Evaluation Of Salmonella Typhi Antigens Hlye And Ynce For The Detection Of Typhoid Fever And Its Carriers

Salmonella Typhi (S. Typhi) is the causative agent of typhoid fever (TF) that causes millions of infections and 1% of mortality worldwide. TF is highly endemic in Southeast Asia and sub-Saharan Africa. Certain individuals with TF may not recover fully and can become carriers that do not show any sym...

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Main Author: Joseph, Freddy Franklin Anthony
Format: Thesis
Language:English
Published: 2019
Subjects:
Online Access:http://eprints.usm.my/48099/1/FREDDY%20FRANKLIN%20AL%20ANTHONY%20JOSEPH%20cut.pdf
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author Joseph, Freddy Franklin Anthony
author_facet Joseph, Freddy Franklin Anthony
author_sort Joseph, Freddy Franklin Anthony
collection USM
description Salmonella Typhi (S. Typhi) is the causative agent of typhoid fever (TF) that causes millions of infections and 1% of mortality worldwide. TF is highly endemic in Southeast Asia and sub-Saharan Africa. Certain individuals with TF may not recover fully and can become carriers that do not show any symptoms of the disease. The carriers can then spread the disease when they come into contact with food and water. Antibodies against S. Typhi HlyE are elevated among patients with TF compared to healthy individuals, while antibodies against YncE were reported to be elevated among carriers of S. Typhi. Rapid and accurate methods to diagnose individuals with TF or who are carriers are crucial to manage the disease. In this study, recombinant HlyE and YncE antigens were found to be useful for the identification of individuals with TF and those who are possible carriers. Firstly, recombinant HlyE and YncE were expressed and purified. Next, rHlyE and rYncE ELISAs were developed to enable quantitative screening of many samples simultaneously to identify those with elevated IgM, IgG and IgA antibodies against the antigen. A total of 425 serum samples (acute typhoid patients, carriers, food handlers, other febrile, and healthy individuals) were screened with the ELISAs.The rHlyE-IgG, -IgA and -IgM ELISAs demonstrated a sensitivity of 70%, 80% and 11% respectively to detect acute typhoid patients, and with a combined sensitivity of 83%.The rYncE ELISA identified 16 possible carriers based on their antibody profiles. Taken together, this study showed that HlyE antigen could be used to identify individuals with TF while the YncE antigen may be used to identify possible carriers, but further validation is required.
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spelling usm.eprints-480992021-01-14T03:00:55Z http://eprints.usm.my/48099/ Evaluation Of Salmonella Typhi Antigens Hlye And Ynce For The Detection Of Typhoid Fever And Its Carriers Joseph, Freddy Franklin Anthony RK1-715 Dentistry Salmonella Typhi (S. Typhi) is the causative agent of typhoid fever (TF) that causes millions of infections and 1% of mortality worldwide. TF is highly endemic in Southeast Asia and sub-Saharan Africa. Certain individuals with TF may not recover fully and can become carriers that do not show any symptoms of the disease. The carriers can then spread the disease when they come into contact with food and water. Antibodies against S. Typhi HlyE are elevated among patients with TF compared to healthy individuals, while antibodies against YncE were reported to be elevated among carriers of S. Typhi. Rapid and accurate methods to diagnose individuals with TF or who are carriers are crucial to manage the disease. In this study, recombinant HlyE and YncE antigens were found to be useful for the identification of individuals with TF and those who are possible carriers. Firstly, recombinant HlyE and YncE were expressed and purified. Next, rHlyE and rYncE ELISAs were developed to enable quantitative screening of many samples simultaneously to identify those with elevated IgM, IgG and IgA antibodies against the antigen. A total of 425 serum samples (acute typhoid patients, carriers, food handlers, other febrile, and healthy individuals) were screened with the ELISAs.The rHlyE-IgG, -IgA and -IgM ELISAs demonstrated a sensitivity of 70%, 80% and 11% respectively to detect acute typhoid patients, and with a combined sensitivity of 83%.The rYncE ELISA identified 16 possible carriers based on their antibody profiles. Taken together, this study showed that HlyE antigen could be used to identify individuals with TF while the YncE antigen may be used to identify possible carriers, but further validation is required. 2019-06 Thesis NonPeerReviewed application/pdf en http://eprints.usm.my/48099/1/FREDDY%20FRANKLIN%20AL%20ANTHONY%20JOSEPH%20cut.pdf Joseph, Freddy Franklin Anthony (2019) Evaluation Of Salmonella Typhi Antigens Hlye And Ynce For The Detection Of Typhoid Fever And Its Carriers. Masters thesis, Universiti Sains Malaysia.
spellingShingle RK1-715 Dentistry
Joseph, Freddy Franklin Anthony
Evaluation Of Salmonella Typhi Antigens Hlye And Ynce For The Detection Of Typhoid Fever And Its Carriers
title Evaluation Of Salmonella Typhi Antigens Hlye And Ynce For The Detection Of Typhoid Fever And Its Carriers
title_full Evaluation Of Salmonella Typhi Antigens Hlye And Ynce For The Detection Of Typhoid Fever And Its Carriers
title_fullStr Evaluation Of Salmonella Typhi Antigens Hlye And Ynce For The Detection Of Typhoid Fever And Its Carriers
title_full_unstemmed Evaluation Of Salmonella Typhi Antigens Hlye And Ynce For The Detection Of Typhoid Fever And Its Carriers
title_short Evaluation Of Salmonella Typhi Antigens Hlye And Ynce For The Detection Of Typhoid Fever And Its Carriers
title_sort evaluation of salmonella typhi antigens hlye and ynce for the detection of typhoid fever and its carriers
topic RK1-715 Dentistry
url http://eprints.usm.my/48099/1/FREDDY%20FRANKLIN%20AL%20ANTHONY%20JOSEPH%20cut.pdf
work_keys_str_mv AT josephfreddyfranklinanthony evaluationofsalmonellatyphiantigenshlyeandynceforthedetectionoftyphoidfeveranditscarriers