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Kim HJ, Jung Y, Kim MJ, Kim HY. Novel Heptaplex PCR-Based Diagnostics for Enteric Fever Caused by Typhoidal Salmonella Serovars and Its Applicability in Clinical Blood Culture. J Microbiol Biotechnol 2023; 33:1457-1466. [PMID: 37674393 DOI: 10.4014/jmb.2307.07031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 08/12/2023] [Accepted: 08/14/2023] [Indexed: 09/08/2023]
Abstract
Enteric fever is caused by typhoidal Salmonella serovars (Typhi, Paratyphi A, Paratyphi B, and Paratyphi C). Owing to the importance of Salmonella serovars in clinics and public hygiene, reliable diagnostics for typhoidal serovars are crucial. This study aimed to develop a novel diagnostic tool for typhoidal Salmonella serovars and evaluate the use of human blood for clinically diagnosing enteric fever. Five genes were selected to produce specific PCR results against typhoidal Salmonella serovars based on the genes of Salmonella Typhi. Heptaplex PCR, including genetic markers of generic Salmonella, Salmonella enterica subsp. enterica, and typhoidal Salmonella serovars, was developed. Typhoidal Salmonella heptaplex PCR using genomic DNAs from 200 Salmonella strains (112 serovars) provided specifically amplified PCR products for each typhoidal Salmonella serovar. These results suggest that heptaplex PCR can sufficiently discriminate between typhoidal and nontyphoidal Salmonella serovars. Heptaplex PCR was applied to Salmonella-spiked blood cultures directly and provided diagnostic results after 12- or 13.5-h blood culture. Additionally, it demonstrated diagnostic performance with colonies recovered from a 6-h blood culture. This study provides a reliable DNA-based tool for diagnosing typhoidal Salmonella serovars that may be useful in clinical microbiology and epidemiology.
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Affiliation(s)
- Hyun-Joong Kim
- Department of Food Engineering, Mokpo National University, Muan 58554, Republic of Korea
| | - Younsik Jung
- Institute of Life Sciences and Resources and the Department of Food Science and Biotechnology, Kyung Hee University, Yongin 17104 Republic of Korea
| | - Mi-Ju Kim
- Institute of Life Sciences and Resources and the Department of Food Science and Biotechnology, Kyung Hee University, Yongin 17104 Republic of Korea
| | - Hae-Yeong Kim
- Institute of Life Sciences and Resources and the Department of Food Science and Biotechnology, Kyung Hee University, Yongin 17104 Republic of Korea
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2
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Teh CSJ, Lau MY, Chong CW, Ngoi ST, Chua KH, Lee WS, Thong KL. One-step differential detection of Salmonella enterica serovar Typhi, serovar Paratyphi A and other Salmonella spp. by using a quadruplex real-time PCR assay. J Microbiol Methods 2021; 183:106184. [PMID: 33662480 DOI: 10.1016/j.mimet.2021.106184] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Revised: 02/24/2021] [Accepted: 02/26/2021] [Indexed: 12/14/2022]
Abstract
Diseases caused by typhoidal and non-typhoidal Salmonella remain a considerable threat to both developed and developing countries. Based on the clinical symptoms and serological tests, it is sometimes difficult to differentiate the Salmonella enterica serovar Paratyphi A (S. enterica serovar Paratyphi A) from serovar Typhi (S. enterica serovar Typhi). In this study, we developed a quadruplex real-time polymerase chain reaction (PCR) assay with an internal amplification control (IAC), to simultaneously differentiate S. enterica serovar Paratyphi A from serovar Typhi and to detect other Salmonella serovars which cause salmonellosis in humans. This assay was evaluated on 155 salmonellae and non-salmonellae strains and demonstrated 100% specificity in species differentiation. Inclusion of an IAC did not affect the efficiency of the assay. Further evaluation using a blind test on spiked stool, blood and food specimens showed that the detection limit was at 103 -104 CFU/mL (or g) and a high PCR efficiency with different targets (R2 > 0.99), except for S. enterica serovar Paratyphi A in blood. This assay has been applied to clinical specimens to detect the causative agents of gastrointestinal infections and has successfully identified 6 salmonellosis patients from the 50 diarrhoea patients. The quadruplex real-time PCR developed in this study could enhance the detection and differentiation of salmonellae. This assay could be applied to stools, blood and food based on the notable performance in the simulation tests and field evaluation.
