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Chatterjee R, Chowdhury AR, Mukherjee D, Chakravortty D. From Eberthella typhi to Salmonella Typhi: The Fascinating Journey of the Virulence and Pathogenicity of Salmonella Typhi. ACS OMEGA 2023; 8:25674-25697. [PMID: 37521659 PMCID: PMC10373206 DOI: 10.1021/acsomega.3c02386] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Accepted: 06/30/2023] [Indexed: 08/01/2023]
Abstract
Salmonella Typhi (S. Typhi), the invasive typhoidal serovar of Salmonella enterica that causes typhoid fever in humans, is a severe threat to global health. It is one of the major causes of high morbidity and mortality in developing countries. According to recent WHO estimates, approximately 11-21 million typhoid fever illnesses occur annually worldwide, accounting for 0.12-0.16 million deaths. Salmonella infection can spread to healthy individuals by the consumption of contaminated food and water. Typhoid fever in humans sometimes is accompanied by several other critical extraintestinal complications related to the central nervous system, cardiovascular system, pulmonary system, and hepatobiliary system. Salmonella Pathogenicity Island-1 and Salmonella Pathogenicity Island-2 are the two genomic segments containing genes encoding virulent factors that regulate its invasion and systemic pathogenesis. This Review aims to shed light on a comparative analysis of the virulence and pathogenesis of the typhoidal and nontyphoidal serovars of S. enterica.
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Affiliation(s)
- Ritika Chatterjee
- Department
of Microbiology and Cell Biology, Division of Biological Sciences, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Atish Roy Chowdhury
- Department
of Microbiology and Cell Biology, Division of Biological Sciences, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Debapriya Mukherjee
- Department
of Microbiology and Cell Biology, Division of Biological Sciences, Indian Institute of Science, Bangalore, Karnataka 560012, India
| | - Dipshikha Chakravortty
- Department
of Microbiology and Cell Biology, Division of Biological Sciences, Indian Institute of Science, Bangalore, Karnataka 560012, India
- Centre
for Biosystems Science and Engineering, Indian Institute of Science, Bangalore, Karnataka 560012, India
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Igiri BE, Okoduwa SIR, Munirat SA, Otu-Bassey IB, Bashir A, Onyiyioza OM, Enang IA, Okoduwa UJ. Diversity in Enteric Fever Diagnostic Protocols and Recommendation for Composite Reference Standard. IRANIAN JOURNAL OF MEDICAL MICROBIOLOGY 2023; 17:22-38. [DOI: 10.30699/ijmm.17.1.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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Bahramian A, Kachoie MA, Rahimi E. Antimicrobial effects of Arctium lappa against infectious bacteria: Experimental in vitro analysis. MAIN GROUP CHEMISTRY 2022. [DOI: 10.3233/mgc-220002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Arctium lappa (A. lappa) is one of the most significant edible medicinal plants with high antibacterial effects, in which it could be supposed to grow with more beneficial effects under administration by salicylic acid and chitosan based biofertilizers. Accordingly, the effects of salicylic acid, chitosan, and 50% moisture discharge were investigated in this work to see the antimicrobial treatments of some foodborne pathogens effects by A. lappa. To this aim, plants were cultivated based on different concentrations of salicylic acid and chitosan with/without drought stress, in which their extracted essential oils were examined for showing the antimicrobial effect against different bacterial agents. The results indicated that the salicylic acid and chitosan administrated A. lappa could work with improved inhibitory functions. Comparing with referenced antibiotics showed even higher antimicrobial effects of A. lappa against the targeted bacterial agents, in which the species with 14 mmol of salicylic acid and 2 g/l of chitosan was a distinguished one for approaching the purpose. Consequently, the achievements of this work could be further investigated for producing novel antibiotic drug agents.
