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Musanna, Faridoon Khan U, Habib G, Gul H, Hayat A, Ur Rehman M. Contribution of the gyrA and waaG mutants to fluoroquinolones resistance, biofilm development, and persister cells formation in Salmonella enterica serovar Typhi. Gene 2024; 894:147943. [PMID: 37956962 DOI: 10.1016/j.gene.2023.147943] [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: 03/27/2023] [Revised: 09/01/2023] [Accepted: 10/27/2023] [Indexed: 11/21/2023]
Abstract
Fluoroquinolone resistance in Salmonella has been reported worldwide and poses a serious public health threat in developing countries. Multiple factors contribute to fluoroquinolone resistance, including mutations in DNA gyrase and the acquisition of antimicrobial resistance genes. Salmonella enterica serovar Typhi (S. Typhi) causes typhoid fever in humans, which is highly prevalent in counties with poor sanitation and hygiene standards. Here, we reported S. Typhi clinical isolates that showed varying degrees of susceptibility to fluoroquinolones and were characterized by Analytical Profile Index 20E test kit and 16S rRNA sequencing. S. Typhi strain S27 was resistant to fluoroquinolones and had multiple mutations in the gyrA gene. The gyrA lies in the quinolone resistance determining region of S. Typhi and has mutations at codon 83 (Ser83Phe), codon 87 (Asp87Gly), codon 308 (Lys308Glu), and codon 328 (Val328Ile). S. Typhi strain S6 has no gyrA mutations and is sensitive to fluoroquinolones but forms a strong biofilm relative to S. Typhi S27. Transcriptional analysis of biofilm associated genes revealed that the waaG gene was significantly downregulated. The ΔwaaG mutant showed a significant decrease in persister cells and a strong biofilm formation relative to wild type and gyrA mutant. The gyrA tetra mutant persister assay revealed a significant increase in persister cells compared to wild type and ΔwaaG. Collectively, this is the first report of S. Typhi's two key genes and their roles in antibiotic tolerance, biofilm formation, and fluoroquinolone resistance that can help in understanding the mechanism of persister formation and eradication.
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Affiliation(s)
- Musanna
- Department of Microbiology, Abbottabad University of Science and Technology, Havelian, Abbottabad 22500, Pakistan
| | - Ummara Faridoon Khan
- Department of Microbiology, Abbottabad University of Science and Technology, Havelian, Abbottabad 22500, Pakistan
| | - Gul Habib
- Department of Microbiology, Abbottabad University of Science and Technology, Havelian, Abbottabad 22500, Pakistan.
| | - Haji Gul
- Faculty of Veterinary and Animal Sciences, Gomal University, Dera Ismail Khan 29220, Pakistan; College of Animal Science and Technology, Anhui Agricultural University, No. 130 Changjiang West Road, Hefei 230036, China
| | - Azam Hayat
- Department of Microbiology, Abbottabad University of Science and Technology, Havelian, Abbottabad 22500, Pakistan
| | - Mujaddad Ur Rehman
- Department of Microbiology, Abbottabad University of Science and Technology, Havelian, Abbottabad 22500, Pakistan
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Birger R, Antillón M, Bilcke J, Dolecek C, Dougan G, Pollard AJ, Neuzil KM, Frost I, Laxminarayan R, Pitzer VE. Estimating the effect of vaccination on antimicrobial-resistant typhoid fever in 73 countries supported by Gavi: a mathematical modelling study. THE LANCET INFECTIOUS DISEASES 2022; 22:679-691. [PMID: 35123673 PMCID: PMC9021026 DOI: 10.1016/s1473-3099(21)00627-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 08/20/2021] [Accepted: 09/23/2021] [Indexed: 11/24/2022]
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Yasin N, Rahman H, Sarwar Y, Qasim M, Nisa I, Ikram A, Zaman G, Khan Z, Mirza MR, Khan N, Safi AUR, Alzahrani KJ. Salmonella Typhi from Northwest Pakistan: Molecular Strain Typing and Drug Resistance Signature. Microb Drug Resist 2021; 28:120-126. [PMID: 34357814 DOI: 10.1089/mdr.2020.0304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Objective: To determine the molecular strain typing and drug resistance pattern of Salmonella enterica serovar Typhi prevalent in Northwest Pakistan. Methodology: A total of 2,138 blood samples of suspected typhoid patients from Northwest Pakistan were collected followed by identification of Salmonella Typhi through biochemical, serological, and species-specific fliC-d gene amplification. These isolates were typed by variable-number tandem repeat (VNTR) profiling and investigated for drug resistance. Results: The overall prevalence of Salmonella Typhi was found to be 8.8% (n = 189). Thirty different VNTR strain types of Salmonella Typhi were detected and the most prevalent strain types were T1 and T4, whereas T27 was less prevalent strain. Among the 189 isolates 175 (92.5%) isolates were multidrug resistant, whereas 12 (5.8%) isolates were extensively drug resistant. Resistance to imipenem in Salmonella Typhi was not observed. Most of the isolates have genes encoding for resistance to fluoroquinolones, including gyrA (n = 164), gyrB (n = 160), parC (n = 164), parE (n = 160), ac(6')-ib-cr (n = 163), qnrS (n = 15), and qnrB (n = 3). Similarly, chloramphinicol (cat; n = 147), azithromycin (msrA; n = 3), and co-trimoxazole (dfrA7; n = 145) resistance genes were detected among Salmonella Typhi isolates. Conclusion: In this study, T1 and T4 type Salmonella Typhi strains were predominantly prevalent in Northwest Pakistan. Antibiotic resistance among Salmonella Typhi isolates were observed. Findings of the study would be helpful to devise an appropriate antibiotic policy to control the emergence of drug-resistant Salmonella Typhi in Pakistan.
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Affiliation(s)
- Nusrat Yasin
- Department of Microbiology, Kohat University of Science and Technology, Kohat, Pakistan
| | - Hazir Rahman
- Department of Microbiology, Kohat University of Science and Technology, Kohat, Pakistan.,Department of Microbiology, Abdul Wali Khan University Mardan, Mardan, Pakistan
| | - Yasra Sarwar
- Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering, Faisalabad, Pakistan
| | - Muhammad Qasim
- Department of Microbiology, Kohat University of Science and Technology, Kohat, Pakistan
| | - Iqbal Nisa
- Department of Microbiology, Kohat University of Science and Technology, Kohat, Pakistan
| | - Aamer Ikram
- Department of Pathology, Armed Forces Institute of Pathology, CMH, Rawalpindi, Pakistan.,National Institute of Health, Islamabad, Pakistan
| | - Gohar Zaman
- Department of Pathology, Armed Forces Institute of Pathology, CMH, Rawalpindi, Pakistan
| | - Zakir Khan
- Institute of Health Sciences, Curkvoa University Adana, Adana, Turkey
| | - Munazza Raza Mirza
- Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan
| | - Niamat Khan
- Department of Biotechnology and Genetic Engineering, Kohat University of Science and Technology, Kohat, Pakistan
| | - Aziz-Ur-Rehman Safi
- Department of Microbiology, Kohat University of Science and Technology, Kohat, Pakistan
| | - Khalid J Alzahrani
- Department of Clinical Laboratories Sciences, College of Applied Medical Sciences, Taif University, Taif 21944, Saudi Arabia
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Ceylan Ş, Cebeci YU, Demirbaş N, Batur ÖÖ, Özakpınar ÖB. Antimicrobial, Antioxidant and Antiproliferative Activities of Novel Quinolones. ChemistrySelect 2020. [DOI: 10.1002/slct.202002779] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Şule Ceylan
- Artvin Çoruh University Department of Occupational Health and Safety 08000 Artvin TURKEY
| | | | - Neslihan Demirbaş
- Karadeniz Technical University Department of Chemistry 61080 Trabzon Turkey
| | - Özge Özşen Batur
- Eskisehir Osmangazi University Department of Chemistry 26480 Eskisehir Turkey
| | - Özlem Bingöl Özakpınar
- Marmara University Faculty of Pharmacy Department of Biochemistry, Haydarpasa 34668 Istanbul Turkey
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Antibodies and Protection in Systemic Salmonella Infections: Do We Still Have More Questions than Answers? Infect Immun 2020; 88:IAI.00219-20. [PMID: 32601109 DOI: 10.1128/iai.00219-20] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Salmonella causes grave systemic infections in humans and other animals and provides a paradigm for other diseases in which the bacteria have both intracellular and extracellular lifestyles. New generations of vaccines rely on the essential contribution of the antibody responses for their protection. The quality, antigen specificity, and functions associated with antibody responses to this pathogen have been elusive for a long time. Recent approaches that combine studies in humans and genetically manipulated experimental models and that exploit awareness of the location and within-host life cycle of the pathogen are shedding light on how humoral immunity to Salmonella operates. However, this area of research remains full of controversy and discrepancies. The overall scenario indicates that antibodies are essential for resistance against systemic Salmonella infections and can express the highest protective function when operating in conjunction with cell-mediated immunity. Antigen specificity, isotype profile, Fc-gamma receptor usage, and complement activation are all intertwined factors that still arcanely influence antibody-mediated protection to Salmonella.