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Affiliation(s)
- Cindy Shuan Ju Teh
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| | - Min Yi Lau
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Chun Wie Chong
- School of Pharmacy, Monash University Malaysia, 47500 Bandar Sunway, Selangor, Malaysia
| | - Soo Tein Ngoi
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Kek Heng Chua
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Way Seah Lee
- Department of Paediatrics, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Kwai Lin Thong
- Nanotechnology & Catalysis Research Centre, Deputy Vice Chancellor (Research & Innovation), University of Malaya, 50603 Kuala Lumpur, Malaysia
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Tawfick MM, Rosser A, Rajakumar K. Heterologous expression of the Salmonella enterica serovar Paratyphi A stk fimbrial operon suggests a potential for repeat sequence-mediated low-frequency phase variation. INFECTION GENETICS AND EVOLUTION 2020; 85:104508. [PMID: 32835875 DOI: 10.1016/j.meegid.2020.104508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Revised: 08/11/2020] [Accepted: 08/18/2020] [Indexed: 10/23/2022]
Abstract
Fimbriae mediate adhesion of Salmonella enterica organisms to the intestinal epithelium, which is an essential step in the pathogenesis process preceding invasion and/or systemic spread. In addition, Salmonella fimbrial genes transcripts were detected in the blood samples from Salmonella infected human patients, which supports the proposal that fimbriae play a role in invasive Salmonella infections. In this study, BlastN-based interrogation of the NCBI bacterial genome database and PCR investigation of Salmonella serovars have shown that the S. Paratyphi A stkF gene and/or the whole stk fimbrial gene cluster is present in about ~30% of S. enterica serovars investigated up to date. Furthermore, bioinformatics and phenotypic characterization have revealed that the stk fimbrial operon belongs to the chaperone/usher-γ4- fimbrial clade and that it encodes a mannose-sensitive hemagglutinating fimbrial structure. The latter trait is typical of type 1 fimbriae, in which fimbrial phase variation is common. The observed intragenic, 26 bp tandem repeat triplication event in stkF would suggest that slipped-strand mispairing and/or recombination within a signature stkF-borne tandem repeat motif as a likely mechanism for a form of low-frequency phase switching at the translational level leading to allelic OFF forms, hence the inability of production and/or absence of fimbriae by EM-examination on E. coli HB101/pUCstk-stkFOFFv2. The in vitro profile of marked anti-StkF-mediated opsonophagocytosis and complement-mediated killing activity observed coupled with the mice immunogenicity profile strongly supports further investigation of StkF as a potential Salmonella vaccine candidate.
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Affiliation(s)
- Mahmoud M Tawfick
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom; Department of Microbiology and Immunology, Faculty of Pharmacy, Al-Azhar University, Nasr City, Cairo, Egypt.
| | - Andrew Rosser
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Kumar Rajakumar
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
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4
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Pouzol S, Tanmoy AM, Ahmed D, Khanam F, Brooks WA, Bhuyan GS, Fabre L, Bryant JE, Gustin MP, Vanhems P, Carman B, Weill FX, Qadri F, Saha S, Endtz H. Clinical Evaluation of a Multiplex PCR for the Detection of Salmonella enterica Serovars Typhi and Paratyphi A from Blood Specimens in a High-Endemic Setting. Am J Trop Med Hyg 2020; 101:513-520. [PMID: 31287048 PMCID: PMC6726943 DOI: 10.4269/ajtmh.18-0992] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Enteric fever is a major public health concern in endemic areas, particularly in infrastructure-limited countries where Salmonella Paratyphi A has emerged in increasing proportion of cases. We aimed to evaluate a method to detect Salmonella Typhi (S. Typhi) and Salmonella Paratyphi A (S. Paratyphi A) in febrile patients in Bangladesh. We conducted a prospective study enrolling patients with fever > 38°C admitted to two large urban hospitals and two outpatient clinics located in Dhaka, Bangladesh. We developed and evaluated a method combining short culture with a new molecular assay to simultaneously detect and differentiate S. Typhi and S. Paratyphi A from other Salmonella directly from 2 to 4 mL of whole blood in febrile patients (n = 680). A total of 680 cases were enrolled from the four participating sites. An increase in the detection rate (+38.8%) in S. Typhi and S. Paratyphi A was observed with a multiplex polymerase chain reaction (PCR) assay, and absence of non-typhoidal Salmonella detection was reported. All 45 healthy controls were culture and PCR negative, generating an estimated 92.9% of specificity on clinical samples. When clinical performance was assessed in the absence of blood volume prioritization for testing, a latent class model estimates clinical performance ≥ 95% in sensitivity and specificity with likelihood ratio (LR) LR+ > 10 and LR− < 0.1 for the multiplex PCR assay. The alternative method to blood culture we developed may be useful alone or in combination with culture or serological tests for epidemiological studies in high disease burden settings and should be considered as secondary endpoint test for future vaccine trials.