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Affiliation(s)
- Asghar Bahramian
- Department of Agro-ecology, Faculty of Agriculture, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran
| | - Mehrdad Ataie Kachoie
- Department of Agro-ecology, Faculty of Agriculture, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran
| | - Ebrahim Rahimi
- Department of Food Hygiene and Public Health, Faculty of Veterinary Medicine, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran
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Enteric Fever Diagnosis: Current Challenges and Future Directions. Pathogens 2021; 10:pathogens10040410. [PMID: 33915749 PMCID: PMC8065732 DOI: 10.3390/pathogens10040410] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 03/23/2021] [Accepted: 03/27/2021] [Indexed: 12/21/2022] Open
Abstract
Enteric fever is a life-threatening systemic febrile disease caused by Salmonella enterica serovars Typhi and Paratyphi (S. Typhi and S. Paratyphi). Unfortunately, the burden of the disease remains high primarily due to the global spread of various drug-resistant Salmonella strains despite continuous advancement in the field. An accurate diagnosis is critical for effective control of the disease. However, enteric fever diagnosis based on clinical presentations is challenging due to overlapping symptoms with other febrile illnesses that are also prevalent in endemic areas. Current laboratory tests display suboptimal sensitivity and specificity, and no diagnostic methods are available for identifying asymptomatic carriers. Several research programs have employed systemic approaches to identify more specific biomarkers for early detection and asymptomatic carrier detection. This review discusses the pros and cons of currently available diagnostic tests for enteric fever, the advancement of research toward improved diagnostic tests, and the challenges of discovering new ideal biomarkers and tests.
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Gal-Mor O. Persistent Infection and Long-Term Carriage of Typhoidal and Nontyphoidal Salmonellae. Clin Microbiol Rev 2019; 32:e00088-18. [PMID: 30487167 PMCID: PMC6302356 DOI: 10.1128/cmr.00088-18] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The ability of pathogenic bacteria to affect higher organisms and cause disease is one of the most dramatic properties of microorganisms. Some pathogens can establish transient colonization only, but others are capable of infecting their host for many years or even for a lifetime. Long-term infection is called persistence, and this phenotype is fundamental for the biology of important human pathogens, including Helicobacter pylori, Mycobacterium tuberculosis, and Salmonella enterica Both typhoidal and nontyphoidal serovars of the species Salmonella enterica can cause persistent infection in humans; however, as these two Salmonella groups cause clinically distinct diseases, the characteristics of their persistent infections in humans differ significantly. Here, following a general summary of Salmonella pathogenicity, host specificity, epidemiology, and laboratory diagnosis, I review the current knowledge about Salmonella persistence and discuss the relevant epidemiology of persistence (including carrier rate, duration of shedding, and host and pathogen risk factors), the host response to Salmonella persistence, Salmonella genes involved in this lifestyle, as well as genetic and phenotypic changes acquired during prolonged infection within the host. Additionally, I highlight differences between the persistence of typhoidal and nontyphoidal Salmonella strains in humans and summarize the current gaps and limitations in our understanding, diagnosis, and curing of persistent Salmonella infections.
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Affiliation(s)
- Ohad Gal-Mor
- Infectious Diseases Research Laboratory, Sheba Medical Center, Tel-Hashomer, Israel
- Department of Clinical Microbiology and Immunology, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
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Keikha M. LAMP Method as One of the Best Candidates for Replacing with PCR Method. Malays J Med Sci 2018; 25:121-123. [PMID: 29599643 DOI: 10.21315/mjms2018.25.1.15] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 10/01/2017] [Indexed: 02/06/2023] Open
Affiliation(s)
- Masoud Keikha
- Department of Microbiology, School of Medicine, Isfahan Medical University, Isfahan, Iran
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Zhou L, Jones C, Gibani MM, Dobinson H, Thomaides-Brears H, Shrestha S, Blohmke CJ, Darton TC, Pollard AJ. Development and Evaluation of a Blood Culture PCR Assay for Rapid Detection of Salmonella Paratyphi A in Clinical Samples. PLoS One 2016; 11:e0150576. [PMID: 26930553 PMCID: PMC4773247 DOI: 10.1371/journal.pone.0150576] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 02/17/2016] [Indexed: 01/15/2023] Open
Abstract