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Turner AK, Eckert SE, Turner DJ, Yasir M, Webber MA, Charles IG, Parkhill J, Wain J. A whole-genome screen identifies Salmonella enterica serovar Typhi genes involved in fluoroquinolone susceptibility. J Antimicrob Chemother 2020; 75:2516-2525. [PMID: 32514543 PMCID: PMC7443733 DOI: 10.1093/jac/dkaa204] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/31/2020] [Accepted: 04/21/2020] [Indexed: 12/03/2022] Open
Abstract
OBJECTIVES A whole-genome screen at sub-gene resolution was performed to identify candidate loci that contribute to enhanced or diminished ciprofloxacin susceptibility in Salmonella enterica serovar Typhi. METHODS A pool of over 1 million transposon insertion mutants of an S. Typhi Ty2 derivative were grown in a sub-MIC concentration of ciprofloxacin, or without ciprofloxacin. Transposon-directed insertion site sequencing (TraDIS) identified relative differences between the mutants that grew following the ciprofloxacin treatment compared with the untreated mutant pool, thereby indicating which mutations contribute to gain or loss of ciprofloxacin susceptibility. RESULTS Approximately 88% of the S. Typhi strain's 4895 annotated genes were assayed, and at least 116 were identified as contributing to gain or loss of ciprofloxacin susceptibility. Many of the identified genes are known to influence susceptibility to ciprofloxacin, thereby providing method validation. Genes were identified that were not known previously to be involved in susceptibility, and some of these had no previously known phenotype. Susceptibility to ciprofloxacin was enhanced by insertion mutations in genes coding for efflux, other surface-associated functions, DNA repair and expression regulation, including phoP, barA and marA. Insertion mutations that diminished susceptibility were predominantly in genes coding for surface polysaccharide biosynthesis and regulatory genes, including slyA, emrR, envZ and cpxR. CONCLUSIONS A genomics approach has identified novel contributors to gain or loss of ciprofloxacin susceptibility in S. Typhi, expanding our understanding of the impact of fluoroquinolones on bacteria and of mechanisms that may contribute to resistance. The data also demonstrate the power of the TraDIS technology for antibacterial research.
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Affiliation(s)
- A Keith Turner
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Sabine E Eckert
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
| | - Daniel J Turner
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
- Oxford Nanopore Technologies Ltd, Gosling Building, Edmund Halley Road, Oxford Science Park OX4 4DQ, UK
| | - Muhammud Yasir
- Quadram Institute, Norwich Research Park, Colney, Norwich NR4 7UA, UK
| | - Mark A Webber
- Quadram Institute, Norwich Research Park, Colney, Norwich NR4 7UA, UK
- University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Ian G Charles
- Quadram Institute, Norwich Research Park, Colney, Norwich NR4 7UA, UK
- University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Julian Parkhill
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
- Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 OES, UK
| | - John Wain
- Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK
- University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
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O'Reilly PJ, Pant D, Shakya M, Basnyat B, Pollard AJ. Progress in the overall understanding of typhoid fever: implications for vaccine development. Expert Rev Vaccines 2020; 19:367-382. [PMID: 32238006 DOI: 10.1080/14760584.2020.1750375] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
INTRODUCTION Typhoid fever continues to have a substantial impact on human health, especially in Asia and sub-Saharan Africa. Access to safe water, and adequate sanitation and hygiene remain the cornerstone of prevention, but these are not widely available in many impoverished settings. The emergence of antibiotic resistance affects typhoid treatment and adds urgency to typhoid control efforts. Vaccines provide opportunities to prevent and control typhoid fever in endemic settings. AREAS COVERED Literature search was performed looking for evidence concerning the global burden of typhoid and strategies for the prevention and treatment of typhoid fever. Cost of illness, available typhoid and paratyphoid vaccines and cost-effectiveness were also reviewed. The objective was to provide a critical overview of typhoid fever, in order to assess the current understanding and potential future directions for typhoid treatment and control. EXPERT COMMENTARY Our understanding of typhoid burden and methods of prevention has grown over recent years. However, typhoid fever still has a significant impact on health in low and middle-income countries. Introduction of typhoid conjugate vaccines to the immunization schedule is expected to make a major contribution to control of typhoid fever in endemic countries, although vaccination alone is unlikely to eliminate the disease.
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Affiliation(s)
- Peter J O'Reilly
- Oxford Vaccine Group, Department of Pediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre , Oxford, UK
| | - Dikshya Pant
- Department of Paediatrics, Patan Academy of Health Sciences, Patan Hospital , Kathmandu, Nepal
| | - Mila Shakya
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences , Kathmandu, Nepal
| | - Buddha Basnyat
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences , Kathmandu, Nepal
| | - Andrew J Pollard
- Oxford Vaccine Group, Department of Pediatrics, University of Oxford and the NIHR Oxford Biomedical Research Centre , Oxford, UK
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Abstract
We combine methodology from history and genetics to reconstruct the biosocial history of antimicrobial resistance (AMR) in the bacterium Salmonella enterica serovar Typhi (S. Typhi). We show how evolutionary divergence in S. Typhi was driven by rising global antibiotic use and by the neglect of typhoid outside of high-income countries. Although high-income countries pioneered 1960s precautionary antibiotic regulations to prevent selection for multidrug resistance, new antibiotic classes, typhoid's cultural status as a supposedly ancient disease of "undeveloped" countries, limited international funding, and narrow biosecurity agendas helped fragment effective global collective action for typhoid control. Antibiotic-intensive compensation for weak water and healthcare systems subsequently fueled AMR selection in low- and middle-income countries but often remained invisible due to lacking surveillance capabilities. The recent rise of extensively drug-resistant typhoid bears the biosocial footprint of more than half a century of antibiotic-intensive international neglect.
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Affiliation(s)
- Claas Kirchhelle
- Wellcome Unit for the History of Medicine/Oxford Martin School, University of Oxford, Addenbrooke’s Hospital, United Kingdom
| | - Zoe Anne Dyson
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, United Kingdom
| | - Gordon Dougan
- Department of Medicine, University of Cambridge, Addenbrooke’s Hospital, United Kingdom
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Admassu D, Egata G, Teklemariam Z. Prevalence and antimicrobial susceptibility pattern of Salmonella enterica serovar Typhi and Salmonella enterica serovar Paratyphi among febrile patients at Karamara Hospital, Jigjiga, eastern Ethiopia. SAGE Open Med 2019; 7:2050312119837854. [PMID: 30906553 PMCID: PMC6421600 DOI: 10.1177/2050312119837854] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 02/21/2019] [Indexed: 11/17/2022] Open
Abstract
Objective: The aim of this study was to determine the prevalence and antimicrobial susceptibility pattern of Salmonella enterica serovar Typhi and Salmonella enterica serovar Paratyphi among febrile patients at Karamara Hospital, Jigjiga, eastern Ethiopia. Methods: A cross-sectional study was conducted among 203 febrile patients presumptive of enteric fever (Salmonella enterica serovar Typhi and Salmonella enterica serovar Paratyphi) at Karamara Hospital from 15 February to 20 March 2016. Venous blood was collected, cultured, and biochemical tests were performed. Antimicrobial susceptibility testing was performed for each isolate using modified Kirby–Bauer disk diffusion technique. Results: The overall prevalence of enteric fever (Salmonella enterica serovar Typhi and Salmonella enterica serovar Paratyphi) was 11%. The prevalence of Salmonella enterica serovar Typhi (7%) was higher than Salmonella enterica serovar Paratyphi (4%). The odds of having enteric fever were higher among the study participants aged 31–45 years and with previous history of enteric fever. Most of the Salmonella enterica serovar Typhi isolates were sensitive to tetracycline (78.6%), gentamycin (64.3%), and ceftriaxone (64%), while most of the isolates of Salmonella enterica serovar Paratyphi were sensitive to tetracycline (100%), gentamycin (100%), and ciprofloxacin (62.5%). All the isolates were resistant to ampicillin and chloramphenicol. Multidrug resistances were found among most of the isolates. Conclusion: A high prevalence of enteric fever and drug resistance to most commonly prescribed antimicrobials were observed in this study. Those of old age with previous history of enteric infection were more affected by enteric fever. Health information should be given about the transmission, prevention of enteric fever, and antimicrobial use. The treatment of enteric fever should be supported by antimicrobial susceptibility tests in the study areas.