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Affiliation(s)
- Stephane Pouzol
- Laboratoire des Pathogènes Emergents, Fondation Mérieux, Centre International de Recherche en Infectiologie (CIRI), Lyon, France
| | - Arif Mohammad Tanmoy
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, The Netherlands.,Child Health Research Foundation (CHRF), Dhaka, Bangladesh
| | - Dilruba Ahmed
- International Centre for Diarrhoeal Disease Research (icddr,b), Dhaka, Bangladesh
| | - Farhana Khanam
- International Centre for Diarrhoeal Disease Research (icddr,b), Dhaka, Bangladesh
| | - W Abdullah Brooks
- Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland
| | - Golam Sarower Bhuyan
- Institute for Developing Science and Health Initiatives (ideSHi), Dhaka, Bangladesh
| | - Laetitia Fabre
- Unité des Bactéries Pathogènes Entériques, Institut Pasteur, Paris, France
| | - Juliet E Bryant
- Laboratoire des Pathogènes Emergents, Fondation Mérieux, Centre International de Recherche en Infectiologie (CIRI), Lyon, France
| | - Marie-Paule Gustin
- Department of Public Health, Institute of Pharmacy, University of Lyon 1, Lyon, France.,Laboratoire des Pathogènes Emergents, Fondation Mérieux, Centre International de Recherche en Infectiologie (CIRI), Lyon, France
| | - Philippe Vanhems
- Service d'Hygiène, Epidémiologie et Prévention, Hôpital Edouard Herriot, Hospices Civils de Lyon, Lyon, France.,Laboratoire des Pathogènes Emergents, Fondation Mérieux, Centre International de Recherche en Infectiologie (CIRI), Lyon, France
| | - Bill Carman
- Fast Track Diagnostics, Esch sur alzette, Esch-sur-Alzette, Luxembourg
| | | | - Firdausi Qadri
- International Centre for Diarrhoeal Disease Research (icddr,b), Dhaka, Bangladesh
| | - Samir Saha
- Child Health Research Foundation (CHRF), Dhaka, Bangladesh
| | - Hubert Endtz
- Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, The Netherlands.,Laboratoire des Pathogènes Emergents, Fondation Mérieux, Centre International de Recherche en Infectiologie (CIRI), Lyon, France
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5
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Afroj S, Aldahami K, Reddy G, Guard J, Adesiyun A, Samuel T, Abdela W. Simultaneous Detection of Multiple Salmonella Serovars from Milk and Chicken Meat by Real-Time PCR Using Unique Genomic Target Regions. J Food Prot 2017; 80:1944-1957. [PMID: 29058479 DOI: 10.4315/0362-028x.jfp-17-133] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 07/19/2017] [Indexed: 12/29/2022]
Abstract
A novel genomic and plasmid target-based PCR platform was developed for the detection of Salmonella serovars Heidelberg, Dublin, Hadar, Kentucky, and Enteritidis. Unique genome loci were obtained through extensive genome mining of protein databases and comparative genomic analysis of these serovars. Assays targeting Salmonella serovars Hadar, Heidelberg, Kentucky, and Dublin had 100% specificity and sensitivity, whereas those for Salmonella Enteritidis had 97% specificity and 88% sensitivity. The limits of detection for Salmonella serovars Heidelberg, Kentucky, Hadar, Enteritidis, and Dublin were 12, 9, 40, 13, and 5,280 CFU, respectively. A sensitivity assay was also performed by using milk artificially inoculated with pooled Salmonella serovars, yielding a detection limit of 1 to10 CFU/25 mL of milk samples after enrichment. The minimum DNA detected using the multiplexed TaqMan assay was 75.8 fg (1.53 × 101 genomic equivalents [GE]) for Salmonella Heidelberg, 140.8 fg (2.8 × 101 GE) for Salmonella Enteritidis, and 3.48 pg (6.96 × 102 GE) for Salmonella Dublin. PCR efficiencies were 89.8% for Salmonella Heidelberg, 94.5% for Salmonella Enteritidis, and 75.5% for Salmonella Dublin. Four types of 30 pasteurized milk samples were tested negative by culture techniques and with a genus-specific Salmonella invA gene PCR assay. Among 30 chicken samples similarly tested, 12 (40%) were positive by both culture and the invA PCR. Testing of these 12 samples with the serovar-specific PCR assay detected single and mixed contamination with Salmonella Kentucky, Salmonella Enteritidis, and Salmonella Heidelberg. Five unique primers were designed and tested by multiplex conventional PCR in conjunction with the use of the multiplex TaqMan assay with three of the primers. The diagnostic assays developed in this study could be used as tools for routine detection of these five Salmonella serovars and for epidemiological investigations of foodborne disease outbreaks.
