E-Book

E-Book 2nd Congress

  • Phenotypic and Genotypic Diagnosis of Carbapenem-Resistant Enterobacteriaceae
  • Hamed Ebrahimzadeh Leylabadlo,1 Sevda Zoghi,2,*
    1. Liver and Gastrointestinal Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
    2. Liver and Gastrointestinal Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran


  • Introduction: The resistance to carbapenem among carbapenem-resistant enterobacteriaceae (CRE) is the key factor in the lack of definitive and effective treatment for widespread infections with enterobacteriaceae. Moreover, the high prevalence rate of CRE in contaminated environments indicates the necessity of timely screening of infected patients. Hence, identification of enterobacteriaceae based on molecular and biochemical methods is an appropriate therapeutic-epidemiological priority.
  • Methods: In the analysis of the results of selected research articles of the last decade in the databases of PubMed and Google Scholar, the efficiency of phenotypic tests used include disk diffusion, multi or combined disks, chromogenic media, immunochromatography, mass spectrometry, modified hodge test, carba NP , inactivation of carbapenem (CIM) and its modified forms and genotypic techniques especially polymerase chain reaction, whole genome sequencing and biochips such as microarrays were evaluated.
  • Results: Over time, under the supervision of clinical and laboratory standard institute, phenotypic methods with high sensitivity and accuracy namely msupercarba chromogenic medium, mCIM/eCIM assay, K-SeT rapid tests (Commercial Kits), ionization technique and specific enzyme inhibitor discs to identify carbapenemase hydrolyzing carbapenems or verification of the results of preliminary tests based on the change in pH, color and growth zone of the medium have been confirmed. However, genotyping methods based on bacterial DNA sequences have the validity and speed with remarkable accuracy compared to visual methods and in epidemiological emergencies, they are an important diagnostic option. The need for cost, special equipment and specialized personnel are obstacles to the use of genotyping methods for extensive clinical requires.
  • Conclusion: The current limitations guide CRE detection methods toward potential phenotypic tests for daily clinical situations. Benefiting from genetic detection mechanisms in research to control CRE infections, such as how to inhibit active vertical transfer of carbapenemase coding genes along with other drug resistance genes between bacteria, development of economic techniques and synergistic effect of two or more phenotypic or genotypic methods are the diagnostic challenges in the protocol of CRE-related infectious diseases.
  • Keywords: Enterobacterial infections; carbapenem; drug resistance genes; beta-lactamase; phenotypic detection