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Affiliation(s)
- Dawit Admassu
- Department of Medical Microbiology, Dire Dawa University, Dire Dawa, Ethiopia
| | - Gudina Egata
- School of Public Health, College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
| | - Zelalem Teklemariam
- College of Health and Medical Sciences, Haramaya University, Harar, Ethiopia
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Day MR, Doumith M, Do Nascimento V, Nair S, Ashton PM, Jenkins C, Dallman TJ, Stevens FJ, Freedman J, Hopkins KL, Woodford N, De Pinna EM, Godbole G. Comparison of phenotypic and WGS-derived antimicrobial resistance profiles of Salmonella enterica serovars Typhi and Paratyphi. J Antimicrob Chemother 2019; 73:365-372. [PMID: 29216342 DOI: 10.1093/jac/dkx379] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 09/19/2017] [Indexed: 01/12/2023] Open
Abstract
Objectives Surveillance of antimicrobial resistance (AMR) in Salmonella enterica serovars Typhi and Paratyphi is essential to provide an evidence base for empirical treatment protocols and to monitor emerging AMR. We sought to compare phenotypic and WGS-based genotypic methods for the detection of AMR in Salmonella Typhi and Salmonella Paratyphi. Methods WGS data from 603 isolates of Salmonella Typhi (n = 332) and Salmonella Paratyphi (n = 271) were mapped to genes or chromosomal mutations known to be associated with phenotypic AMR and compared with phenotypic susceptibility data interpreted using breakpoints recommended by EUCAST. Results There were two (0.03%) discordant interpretations out of a possible 6030 isolate/antimicrobial class combinations. MDR (resistant to three or more classes of antimicrobial) was detected in 83/332 (25.0%) Salmonella Typhi isolates, but was not detected in Salmonella Paratyphi. Thirty-six (10.8%) isolates of Salmonella Typhi were resistant to ciprofloxacin (MIC >0.5 mg/L), with 33 (9.9%) of 332 exhibiting mutations in gyrA and parC, and 244 (73.5%) isolates had reduced susceptibility to ciprofloxacin (MIC 0.06-0.25 mg/L). In comparison, 209/227 (92.1%) isolates of Salmonella Paratyphi A exhibited resistance to ciprofloxacin (MIC >0.5 mg/L). No resistance to azithromycin or the third-generation cephalosporins was detected. Conclusions WGS data provided a robust and informative approach for monitoring MDR and emerging resistance to ciprofloxacin in Salmonella Typhi and Salmonella Paratyphi. Phenotypic antimicrobial susceptibility testing continues to be performed to guide targeted individual patient treatment, but inferred AMR profiles from WGS data may be used for surveillance and to guide empirical therapy.
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Affiliation(s)
- Martin R Day
- Bacteriology Reference Department, National Infection Service, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Michel Doumith
- Bacteriology Reference Department, National Infection Service, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Vivienne Do Nascimento
- Bacteriology Reference Department, National Infection Service, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Satheesh Nair
- Bacteriology Reference Department, National Infection Service, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Philip M Ashton
- Bacteriology Reference Department, National Infection Service, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Claire Jenkins
- Bacteriology Reference Department, National Infection Service, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Timothy J Dallman
- Bacteriology Reference Department, National Infection Service, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Flora J Stevens
- Travel and Migrant Health Section, National Infection Service, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Joanne Freedman
- Travel and Migrant Health Section, National Infection Service, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Katie L Hopkins
- Bacteriology Reference Department, National Infection Service, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Neil Woodford
- Bacteriology Reference Department, National Infection Service, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Elizabeth M De Pinna
- Bacteriology Reference Department, National Infection Service, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
| | - Gauri Godbole
- Bacteriology Reference Department, National Infection Service, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK
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Das S, Samajpati S, Roy I, Sankar S, Gaind R, Deb M, Kulkarni R, Paul DK, Dutta S. Molecular Subtyping of Salmonella enterica Serovar Typhi by Pulsed-Field Gel Electrophoresis and Multiple-Locus Variable-Number Tandem-Repeat Analysis in India: Their Association with Antimicrobial Resistance Profiles. Jpn J Infect Dis 2017; 70:536-543. [PMID: 28674312 DOI: 10.7883/yoken.jjid.2016.478] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Molecular subtyping and DNA sequencing-based methods, which are commonly used for discriminating Salmonella enterica serovar Typhi (S. Typhi) isolates, lead to improved molecular epidemiological investigations for prevention and control of typhoid fever. We obtained S. Typhi blood isolates (n = 66) from India during 2007-14 for molecular subtyping by pulsed-field gel electrophoresis (PFGE) and multiple-locus variable-number tandem-repeat (VNTR) analysis (MLVA) in association with antibiotic resistance profiles. Genotypic diversity was observed more by MLVA (Simpson's index of diversity, D value = 0.997) than PFGE (D value = 0.864). Two prevalent pulsotypes containing nalidixic acid-resistant (NALR) and NALR-ciprofloxacin-resistant (CIPR) S. Typhi isolates circulated in India. Multidrug-resistant (MDR), NALR-CIPR, and most NALR isolates were found to be clonal by PFGE. MLVA could differentiate the clonal isolates. Most of the MDR and NALR-CIPR isolates showed variation in single or double VNTR loci, whereas NALR isolates varied in more than 2 loci, reflecting higher genetic diversity among the NALR isolates. Of the 6 VNTR loci, TR4,699 (D value = 0.838) and Sal02 (D value = 0.890) loci played important roles as MLVA cluster-supporting alleles. The rapid turnaround time and high-level discriminatory power of MLVA may be useful for tracking and controlling the transmission of S. Typhi isolates during epidemiological investigations.
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Affiliation(s)
- Surojit Das
- Microbiology Division, National Institute of Cholera and Enteric Diseases
| | - Sriparna Samajpati
- Microbiology Division, National Institute of Cholera and Enteric Diseases
| | - Indranil Roy
- Microbiology Division, Calcutta Medical Research Institute
| | - Sathish Sankar
- Sri Sakthi Amma Institute of Biomedical Research, Sri Narayani Hospital & Research Centre
| | - Rajni Gaind
- Microbiology Division, Vardhaman Mahavir Medical College & Safdarjung Hospital
| | - Monorama Deb
- Microbiology Division, Vardhaman Mahavir Medical College & Safdarjung Hospital
| | | | - Dilip Kumar Paul
- Clinical Division, Dr. B. C. Roy Post Graduate Institute of Pediatric Sciences
| | - Shanta Dutta
- Microbiology Division, National Institute of Cholera and Enteric Diseases
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Rossi O, Grant AJ, Mastroeni P. Effect of in vivo neutralization of tumor necrosis alpha on the efficacy of antibiotic treatment in systemic Salmonella enterica infections. Pathog Dis 2017; 75:ftx002. [PMID: 28087648 PMCID: PMC5353993 DOI: 10.1093/femspd/ftx002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 10/13/2016] [Accepted: 01/12/2017] [Indexed: 02/06/2023] Open
Abstract
Immunity can co-operate with antibiotics, but can also antagonize drug efficacy by segregating the bacteria to areas of the body that are less accessible to antimicrobials, and by selecting for subpopulations with low division rates that are often difficult to eradicate. We studied the effect of an anti-inflammatory/immunosuppressive anti-TNFα treatment, which accelerates bacterial growth in the tissues and inhibits or reverses the formation of granulomas, on the efficacy of ampicillin and ciprofloxacin during a systemic Salmonella enterica infection of the mouse. The anti-TNFα treatment neither precluded nor enhanced the efficacy of antibiotic treatment. However, the anti-TNFα treatment rendered the animals susceptible to the rapid relapse of the infection seen after cessation of the antibiotic treatment. Reactivation of an established infection, due to late administration of anti-TNFα antibodies, could be successfully controlled by antibiotics, but full clearance of the bacterial load from the tissues was not achieved. We conclude that the lack of TNFα does not preclude the efficacy of antibiotic treatment and must be monitored with care due to post-treatment relapses. Combinations of anti-cytokine compounds and antibiotic molecules may not be the best way to treat persistent infections with intracellular bacteria like Salmonella.
