Related Experiment Video

Updated: Apr 15, 2026

A Multiplex Serological Assay for the Detection of Antibody Responses to Arboviruses

A Multiplex Serological Assay for the Detection of Antibody Responses to Arboviruses

Published on: November 4, 2025

Impact of serology and molecular methods on improving the microbiologic diagnosis of infective endocarditis in Egypt

Amany Aly El-Kholy¹, Nevine Gamal El-din El-Rachidi¹, Mervat Gaber El-Enany¹

¹Clinical Pathology Department, Faculty of Medicine, Cairo University, Giza, Egypt.

|March 27, 2015

Abstract

Background:

Conventional diagnosis of infective endocarditis (IE) is based mainly on culture-dependent methods that may fail because of antibiotic therapy or fastidious microorganisms.

Objectives:

We aimed to evaluate the added values of serological and molecular methods for diagnosis of infective endocarditis.

Patients And Methods:

One hundred and fifty-six cases of suspected endocarditis were enrolled in the study. For each patient, three sets of blood culture were withdrawn and serum sample was collected for Brucella, Bartonella and Coxiella burnetii antibody testing. Galactomannan antigen was added if fungal endocarditis was suspected. Broad range PCR targeting bacterial and fungal pathogens were done on blood culture bottles followed by sequencing. Culture and molecular studies were done on excised valve tissue when available.

Results:

One hundred and thirty-two cases were diagnosed as definite IE. Causative organisms were detected by blood cultures in 40 (30.3 %) of cases. Blood culture-negative endocarditis (BCNE) represented 69.7 %. Of these cases, PCR followed by sequencing on blood and valvular tissue could diagnose five cases of Aspergillus flavus. Eleven patients with BCNE (8.3 %) were diagnosed as zoonotic endocarditis by serology and PCR including five cases of Brucella spp, four cases of Bartonella spp and two cases of Coxiella burnetii. PCR detected three cases of Brucella spp and two cases of Bartonella spp, while cases of Coxiella burnetii were PCR negative. The results of all diagnostic tools decreased the percentage of non-identified cases of BCNE from 69.7 to 49.2 %.

Conclusion:

Our data underline the role of serologic and molecular tools for the diagnosis of blood culture-negative endocarditis.

Insights

Serological and molecular methods significantly improve the diagnosis of infective endocarditis (IE), especially in blood culture-negative endocarditis (BCNE) cases. These advanced techniques enhance pathogen detection, reducing the percentage of unidentified IE cases.

Area of Science:

Infectious Diseases
Microbiology
Medical Diagnostics

Background:

Conventional infective endocarditis (IE) diagnosis relies on culture-dependent methods.
These methods can be unreliable due to prior antibiotic use or difficult-to-grow microorganisms.

Purpose of the Study:

To evaluate the added diagnostic value of serological and molecular methods for IE.
To improve the detection rates of causative agents in blood culture-negative endocarditis (BCNE).

Main Methods:

Study enrolled 156 suspected IE cases.
Blood cultures, serological tests (Brucella, Bartonella, Coxiella burnetii antibodies), and galactomannan antigen testing were performed.
Broad-range PCR on blood culture bottles and valve tissue, followed by sequencing, was utilized.

Main Results:

Definite IE was diagnosed in 132 cases; blood cultures identified causative agents in only 30.3%.
BCNE accounted for 69.7% of cases; molecular and serological methods reduced unidentified cases to 49.2%.
PCR and serology diagnosed zoonotic IE (Brucella, Bartonella, Coxiella burnetii) in 8.3% of BCNE cases.

Conclusions:

Serological and molecular tools are crucial for diagnosing BCNE.
These methods significantly enhance the identification of causative pathogens in IE.
The study highlights the limitations of traditional methods and the benefits of advanced diagnostics.

Read full analysis

Keywords:

Blood culture-negative endocarditis Broad range PCR Brucella spp.

More Related Videos

Identification of Rare Bacterial Pathogens by 16S rRNA Gene Sequencing and MALDI-TOF MS

Identification of Rare Bacterial Pathogens by 16S rRNA Gene Sequencing and MALDI-TOF MS

Published on: July 11, 2016

Antigen-Capture Enzyme-Linked Immunosorbent Assay for Specific Detection of Mycoplasma pneumoniae

Antigen-Capture Enzyme-Linked Immunosorbent Assay for Specific Detection of Mycoplasma pneumoniae

Published on: February 24, 2023

Related Concept Videos

Automated Microbial Diagnostics

Automated Microbial Diagnostics

Automated diagnostic analyzers have transformed clinical microbiology by providing rapid and reliable methods for pathogen identification and antibiotic susceptibility testing. Among these systems, the Vitek 2 is widely used because it automates the traditionally labor-intensive processes of microbial identification (ID) and antibiotic susceptibility testing (AST), delivering standardized and timely results that are essential for effective patient care.Microbial Identification with ID CardsThe...

Methods of Classification and Identification

Methods of Classification and Identification

Bacterial identification relies on a diverse array of techniques to classify and understand microorganisms, each tailored to uncover specific characteristics. Traditional morphological approaches, while still valuable, are limited for closely related or structurally simple organisms. Modern methods integrate biochemical, serological, genetic, and advanced molecular tools to achieve greater accuracy.Morphological and Biochemical TechniquesMorphological characteristics, such as cell shape and...

Endocarditis III: Medical Management

Endocarditis III: Medical Management

Infective endocarditis management involves a multifaceted approach encompassing infection prevention, lifestyle modifications, pharmacological therapy, and surgical management.Infection Prevention:Hand Hygiene: Thorough handwashing is crucial to prevent the spread of infection. Hand hygiene should be performed regularly, especially before and after using the restroom.Oral Hygiene: Good oral hygiene is essential. It includes brushing teeth immediately after waking up and before bed, flossing...

Endocarditis II: Clinical Features of Infective Endocarditis

Endocarditis II: Clinical Features of Infective Endocarditis

Endocarditis can present various clinical features depending on the causative organism and the patient's underlying health conditions. Initially, the clinical features of infective endocarditis develop gradually, presenting with nonspecific symptoms that can be easily mistaken for other illnesses.General SymptomsEarly symptoms of infective endocarditis are fever, chills, weakness, malaise, fatigue, and weight loss. These symptoms reflect the systemic nature of the infection and the body's...

Myocarditis II: Clinical Features and Diagnostic Tests

Myocarditis II: Clinical Features and Diagnostic Tests

Myocarditis is an inflammation of the heart muscle. The symptoms vary widely, encompassing asymptomatic presentations to severe, acute manifestations.Clinical PresentationAsymptomatic cases: In some instances, myocarditis may be asymptomatic, with the infection resolving without intervention. These cases often go undetected unless discovered incidentally through diagnostic imaging or tests conducted for other reasons.General Early Symptoms: Early symptoms of myocarditis are non-specific and can...

Endocarditis I: Introduction

Endocarditis I: Introduction

Introduction:Endocarditis is the infection of the endocardium, the inner lining of the heart and its valves. When the heart muscle is involved, the condition is termed myocarditis, while an infection of the outer lining is called pericarditis. Infective endocarditis (IE) primarily affects the endocardium, where pathogens adhere to the valves or lining, forming vegetation that can lead to severe complications. Infective endocarditis occurs when microorganisms, usually bacteria from other body...

Articles linked to this work by shared authors, journal, and citation graph.

GeneXpert CARBA-R assay for molecular characterization of carbapenem-resistance in Gram-negative bacteria in a tertiary care university hospital in Cairo-Egypt.

Infection·2026

See all related articles