Background Enteric fever remains an important cause of morbidity in many low-income countries and Salmonella Paratyphi A has emerged as the aetiological agent in an increasing proportion of cases. Lack of adequate diagnostics hinders early diagnosis and prompt treatment of both typhoid and paratyphoid but development of assays to identify paratyphoid has been particularly neglected. Here we describe the development of a rapid and sensitive blood culture PCR method for detection of Salmonella Paratyphi A from blood, potentially allowing for appropriate diagnosis and antimicrobial treatment to be initiated on the same day. Methods Venous blood samples from volunteers experimentally challenged orally with Salmonella Paratyphi A, who subsequently developed paratyphoid, were taken on the day of diagnosis; 10 ml for quantitative blood culture and automated blood culture, and 5 ml for blood culture PCR. In the latter assay, bacteria were grown in tryptone soy broth containing 2.4% ox bile and micrococcal nuclease for 5 hours (37°C) before bacterial DNA was isolated for PCR detection targeting the fliC-a gene of Salmonella Paratyphi A. Results An optimized broth containing 2.4% ox bile and micrococcal nuclease, as well as a PCR test was developed for a blood culture PCR assay of Salmonella Paratyphi A. The volunteers diagnosed with paratyphoid had a median bacterial burden of 1 (range 0.1–6.9) CFU/ml blood. All the blood culture PCR positive cases where a positive bacterial growth was shown by quantitative blood culture had a bacterial burden of ≥ 0.3 CFU/ ml blood. The blood culture PCR assay identified an equal number of positive cases as automated blood culture at higher bacterial loads (≥0.3 CFU/ml blood), but utilized only half the volume of specimens. Conclusions The blood culture PCR method for detection of Salmonella Paratyphi A can be completed within 9 hours and offers the potential for same-day diagnosis of enteric fever. Using 5 ml blood, it exhibited a lower limit of detection equal to 0.3 CFU/ml blood, and it performed at least as well as automated blood culture at higher bacterial loads (≥0.3 CFU/ml blood) of clinical specimens despite using half the volume of blood. The findings warrant its further study in endemic populations with a potential use as a novel diagnostic which fills the present gap of paratyphoid diagnostics.
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Affiliation(s)
- Liqing Zhou
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
- * E-mail:
| | - Claire Jones
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Malick M. Gibani
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Hazel Dobinson
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Helena Thomaides-Brears
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Sonu Shrestha
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Christoph J. Blohmke
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Thomas C. Darton
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
| | - Andrew J. Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
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Storey HL, Huang Y, Crudder C, Golden A, de los Santos T, Hawkins K. A Meta-Analysis of Typhoid Diagnostic Accuracy Studies: A Recommendation to Adopt a Standardized Composite Reference. PLoS One 2015; 10:e0142364. [PMID: 26566275 PMCID: PMC4643909 DOI: 10.1371/journal.pone.0142364] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 10/21/2015] [Indexed: 01/09/2023] Open
Abstract
Novel typhoid diagnostics currently under development have the potential to improve clinical care, surveillance, and the disease burden estimates that support vaccine introduction. Blood culture is most often used as the reference method to evaluate the accuracy of new typhoid tests; however, it is recognized to be an imperfect gold standard. If no single gold standard test exists, use of a composite reference standard (CRS) can improve estimation of diagnostic accuracy. Numerous studies have used a CRS to evaluate new typhoid diagnostics; however, there is no consensus on an appropriate CRS. In order to evaluate existing tests for use as a reference test or inclusion in a CRS, we performed a systematic review of the typhoid literature to include all index/reference test combinations observed. We described the landscape of comparisons performed, showed results of a meta-analysis on the accuracy of the more common combinations, and evaluated sources of variability based on study quality. This wide-ranging meta-analysis suggests that no single test has sufficiently good performance but some existing diagnostics may be useful as part of a CRS. Additionally, based on findings from the meta-analysis and a constructed numerical example demonstrating the use of CRS, we proposed necessary criteria and potential components of a typhoid CRS to guide future recommendations. Agreement and adoption by all investigators of a standardized CRS is requisite, and would improve comparison of new diagnostics across independent studies, leading to the identification of a better reference test and improved confidence in prevalence estimates.
