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277781

Evaluation of Real Time Polymerase Chain Reaction for Salmonella Invasion Gene A and Salmonella Tetrathionate Respiration Gene as a Diagnostic Test for Typhoid Fever

Article

Last updated: 28 Dec 2024

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Subjects

-

Tags

Clinical microbiology

Abstract

Background: Enteric (typhoid and paratyphoid) fever is a serious systemic disease caused by Salmonella enterica (S. enterica) that needs appropriate microbiological diagnosis mainly with atypical clinical signs due to antibiotics misuse. In Egypt, there are insufficient data about molecular detection of enteric fever. Objectives: To evaluate the quantitative real- time polymerase chain reaction (qPCR) for Salmonella invasion gene A (Inv A) and Salmonella tetrathionate respiration gene (ttr) of S. enterica in typhoid fever patients. Methodology: This was a case-control study that included 100 patients with typhoid fever and 100 control subjects. Ten ml blood were obtained for blood culture, Widal testing and enrichment on tryptic soya broth (TSB) with bile. Positive blood culture was sub cultured, identified and serotyped for isolation of S. enterica. Finally, qPCR was applied for detection of Inv A and ttr genes from blood samples and after enrichment. Results: Blood culture was positive in 51% and Widal test was positive in 70% of patients. Combination of Widal and/or blood culture increased their sensitivity, specificity and accuracy to 82%, 89.2% and 85.5% respectively. qPCR was positive in 95% of patients (95 for ttr and 89 for Inv A) while, pre-enriched blood qPCR was positive in 99%. The highest sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy was for qPCR for pre-enriched blood (99%, 100%, 100%, 99.01%, 99% respectively). Conclusion: The study highlighted the high accuracy of qPCR for genes Inv A and ttr in diagnosis of S. typhi from blood.

DOI

10.21608/ejmm.2023.277781

Keywords

Salmonella Enterica, qPCR, Inv A gene, ttr gene, pre-enriched blood

Authors

First Name

Noha

Last Name

Mostafa Mahmoud

MiddleName

-

Affiliation

Medical Microbiology & Immunology Department Faculty of Medicine Mansoura University Mansoura Egypt

Email

nohamostafa_81@yahoo.com

City

Mansoura

Orcid

https://orcid.org/00

First Name

Maysaa

Last Name

El Sayed Zaki

MiddleName

-

Affiliation

Clinical Pathology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt.

Email

maysaazaki5@hotmail.com

City

-

Orcid

-

First Name

Mostafa

Last Name

Abd El Salam

MiddleName

-

Affiliation

Internal Medicine Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt.

Email

darsh1980@mans.edu.eg

City

-

Orcid

-

First Name

Nora

Last Name

Abdelaziz Mohammad Farag

MiddleName

-

Affiliation

Clinical Pathology Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt. Clinical Pathology Department, Faculty of Medicine, Delta University for science and Technology, Gamasa, Egypt

Email

dr_noraabdelaziz@mans.edu.eg

City

-

Orcid

-

First Name

Reem

Last Name

Mohsen Elkholy

MiddleName

-

Affiliation

Clinical Pathology Department, Faculty of Medicine, Menoufia University, Menoufia, Egypt

Email

reem.mohsen97@yahoo.com

City

-

Orcid

-

Volume

32

Article Issue

1

Related Issue

38243

Issue Date

2023-01-01

Receive Date

2023-01-01

Publish Date

2023-01-01

Page Start

69

Page End

75

Print ISSN

1110-2179

Online ISSN

2537-0979

Article File

EJMM_Volume 32_Issue 1_Pages 69-75.pdf

PDF . 234.1kB

Link

https://ejmm.journals.ekb.eg/article_277781.html

Detail API

https://ejmm.journals.ekb.eg/service?article_code=277781

Order

277,781

Type

New and original researches in the field of Microbiology.

Type Code

2,038

Publication Type

Journal

Publication Title

Egyptian Journal of Medical Microbiology

Publication Link

https://ejmm.journals.ekb.eg/

MainTitle

Evaluation of Real Time Polymerase Chain Reaction for Salmonella Invasion Gene A and Salmonella Tetrathionate Respiration Gene as a Diagnostic Test for Typhoid Fever

Details

Type

Article

Created At

23 Jan 2023