تقييم اختبارات PCR وطرق الزرع الاعتيادية في التشخيص المبكر لتجرثم الدم لدى الاطفال في مستشفى حماية الاطفال التعليمي في مدينة الطب / بغداد == Evaluation of PCR And Culture Methods For The Early Diagnosis of Bacteremia In Children From Welfare Teaching Hospital In Medicine City /Baghdad
Author name:
زينب صالح هادي الزبيدي
Supervisor name:
محمد ابراهيم نادر
General topic:
Biology
Specific topic:
Biotechnologies
Degree:
Master
University:
University of Baghdad - Institute Of Genetic Engineering And Biotechnology - Department Of Biotechnology
Language:
English
University location:
Baghdad
First pages:
24T2660 - p.pdf
Abstract:
استهدفت الدراسة الحالية تقييم الفحص المعتمد على تقنية PCR (polymerase chain reaction) (وطرق الزرع الاعتيادية في التشخيص المبكر لتسمم او تجرثم الدم في الاطفال.531 نماذج دم تم جمعها من الاطفال المرضى الذين اعمارهم اقل من 51 سنة ومشتبه بان لديهم اعراض تجرثم | The present study has been undertaken to evaluate polymerase chain reaction (PCR) technique in the diagnosis of bacteremia in comparison with the conventional blood culture techniques in children (infant and newborn).Blood specimens were collected from 135 children under 12 years of age suspected with fever and sepsis, obtained from Welfare Teaching Hospital/Medical City/Baghdad, for the period from April/ 2013 till January/ 2014.Blood specimens were collected and processed for Blood culture and PCR. Blood culture was performed using blood culture bottles contain brain heart infusion broth and positive results were subcultured using three media (macConkey - , chocolate - and blood agar), Gram stain, biochemical tests and conformational test (Api staph and Api 20E). Polymerase chain reaction was done using the universal primer, gram positive specific primer, gram negative specific primer, 16s rRNA primer for coagulase negative staphylococci and LacZ primer for Enterobacteriaceae.Optimization trials was carried out to increase the sensitivity of the PCR by applying 57°C in the annealing step for Gram positive specific primer and Gram negative specific primer to detect Gram positive and negative bacteria in blood respectively.Blood specimens were positive for bacteria in 69 cases (51.1%) by blood culture and 74 cases (54.8%) by PCR out of a total of 135 specimens analyzed. PCR showed more sensitive results compared to blood culture for detection of neonatal bacteremia. current results were revealed the ability of PCR to recognize five pathogens which have been negative by culture, all have been coagulase negative Staphylococci.The most frequent bacteria isolated and detected by PCR and Blood culture methods were Coagulase negative staphylococci (CoNS) (n = 60) followed by Enterobacter spp. (n = 8), E.coli (n = 5) and K.pneumoniae (n= 1). Interestingly, higher incidence rate (81.1%) were documented for the late onset sepsis (LOS) in our study compared to the early onset sepsis (EOS) (18.9%) for all bacteria. LacZ PCR efficiency have been 100% for detection of Enterobacteriaceae in blood.