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Affiliation(s)
- Helen L. Storey
- Diagnostics Program, PATH, Seattle, Washington, United States of America
- * E-mail:
| | - Ying Huang
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
| | - Chris Crudder
- Diagnostics Program, PATH, Seattle, Washington, United States of America
| | - Allison Golden
- Diagnostics Program, PATH, Seattle, Washington, United States of America
| | - Tala de los Santos
- Diagnostics Program, PATH, Seattle, Washington, United States of America
| | - Kenneth Hawkins
- Diagnostics Program, PATH, Seattle, Washington, United States of America
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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: 630] [Impact Index Per Article: 70.0] [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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Parry CM, Wijedoru L, Arjyal A, Baker S. The utility of diagnostic tests for enteric fever in endemic locations. Expert Rev Anti Infect Ther 2014; 9:711-25. [DOI: 10.1586/eri.11.47] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Lunguya O, Phoba MF, Mundeke SA, Bonebe E, Mukadi P, Muyembe JJ, Verhaegen J, Jacobs J. The diagnosis of typhoid fever in the Democratic Republic of the Congo. Trans R Soc Trop Med Hyg 2012; 106:348-55. [DOI: 10.1016/j.trstmh.2012.03.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Revised: 03/16/2012] [Accepted: 03/16/2012] [Indexed: 10/28/2022] Open
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Tennant SM, Zhang Y, Galen JE, Geddes CD, Levine MM. Ultra-fast and sensitive detection of non-typhoidal Salmonella using microwave-accelerated metal-enhanced fluorescence ("MAMEF"). PLoS One 2011; 6:e18700. [PMID: 21494634 PMCID: PMC3073000 DOI: 10.1371/journal.pone.0018700] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Accepted: 03/08/2011] [Indexed: 01/11/2023] Open
Abstract
Certain serovars of Salmonella enterica subsp. enterica cause invasive disease (e.g., enteric fever, bacteremia, septicemia, meningitis, etc.) in humans and constitute a global public health problem. A rapid, sensitive diagnostic test is needed to allow prompt initiation of therapy in individual patients and for measuring disease burden at the population level. An innovative and promising new rapid diagnostic technique is microwave-accelerated metal-enhanced fluorescence (MAMEF). We have adapted this assay platform to detect the chromosomal oriC locus common to all Salmonella enterica subsp. enterica serovars. We have shown efficient lysis of biologically relevant concentrations of Salmonella spp. suspended in bacteriological media using microwave-induced lysis. Following lysis and DNA release, as little as 1 CFU of Salmonella in 1 ml of medium can be detected in <30 seconds. Furthermore the assay is sensitive and specific: it can detect oriC from Salmonella serovars Typhi, Paratyphi A, Paratyphi B, Paratyphi C, Typhimurium, Enteritidis and Choleraesuis but does not detect Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Streptococcus pneumoniae, Haemophilus influenzae or Acinetobacter baumanii. We have also performed preliminary experiments using a synthetic Salmonella oriC oligonucleotide suspended in whole human blood and observed rapid detection when the sample was diluted 1∶1 with PBS. These pre-clinical data encourage progress to the next step to detect Salmonella in blood (and other ordinarily sterile, clinically relevant body fluids).
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Affiliation(s)
- Sharon M Tennant
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, Maryland, United States of America.
