708, USA; Oak Ridge Institute for Science and Technology, Oak Ridge, TN, USA
| | - Laura Ewing
- U.S. Food and Drug Administration, Laurel, MD, 20708, USA
| | - Gopal Gopinath
- U.S. Food and Drug Administration, Laurel, MD, 20708, USA
| | - Karen Jarvis
- U.S. Food and Drug Administration, Laurel, MD, 20708, USA
| | - Chris Grim
- U.S. Food and Drug Administration, Laurel, MD, 20708, USA; Oak Ridge Institute for Science and Technology, Oak Ridge, TN, USA
| | - Darcy E Hanes
- U.S. Food and Drug Administration, Laurel, MD, 20708, USA
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14
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Jarvis KG, White JR, Grim CJ, Ewing L, Ottesen AR, Beaubrun JJG, Pettengill JB, Brown E, Hanes DE. Cilantro microbiome before and after nonselective pre-enrichment for Salmonella using 16S rRNA and metagenomic sequencing. BMC Microbiol 2015; 15:160. [PMID: 26264042 PMCID: PMC4534111 DOI: 10.1186/s12866-015-0497-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Accepted: 07/28/2015] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Salmonella enterica is a common cause of foodborne gastroenteritis in the United States and is associated with outbreaks in fresh produce such as cilantro. Salmonella culture-based detection methods are complex and time consuming, and improvments to increase detection sensitivity will benefit consumers. In this study, we used 16S rRNA sequencing to determine the microbiome of cilantro. We also investigated changes to the microbial community prior to and after a 24-hour nonselective pre-enrichment culture step commonly used by laboratory analysts to resuscitate microorganisms in foods suspected of contamination with pathogens. Cilantro samples were processed for Salmonella detection according to the method in the United States Food and Drug Administration Bacteriological Analytical Manual. Genomic DNA was extracted from culture supernatants prior to and after a 24-hour nonselective pre-enrichment step and 454 pyrosequencing was performed on 16S rRNA amplicon libraries. A database of Enterobacteriaceae 16S rRNA sequences was created, and used to screen the libraries for Salmonella, as some samples were known to be culture positive. Additionally, culture positive cilantro samples were examined for the presence of Salmonella using shotgun metagenomics on the Illumina MiSeq. RESULTS Time zero uncultured samples had an abundance of Proteobacteria while the 24-hour enriched samples were composed mostly of Gram-positive Firmicutes. Shotgun metagenomic sequencing of Salmonella culture positive cilantro samples revealed variable degrees of Salmonella contamination among the sequenced samples. CONCLUSIONS Our cilantro study demonstrates the use of high-throughput sequencing to reveal the microbiome of cilantro, and how the microbiome changes during the culture-based protocols employed by food safety laboratories to detect foodborne pathogens. Finding that culturing the cilantro shifts the microbiome to a predominance of Firmicutes suggests that changing our culture-based methods will improve detection sensitivity for foodborne enteric pathogens.
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Affiliation(s)
- Karen G Jarvis
- U. S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, OARSA, Laurel, MD, USA.
| | - James R White
- Oak Ridge Institute for Science and Technology, Oak Ridge, TN, USA.
| | - Christopher J Grim
- U. S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, OARSA, Laurel, MD, USA.
- Oak Ridge Institute for Science and Technology, Oak Ridge, TN, USA.
| | - Laura Ewing
- U. S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, OARSA, Laurel, MD, USA.
| | - Andrea R Ottesen
- U. S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, ORS, College Park, MD, USA.
| | - Junia Jean-Gilles Beaubrun
- U. S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, OARSA, Laurel, MD, USA.
| | - James B Pettengill
- U. S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, ORS, College Park, MD, USA.
| | - Eric Brown
- U. S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, ORS, College Park, MD, USA.
| | - Darcy E Hanes
- U. S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, OARSA, Laurel, MD, USA.
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