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Affiliation(s)
- Sayma Afroj
- Department of Biology and.,Department of Pathobiology, College of Veterinary Medicine, Tuskegee University, Tuskegee, Alabama 36088, USA (ORCID: http://orcid.org/0000-0002-9262-5117 [W.A.]).,Cellular and Molecular Biosciences Program, Auburn University, Auburn, Alabama 36849, USA
| | - Khaled Aldahami
- Department of Pathobiology, College of Veterinary Medicine, Tuskegee University, Tuskegee, Alabama 36088, USA (ORCID: http://orcid.org/0000-0002-9262-5117 [W.A.])
| | - Gopal Reddy
- Department of Pathobiology, College of Veterinary Medicine, Tuskegee University, Tuskegee, Alabama 36088, USA (ORCID: http://orcid.org/0000-0002-9262-5117 [W.A.])
| | - Jean Guard
- U.S. Department of Agriculture, Agricultural Research Service, Athens, Georgia 30602, USA
| | - Abiodun Adesiyun
- School of Veterinary Medicine, Faculty of Medical Sciences, University of the West Indies, St. Augustine, Trinidad and Tobago
| | - Temesgen Samuel
- Department of Pathobiology, College of Veterinary Medicine, Tuskegee University, Tuskegee, Alabama 36088, USA (ORCID: http://orcid.org/0000-0002-9262-5117 [W.A.])
| | - Woubit Abdela
- Department of Pathobiology, College of Veterinary Medicine, Tuskegee University, Tuskegee, Alabama 36088, USA (ORCID: http://orcid.org/0000-0002-9262-5117 [W.A.])
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6
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Zhou X, Zhang L, Shi C, Fratamico PM, Liu B, Paoli GC, Dan X, Zhuang X, Cui Y, Wang D, Shi X. Genome-Scale Screening and Validation of Targets for Identification of Salmonella enterica and Serovar Prediction. J Food Prot 2016; 79:376-83. [PMID: 26939647 DOI: 10.4315/0362-028x.jfp-15-286] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Salmonella enterica is the most common foodborne pathogen worldwide, with 2,500 recognized serovars. Detection of S. enterica and its classification into serovars are essential for food safety surveillance and clinical diagnosis. The PCR method is useful for these applications because of its rapidity and high accuracy. We obtained 412 candidate detection targets for S. enterica using a comparative genomics mining approach. Gene ontology (GO) functional enrichment analysis of these candidate targets revealed that the GO term with the largest number of unigenes with known function (38 of 177, 21.5%) was significantly involved in pathogenesis (P < 10(-24)). All the candidate targets were then evaluated by PCR assays. Fifteen targets showed high specificity for the detection of S. enterica by verification with 151 S. enterica strains and 34 non-Salmonella strains. The phylogenetic trees of verified targets were highly comparable with those of housekeeping genes, especially for differentiating S. enterica strains into serovars. The serovar prediction ability was validated by sequencing one target (S9) for 39 S. enterica strains belonging to six serovars. Identical mutation sites existed in the same serovar, and different mutation sites were found in diverse serovars. Our findings revealed that 15 verified targets can be potentially used for molecular detection, and some of them can be used for serotyping of S. enterica strains.