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Affiliation(s)
- Omar Rossi
- Department of Veterinary Medicine, University of Cambridge, Cambridge CB3 0ES, UK
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13
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Abstract
The interaction between schistosomiasis and Salmonella is a particularly important issue in Africa, where dual infection by the parasite and the bacterium are likely common. In this review, the ways in which schistosomiasis affects human biology as it relates to Salmonella are described. Those who are infected by both organisms experience reduced immunological functioning, exhibit irreversible organ damage due to prolonged schistosomiasis infection, and become latent carriers of Salmonella enterica serotypes Typhi and Paratyphi and S. Typhimurium. The sequestration of the bacteria in the parasite leads to ineffective antibiotic treatment because the bacteria cannot be completely killed, and lingering infection may then lead to antimicrobial resistance. These manifestations are likely not just for those dually infected but also for those first infected with schistosomes and, later, Salmonella. More data are needed to better understand dual infection, particularly as it may impact treatment and prevention of schistosomiasis and Salmonella in sub-Saharan Africa.
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Affiliation(s)
- Amber Hsiao
- International Vaccine Institute, Department of Epidemiology, Republic of Korea
- Technische Universität Berlin, Department of Health Care Management, Berlin, Germany
| | - Trevor Toy
- International Vaccine Institute, Department of Epidemiology, Republic of Korea
| | - Hye Jin Seo
- International Vaccine Institute, Department of Epidemiology, Republic of Korea
| | - Florian Marks
- International Vaccine Institute, Department of Epidemiology, Republic of Korea
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14
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Kant R, Singh V, Nath G, Awasthi SK, Agarwal A. Design, synthesis and biological evaluation of ciprofloxacin tethered bis-1,2,3-triazole conjugates as potent antibacterial agents. Eur J Med Chem 2016; 124:218-228. [DOI: 10.1016/j.ejmech.2016.08.031] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 07/24/2016] [Accepted: 08/14/2016] [Indexed: 01/09/2023]
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15
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Das S, Ray U, Dutta S. Revisit of fluoroquinolone and azithromycin susceptibility breakpoints for Salmonella enterica serovar Typhi. J Med Microbiol 2016; 65:632-640. [PMID: 27221661 DOI: 10.1099/jmm.0.000288] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
In recent years, increase in occurrence of fluoroquinolone (FQ)-resistant S almonella Typhi isolates has caused considerable inconvenience in selecting appropriate antimicrobials for treatment of typhoid. The World Health Organization (WHO) recommends azithromycin for the empirical treatment option of uncomplicated typhoid. The CLSI updated the breakpoints of disc diffusion (DD) and MIC results of FQs and azithromycin for Salmonella Typhi in 2015, but DD breakpoints of ofloxacin and levofloxacin were not included. In this study, the inhibition zone diameters and MICs of nalidixic acid, ciprofloxacin, ofloxacin, levofloxacin and azithromycin were determined in Salmonella Typhi Kolkata isolates (n =146) over a 16-year period (1998 to 2013) and the data were compared with the available CLSI breakpoints. Very major error and major error (ME) of FQs were not observed in the study isolates, but the minor error of ciprofloxacin (15.8 %) and ME of azithromycin (3.5 %) exceeded the acceptable limit. A positive correlation between MICs of FQ and mutations in the quinolone-resistance-determining region (QRDR) showed the reliability of MIC results to determine FQ susceptibility of Salmonella Typhi (n =74). Isolates showing decreased ciprofloxacin susceptibility (MIC 0.125-0.5 µg ml-1) were likely to have at least one mutation in the QRDR region. The results on DD breakpoints of ofloxacin (resistant, ≤15 mm; intermediate, 16-24 mm, and susceptible, ≥25 mm) and levofloxacin (resistant, ≤18 mm; intermediate, 19-27 mm, and susceptible, ≥28 mm) corroborated those of earlier studies. In view of the emerging FQ- and azithromycin-resistant Salmonella Typhi isolates, DD and MIC breakpoints of those antimicrobials should be revisited routinely.
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Affiliation(s)
- Surojit Das
- Microbiology Division, National Institute of Cholera and Enteric Diseases, Kolkata, West Bengal, India
| | - Ujjwayini Ray
- Microbiology Division, Apollo Gleneagles Hospitals, Kolkata, West Bengal, India
| | - Shanta Dutta
- Microbiology Division, National Institute of Cholera and Enteric Diseases, Kolkata, West Bengal, India
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16
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Bakach I, Just MR, Gambhir M, Fung ICH. Typhoid transmission: a historical perspective on mathematical model development. Trans R Soc Trop Med Hyg 2015; 109:679-89. [PMID: 26396161 DOI: 10.1093/trstmh/trv075] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 08/13/2015] [Indexed: 11/13/2022] Open
Abstract
Mathematical models of typhoid transmission were first developed nearly half a century ago. To facilitate a better understanding of the historical development of this field, we reviewed mathematical models of typhoid and summarized their structures and limitations. Eleven models, published in 1971 to 2014, were reviewed. While models of typhoid vaccination are well developed, we highlight the need to better incorporate water, sanitation and hygiene interventions into models of typhoid and other foodborne and waterborne diseases. Mathematical modeling is a powerful tool to test and compare different intervention strategies which is important in the world of limited resources. By working collaboratively, epidemiologists and mathematicians should build better mathematical models of typhoid transmission, including pharmaceutical and non-pharmaceutical interventions, which will be useful in epidemiological and public health practice.
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Affiliation(s)
- Iurii Bakach
- Department of Mathematical Sciences, College of Science and Mathematics, Georgia Southern University, Statesboro, Georgia, USA
| | - Matthew R Just
- Department of Mathematical Sciences, College of Science and Mathematics, Georgia Southern University, Statesboro, Georgia, USA
| | - Manoj Gambhir
- Epidemiological Modelling Unit, Department of Epidemiology and Preventive Medicine, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Victoria, Australia
| | - Isaac Chun-Hai Fung
- Department of Epidemiology, Jiann-Ping Hsu College of Public Health, Georgia Southern University, P.O. Box 8015, Statesboro 30460-8015, Georgia, USA
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17
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IMANISHI M, NEWTON AE, VIEIRA AR, GONZALEZ-AVILES G, KENDALL SCOTT ME, MANIKONDA K, MAXWELL TN, HALPIN JL, FREEMAN MM, MEDALLA F, AYERS TL, DERADO G, MAHON BE, MINTZ ED. Typhoid fever acquired in the United States, 1999-2010: epidemiology, microbiology, and use of a space-time scan statistic for outbreak detection. Epidemiol Infect 2015; 143:2343-54. [PMID: 25427666 PMCID: PMC5207021 DOI: 10.1017/s0950268814003021] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 09/25/2014] [Accepted: 10/20/2014] [Indexed: 01/04/2023] Open
Abstract
Although rare, typhoid fever cases acquired in the United States continue to be reported. Detection and investigation of outbreaks in these domestically acquired cases offer opportunities to identify chronic carriers. We searched surveillance and laboratory databases for domestically acquired typhoid fever cases, used a space-time scan statistic to identify clusters, and classified clusters as outbreaks or non-outbreaks. From 1999 to 2010, domestically acquired cases accounted for 18% of 3373 reported typhoid fever cases; their isolates were less often multidrug-resistant (2% vs. 15%) compared to isolates from travel-associated cases. We identified 28 outbreaks and two possible outbreaks within 45 space-time clusters of ⩾2 domestically acquired cases, including three outbreaks involving ⩾2 molecular subtypes. The approach detected seven of the ten outbreaks published in the literature or reported to CDC. Although this approach did not definitively identify any previously unrecognized outbreaks, it showed the potential to detect outbreaks of typhoid fever that may escape detection by routine analysis of surveillance data. Sixteen outbreaks had been linked to a carrier. Every case of typhoid fever acquired in a non-endemic country warrants thorough investigation. Space-time scan statistics, together with shoe-leather epidemiology and molecular subtyping, may improve outbreak detection.