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Zhou L, Pollard AJ. A fast and highly sensitive blood culture PCR method for clinical detection of Salmonella enterica serovar Typhi. Ann Clin Microbiol Antimicrob 2010; 9:14. [PMID: 20403166 PMCID: PMC2873252 DOI: 10.1186/1476-0711-9-14] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Accepted: 04/19/2010] [Indexed: 11/16/2022] Open
Abstract
Background Salmonella Typhi causes an estimated 21 million new cases of typhoid fever and 216,000 deaths every year. Blood culture is currently the gold standard for diagnosis of typhoid fever, but it is time-consuming and takes several days for isolation and identification of causative organisms. It is then too late to initiate proper antibiotic therapy. Serological tests have very low sensitivity and specificity, and no practical value in endemic areas. As early diagnosis of the disease and prompt treatment are essential for optimal management, especially in children, a rapid sensitive detection method for typhoid fever is urgently needed. Although PCR is sensitive and rapid, initial research indicated similar sensitivity to blood culture and lower specificity. We developed a fast and highly sensitive blood culture PCR method for detection of Salmonella Typhi, allowing same-day initiation of treatment after accurate diagnosis of typhoid. Methods An ox bile tryptone soy broth was optimized for blood culture, which allows the complete lysis of blood cells to release intracellular bacteria without inhibiting the growth of Salmonella Typhi. Using the optimised broth Salmonella Typhi bacteria in artificial blood samples were enriched in blood culture and then detected by a PCR targeting the fliC-d gene of Salmonella Typhi. Results Tests demonstrated that 2.4% ox bile in blood culture not only lyzes blood cells completely within 1.5 hours so that the intracellular bacteria could be released, but also has no inhibiting effect on the growth of Salmonella Typhi. Three hour enrichment of Salmonella Typhi in tryptone soya broth containing 2.4% ox bile could increase the bacterial number from 0.75 CFU per millilitre of blood which is similar to clinical typhoid samples to the level which regular PCR can detect. The whole blood culture PCR assay takes less than 8 hours to complete rather than several days for conventional blood culture. Conclusions This novel blood culture PCR method is superior in speed and sensitivity to both conventional blood culture and PCR assays. Its use in clinical diagnosis may allow early detection of the causative organism and facilitate initiation of prompt treatment among patients with typhoid fever.
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Affiliation(s)
- Liqing Zhou
- Oxford Vaccine Centre, University of Oxford, Oxford, UK.
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Yildirim I, Ceyhan M, Bayrakci B, Uysal M, Kuskonmaz B, Ozaltin F. A Case Report of Thrombocytopenia-associated Multiple Organ Failure Secondary toSalmonella entericaSerotype Typhi Infection in a Pediatric Patient: Successful Treatment With Plasma Exchange. Ther Apher Dial 2010; 14:226-9. [DOI: 10.1111/j.1744-9987.2009.00714.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kumar A, Balachandran Y, Gupta S, Khare S, Suman. Quick PCR based diagnosis of typhoid using specific genetic markers. Biotechnol Lett 2010; 32:707-12. [PMID: 20140635 DOI: 10.1007/s10529-010-0211-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Revised: 01/14/2010] [Accepted: 01/14/2010] [Indexed: 10/19/2022]
Abstract
A quick multiplex PCR based detection method was developed for early diagnosis of typhoid using specific genetic markers of S. typhi. Primers of tyv gene, flag gene, viaB gene and ratA gene confirmed the specificity and sensitivity of the PCR. The serum samples of the suspected typhoid patients were taken directly for PCR without culturing and isolating genomic DNA. Overall diagnosis required 2 h which is the least time ever reported for a PCR based methods. The sensitivity of the method is up to 5 fg genomic DNA. The genetic markers are specific and the four pairs of primers give selective amplification and differentiate S. typhi from closely related S. typhimurium.
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Affiliation(s)
- Ashok Kumar
- Institute of Genomics and Integrative Biology, Mall Road, Delhi, 110007, India.
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Reliable means of diagnosis and serovar determination of blood-borne Salmonella strains: quick PCR amplification of unique genomic loci by novel primer sets. J Clin Microbiol 2009; 47:2435-41. [PMID: 19535522 DOI: 10.1128/jcm.00327-09] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Typhoid fever is becoming an ever increasing threat in the developing countries. We have improved considerably upon the existing PCR-based diagnosis method by designing primers against a region that is unique to Salmonella enterica subsp. enterica serovar Typhi and Salmonella enterica subsp. enterica serovar Paratyphi A, corresponding to the STY0312 gene in S. Typhi and its homolog SPA2476 in S. Paratyphi A. An additional set of primers amplify another region in S. Typhi CT18 and S. Typhi Ty2 corresponding to the region between genes STY0313 to STY0316 but which is absent in S. Paratyphi A. The possibility of a false-negative result arising due to mutation in hypervariable genes has been reduced by targeting a gene unique to typhoidal Salmonella serovars as a diagnostic marker. The amplified region has been tested for genomic stability by amplifying the region from clinical isolates of patients from various geographical locations in India, thereby showing that this region is potentially stable. These set of primers can also differentiate between S. Typhi CT18, S. Typhi Ty2, and S. Paratyphi A, which have stable deletions in this specific locus. The PCR assay designed in this study has a sensitivity of 95% compared to the Widal test which has a sensitivity of only 63%. As observed, in certain cases, the PCR assay was more sensitive than the blood culture test was, as the PCR-based detection could also detect dead bacteria.