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Affiliation(s)
- Xiujuan Zhou
- Chinese Ministry of Science and Technology and U.S. Department of Agriculture Joint Research Center for Food Safety, School of Agriculture and Biology, and State Key Lab of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Lida Zhang
- Chinese Ministry of Science and Technology and U.S. Department of Agriculture Joint Research Center for Food Safety, School of Agriculture and Biology, and State Key Lab of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Chunlei Shi
- Chinese Ministry of Science and Technology and U.S. Department of Agriculture Joint Research Center for Food Safety, School of Agriculture and Biology, and State Key Lab of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Pina M Fratamico
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, Pennsylvania 19038, USA
| | - Bin Liu
- College of Food Science and Engineering, Northwest Agriculture and Forestry University, Shaanxi Yangling, People's Republic of China
| | - George C Paoli
- U.S. Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, Pennsylvania 19038, USA
| | - Xianlong Dan
- Chinese Ministry of Science and Technology and U.S. Department of Agriculture Joint Research Center for Food Safety, School of Agriculture and Biology, and State Key Lab of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Xiaofei Zhuang
- Chinese Ministry of Science and Technology and U.S. Department of Agriculture Joint Research Center for Food Safety, School of Agriculture and Biology, and State Key Lab of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Yan Cui
- Chinese Ministry of Science and Technology and U.S. Department of Agriculture Joint Research Center for Food Safety, School of Agriculture and Biology, and State Key Lab of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Dapeng Wang
- Chinese Ministry of Science and Technology and U.S. Department of Agriculture Joint Research Center for Food Safety, School of Agriculture and Biology, and State Key Lab of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - Xianming Shi
- Chinese Ministry of Science and Technology and U.S. Department of Agriculture Joint Research Center for Food Safety, School of Agriculture and Biology, and State Key Lab of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China.
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7
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Crump JA, Sjölund-Karlsson M, Gordon MA, Parry CM. Epidemiology, Clinical Presentation, Laboratory Diagnosis, Antimicrobial Resistance, and Antimicrobial Management of Invasive Salmonella Infections. Clin Microbiol Rev 2015; 28:901-37. [PMID: 26180063 PMCID: PMC4503790 DOI: 10.1128/cmr.00002-15] [Citation(s) in RCA: 651] [Impact Index Per Article: 72.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Salmonella enterica infections are common causes of bloodstream infection in low-resource areas, where they may be difficult to distinguish from other febrile illnesses and may be associated with a high case fatality ratio. Microbiologic culture of blood or bone marrow remains the mainstay of laboratory diagnosis. Antimicrobial resistance has emerged in Salmonella enterica, initially to the traditional first-line drugs chloramphenicol, ampicillin, and trimethoprim-sulfamethoxazole. Decreased fluoroquinolone susceptibility and then fluoroquinolone resistance have developed in association with chromosomal mutations in the quinolone resistance-determining region of genes encoding DNA gyrase and topoisomerase IV and also by plasmid-mediated resistance mechanisms. Resistance to extended-spectrum cephalosporins has occurred more often in nontyphoidal than in typhoidal Salmonella strains. Azithromycin is effective for the management of uncomplicated typhoid fever and may serve as an alternative oral drug in areas where fluoroquinolone resistance is common. In 2013, CLSI lowered the ciprofloxacin susceptibility breakpoints to account for accumulating clinical, microbiologic, and pharmacokinetic-pharmacodynamic data suggesting that revision was needed for contemporary invasive Salmonella infections. Newly established CLSI guidelines for azithromycin and Salmonella enterica serovar Typhi were published in CLSI document M100 in 2015.
