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العنوان
Phenotypic and Molecular Detection of Klebsiella pneumonia Carbapenemase in Enterobacteriaceae /
المؤلف
Abdou, Shereen Mahmoud.
هيئة الاعداد
باحث / Shereen Mahmoud Abdou
مشرف / Nevine Nabil Kassem
مشرف / Samia Abdou Girgis
مناقش / Hala Badr El-Din Ali
تاريخ النشر
2014.
عدد الصفحات
214 P. :
اللغة
الإنجليزية
الدرجة
ماجستير
التخصص
علم الأحياء الدقيقة (الطبية)
تاريخ الإجازة
1/1/2014
مكان الإجازة
جامعة عين شمس - كلية الطب - قسم باثولوجيا الاكلينيكية
الفهرس
Only 14 pages are availabe for public view

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Abstract

Carbapenems resistance among Enterobacteriaceae, in particular K. pneumoniae and E.coli, is an emerging problem worldwide. Several resistance mechanisms have been reported to circumvent the efficacy of carbapenems, and carbapenemases. KPC-type carbapenemases (Class A carbapenemases) which include blaKPC are being an increasingly important mechanism of acquired resistance to carbapenems and other β-lactams.
The KPC enzyme confers resistance to all β-lactam agents including penicillins, cephalosporins, monobactams, and carbapenems. The patient groups most likely to acquire KPC-producing bacteria include patients at risk for infections caused by multidrug resistant organisms: patients with invasive devices, prolonged hospital stays (especially in an ICU), and heavy antibiotic exposure and those who are immunocompromised. Therefore, it is important to isolate infected patients and take contact precautions because of the potential for nosocomial transmission.
Practical phenotypic screening and confirmatory tests are needed to facilitate the timely detection of such strains by clinical microbiology laboratories. Adequate detection of carbapenemase-producing microorganisms in the routine diagnostic laboratory is essential for patient care because (i) it is vital for the correct choice of antibiotic therapy and (ii) appropriate hospital hygiene precautions are indicated for patients harboring carbapenemase-producing microorganisms as these strains are associated with multiresistance and epidemics that result in reduced patient safety and increased costs.
In our study, all the carbapenem resistant 57 isolates had positive results by the modified Hodge test (100 %) indicating carbapenemase production; 12/57 isolates were positive for blaKPC gene by PCR.
By comparing the different antibiotic disks (IPM(10µg); MEM(10µg); ETP(10µg), FEP(30µg); FOX (30µg) disks) with and without boronic acid in a final concentration of 400 µg to detect KPC production. All showed 100% sensitivity however ETP showed the highest specificity (95 %) followed by MEM (84 %) then IPM (82 %) and the least was for FEP (71 %).
We concluded that the modified Hodge test is a sensitive method for detection of KPC however not specific. Boronic acid assays using ETP is a simple, highly sensitive and specific test for the phenotypic confirmation of KPC possessing Enterobacteriaceae isolates.
We recommend the evaluation of addition of BA to different carbapenem substrates (IPM, MEM and ETP) to improve the specificity of MHT in detection of KPC producing strains.