Open AccessMolecular and serological techniques for the diagnosis of culture negative infective endocarditis in Alexandria Main University Hospital
Author(s) -
Salama Mohamed Sadaka,
Iman F. El-Ghazzawy,
Mahmoud M. Hassanen,
Ahmed S. Abu El Kasem,
Amina M. Nour El Din,
Marwa Ahmed Meheissen
Publication year - 2013
Publication title -
the egyptian heart journal /the egyptian heart journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.212
H-Index - 9
eISSN - 2090-911X
pISSN - 1110-2608
DOI - 10.1016/j.ehj.2012.08.001
Subject(s) - serology , medicine , infective endocarditis , etiology , blood culture , endocarditis , antibiotics , immunology , microbiology and biotechnology , antibody , biology
Background and aimCulture-negative infective endocarditis (CNIE) is a diagnostic dilemma. The study was carried out to estimate the prevalence of CNIE among definite IE cases, to describe the epidemiologic and clinical characteristics of CNIE patients and to diagnose the microbial etiology of CNIE using molecular and serological techniques.Subjects and methodsSixty-five definite IE cases were enrolled in a prospective observational study between January and December 2010. CNIE cases were tested by 16SrRNA and seminested PCR for 35 blood samples, serological tests and the study of ten valve tissue specimens.ResultsCNIE constituted 39 (60%) cases. The mean age of CNIE patients was 31years. Male to female ratio was 2.9:1. Healthcare associated IE accounted for 15.4%, native valve IE for 66.7% and intravenous drug abuse for 20.5% of cases. The mitral valve was the most frequently involved (56.4%). Out of 39 CNIE cases, seminested blood PCR detected 12 cases (ten Staphylococci, two Streptococci). Five cases were reactive by serology (three Bartonella, one Coxiella, and one Brucella). Six cases were positive by analysis of valve tissue (three Staphylococci, three Streptococci). The combined results of all diagnostic tools decreased the percentage of non-identified causes of CNIE from 60% to 24.6%.ConclusionsOur data underlined the role of collecting blood culture before starting antibiotics and the role of seminested PCR in the diagnosis of conventional causes of CNIE. The importance of serology to identify non conventional causes was also highlighted