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The comparison of cultures, widal agglutination test and polymerase chain reaction as a diagnostic tool in typhoid fever. Open Med (Wars) 2008. [DOI: 10.2478/s11536-008-0052-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractTyphoid fever caused by Salmonella typhi, paratyphi A and B, is an important cause of morbidity and mortality in many developing countries. A rapid and sensitive method for the detection of S. typhi is essential for early diagnosis of typhoid fever and effective therapy. In this study 45 febrile patients who were suspected to have enteric fever were enrolled, and the results of blood cultures, widal agglutination tests and Polymerase Chain Reaction in these cases were evaluated. Group I consisted of 11 patients with diseases other than salmonella infections, group II represented 6 patients with positive cultures, and group III represented 28 patients with negative blood cultures negative but who were clinically suspected cases that had a medical history of using variable antimicrobial agents. Two positive PCR results were present; one of them was in culture positive group (16,6%) and the other was in culture negative group (3,5%). In our study widal agglutination tests and cultures were found not to be helpful in differential dignosis. Although PCR based detection of S. typhi is reported to be a sensitive and specific test for the diagnosis of enteric fever, in our study the benefit of this method in the diagnosis of especially patients who were treated with antimicrobial therapy was not clearly determined. Other methods to increase sensitiviy and specificity to levels such as those of real time PCR should be developed and large-scaled studies should be done in endemic and non-epidemic regions.
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Abstract
Estimates for the year 2000 suggested that there were approximately 21.5 million infections and 200,000 deaths from typhoid fever globally each year, making the disease one of the most serious infectious disease threats to public health on a global scale. However, these estimates were based on little data, especially from Africa. Global prominence and high-profile outbreaks have created the perception in Kenya that typhoid is a common cause of febrile illness. The Widal test is used widely in diagnosis. We have reviewed recent literature, taking the perspective of a healthcare provider, to collate information on the prevalence of typhoid in children particularly, and to explore the role of clinical diagnosis and diagnosis based on a crude, but common, interpretation of the Widal test. Data suggest that typhoid in children in rural Africa is uncommon, perhaps 100 times or 250 times less common than invasive disease because of Haemophilus influenzae or Streptococcus pneumoniae, respectively. Frequent use of the Widal test may result in many hundreds of over-treatment episodes for every true case treated and may perpetuate the perception that typhoid is common. Countries such as Kenya need better bacterial disease surveillance systems allied to better information for healthcare providers to promote appropriate decision-making on prevention and treatment strategies.