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Affiliation(s)
- M. IMANISHI
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - A. E. NEWTON
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - A. R. VIEIRA
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - G. GONZALEZ-AVILES
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - M. E. KENDALL SCOTT
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - K. MANIKONDA
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - T. N. MAXWELL
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - J. L. HALPIN
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - M. M. FREEMAN
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - F. MEDALLA
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - T. L. AYERS
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - G. DERADO
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - B. E. MAHON
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - E. D. MINTZ
- Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
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Rajesh AM, Bhatt SA, Brahmbhatt H, Anand PS, Popat KM. Taste masking of ciprofloxacin by ion-exchange resin and sustain release at gastric-intestinal through interpenetrating polymer network. Asian J Pharm Sci 2015. [DOI: 10.1016/j.ajps.2015.01.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
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19
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Antimicrobial susceptibility of travel-related Salmonella enterica serovar Typhi isolates detected in Switzerland (2002-2013) and molecular characterization of quinolone resistant isolates. BMC Infect Dis 2015; 15:212. [PMID: 25963025 PMCID: PMC4435775 DOI: 10.1186/s12879-015-0948-2] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 05/07/2015] [Indexed: 11/13/2022] Open
Abstract
Background Typhoid fever is an acute, invasive, and potentially fatal systemic infection caused by Salmonella enterica subspecies enterica serotype Typhi (S. Typhi). Drug resistance to antimicrobials such as ciprofloxacin is emerging in developing countries, threatening the efficacy of treatment of patients in endemic regions as well as of travellers returning from these countries. Methods We compared the antimicrobial resistance profiles of 192 S. Typhi isolated from patients over a time span of twelve years. Susceptibility testing was done by the disk diffusion method. A representative selection of isolates (n = 41) was screened by PCR for mutations in the quinolone resistance-determining regions (QRDRs) of the gyrA and parC genes and all 192 isolates were screened for plasmid-mediated quinolone resistance (PMQR) genes. Multilocus sequence typing (MLST) was used to investigate the sequence type of isolates from patients with a known history of international travel. Results Resistance rates for nalidixic acid increased from 20 % to 66.7 % between 2002 and 2013. Resistance to ciprofloxacin was detected in 55.6 % of the isolates by 2013. Ciprofloxacin resistance was predominantly associated with the triple substitutions Ser83 → Phe and Asp87 → Asn in GyrA and Ser80 → Ile in ParC. The plasmid-mediated resistance gene qnrS1 was detected in two isolates. Sequence type ST1 was associated with the Indian subcontinent, while ST2 was distributed internationally. Multidrug resistance was noted for 11.5 % of the isolates. Conclusions Fluoroquinolone resistant S. Typhi constitute a serious public health concern in endemic areas as well as in industrialized countries. Increased surveillance of global patterns of antimicrobial resistance is necessary and the control of resistant strains is of the utmost importance to maintain treatment options. Electronic supplementary material The online version of this article (doi:10.1186/s12879-015-0948-2) contains supplementary material, which is available to authorized users.
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20
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Dhal PK, Barman RK, Saha S, Das S. Dynamic modularity of host protein interaction networks in Salmonella Typhi infection. PLoS One 2014; 9:e104911. [PMID: 25144185 PMCID: PMC4140748 DOI: 10.1371/journal.pone.0104911] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 07/17/2014] [Indexed: 01/08/2023] Open
Abstract
Background Salmonella Typhi is a human-restricted pathogen, which causes typhoid fever and remains a global health problem in the developing countries. Although previously reported host expression datasets had identified putative biomarkers and therapeutic targets of typhoid fever, the underlying molecular mechanism of pathogenesis remains incompletely understood. Methods We used five gene expression datasets of human peripheral blood from patients suffering from S. Typhi or other bacteremic infections or non-infectious disease like leukemia. The expression datasets were merged into human protein interaction network (PIN) and the expression correlation between the hubs and their interacting proteins was measured by calculating Pearson Correlation Coefficient (PCC) values. The differences in the average PCC for each hub between the disease states and their respective controls were calculated for studied datasets. The individual hubs and their interactors with expression, PCC and average PCC values were treated as dynamic subnetworks. The hubs that showed unique trends of alterations specific to S. Typhi infection were identified. Results We identified S. Typhi infection-specific dynamic subnetworks of the host, which involve 81 hubs and 1343 interactions. The major enriched GO biological process terms in the identified subnetworks were regulation of apoptosis and biological adhesions, while the enriched pathways include cytokine signalling in the immune system and downstream TCR signalling. The dynamic nature of the hubs CCR1, IRS2 and PRKCA with their interactors was studied in detail. The difference in the dynamics of the subnetworks specific to S. Typhi infection suggests a potential molecular model of typhoid fever. Conclusions Hubs and their interactors of the S. Typhi infection-specific dynamic subnetworks carrying distinct PCC values compared with the non-typhoid and other disease conditions reveal new insight into the pathogenesis of S. Typhi.
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Affiliation(s)
- Paltu Kumar Dhal
- Biomedical Informatics Centre, National Institute of Cholera and Enteric Diseases, Kolkata, West Bengal, India
| | - Ranjan Kumar Barman
- Biomedical Informatics Centre, National Institute of Cholera and Enteric Diseases, Kolkata, West Bengal, India
| | - Sudipto Saha
- Bioinformatics Centre, Bose Institute, Kolkata, West Bengal, India
| | - Santasabuj Das
- Biomedical Informatics Centre, National Institute of Cholera and Enteric Diseases, Kolkata, West Bengal, India; Division of Clinical Medicine, National Institute of Cholera and Enteric Diseases, Kolkata, West Bengal, India
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21
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Elumalai S, Muthu G, Selvam REM, Ramesh S. Detection of TEM-, SHV- and CTX-M-type β-lactamase production among clinical isolates of Salmonella species. J Med Microbiol 2014; 63:962-967. [DOI: 10.1099/jmm.0.068486-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Enteric fever is a major public health problem in developing countries. Due to the problem of resistance to first-line drugs and fluoroquinolone, cephalosporins are currently used for treatment of enteric fever. Cephalosporin resistance in Salmonella spp. is mainly due to production of extended-spectrum β-lactamases (ESBLs). The majority of ESBLs in Salmonella are derivatives of the TEM and SHV β-lactamase families. The objectives of this study were to detect antibiotic susceptibility patterns, ESBL production and TEM-, SHV- and CTX-M-encoding genes (bla
TEM, bla
SHV and bla
CTX-M) among clinical isolates of Salmonella spp. A total of 134 Salmonella isolates [Salmonella Typhi (n = 101), Salmonella Paratyphi A (n = 31), Salmonella Paratyphi B (n = 1) and Salmonella Typhimurium (n = 1)] were included in this study. Multidrug resistance was seen in 5/134 (3.73 %) isolates, all of which belonged to serotype S. Typhi. A better susceptibility profile was observed for first-line drugs (ampicillin, chloramphenicol, co-trimoxazole and tetracycline) and cephalosporins (cefotaxime, ceftazidime, ceftriaxone, cefixime and cefepime). However, 131 (97.76 %) of the 134 isolates were resistant to nalidixic acid and one (0.75 %) was resistant to ciprofloxacin. TEM-1-type β-lactamase (bla
TEM-1) was detected in six (4.47 %) of the 134 isolates, which belonged to the serotype S. Typhi. All six TEM-positive isolates were negative for the bla
SHV gene and none of the isolates was positive for the bla
CTX-M gene. The presence of the bla
TEM gene encoding TEM-1 β-lactamase is believed to confer resistance only to penicillins and early cephalosporins; however, the resistance spectrum of TEM-1 descendants may extend to second-, third- and fourth-generation cephalosporins. The ESBLs derived from TEM-1 differ from their progenitors by as few as 1 aa, and have the ability to hydrolyse third-generation cephalosporins. Therefore, appropriate selection and rotation of antibiotics as well as continuous monitoring of antibiotic susceptibility profiles could help to control the emergence and spread of resistant strains.