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Affiliation(s)
- John A Crump
- Centre for International Health, University of Otago, Dunedin, Otago, New Zealand Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Maria Sjölund-Karlsson
- Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Melita A Gordon
- Department of Clinical Infection, Microbiology and Immunology, Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Christopher M Parry
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
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9
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Teh CSJ, Chua KH, Thong KL. Paratyphoid fever: splicing the global analyses. Int J Med Sci 2014; 11:732-41. [PMID: 24904229 PMCID: PMC4045793 DOI: 10.7150/ijms.7768] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Accepted: 03/05/2014] [Indexed: 11/24/2022] Open
Abstract
The incidence of enteric fever caused by Salmonella enterica serovar Paratyphi A (S. Paratyphi A) is increasing in many parts of the world. Although there is no major outbreak of paratyphoid fever in recent years, S. Paratyphi A infection still remains a public health problem in many tropical countries. Therefore, surveillance studies play an important role in monitoring infections and the emergence of multidrug resistance, especially in endemic countries such as India, Nepal, Pakistan and China. In China, enteric fever was caused predominantly by S. Paratyphi A rather than by Salmonella enterica serovar Typhi (S. Typhi). Sometimes, S. Paratyphi A infection can evolve into a carrier state which increases the risk of transmission for travellers. Hence, paratyphoid fever is usually classified as a "travel-associated" disease. To date, diagnosis of paratyphoid fever based on the clinical presentation is not satisfactory as it resembles other febrile illnesses, and could not be distinguished from S. Typhi infection. With the availability of Whole Genome Sequencing technology, the genomes of S. Paratyphi A could be studied in-depth and more specific targets for detection will be revealed. Hence, detection of S. Paratyphi A with Polymerase Chain Reaction (PCR) method appears to be a more reliable approach compared to the Widal test. On the other hand, due to increasing incidence of S. Paratyphi A infections worldwide, the need to produce a paratyphoid vaccine is essential and urgent. Hence various vaccine projects that involve clinical trials have been carried out. Overall, this review provides the insights of S. Paratyphi A, including the bacteriology, epidemiology, management and antibiotic susceptibility, diagnoses and vaccine development.
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Affiliation(s)
- Cindy Shuan Ju Teh
- 1. Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur
| | - Kek Heng Chua
- 2. Department of Biomedical Science, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur
| | - Kwai Lin Thong
- 3. Institute of Biological Sciences, Faculty of Science, University of Malaya, 50603 Kuala Lumpur
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10
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Fabre L, Le Hello S, Roux C, Issenhuth-Jeanjean S, Weill FX. CRISPR is an optimal target for the design of specific PCR assays for salmonella enterica serotypes Typhi and Paratyphi A. PLoS Negl Trop Dis 2014; 8:e2671. [PMID: 24498453 PMCID: PMC3907412 DOI: 10.1371/journal.pntd.0002671] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 12/13/2013] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Serotype-specific PCR assays targeting Salmonella enterica serotypes Typhi and Paratyphi A, the causal agents of typhoid and paratyphoid fevers, are required to accelerate formal diagnosis and to overcome the lack of typing sera and, in some situations, the need for culture. However, the sensitivity and specificity of such assays must be demonstrated on large collections of strains representative of the targeted serotypes and all other bacterial populations producing similar clinical symptoms. METHODOLOGY Using a new family of repeated DNA sequences, CRISPR (clustered regularly interspaced short palindromic repeats), as a serotype-specific target, we developed a conventional multiplex PCR assay for the detection and differentiation of serotypes Typhi and Paratyphi A from cultured isolates. We also developed EvaGreen-based real-time singleplex PCR assays with the same two sets of primers. PRINCIPAL FINDINGS We achieved 100% sensitivity and specificity for each protocol after validation of the assays on 188 serotype Typhi and 74 serotype Paratyphi A strains from diverse genetic groups, geographic origins and time periods and on 70 strains of bacteria frequently encountered in bloodstream infections, including 29 other Salmonella serotypes and 42 strains from 38 other bacterial species. CONCLUSIONS The performance and convenience of our serotype-specific PCR assays should facilitate the rapid and accurate identification of these two major serotypes in a large range of clinical and public health laboratories with access to PCR technology. These assays were developed for use with DNA from cultured isolates, but with modifications to the assay, the CRISPR targets could be used in the development of assays for use with clinical and other samples.