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Affiliation(s)
- Evanson Mweu
- Kenya Medical Research Institute (KEMRI), Centre for Geographic Medicine Research, Nairobi, Kenya, and College of Health Sciences, University of Nairobi, Nairobi, Kenya
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Ou HY, Ju CTS, Thong KL, Ahmad N, Deng Z, Barer MR, Rajakumar K. Translational genomics to develop a Salmonella enterica serovar Paratyphi A multiplex polymerase chain reaction assay. J Mol Diagn 2007; 9:624-30. [PMID: 17975028 PMCID: PMC2049048 DOI: 10.2353/jmoldx.2007.070064] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/23/2007] [Indexed: 11/20/2022] Open
Abstract
The use of pathogen genome sequence data for the control and management of infections remains an ongoing challenge. We describe a broadly applicable, web-enabled approach that can be used to develop bacteria-specific polymerase chain reaction (PCR) assays. Salmonella enterica Paratyphi A has emerged as a major cause of enteric fever in Asia. Culture-based diagnosis is slow and frequently negative in patients with suspected typhoid and paratyphoid fever, potentially compromising patient management and public health. We used the MobilomeFINDER web-server to perform in silico subtractive hybridization, thus identifying 43 protein-coding sequences (CDSs) that were present in two Paratyphi A strains but not in other sequenced Salmonella genomes. After exclusion of 29 CDSs found to be variably present in Paratyphi A strains by microarray hybridization and grouping of remaining CDSs by genomic location, four dispersed targets (stkF, spa2473, spa2539, hsdM) were used to develop a highly discriminatory multiplex PCR assay. All 52 Paratyphi A strains within the diverse panel investigated produced one of two pathognomonic four-band signatures. Given rapid and ongoing expansion of DNA and comparative genomics databases, our universally accessible web-server-supported do-it-yourself approach offers the potential to contribute significantly to the rapid development of species-, serovar-, or pathotype-specific PCR assays targeting pre-existing and emerging bacterial pathogens.
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Affiliation(s)
- Hong-Yu Ou
- Laboratory of Microbial Metabolism and School of Life Science and Biotechnology, Shanghai Jiaotong University, Shanghai, China
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Aziah I, Ravichandran M, Ismail A. Amplification of ST50 gene using dry-reagent-based polymerase chain reaction for the detection of Salmonella typhi. Diagn Microbiol Infect Dis 2007; 59:373-7. [PMID: 17964105 DOI: 10.1016/j.diagmicrobio.2007.05.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2007] [Revised: 05/28/2007] [Accepted: 05/29/2007] [Indexed: 11/28/2022]
Abstract
Conventional polymerase chain reaction (PCR) testing requires many pipetting steps and has to be transported and stored in cold chain. To overcome these limitations, we designed a ready-to-use PCR test for Salmonella typhi using PCR reagents, primers against the ST50 gene of S. typhi, a built-in internal amplification control (IAC), and gel loading dye mixed and freeze-dried in a single tube. The 2-step dry-reagent-based assay was used to amplify a 1238-bp target gene and an 810-bp IAC gene from 73 BACTEC blood culture broths (33 true positives for S. typhi and 40 true negatives for non-S. typhi). The sensitivity, specificity, positive predictive value, and negative predictive value of the PCR assay were 87.9%, 100%, 100%, and 90.9%, respectively. We suggest that this rapid 2-step PCR test could be used for the rapid diagnosis of typhoid fever.
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Affiliation(s)
- Ismail Aziah
- Institute for Research in Molecular Medicine, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
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Nizami SQ, Bhutta ZA, Siddiqui AA, Lubbad L. Enhanced detection rate of typhoid fever in children in a periurban slum in Karachi, Pakistan using polymerase chain reaction technology. Scandinavian Journal of Clinical and Laboratory Investigation 2007; 66:429-36. [PMID: 16901852 DOI: 10.1080/00365510600791724] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
OBJECTIVE Yield of blood culture in clinically suspected cases of typhoid fever is low, whereas indirect serological diagnostic tests are unreliable. Hence, polymerase chain reaction (PCR)-based detection of Salmonella enterica Serovar typhi was used as an aid for diagnosis of typhoid fever in addition to other diagnostic tests. Two periurban communities in Karachi were selected for an epidemiological study of typhoid fever. The aim of the study was to assess whether PCR increased the detection rate of typhoid fever in children in the community. MATERIAL AND METHODS Children aged 2 to 14 years presenting with fever lasting for three or more days were selected. PCR using Hashimoto's protocol based on ViaB gene sequence was used in addition to blood culture and other serological tests. RESULTS Of the 214 children included in the study, blood culture was found positive for S. enterica S. typhi in 26 (12.4%) cases, whereas 24 children (11.7%) were diagnosed as suffering from typhoid fever when the PCR-based method was used. Both tests were positive in only 10 (4.9%) children. The number of children found positive for either test was 40. PCR increased the rate of detection of typhoid fever by 51%. CONCLUSION The sensitivity, specificity, +ve and -ve predictive values of PCR in this study were 40%, 93%, 45% and 92%, respectively.