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Affiliation(s)
- Sathishkumar Elumalai
- Department of Microbiology, Dr ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani, Chennai 600 113, Tamil Nadu, India
| | - G. Muthu
- Central Research Laboratory, Sri Manakula Vinayagar Medical College and Hospital, Madagadipet, Pondicherry 605 107, India
| | - R. Esther Mary Selvam
- Department of Microbiology, ESIC Hospital, K. K. Nagar, Chennai 600078, Tamil Nadu, India
| | - Srivani Ramesh
- Department of Microbiology, Dr ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani, Chennai 600 113, Tamil Nadu, India
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22
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Prioritising immunisations for travel: International and Japanese perspectives. Travel Med Infect Dis 2014; 12:118-28. [DOI: 10.1016/j.tmaid.2013.11.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2013] [Revised: 11/20/2013] [Accepted: 11/29/2013] [Indexed: 12/27/2022]
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23
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Coulliette AD, Enger KS, Weir MH, Rose JB. Risk reduction assessment of waterborne Salmonella and Vibrio by a chlorine contact disinfectant point-of-use device. Int J Hyg Environ Health 2012; 216:355-61. [PMID: 23041054 DOI: 10.1016/j.ijheh.2012.08.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 08/03/2012] [Accepted: 08/28/2012] [Indexed: 11/24/2022]
Abstract
Unsafe drinking water continues to burden developing countries despite improvements in clean water delivery and sanitation, in response to Millennium Development Goal 7. Salmonella serotype Typhi and Vibrio cholerae bacteria can contaminate drinking water, causing waterborne typhoid fever and cholera, respectively. Household water treatment (HWT) systems are widely promoted to consumers in developing countries but it is difficult to establish their benefits to the population for specific disease reduction. This research uses a laboratory assessment of halogenated chlorine beads treating contaminated water to inform a quantitative microbial risk assessment (QMRA) of S. Typhi and V. cholerae disease in a developing country community of 1000 people. Laboratory challenges using seeded well water resulted in log10 reductions of 5.44 (± 0.98 standard error (SE)) and 6.07 (± 0.09 SE) for Salmonella serotype Typhimurium and V. cholerae, respectively. In well water with 10% sewage and seeded bacteria, the log10 reductions were 6.06 (± 0.62 SE) and 7.78 (± 0.11 SE) for S. Typhimurium and V. cholerae, respectively. When one infected individual was contributing to the water contamination through fecal material leaking into the water source, the risk of disease associated with drinking untreated water was high according to a Monte Carlo analysis: a median of 0.20 (interquartile range [IQR] 0.017-0.54) for typhoid fever and a median of 0.11 (IQR 0.039-0.20) for cholera. If water was treated, risk greatly decreased, to a median of 4.1 × 10(-7) (IQR 1.6 × 10(-8) to 1.1 × 10(-5)) for typhoid fever and a median of 3.5 × 10(-9) (IQR 8.0 × 10(-10) to 1.3 × 10(-8)) for cholera. Insights on risk management policies and strategies for public health workers were gained using a simple QMRA scenario informed by laboratory assessment of HWT.
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Affiliation(s)
- Angela D Coulliette
- Michigan State University, Department of Fisheries and Wildlife, East Lansing, MI 48824, USA.
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24
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Humphries RM, Fang FC, Aarestrup FM, Hindler JA. In vitro susceptibility testing of fluoroquinolone activity against Salmonella: recent changes to CLSI standards. Clin Infect Dis 2012; 55:1107-13. [PMID: 22752519 DOI: 10.1093/cid/cis600] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Fluoroquinolone (FQ) resistance in Salmonella enterica is a significant clinical concern. Recognition of resistance by the clinical laboratory is complicated by the multiple FQ resistance mechanisms found in Salmonella. The Clinical Laboratory Standards Institute (CLSI) recently addressed this issue by revising the ciprofloxacin break points for Salmonella species. It is critical for clinicians and laboratory workers to be aware of the multiple technical issues surrounding these revised break points. In this article, we review FQ resistance mechanisms in Salmonella, their clinical significance, and data supporting the revised ciprofloxacin break points. We encourage clinical laboratories to adopt the revised CLSI ciprofloxacin break points for all Salmonella isolates in which susceptibility testing is indicated and discuss the technical issues for laboratories using commercial antimicrobial susceptibility systems.
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Affiliation(s)
- Romney M Humphries
- Department of Pathology and Laboratory Medicine, David Geffen School of Medicine at UCLA, Los Angeles California, USA.
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25
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Pilonieta MC, Nagy TA, Jorgensen DR, Detweiler CS. A glycine betaine importer limits Salmonella stress resistance and tissue colonization by reducing trehalose production. Mol Microbiol 2012; 84:296-309. [PMID: 22375627 DOI: 10.1111/j.1365-2958.2012.08022.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Mechanisms by which Salmonella establish chronic infections are not well understood. Microbes respond to stress by importing or producing compatible solutes, small molecules that stabilize proteins and lipids. The Salmonella locus opuABCD (also called OpuC) encodes a predicted importer of the compatible solute glycine betaine. Under stress conditions, if glycine betaine cannot be imported, Salmonella enterica produce the disaccharide trehalose, a highly effective compatible solute. We demonstrate that strains lacking opuABCD accumulate more trehalose under stress conditions than wild-type strains. ΔopuABCD mutant strains are more resistant to high-salt, low-pH and -hydrogen peroxide, conditions that mimic aspects of innate immunity, in a trehalose-dependent manner. In addition, ΔopuABCD mutant strains require the trehalose production genes to out-compete wild-type strains in mice and macrophages. These data suggest that in the absence of opuABCD, trehalose accumulation increases bacterial resistance to stress in broth and mice. Thus, opuABCD reduces bacterial colonization via a mechanism that limits trehalose production. Mechanisms by which microbes limit disease may reveal novel pathways as therapeutic targets.
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Affiliation(s)
- M Carolina Pilonieta
- Department of Molecular Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA.
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Abstract
Infections with Salmonella are an important public health problem worldwide. On a global scale, it has been appraised that Salmonella is responsible for an estimated 3 billion human infections each year. The World Health Organization (WHO) has estimated that annually typhoid fever accounts for 21.7 million illnesses (217,000 deaths) and paratyphoid fever accounts for 5.4 million of these cases. Infants, children, and adolescents in south-central and South-eastern Asia experience the greatest burden of illness. In cases of enteric fever, including infections with S. Typhi and S. Paratyphi A and B, it is often necessary to commence treatment before the results of laboratory sensitivity tests are available. Hence, it is important to be aware of options and possible problems before beginning treatment. Ciprofloxacin has become the first-line drug of choice since the widespread emergence and spread of strains resistant to chloramphenicol, ampicillin, and trimethoprim. There is increase in the occurrence of strains resistant to ciprofloxacin. Reports of typhoidal salmonellae with increasing minimum inhibitory concentration (MIC) and resistance to newer quinolones raise the fear of potential treatment failures and necessitate the need for new, alternative antimicrobials. Extended-spectrum cephalosporins and azithromycin are the options available for the treatment of enteric fever. The emergence of broad spectrum β-lactamases in typhoidal salmonellae constitutes a new challenge. Already there are rare reports of azithromycin resistance in typhoidal salmonellae leading to treatment failure. This review is based on published research from our centre and literature from elsewhere in the world. This brief review tries to summarize the history and recent trends in antimicrobial resistance in typhoidal salmonellae.
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Affiliation(s)
- B N Harish
- Department of Microbiology, Institute of National Importance, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry - 605 006, India.
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27
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Medalla F, Sjölund-Karlsson M, Shin S, Harvey E, Joyce K, Theobald L, Nygren BN, Pecic G, Gay K, Austin J, Stuart A, Blanton E, Mintz ED, Whichard JM, Barzilay EJ. Ciprofloxacin-resistant Salmonella enterica Serotype Typhi, United States, 1999-2008. Emerg Infect Dis 2011. [PMID: 21749779 PMCID: PMC3363319 DOI: 10.3201/eid1706.100594] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We report 9 ciprofloxacin-resistant Salmonella enterica serotype Typhi isolates submitted to the US National Antimicrobial Resistance Monitoring System during 1999-2008. The first 2 had indistinguishable pulsed-field gel electrophoresis patterns and identical gyrA and parC mutations. Eight of the 9 patients had traveled to India within 30 days before illness onset.
