Molecular characterization of carbapenem resistant Gram-negative rods in Neonatal Intensive Care Unit of Mansoura University Childrens Hospital

Carbapenems are group of extended-spectrum β-lactam antimicrobials frequently used for treating multidrug-resistant Gram-negative bacilli (GNB) infections. This study aimed at detecting and characterizing carbapenem resistance (CR) genes among GNB isolated from patients treated in neonatal intensive care unit (NICU) Mansoura University Children's Hospital (MUCH), Egypt. It is a prospective conducted 2015 to 2016. A total 158 isolates were examined CR both phenotypically genotypically. Among Gram negative isolates, there 58 (36.7%) strains. Extended-spectrum β-lactamase (ESBL) production was confirmed all (100%) isolates. Carbapenemase detected 52 (89.5%) strains while metallo beta-lactamase (MBL) found 33 (56.9%) strains.  Molecular characterization revealed that 57 (98.3%) positive carbapenemase encoding genes. KPC gene the most frequent (34/58).  VIM, IPM, OXA NDM also 15, 13, 9 1 isolate, respectively. Only one isolate despite ESBL phenotype. Infection with has been increasing clinical settings which limit use carbapenems.   Key words: bacilli, resistance, carbapenemase, beta-lactamase, multiplex polymerase chain reaction (PCR), genes, unit.