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Affiliation(s)
- Laetitia Fabre
- Unité des Bactéries Pathogènes Entériques, Centre National de Référence des Escherichia coli, Shigella et Salmonella, WHO Collaborative Center for Reference and Research on Salmonella, Institut Pasteur, Paris, France
| | - Simon Le Hello
- Unité des Bactéries Pathogènes Entériques, Centre National de Référence des Escherichia coli, Shigella et Salmonella, WHO Collaborative Center for Reference and Research on Salmonella, Institut Pasteur, Paris, France
| | - Chrystelle Roux
- Unité des Bactéries Pathogènes Entériques, Centre National de Référence des Escherichia coli, Shigella et Salmonella, WHO Collaborative Center for Reference and Research on Salmonella, Institut Pasteur, Paris, France
| | - Sylvie Issenhuth-Jeanjean
- Unité des Bactéries Pathogènes Entériques, Centre National de Référence des Escherichia coli, Shigella et Salmonella, WHO Collaborative Center for Reference and Research on Salmonella, Institut Pasteur, Paris, France
| | - François-Xavier Weill
- Unité des Bactéries Pathogènes Entériques, Centre National de Référence des Escherichia coli, Shigella et Salmonella, WHO Collaborative Center for Reference and Research on Salmonella, Institut Pasteur, Paris, France
- * E-mail:
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11
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Yu S, Liu W, Shi C, Wang D, Dan X, Li X, Shi X. SMM-system: A mining tool to identify specific markers in Salmonella enterica. J Microbiol Methods 2011; 84:423-9. [PMID: 21256892 DOI: 10.1016/j.mimet.2011.01.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Revised: 12/21/2010] [Accepted: 01/03/2011] [Indexed: 10/18/2022]
Abstract
This report presents SMM-system, a software package that implements various personalized pre- and post-BLASTN tasks for mining specific markers of microbial pathogens. The main functionalities of SMM-system are summarized as follows: (i) converting multi-FASTA file, (ii) cutting interesting genomic sequence, (iii) automatic high-throughput BLASTN searches, and (iv) screening target sequences. The utility of SMM-system was demonstrated by using it to identify 214 Salmonella enterica-specific protein-coding sequences (CDSs). Eighteen primer pairs were designed based on eighteen S. enterica-specific CDSs, respectively. Seven of these primer pairs were validated with PCR assay, which showed 100% inclusivity for the 101 S. enterica genomes and 100% exclusivity of 30 non-S. enterica genomes. Three specific primer pairs were chosen to develop a multiplex PCR assay, which generated specific amplicons with a size of 180bp (SC1286), 238bp (SC1598) and 405bp (SC4361), respectively. This study demonstrates that SMM-system is a high-throughput specific marker generation tool that can be used to identify genus-, species-, serogroup- and even serovar-specific DNA sequences of microbial pathogens, which has a potential to be applied in food industries, diagnostics and taxonomic studies. SMM-system is freely available and can be downloaded from http://foodsafety.sjtu.edu.cn/SMM-system.html.
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Affiliation(s)
- Shuijing Yu
- Joint Sino-US Food Safety Research Center and Bor Luh Food Safety Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, PR China
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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]
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Development of a novel multiplex PCR for the detection and differentiation of Salmonella enterica serovars Typhi and Paratyphi A. Res Microbiol 2010; 161:243-8. [DOI: 10.1016/j.resmic.2010.03.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Revised: 03/03/2010] [Accepted: 03/11/2010] [Indexed: 11/24/2022]
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Shao Y, He X, Harrison EM, Tai C, Ou HY, Rajakumar K, Deng Z. mGenomeSubtractor: a web-based tool for parallel in silico subtractive hybridization analysis of multiple bacterial genomes. Nucleic Acids Res 2010; 38:W194-200. [PMID: 20435682 PMCID: PMC2896100 DOI: 10.1093/nar/gkq326] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
mGenomeSubtractor performs an mpiBLAST-based comparison of reference bacterial genomes against multiple user-selected genomes for investigation of strain variable accessory regions. With parallel computing architecture, mGenomeSubtractor is able to run rapid BLAST searches of the segmented reference genome against multiple subject genomes at the DNA or amino acid level within a minute. In addition to comparison of protein coding sequences, the highly flexible sliding window-based genome fragmentation approach offered can be used to identify short unique sequences within or between genes. mGenomeSubtractor provides powerful schematic outputs for exploration of identified core and accessory regions, including searches against databases of mobile genetic elements, virulence factors or bacterial essential genes, examination of G+C content and binucleotide distribution bias, and integrated primer design tools. mGenomeSubtractor also allows for the ready definition of species-specific gene pools based on available genomes. Pan-genomic arrays can be easily developed using the efficient oligonucleotide design tool. This simple high-throughput in silico ‘subtractive hybridization’ analytical tool will support the rapidly escalating number of comparative bacterial genomics studies aimed at defining genomic biomarkers of evolutionary lineage, phenotype, pathotype, environmental adaptation and/or disease-association of diverse bacterial species. mGenomeSubtractor is freely available to all users without any login requirement at: http://bioinfo-mml.sjtu.edu.cn/mGS/.