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Affiliation(s)
- Felicita Medalla
- Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
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28
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Medalla F, Sjölund-Karlsson M, Shin S, Harvey E, Joyce K, Theobald L, Nygren BN, Pecic G, Gay K, Austin J, Stuart A, Blanton E, Mintz ED, Whichard JM, Barzilay EJ. Ciprofloxacin-resistant Salmonella enterica Serotype Typhi, United States, 1999-2008. Emerg Infect Dis 2011; 17:1095-8. [PMID: 21749779 DOI: 10.3201/eid/1706.100594] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We report 9 ciprofloxacin-resistant Salmonella enterica serotype Typhi isolates submitted to the US National Antimicrobial Resistance Monitoring System during 1999-2008. The first 2 had indistinguishable pulsed-field gel electrophoresis patterns and identical gyrA and parC mutations. Eight of the 9 patients had traveled to India within 30 days before illness onset.
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Affiliation(s)
- Felicita Medalla
- Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
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29
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Khoo SK, Petillo D, Parida M, Tan AC, Resau JH, Obaro SK. Host response transcriptional profiling reveals extracellular components and ABC (ATP-binding cassette) transporters gene enrichment in typhoid fever-infected Nigerian children. BMC Infect Dis 2011; 11:241. [PMID: 21914192 PMCID: PMC3189140 DOI: 10.1186/1471-2334-11-241] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 09/13/2011] [Indexed: 12/18/2022] Open
Abstract
Background Salmonella enterica serovar Typhi (S. Typhi) is a human-specific pathogen that causes typhoid fever, and remains a global health problem especially in developing countries. Its pathogenesis is complex and host response is poorly understood. In Africa, typhoid fever can be a major cause of morbidity in young infected children. The onset of the illness is insidious and clinical diagnosis is often unreliable. Gold standard blood culture diagnostic services are limited, thus rapid, sensitive, and affordable diagnostic test is essential in poor-resourced clinical settings. Routine typhoid fever vaccination is highly recommended but currently licensed vaccines provide only 55-75% protection. Recent epidemiological studies also show the rapid emergence of multi-drug resistant S. Typhi strains. High-throughput molecular technologies, such as microarrays, can dissect the molecular mechanisms of host responses which are S. Typhi-specific to provide a comprehensive genomic component of immunological responses and suggest new insights for diagnosis and treatment. Methods Global transcriptional profiles of S. Typhi-infected young Nigerian children were obtained from their peripheral blood and compared with that of other bacteremic infections using Agilent gene expression microarrays. The host-response profiles of the same patients in acute vs. convalescent phases were also determined. The top 96-100 differentially-expressed genes were identified and four genes were validated by quantitative real-time PCR. Gene clusters were obtained and functional pathways were predicted by DAVID (Database for Annotation, Visualization and Integrated Discovery). Results Transcriptional profiles from S. Typhi-infected children could be distinguished from those of other bacteremic infections. Enriched gene clusters included genes associated with extracellular peptides/components such as lipocalin (LCN2) and systemic immune response which is atypical in bacterial invasion. Distinct gene expression profiles can also be obtained from acute vs. convalescent phase during typhoid fever infection. We found novel down-regulation of ABC (ATP-binding cassette) transporters genes such as ABCA7, ABCC5, and ABCD4 and ATPase activity as the highest enriched pathway. Conclusions We identified unique extracellular components and ABC transporters gene enrichments in typhoid fever-infected Nigerian children, which have never been reported. These enriched gene clusters may represent novel targeted pathways to improve diagnostic, prognostic, therapeutic and next-generation vaccine strategies for typhoid fever in Africa.
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Affiliation(s)
- Sok Kean Khoo
- Department of Pediatrics and Human Development, College of Human Medicine, Michigan State University, East Lansing, MI, USA.
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Menezes GA, Harish BN, Khan MA, Goessens WHF, Hays JP. Antimicrobial resistance trends in blood culture positive Salmonella Typhi isolates from Pondicherry, India, 2005-2009. Clin Microbiol Infect 2011; 18:239-45. [PMID: 21714829 DOI: 10.1111/j.1469-0691.2011.03546.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Typhoid fever is caused by Salmonella enterica serovar Typhi, a major public health concern in developing countries. Recently, there has been an upsurge in the occurrence of bacterial isolates that are resistant to ciprofloxacin, and the emergence of broad spectrum β-lactamases in typhoidal salmonellae constitutes a new challenge for the clinician. A total of 337 blood culture isolates of S. Typhi, isolated from Pondicherry, India, between January 2005 and December 2009, were investigated using phenotypic, molecular and serological methods. Of the 337 isolates, 74 (22%) were found to be multidrug resistant (MDR) and 264 (78%) nalidixic acid resistant (NAR). Isolates with reduced susceptibility to ciprofloxacin possessed single mutations in the gyrA gene. A high rate of resistance (8%) was found to ciprofloxacin. All isolates with a ciprofloxacin MIC ≥ 4 mg/L possessed both double mutations in the QRDR of the gyrA gene and a single mutation in the parC gene. Active efflux pump mechanisms were also found to be involved in ciprofloxacin resistance. Finally, a large number of PFGE patterns (non-clonal genotypes) were observed among the S. Typhi isolates. In conclusion, a high rate of ciprofloxacin resistance was observed in comparison to other endemic areas in blood culture isolates of S. Typhi from Pondicherry, India, with steadily increasing NAR but decreasing MDR isolations over the study period. This is most likely to be due to an increased use of ciprofloxacin as a first-line drug of choice over more traditional antimicrobial agents for the treatment of typhoid fever.
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Affiliation(s)
- G A Menezes
- Department of Microbiology, Institute of National Importance, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Pondicherry, India
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Ty AU, Ang GY, Ang LW, James L, Goh KT. Changing Epidemiology of Enteric Fevers in Singapore. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 2010. [DOI: 10.47102/annals-acadmedsg.v39n12p889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Introduction: We studied the epidemiological trends of enteric fevers (typhoid and paratyphoid fever) in Singapore from 1990 to 2009 and carried out a review of the current prevention and control measures. Materials and Methods: Epidemiological records of all reported enteric fevers maintained by the Communicable Diseases Division, Ministry of Health from 1990 to 2009 were analysed. Results: A total of 2464 laboratory confirmed cases of enteric fevers (1699 cases of typhoid and 765 cases of paratyphoid) were reported. Of these, 75% were imported, mainly from India and Indonesia. There had been a significant fall in the mean annual incidence rate of indigenous enteric fevers from 4.3 per 100,000 population in 1990 to 0.26 per 100,000 population in 2009 (P <0.005) with a corresponding increase in the proportion of imported cases from 71% between 1990 and 1993 to 92% between 2006 and 2009 (P <0.0005). Imported cases involving foreign contract workers increased significantly from 12.8% between 1990 and 1993 to 40.4% between 2006 and 2009 (P <0.0005). Conclusion: Singapore has experienced a marked decline in the incidence of enteric fevers that is now comparable to that of other developed countries. Continued vigilance and proactive measures that address the changing epidemiology of enteric fevers in Singapore are necessary to sustain the milestone achieved in the past 2 decades.