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Affiliation(s)
- S Q Nizami
- Department of Pediatrics, The Aga Khan University and Hospital, Karachi, Pakistan.
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Prakash P, Mishra OP, Singh AK, Gulati AK, Nath G. Evaluation of nested PCR in diagnosis of typhoid fever. J Clin Microbiol 2005; 43:431-2. [PMID: 15635006 PMCID: PMC540097 DOI: 10.1128/jcm.43.1.431-432.2005] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this study, nested PCR using H1-d primers, which is specific for Salmonella enterica serovar Typhi, was compared to blood culture and the single-tube Widal test. Results indicate that nested PCR can be used as a gold standard to determine the cutoff titer of the Widal test for diagnosis of typhoid fever.
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Affiliation(s)
- Pradyot Prakash
- Department of Microbiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi 221005, India.
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Morin NJ, Gong Z, Li XF. Reverse Transcription-Multiplex PCR Assay for Simultaneous Detection of Escherichia coli O157:H7, Vibrio cholerae O1, and Salmonella Typhi. Clin Chem 2004; 50:2037-44. [PMID: 15364889 DOI: 10.1373/clinchem.2004.036814] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Abstract
Background: Escherichia coli O157:H7, Vibrio cholerae O1, and Salmonella Typhi are pathogenic bacteria that can be found in contaminated water supplies throughout the world. No currently available assays can simultaneously detect and identify all three pathogens. Our aim was to develop a rapid and reliable technique for simultaneous detection of these pathogens.
Methods: Four unique genes were chosen as the targets of detection. Forward and reverse primers were designed to specifically amplify different sizes of these target genes: a 239-bp region of the E. coli O157 lipopolysaccharide (LPS) gene (rfbE); a 179-bp region of the H7 flagellin gene (fliC); a 419-bp region of the V. cholerae O1 LPS gene (rfbE); and a 329-bp region of Salmonella Typhi LPS gene (tyv). To ensure the detection of only viable replicating bacteria, RNA was extracted for analysis. After reverse transcription, cDNAs were simultaneously amplified in a single tube by multiplex PCR. The multiplex PCR products were analyzed by gel electrophoresis. To characterize the assay we analyzed, in a blinded fashion, seven unknown RNA samples containing various combinations of total RNA from these bacteria as well as clinical isolates.
Results: All seven unknown RNA samples were correctly identified. The assay was able to detect and identify as few as 30 cells of E. coli O157:H7 and Salmonella Typhi in clinical isolates, and the presence of other bacteria did not interfere with the analysis.
Conclusion: An assay combining reverse transcription with single-tube multiplex PCR was successfully developed and validated for simultaneous detection of viable E. coli O157:H7, V. cholerae O1, and Salmonella Typhi.
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Affiliation(s)
- Nicole J Morin
- Environmental Health Sciences, Department of Public Health Sciences, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
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Abstract
Typhoid fever is caused by infection with Salmonella enterica serovar Typhi. The completion of the genome sequence of two Salmonella enterica serovar Typhi isolates is leading to new insights into the biology of this pathogen. Approximately 16 million cases occur worldwide each year. The lack of culture facilities in endemic areas and the poor performance of the Widal test means the disease is frequently unconfirmed. Simple new serologic tests are being developed and show promise. Resistance to chloramphenicol, ampicillin, and trimethoprim/sulfamethoxazole is widespread in Asia and some areas of Africa, although fully susceptible isolates have re-emerged in some countries. Fluoroquinolones, third-generation cephalosporins, and azithromycin are effective alternatives. Low-level fluoroquinolone resistance (indicated by resistance to nalidixic acid) is now common in Asia and results in a suboptimal response to fluoroquinolones. Two vaccines are licensed and others are being developed, but neither licensed vaccine is used in endemic areas as a public health measure.
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Affiliation(s)
- Christopher M. Parry
- University Department of Medical Microbiology and Genitourinary Medicine, Duncan Building, Royal Liverpool University Hospital, Daulby Street, University of Liverpool, Liverpool, L69 3GA, UK.
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