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Affiliation(s)
- Yucheng Shao
- Laboratory of Microbial Metabolism and School of Life Sciences & Biotechnology, Shanghai Jiaotong University, P. R. China
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Yu S, Chen W, Wang D, He X, Zhu X, Shi X. Species-specific PCR detection of the food-borne pathogen Vibrio parahaemolyticus using the irgB gene identified by comparative genomic analysis. FEMS Microbiol Lett 2010; 307:65-71. [PMID: 20402781 DOI: 10.1111/j.1574-6968.2010.01952.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Vibrio parahaemolyticus is an enteric pathogen, which can cause acute gastroenteritis in humans after consumption of raw or partially cooked seafood, and specific molecular markers are necessary for its accurate identification by PCR methods. In the present study, 23 protein-coding sequences were identified by the comparative genomics method as V. parahaemolyticus-specific candidate markers. We targeted the irgB gene (vp2603), coding for iron-regulated virulence regulatory protein IrgB, in order to develop a PCR method for the detection of V. parahaemolyticus. PCR specificity was identified by amplification of 293 V. parahaemolyticus templates and by the loss of a PCR product with 11 strains from other Vibrio species and 35 non-Vibrio bacterial strains. The PCR assay had the 369-bp fragment and the sensitivity of 0.17 pg purified genomic DNA from V. parahaemolyticus. Furthermore, a multiplex PCR assay for the detection of total and virulent strains of V. parahaemolyticus was developed by targeting irgB, tdh and trh genes. These data indicated that the irgB gene is a new and effective marker for the detection of V. parahaemolyticus. In addition, this study demonstrates that genome sequence comparison has a powerful application in identifying specific markers for the detection and identification of bacterial pathogens.
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Affiliation(s)
- Shuijing Yu
- Department of Food Science and Technology, Joint Sino-US Food Safety Research Center & Bor Luh Food Safety Center, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai, China
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A real-time PCR method for the detection of Salmonella enterica from food using a target sequence identified by comparative genomic analysis. Int J Food Microbiol 2010; 137:168-74. [PMID: 20060189 DOI: 10.1016/j.ijfoodmicro.2009.12.004] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Revised: 11/04/2009] [Accepted: 12/03/2009] [Indexed: 12/25/2022]
Abstract
A 5'-nuclease real-time PCR assay using a minor groove binding probe was developed for the detection of Salmonella enterica from artificially contaminated foods. S. enterica-specific sequences were identified by a comparative genomic approach. Several species-specific target sequences were evaluated for specificity. A real-time PCR assay was developed targeting a nucleotide sequence within the putative type III secretion ATP synthase gene (ssaN). An internal amplification control (IAC) probe was designed by randomly shuffling the target probe sequence and a single-stranded oligonucleotide was synthesized to serve as an IAC. The assay demonstrated 100% inclusivity for the 40 Salmonella strains tested and 100% exclusivity for 24 non-Salmonella strains. The detection limit of the real-time PCR assay was 41.2 fg/PCR with Salmonella Typhimurium genomic DNA and 18.6 fg/PCR using Salmonella Enteritidis genomic DNA; 8 and 4 genome equivalents, respectively. In the presence of a natural background flora derived from chicken meat enrichment cultures, the sample preparation and PCR method were capable of detecting as few as 130 Salmonella cfu/mL. Using the developed real-time PCR method to detect Salmonella in artificially contaminated chicken, liquid egg and peanut butter samples, as few as 1 cfu/10 g of sample was detectable after a brief (6h) non-selective culture enrichment.
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Zhang WW, Versalovic J. Expanding the diagnostic capabilities of molecular microbiology by genomic methods. J Mol Diagn 2007; 9:572-3. [PMID: 17872972 PMCID: PMC2049058 DOI: 10.2353/jmoldx.2007.070109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Wenyong W Zhang
- Department of Pathology, Texas Children's Hospital, 6621 Fannin, Houston, TX 77030, USA
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