Keywords: Imported Cases, Outbreaks, Paratyphoid, Typhoid
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Affiliation(s)
- Albert U Ty
- Epidemiology & Disease Control Division, Ministry of Health, Singapore
| | - Gary Y Ang
- National Healthcare Group (NHG) Headquarters, Singapore
| | - Li Wei Ang
- Communicable Diseases Division, Ministry of Health, Singapore
| | - Lyn James
- Communicable Diseases Division, Ministry of Health, Singapore
| | - Kee Tai Goh
- Office of the Director of Medical Services, Ministry of Health, Singapore
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Gautret P, Schlagenhauf P, Gaudart J, Castelli F, Brouqui P, von Sonnenburg F, Loutan L, Parola P. Multicenter EuroTravNet/GeoSentinel study of travel-related infectious diseases in Europe. Emerg Infect Dis 2010; 15:1783-90. [PMID: 19891866 PMCID: PMC2857260 DOI: 10.3201/eid1511.091147] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We analyzed prospective data on 17,228 European patients who sought treatment at GeoSentinel sites from 1997 to 2007. Gastrointestinal illness (particularly in tourists), fever (those visiting friends and relatives [VFRs]), and skin disorders (in tourists) were the most common reasons for seeking medical care. Diagnoses varied by country of origin, region visited, or categories of travelers. VFRs who returned from sub-Saharan Africa and Indian Ocean islands were more likely to experience falciparum malaria than any other group. Multiple correspondence analysis identified Italian, French, and Swiss VFRs and expatriate travelers to sub-Saharan Africa and Indian Ocean Islands as most likely to exhibit febrile illnesses. German tourists to Southeast and south-central Asia were most likely to seek treatment for acute diarrhea. Non-European travelers (12,663 patients from other industrialized countries) were less likely to acquire certain travel-associated infectious diseases. These results should be considered in the practice of travel medicine and development of health recommendations for European travelers.
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Hume S, Schulz T, Vinton P, Korman T, Torresi J. Increasing rates and clinical consequences of nalidixic acid-resistant isolates causing enteric fever in returned travellers: an 18-year experience. Eur J Clin Microbiol Infect Dis 2009; 28:963-70. [PMID: 19357879 DOI: 10.1007/s10096-009-0732-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2008] [Accepted: 03/18/2009] [Indexed: 10/20/2022]
Abstract
The purpose of this study was to examine the rate and clinical consequences of nalidixic acid-resistant (NAR) isolates in travellers with enteric fever presenting to a hospital in a developed country. We retrospectively examined microbiologically confirmed cases of enteric fever in adult returned travellers over an 18-year period presenting to two tertiary referral hospitals in Melbourne, Australia. There were 59 cases of Salmonella typhi infection, 43 cases of S. paratyphi A infection and two cases of S. paratyphi B infection. Most patients reported recent travel to India (36%) or Indonesia (29%). NAR isolates were commonly encountered (41% of all isolates), particularly from India (75%), Pakistan (80%) and Bangladesh (60%). The number of NAR isolates increased progressively after 2003. Patients with NAR isolates had prolonged mean fever clearance time (5.6 vs. 3.3 days, P = 0.03) and prolonged hospital stay (7.9 vs. 5.7 days, P = 0.02) compared to non-resistant isolates. This represents the largest report of NAR enteric fever in returned travellers. NAR isolates predominate in cases of enteric fever from South Asia and result in prolonged fever clearance time and hospital stay. Empiric therapy with alternative antibiotics such as ceftriaxone or azithromycin should be considered in patients with suspected enteric fever from this region.
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Affiliation(s)
- S Hume
- Victorian Infectious Diseases Service, Royal Melbourne Hospital, Grattan Street, Parkville, VIC 3050, Australia.
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Ahmad B, Shah SMH, Bashir S, Nisar M, Chaudry MI. Antibacterial and antifungal activities ofandrachne cordifoliamuell. J Enzyme Inhib Med Chem 2008; 22:726-9. [DOI: 10.1080/14756360701305828] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Pastoor R, Hatta M, Abdoel TH, Smits HL. Simple, rapid, and affordable point-of-care test for the serodiagnosis of typhoid fever. Diagn Microbiol Infect Dis 2008; 61:129-34. [PMID: 18276100 DOI: 10.1016/j.diagmicrobio.2007.12.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2007] [Revised: 12/06/2007] [Accepted: 12/18/2007] [Indexed: 10/22/2022]
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Ahmad B, Shah SMM, Bashir S, Begum H. Antibacterial and antifungal activities of teucrium royleanum (Labiatea). J Enzyme Inhib Med Chem 2008; 23:136-9. [PMID: 18341265 DOI: 10.1080/14756360701448727] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Abstract
The crude methanolic extract and subsequent fractions of Teucrium royleanum (Labiatea) were screened for antibacterial and antifungal activities. Against tested pathogens, crude extract and subsequent fractions demonstrated moderate to excellent antibacterial activities. Highest antibacterial activity was displayed by the ethyl acetate fraction against S. typhi (100%), against E.coli (76.7%) and against P. aerugenosa (70.8%) followed by the chloroform fraction against S. typhi (85.7%). Similarly, the crude extract and its subsequent fractions showed mild to excellent activities in the antifungal bioassay with maximum antifungal activity against M. canis (87%) by the chloroform fraction followed by the ethyl acetate (71%) and n-butanol (70%) fractions.
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Affiliation(s)
- Bashir Ahmad
- Centre of Biotechnology, University of Peshawar, Pakistan.
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Okeke IN, Aboderin OA, Byarugaba DK, Ojo KK, Opintan JA. Growing problem of multidrug-resistant enteric pathogens in Africa. Emerg Infect Dis 2008; 13:1640-6. [PMID: 18217545 PMCID: PMC3375797 DOI: 10.3201/eid1311.070674] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
A disproportionate number of low-income persons are affected. Control of fecal–orally transmitted pathogens is inadequate in many developing countries, in particular, in sub-Saharan Africa. Acquired resistance to antimicrobial drugs is becoming more prevalent among Vibrio cholerae, Salmonella enteritidis, diarrheagenic Escherichia coli, and other pathogens in this region. The poor, who experience most of the infections caused by these organisms, bear the brunt of extended illness and exacerbated proportion of deaths brought about by resistance. Improved antimicrobial drug stewardship is an often cited, but inadequately implemented, intervention for resistance control. Resistance containment also requires improvements in infectious disease control, access to and quality assurance of antimicrobial agents, as well as diagnostic facilities. Structural improvements along these lines will also enhance disease prevention and control as well as rational antimicrobial drug use. Additionally, more research is needed to identify low-cost, high-impact interventions for resistance control.
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Affiliation(s)
- Iruka N Okeke
- Department of Biology, Haverford College, Haverford, Pennsylvania 19041, USA.
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Raveendran R, Wattal C, Sharma A, Oberoi JK, Prasad KJ, Datta S. HIGH LEVEL CIPROFLOXACIN RESISTANCE IN SALMONELLA ENTERICA ISOLATED FROM BLOOD. Indian J Med Microbiol 2008. [DOI: 10.1016/s0255-0857(21)01992-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Cooke FJ, Day M, Wain J, Ward LR, Threlfall EJ. Cases of typhoid fever imported into England, Scotland and Wales (2000–2003). Trans R Soc Trop Med Hyg 2007; 101:398-404. [PMID: 17014877 DOI: 10.1016/j.trstmh.2006.07.005] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2006] [Revised: 07/28/2006] [Accepted: 07/28/2006] [Indexed: 11/23/2022] Open
Abstract
Although typhoid fever is no longer endemic in most of the developed world, it remains a major infectious disease in less developed regions and imported cases continue to occur in returning travellers, immigrants or migrant workers. We analysed all 692 isolates of Salmonella enterica subspecies enterica serovar Typhi from cases in England, Scotland and Wales that were sent to the Laboratory of Enteric Pathogens at the Health Protection Agency, Centre for Infections, London, UK between 2000 and 2003. The country of acquisition was known for 416 isolates (60%), and the majority of these (70%) came from India or Pakistan. Overall, 24 countries were listed, mainly in Asia and Africa. A total of 48 phage types were detected, 41% of which were Vi-phage type E1. Antimicrobial susceptibility testing revealed that 22% of isolates were multidrug resistant (MDR) (defined as resistance to chloramphenicol, ampicillin and co-trimoxazole) and 39% were quinolone resistant. A significant number of isolates (n=49) were sensitive to nalidixic acid by disk test but exhibited low-level ciprofloxacin resistance, suggesting a novel mechanism of resistance and reinforcing the need for minimum inhibitory concentration determination. Overall, 13% of isolates were both MDR and likely to show a poor response to a fluoroquinolone. A third-generation cephalosporin (e.g. ceftriaxone) should be considered as empirical therapy in regions of the Indian subcontinent where resistance is now at high levels as well as in patients returning from these areas. This study helps to describe the epidemiology of antimicrobial drug resistance in typhoid fever.
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Affiliation(s)
- Fiona J Cooke
- Health Protection Agency, Centre for Infections, 61 Colindale Avenue, London, UK
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